Systematic Survey on Newsprint Production
Technologies in Japan1
Kiyoaki Iida

 Abstract
Since its invention two millennia ago, paper has become near-universal as the medium ofcivilization. Paper-making was industrialized in the Industrial Revolution, transformed throughthe development of mass-production technologies, and continues to be developed and refinedeven today.
In Japan, the methods for hand-made paper, known as “washi,” were brought to the country
back in the 7th century and gradually evolved over the centuries, but the paper industry would
be transformed with the introduction of mass-production using Western European-style machinetechnology after the Meiji Restoration. While World War II left Japan's paper industry in ruins,
it rose swiftly from the ashes to become the world’s second-largest paper producer. Though
China’s recent economic surge has left Japan in third place, Japan remains one of the mostimportant paper producers in the world.
Paper is something we use every day, so we may not notice how it changes, but compared tohalf a century ago, the materials and quality are very different, and the production equipment
has also improved its performance and efficiency by leaps and bounds. It is this technologicaldevelopment in the sixty years following the war that is the focus of this paper.
In the 1950s and 1960s, paper mills in Japan were located throughout the country in areas
where wood resources were available, and their capacities were 100 to 200 tons per day.
However, increasing demand for paper caused a wood shortage, and the newsprint market also
slowly opened to imports as tariffs were gradually abolished. So the Japanese paper industry
found itself having to compete internationally. One important development in the industry was
importing chips from overseas by chip carriers, a trend which started in 1964. Freed from thelimitations of Japan’s domestic wood supply, the industry was now able to build large integrated
pulp and paper mills near any port which could handle these large ships. Now there are several
mills which produce upwards of 3,000 tons of paper a day, giving them the largest production
capacity in the world.
There are about 127 million people in the crowded islands of Japan, who consume amassive 240 kg of paper per capita each year. This means, however, that there is no shortage of
waste paper available. The technology for recycling old newsprint for newsprint production wasdeveloped back in the 1980s. Now, up to 70% of the total pulp of Japanese newsprint is recycled
fiber. This unique use of the twin resources of imported chips and recycled fiber enables Japanto remain one of the biggest paper producers in the world.
Along with this development of resources, technological improvements in paper production
have also helped Japan to remain competitive internationally. The technological capability of
production is defined as having equipment with high productivity, operating it at high efficiency,
and producing products with high levels of reliability and good cost performance. In the 1960s,
Japanese equipment makers licensed the newest technology from leading overseas equipment
suppliers and introduced it into the domestic paper industry. Japanese paper companies weresome of the first in the world to invest in those technologies and improve their productivity. For
example, standard paper machines in the 1950s were 3.5 m wide and ran at a speed of 300
m/min. In 2000, they were 10 m wide and ran at 1,800 m/min. That shows that Japanese paper
companies were willing to take the risk of investing in new technologies. They also worked withthe suppliers to modify the equipment, gaining an expertise in the equipment which could thenbe transferred worldwide. A relationship built on mutual trust has developed between paper
companies and equipment suppliers in Japan.
One of the characteristics of Japanese technology is to operate equipment at high efficiency.

The operating efficiencies of paper machines in Japan are commonly more than 90%, a level
which is very rare in other countries. This efficiency comes from efficient paper machine
operation, as well as from the fact that mills are managed properly, from material supply to
product delivery. This culture of efficiency, nurtured in these mills, has been gradually spreadabroad through technology exchanges and overseas investments.
The other characteristic of Japanese technology is the reliability of the products. One of themain reasons for this is the strict quality demands made by Japanese newspaper printers, but theindustry has been eager to satisfy clients to the greatest extent possible. This attitude results in
extremely reliable products, trusted by clients, so there is little need to import newsprint fromoverseas.
However, a new situation now confronts the Japanese paper industry, and the unique way inwhich it has developed. Historically, the domestic market had expanded in step with the GDP.
The industry’s goal was to use that demand to control the market, which it was able to do. But
with the domestic market saturated, the paper industry is now required to compete in the global
market. To this end, the industry needs both the technological expertise to make its products
competitive internationally, and at the same time, the quality and reliability that will continue tosatisfy demanding Japanese clients.
 Profile
Kiyoaki Iida
Senior Researcher, Center of the History of JapaneseIndustrial Technology, National Museum of Natureand Science, Tokyo
1960

1960
1965

1990
1993

2003

Graduated from the University of Tokyo,
Department of Engineering (Applied
Chemistry)
Jujo Paper Company Ltd.
Master’s degree at the University ofToronto, Department of Engineering(Chemical Engineering and Applied
Chemistry)
General Manager, Central Research, Jujo
Paper Co. Ltd.
Executive Director, Japan Technical
Association of the Pulp and Paper
Industry (JAPAN TAPPI)
RetiredFrom 1990 to 2000, part-time lecturer at the Kyushu
University.
Coordinates the project for preserving and publicizing
technical archives and heritages of the Japanese paperindustry, which JAPAN TAPPI is promoting.
Awards1985 JAPAN TAPPI Award
1986 JAPAN TAPPI Award

Contents
1
2

Introduction .............................................................. 3
A short history of paper making: from its
invention to industrial sustainability ..................... 53 Significance of the theme and perspectives of thestudy ........................................................................... 8
4 Descriptions of basic technologies ...................... 12
5 History of newsprint production over the last 60
years ......................................................................... 20
6 Technological development part 1: pulp
resources.................................................................. 24
7 Technological development part 2: paper
machines.................................................................. 38
8 Technological Development Part 3: Production
Technology and Mill Operation Culture ............ 56
9 Other technologies in the paper industry ............ 60
10 Summary: International comparison of paperindustry business models ...................................... 65
11 Operational data for a typical newsprint machine68
12 Evolutionary chart and chronological table ....... 74
Appendix: List of Candidates for Registration as
Newsprint Manufacturing Technology ............... 87

1 Introduction
Since its invention two millennia ago,
paper has become near-universal as themedium of civilization. Paper-making wasindustrialized in the Industrial Revolution,transformed through the development of
mass-production technologies, and continues
to be developed and refined even today.
In Japan, the methods for hand-madepaper, known as “washi,” were brought to thecountry back in the 7th century and gradually
evolved over the centuries, but the paperindustry would be transformed with theintroduction of mass-production using
Western European-style machine technology
after the Meiji Restoration. While World War
II left Japan's paper industry in ruins, it roseswiftly from the ashes to become the world’s
second-largest paper producer. Though
China’s recent economic surge has left Japanin third place, Japan remains one of the mostimportant paper producers in the world.
Paper is something we use every day, so
we may not notice how it changes, but
compared to half a century ago, the materials
and quality are very different, and the
production equipment has also improved its
performance and efficiency by leaps andbounds. It is this technological developmentin the sixty years following the war that is thefocus of this paper.
Looking objectively, Japan’s paperindustry is not located in a country
particularly blessed with raw materials orenergy. So it is an interesting question to ask
how technology has contributed to thedevelopment of the materials industry,
despite the dependence on raw materials andenergy.
Therefore, this paper attempts to lay out
the particular features of the development of
the Japanese paper industry by taking a lookat newsprint, which is the most commonly
produced type of paper, and the one where
the latest technology is often used first, andinvestigating the process of its technologicaldevelopment. As part of this, this paperemphasizes the following three historicaldevelopments. First, while the demand for

quality in newsprint has changed (become
increasingly strict) as technological reform
has progressed in newspaper printers, the way
this has been dealt with is the history oftechnological development, which will form
the core of this paper. Second, in the paperindustry, which uses materials and large-scaleequipment, how the raw materials and energy
were ensured is an important technologicalperspective. The third point is that it isnecessary to maintain equipment in acompetitive state, and the efforts for that arealso part of the history of the technology.
This paper discusses the history of paperin Chapter 2, while the current state of thepaper industry is presented in Chapter 3.
Chapter 4 is an attempt at explaining thebasic technologies required for understanding
the technical explanations in Chapter 5
onwards.
Chapter 5 provides an explanation of how
both the demand for newsprint and the quality
demands made of newsprint have changed
and how the paper industry responded tothese. These historical changes were madepossible by the technological responses
detailed in Chapter 6 onwards, and form thebasis of this paper.
From Chapter 6 onwards, specifictechnological developments are shown, with
Chapter 6 explaining how the lack of raw
materials due to expanded demand wassolved through independent technologicalresearch in Japan. Next, in Chapter 7, paper
machines are examined as equipment andtheir technological innovations presented,
while the role that the Japanese paperindustry played is considered. In Chapter 8,
Japan’s abilities in production technology,
one of the sources of the country’s
international competitiveness, are consideredin specific terms. Chapter 9 looks at theenergy, environment, and technical trainingthat indirectly contribute to newsprint
production. These explanations are intended
to show that in order to produce newsprintcompetitively, it is not enough to develop
technology for production lines alone; theSystematic Survey on Newsprint Production Technologies in Japan3

entire plant needs to be more efficient andcost less, and in order to achieve that,technological development and cooperation
based on a relationship of trust with the
suppliers of equipment and raw materials isnecessary.
Chapter 10 will present the features ofmajor paper-making nations around the worldand summarize Japan’s technologicaldevelopments by way of contrast.
Chapter 11 will examine one particular
newsprint machine (one of the largest in theworld when first built in 1960, which eventoday, when equipment has grown huge,
produces the highest quality paper of allnewsprints), and present a specific history ofnewsprint production from forty years ofoperational records. These records are avaluable source of data underpinning thispaper.
Chapter 12 will present related news in
the form of a news chronology andsummarize
the
years
when
major
technological developments were made in theform of a technology chronology. In addition,
an evolutionary chart that sums up the entire
paper has been created.

4

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

2 A short history of paper making: from its
invention to industrial sustainability
2.1 Spread of the invention
2.2 The Industrial Revolution
The basic process of paper making isbelieved to have been invented in AD 105 by
the Chinese official Cai Lun. His process
made sheets of paper by hand from vegetationand cloth rags. It is probably more likely thathe compiled methods of hand-manufacturing
sheets used in different regions into a single
system.
This hand-made method spread eastwards
as well as westwards. It arrived in Japan in
the 7th century, and was refined there to
become the traditional Japanese systembefore the Meiji period. Westwards, thetechnology spread through Central Asia to theIslamic world, arriving in the Iberianpeninsula around 1150. From there, it spreadfurther into Europe between 1200 and 1300,
then crossed the Atlantic Ocean to theAmericas around 1690. The traditional
hand-crafted method became modernized in
the Industrial Revolution, replacing rags witha new resource (wood) and improving the
manufacturing process through the use of
mechanization, establishing itself as themodern mass-production system. Thismethod was imported into Japan in the Meiji
period.
This means that in modern Japan thewashi (Japanese paper) industry, based on
traditional sheet manufacturing methods,
co-exists with the modern mass-production
paper industry. As the washi process is far
less productive, it mainly produces specialty
papers, and the market for washi is currently
on the decline. There are, however, somesuccessful washi products that are exported
worldwide, such as battery-separator sheets
and condenser paper.
Now, let us briefly review how themethod of making paper sheets by handdeveloped into the modern mass-production
system.

The Industrial Revolution, which started
in England, allowed the development of anew paper-making process using wood rather
than rags, producing paper throughmechanical rather than human means. That
process became the basis of modern paper
manufacturing.
It was René Antoine Ferchault deRéaumur (1683–1757) who first noticed thepossibilities of wood fiber, followed by Jacob
Scheffer (1718–1790), who studied producing
pulp from wood. Friedrich Keller invented
the first industrial wood-pulping process in
1840, using wood logs. This was followed bymethods such as alkali pulping, sulfite
pulping and sulfate pulping that use
chemicals to dissolve lignin. Wood finallybecame available as an abundant, cheap
resource for pulp production.
Louis-Nicolas Robert (1798) of France
came up with the idea of forming continuous
sheets of paper by using a rotating (endless)wire mesh, instead of the traditional
hand-made batch sheet method. This idea wasdeveloped into a paper-making machine inEngland by Henry Fourdrinier in 1804, andhis paper machine, called the Fourdriniermachine, was widely used throughout
Europe.
Thanks to these two core technologies,
the paper industry prospered in the latter halfof the 19th century. To give an example, one
technical journal published in Germany forthe paper industry, Wöchenblät fürPapierfabrikation, had some 4,500 pages in
its 1908 volume alone, very clearly
demonstrating the underlying strength of theGerman paper industry at the time.

2.3 Developments in the U.S.A.
Modern paper making technology was
introduced to the U.S. in the 1900s.
Systematic Survey on Newsprint Production Technologies in Japan

5

Historically, paper had been used as a carrierof information and culture, but new
applications such as packaging and tissues
were invented in the U.S. in the 1920s. These
new applications caused the demand for
paper to more than double. Thin, weak paper
could be transformed into packaging
materials requiring strength and durability
suchas
corrugatedcontainerboard,paperboard and milk cartons, becoming oneof the greatest inventions in the history of
paper. The “kraft” pulping process, which is
the most common method used today, wasestablished in the same decade as a complete
chemical recovery system. It soon became thebasis of pulp production, and is still the main
method used by the industry. These
technologies were introduced to Japan afterWorld War II, helping the Japanese paperindustry dramatically increase production.

2.4 The spread of office automation
The new revolution in office called officeautomation (abbreviated as “OA” in Japan)
gave birth to new types of paper, classified as“communication paper.” One of these types
was paper for computer printouts. As
computers became more common in offices,
there was an increasing demand for computer
printouts. And as computers became evermore sophisticated, they demanded better
paper, so paper quality was improved as well.
Other types of communication paper werealso created, such as PPC paper, carbonlesspaper, thermal paper and inkjet printing paper.
Though the OA movement was intended toreduce paper consumption in offices, it
actually ended up increasing the amounts
both consumed and discarded. This meantthat waste paper from offices came to be seen
as an environmental issue, and newtechnologies were developed to recycle it as arenewable paper resource.
This field sees rapid technologicaldevelopment, and as new multi-media types
are developed, it will no doubt affect theways in which paper is used.

6

2.5 Development as a modern large-scale
process industry
As markets for paper expanded rapidly
following the start of the 20th century, thepaper industry became a typical large-scale
process industry. At the time, large-scale
process industries wanted, in principle, tohave their equipment be as large as possible
to ensure higher productivity and better
returns on investment. Accordingly, the paperindustry developed the technologies required
for large-scale fabricating equipment. Thesedays, some pulping lines have a capacity of
3,000 tons per day, with some paper
machines being up to 10 m wide andproducing paper at rates of up to 1,800 m/min.
The increasingly large outputs of mills meansthat managing mills efficiently, from material
supply to product delivery, and of course
actualmanufacturing,isbecoming
increasingly sophisticated.

2.6 Environmental conservation
When an industry gets big enough,environmental conservation methods become
critical. Though the paper industry is now at a
very
good
level
of
environmental
preservation, in the past it was a major sourceof problems. This process of improvement
could be said to be a type of technologicaldevelopment, and we will look at it in
Chapter 9.

2.7 Industry sustainability
One of the concepts required for a majorindustry is how sustainable it is. Fortunately,
the paper industry is one of those rare majorindustries which have internal sustainability,
as illustrated in Fig. 2.1.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Fig. 2.1. The complete carbon cycle.
The key is the biomass (trees). Carbon
dioxide in the air is converted into biomass
by sunlight and stored in the form of thewood from which the paper industry produces
pulp. This pulp is made into paper. The paper
is used in any number of ways and thenrecovered as waste paper, which is thenrecycled to create more pulp. Any paper
unsuitable for recycling is discarded as waste.
This waste is burned, providing some energy
recovery, and creating carbon dioxide, whichis in turn becomes fixed in the form of woodbiomass (such as a forest). As seen in the
figure, the carbon dioxide cycle is complete,making the paper industry internallysustainable.
Bibliography[1] K. Iida, “History, characteristics andecology of pulp and paper industry,”
JAPAN TAPPI Journal, vol. 55, No. 4 p.
417, 2001.

Systematic Survey on Newsprint Production Technologies in Japan7

3 Significance of the theme and perspectives of thestudy

3.1 The paper industry in Japan
Quite a number of industries in Japanrank among the global top in terms of
production
volume.
While
not
as
internationally famous as cars or electronics,
the Japanese paper industry was second only
to the United States for a long time, until it
was recently overtaken by China. Despite this,Japan’s output is still greater than those of
noted paper producers such as Canada andScandinavia. However, while other industries
in Japan are export-oriented, the paperindustry has been domestically-oriented, andits export volume has been very small,amounting to no more than 5% of total
production.

Fig. 3.1. Global paper and paperboard
production (2004) [1].
Statistics from 2004 show that the annual
output was about 30 million tons, and if
downstream industries like paper processing
are included, the value of the annual total
output in money was 8.6 trillion yen,providing employment to 260,000 people(Statistical Report, 2004)[1]. This shows theimportance the paper industry plays in theJapanese economy.
The paper industry was notorious forcausing pollution and filling the surroundingarea with foul smells. Since the 1970s,
however, the industry has spent a great deal

8of money in improving its environmental
conservation, and can now meet the severest
regulations in the world, so these problems
are a thing of the past (see Chapter 9).
To give a few examples of the industry’s
concern for the environment, in 1991,
widespread dioxin pollution was noticed,
which people blamed on paper mills.
However, a study by the Environmental
Agency found that the areas around paper
mills did not show this pollution, proving thatthe culprit was not the paper mills after all.
Yet although the biggest culprits were themunicipal waste incinerators, the initial false
report blaming paper mills remained in thepeoples’ consciousness for some time, and it
has only been recently that thismisunderstanding has finally been corrected.
Being a wood product, the paper industry
is said to be devastating forests. It is true thattropical forests are being lost, but this ismostly due to agricultural development, notpaper-making. In Japan, North America andEurope, where forests are managed properly,
the volume of annual growth in forests ismore than the annual harvest volume, andindeed the total volume of wood in forests isincreasing. Japanese paper companies importwood chips, small chunks of pulverized wood
made from waste wood left over from lumber
production or harvested wood from planned
forest plantations, so they are not a cause of
deforestation. In addition, paper companies
actively promote afforestation in areas
unsuitable to farming, and contribute toenvironment conservation efforts.
The increasing volume of waste paper
from offices also gives a bad impression of
paper. But the industry recovers more than
60% of the paper it produces and uses it asrecycled pulp, making it a classic example ofa recycling industry. In Japan, recycled pulp
accounts for 70% of the total pulp used to
produce newsprint.
Thus, the paper industry is actually far
better at environmental preservation than its

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

common image would have it, and in
ecological terms it is actually one of the few
major industries to satisfy sustainability
requirements.

3.2 Whyfocus
manufacturing?

onnewsprint

Paper is classified into three maincategories, depending on how it is used:paper for printing, paperboard for packaging,and other types like tissues and industrial
applications. Paper and paperboard accountfor the bulk of all production.

3.3 Viewpoints

forsurveyingtechnological developments(1) Technological developments in response
to shifting requests
Newspapers need be delivered to each
subscriber’s home by a certain time of a day
without fail. A deep level of trust is
maintained between newsprint manufacturers
and newspaper printers that the newsprint
will be delivered in time. Newspaper printers
have improved their operations in numerous
ways, including increasing the number ofpages per issue, changing their printing
systems, and restructuring their delivery
depots, while at the same time they have beenrequiring better-quality newsprint. Table 3.1
summarizes the changes of the past fifty years,
which will be discussed in detail in Chapter 5.
Table 3.1. Changes in newspaper printing
Printing in the
1950s

Printing in the
2000s

Printing

Letterpress,
black only:
4 pages/copy
Printing speed:
320,000
pages/hour

Offset press,
four colors:
40 pages/copy
Printing speed:
6 million
pages/hour
Sheet break
rate: less than
1/1,000 rolls

Newsprint

Basis weight: 52
2g/m
Brightness: 45%

Basis weight: 432g/m
Brightness: 55%

Consumption

500,000
tons/year

3.75 million
tons/year

Fig. 3.2. Production volume by type in Japan(2004) [1].
Of paper and paperboard products,
newsprint is probably the most symbolic
product of paper industry: not only does it
have a greater output volume than any othersingle product, it has also been frequently
targeted for trialing new manufacturing
technologies. Newspaper is something mostpeople would see on a daily basis, so gradualqualitative changes are harder to notice. Yettechnological developments mean thatnewsprint today is very different from that offifty years ago. Similar things have happened
in other industries, of course. For example,
sheet steel for automobiles is still called by
the same name, but its quality has beensteadily improving, taking advantage oftechnologicaldevelopments
insteel
production. In this paper, the history ofnewsprint manufacturing will be examinedfrom several viewpoints by following
technological developments.

(2) Responses to international competition
Relatively soon after World War II, thetariffs on paper products were removed,
opening up the market to overseas imports.
With newsprint now an internationalcommodity,
Japanese
newsprint
manufacturers have faced severe competition.
What has happened, however, there is very
little importing of newsprint rolls, and very
little export as well. This has come about due
to the characteristics of the Japanese market
and technological developments made bypaper companies. These will be explained in
Chapter 5.

Systematic Survey on Newsprint Production Technologies in Japan

9

(3) Overcoming geographical disadvantages
At a rough estimation, the cost of wood
resources such as chips and recycled fiber
accounts for 50% of the total cost of
producing paper, while energy consumption
accounts for 15% of the cost. As annual paper
output has increased fourteen times in the last
40 years (currently 30 million tons a year),
supplying enough wood resources and energy
has been an indispensable part of this growth.
These efforts will be described in Chapter 6(for wood resources) and Chapter 9 (forenergy supply).
(4) Technological developments that madethe industry competitive
The fact that Japanese newsprint
manufacturing has been competitive suggeststhat it must have had some degree ofunderlying technological capability. However,the phrase “technological capability” isperceived differently by different people.
Those who work in R&D would evaluate
technological capability based on R&D
capabilities. However, those who work in
manufacturing operation would evaluate it by
low-cost high-quality goods manufacturing
capabilities. In other words, “technological”
canbe
brokendown
toseveralsub-technological categories. Therefore thetechnological capabilities of the paperindustry will be reviewed in Chapters 6 to 9,
based on the sub-technological categories
listed below.
• Exploiting resources• Manufacturing products• Productivity, operating efficiency, productperformance• Energy-saving• Environmental conservation• R&D capability• Education and training• Strategic planning

3.4 Historical operational data fromnewsprint machines
Newsprint is manufactured using paper
machines. Newsprint machines are generally
operated for up to several decades, withintermittent rebuilds of various parts of theirstructure. This means that the operational data

10of a given paper machine during its lifetime,such as modifications of parts of the machine,
operating conditions, pulp resources andoperating efficiency, will form a history ofnewsprint production. For that reason, thispaper will look at the records of one
newsprint machine that was installed in 1960,
which at that time was one of the biggest andfastest machines. That machine is still
manufacturing newsprint of the highest
quality, albeit at medium velocity. The
historical record of its operational data issummarized in Chapter 11.

3.5 Characteristics

asalarge-scale

process industry
The way technology is developed isgreatly affected by the industry type. One
type of classification often used is todistinguish between process industries andassembly industries. Industries like steel, oil
refineries and chemicals are processindustries, as is the paper industry.
Automobiles,
home
appliancesandelectronics are assembly industries.
These two groups differ not only in
manufacturing but also in managing plants ingeneral, including issues such as plant site
selection, plant control, and logistics.
Technological developments in newsprint
production
represent
some
of
the
characteristics of process industries, and will
be discussed from that viewpoint in Chapter 8.

3.6 Chronological table and evolutionarychart
A chronological table is a database forreviewing
history.
Twoseparatechronological tables are provided in the
Appendix.
• Chronological table of news of theindustry• Chronological table of technologicaldevelopments in the industry
These tables are excerpts on newsprint
production from the database prepared byJAPAN TAPPI.
In addition, a chart and a table showing
the evolution of technology are provided toserve as a conclusion.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Bibliography[1] Pulp and Paper, Japan Paper Association,
No. 694, p.6, June 2006.

Systematic Survey on Newsprint Production Technologies in Japan

11

4 Descriptions of basic technologies
4.1 Pulp, paper and recycled pulp
4-1.1 Pulp
When a piece of paper is torn, small fluff
is visible along the edges. This fluff is called
pulp, and large quantities of this pulp form
sheets of paper through mutual entanglement.
This pulp comes from wood, so the next issue
is to examine lumber and trees to see how
pulp can be obtained from them.
In order for a plant to grow, water taken
in by its roots is transported to the leaves,
where it is converted to nourishment throughphotosynthesis, and this nourishment is thentransported back to where it is needed. Thismeans that trees need “pipelines” to transportwater and nutrients. These pipelines have tolengthen as the tree grows. One efficient way
of making a pipeline is to create pipes of acertain length then connect them into a single
pipeline. This is how it is done fortransporting oil, for example. One way toconsider this is to imagine a standard drinking
straw. If ten thousand straws are connected toeach other, they will form an extremely longpipeline. Paste adhesive around thosepipelines and combine a hundred million ofthem to form a huge column. One straw isequivalent to one piece of pulp magnified ahundred times. Under the same magnification,
this huge column is equivalent to a tree one
meter in diameter and twenty meters in height.
So a tree trunk consists of a huge number ofstraw-like pulp particles which act as
pipelines for transporting water. At the sametime, they form a honeycomb-like structure
which gives rigidity to the tree to help it standupright (Fig. 4.1).

12

Fig. 4.1. Douglas fir trunk cross-section(magnified) [1].
We have seen how pulp can be seen as a
straw. The next question is, what is the
structure of pulp on the microscopic scale?
Pulp walls consist of cellulose, a linear chain
polymer made up of glucose units oriented
parallel to each other at a given angle to thelong direction. This angle means that
cellulose molecules coil up, like a spiral,
within the pulp wall. This structure gives pulp
its toughness. Due to the orientation ofcellulose, some hydroxyl groups of thecellulose molecules remain on the surface of
the wall and can form hydrogen bonds witheach other. This sort of structure is found in
all plants.
To make pulp, wood has to be broken
down to these pipe-like units. One way is to
twist the wood using force to separate theseunits at their adhesive boundaries. This iscalled mechanical pulping. However, as thismethod is too coercive, some units end up
being broken down, as shown in Fig. 4.2.
The other way is to dissolve the adhesive
layer (called lignin) with chemicals andseparate the units without damaging them.
This is called chemical pulping. Both types ofpulp have specific characteristics, so are
blended with each other to get the desired
paper quality.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Fig. 4.2. Mechanical pulp (groundwood pulp)(magnified) [1].
Hardwood pulp

Softwood pulp

Fig. 4.3. Chemical pulp (magnified) [1].
Scanning electron microscope (SEM)
photos for the two pulp types are shown in
Figs. 4.2 and 4.3. Pulp from softwood is
3 mm long and 0.1 mm wide, while pulp from
hardwood is 1 mm long and 0.03 mm wide.
One of the important technologies for thepaper industry is the ability to continuously
produce these types of pulp at high efficiency
and using large-scale equipment.
Historically, softwood, which has longunits of pulp, has been used. However, asJapan is poor in usable softwood, one of theissues of technological development has been
ways in which to use hardwood for pulp.
4-1-2 Pulp notation
Pulp is broadly classified into two maingroups, mechanical pulp and chemical pulp.
Each group has several types and qualities ofpulp, depending on the pulping process.
Notations are commonly used to identify

these different types. They are summarized
below to help understand the explanations
that follow. The actual pulping processes will
be described in Chapter 6.
1) Chemical pulps
KP: Kraft Pulp or Sulfate Pulp
Pulp produced by the kraft process, using
sodium hydroxide and sodium sulfide.
Noted for its strength compared to thesulfite process.
SP: Sulfite Pulp
Pulp produced by the sulfite process,using calcium hydrogen sulfite. This was
the main type of chemical pulp until KP
became dominant around 1950.
2) Mechanical pulps
GP: Groundwood Pulp
The classic process in which logs are
ground from logs using a grinder (see Fig.
6.3).
CGP: Chemi-groundwood Pulp
The shortage of softwood trees led to thedevelopment of this process. Hardwood
chips are lightly treated with chemicals,
then crushed by a refiner.
SCP: Semi-chemical Pulp
This process can make pulp from
hardwood. Its quality falls between
mechanical pulp and chemical pulp. Not
much used.
TMP: Thermo-mechanical Pulp
Softwood chips are heated by steam andcrushed by a refiner. This process
became popular in Japan when softwoodchips started to be imported. TMP is lessdamaged than GP and has higher strength.
Its disadvantage is less opacity due tocoarser content.
RGP: Refiner Groundwood Pulp
Softwood chips are simply crushed by arefiner. This process was modified tocreate TMP.
3) Recycled pulp
DIP: Deinked Pulp
Reclaimed waste paper is processed tocreate recycled pulp. DIP is a type ofrecycled pulp treated through a deinking
process and is of good quality. Its details
will be discussed in Chapter 4.1.4.
4-1-3 Paper
Paper consists of a huge number of pulp
Systematic Survey on Newsprint Production Technologies in Japan13

fibers between 1 mm and 3 mm long and 0.03
mm and 0.10 mm wide. Figure 4.4 shows a
SEM photo of the surface of newsprint.
Figure 4.5 shows a newsprint cross-section,
showing five to seven layers of pulp.

Fig. 4.4. Newsprint surface (magnified) [1].

papermaking (batch process) is still done forpaper for arts and crafts, but the modern
paper
industryusesacontinuous,mass-production style.
4-1-4 Recycled pulp from used paper
When paper is immersed in water anddisintegrated through mechanical agitation,these hydrogen bonds break up, releasing theindividual pulp fibers. Though the pulp
quality is deteriorated to some extent due tohaving been heated when the initial sheet was
made, it is still strong enough to be usedagain. This is the principle behind paper
recycling, one that is indispensable in theJapanese paper industry. At present, morethan 60% of Japan’s pulp consumption isrecycled pulp.
Recycled pulp has long been used as pulp
stock for cardboard and the back layers of
paperboard. A new development in the lasttwenty years allows recycled pulp to berefined through the deinking process so it canbe used as the main pulp source of newsprint,
which is a higher value-added product thanpaperboard. This is the key technology whichhas permitted the survival of the Japanese
paper industry, and will be discussed in moredetail in Chapter 6.

Fig. 4.5. Newsprint cross-section (45 degrees
to vertical line) (magnified) [1].
As pulp is hydrophilic, due to hydroxyl
groups on its surface, it can be dispersed asslurry in water. When pulp slurry is filteredon a wire mesh, it forms a two-dimensional
sheet. As the wet pulp is flexible and tangled
together, the sheet is just strong enough to beheld by hand. This sheet is placed between
two pieces of felt and pressed to squeeze thewater out. Then it is dried using heat. As the
sheet dries, numerous hydrogen bonds areformed between the pulp fibers, making the
sheet strong. This means that the strength ofpaper is generated through the strength ofthese hydrogen bonds and the intrinsic
strength of individual pulp fibers.
In
Japan,
old-stylehand-made

14

Fig. 4.6. Deinked pulp (DIP) from waste
paper (magnified) [1].
As waste paper has been broken down torecycled pulp, the pulp quality is almost thesame as the original waste paper. Therefore,
the types of waste paper that should berecycled are key to the quality of recycled
pulp, and will be discussed in Chapter 6.2.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

4.2 Paper machines
Newsprint and other types of paper are
manufactured on paper machines. Though thetechnological development of paper machine
will be explained in Chapter 7, the concept of
paper machines will be briefly described inthis section to help in understanding Chapters
5 and 6.
The basic process of paper-making wasinvented in China. A wet sheet is formed
from a pulp slurry of up to 1% concentrationby scooping it with a drain board. The sheet
is then peeled off and placed on a press toremove the excess water. Then the sheet ispasted on a wooden panel and left to dry
naturally. This hand-made process of making
paper in individual batches evolved to acontinuous process using machinery, which
rapidly developed in the 1800s.
In this section, the basic concept of thepaper machine as it was in the 1950s is
explained in order to provide a starting point
for this paper. (Refer to Fig. 4.7)

Fig. 4.7-1. Conceptual image of wire part andpress part.

Fig. 4.7-2. Conceptual image of dryer part.

Fig. 4.7-3. Conceptual image of calendar.
A wire mesh (simply called a “wire” inthe paper industry) moves from the start rollto the end roll, then returns to the start roll, so
in other words, it is continuously rotating.
Pulp slurry is poured on the wire and theexcess water drains as the wire moves
towards to the end roll to form a wet sheet.
This section is called the wire part or the wiresection. The wet sheet is peeled off at the endroll and transferred to the press part. In thepress part, the wet sheet is laid on a moving
felt bed. The wet sheet on the felt moves
forward to pass between rolls under highpressure, where it is dewatered. The felt
returns at the end in the same way as the wirein the wire part, coming back to receive thenext incoming section of wet sheet. The
dewatered sheet is peeled off at the end of thepress part and is transferred to the dryer part.
The dewatered sheet is then pressed against adryer, which is a steam-heated rotating drum
about 1.5 m in diameter. As one dryer is notenough for complete drying, the sheet ispeeled off and pressed against another dryer,
and another in series until it is fully dry.
Dozens of dryers are needed in most cases.
To ensure the sheet remains on track, two setsof canvas are used to press the sheet against
the dryers, one from the top and the otherfrom the bottom. Finally, the dried sheet iswound in a roll at the end of the paper
machine.
It may be difficult for those who havenever seen a paper machine to understand theconcept, so therefore the series of illustrationsin Fig. 4.7 may be of some help. Chapter 7
describes the way in which the design of thisearly model would be greatly changed
Systematic Survey on Newsprint Production Technologies in Japan15

through the technological development.
In the 1950s, a paper machine considered
to be large would be about 3.5 m in width andrun at about 300 m/min. These days, a large
paper machine is 10 m wide and runs at
1,800 m/min. Their images are shown in Figs.
4.8 and 4.9.

develop a machine which has less chance ofthe sheet breaking (see Chapter 7).
The paper machine also needs to be madeas productive as possible in order to help
offset its high cost. One way is make themachine as wide as possible and run it as fast
as possible. This is another technologyrelated subject, and Fig. 4.10 shows how thiswas gradually implemented.

Fig. 4.8. View of a current paper machine [2].
Fig. 4.10. Growth of paper machines in Japan(excerpted from the news chronology in
Chapter 12).

Fig. 4.9. Comparison of newsprint machinesizes (1960 and 2000) [3].
Large paper machines are about 150 m intotal length. Paper has to pass along the entire
length of the machine, and has to travel
without any support as it moves from the wirepart to the press part, and from the press partto the dryer part (see Fig. 4.7). Once in thedryer part, the paper has to pass from one
dryer to another without any assistance. At
this stage, the paper is still weak, and so it
occasionally rips in a “sheet break,” which
can be extremely dangerous. Once the paper
has broken, the machine has to be cleaned
and the process needs to be started again fromthe beginning.
As can be imagined from its size, a paper
machine is a very expensive piece ofequipment, costing tens of billions of yen.
This means that a sheet break will decrease
the machine’s operating efficiency and causea major operational loss. One of the biggest
challenges in technology development was to16

One other key factor for productivity is
operating efficiency. As will be discussed in
Chapter 8, high efficiency is how theJapanese paper industry remains competitive.
As an example, the historical operation
records for one paper machine over forty
years will be presented in Chapter 11.

4.3 Newsprint and newspaper printing
4-3-1 Newsprint
The most basic property of any type of
paper, including newsprint, is its basis weight.
Basis weight is the weight in grams of 1
square meter of paper. For example,
newsprint is 43 g/m2, PPC (plain paper
copier) paper is 64–75 g/m2 and corrugatedcardboard paper is 200–300 g/m2. There is asuitable basis weight for each way paper canbe used. If the function that the paper is used
for can be satisfied with a lower basis weight,
it will save resources and reduce costs. This is
why trying to reduce basis weight remains
one of the challenges for technologicaldevelopment in the paper industry.
Printing paper, which includes newsprint,
has to have some basic qualities. Its surface
has to be smooth enough for printing and be
white enough to make the printed image clear.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

It should be opaque enough that the printing
does not affect the reverse, strong enough thatthe sheet does not break or get damaged
during printing, and stiff enough to handle
easily. These properties are met throughblending different types of pulp. As noted in
Chapter 4.1, pulp is produced by breaking up
the structural units of trees. Chemical pulp isable to form strong sheets due to its ability toform hydrogen bonds. Mechanical pulp has
extremely fine pieces, giving it a highspecific surface area that gives opacity topaper by scattering light on the surface,
though the sheets are not as strong as
chemical pulp. The desired quality ofnewsprint is obtained by blending those two
types of pulp. In the 1950s, newsprint wasmade of 80% mechanical pulp and 20%
chemical pulp, both from quality softwood(fir and spruce). This balance is still used in
Canada and in Scandinavian countries where
softwood is abundant. Faced with a shortageof good softwood in Japan, a core of resource
exploitation was the search for replacements.
This will be discussed further in Chapter 6.
4-3-2 The rotary printing press fornewsprint
Newsprint manufactured on paper
machine is delivered to newspaper printers,
where it printed on printing presses.
Gutenberg is usually credited with inventing
the modern printing system. His system was a
type of lithograph, and book pages wereprinted in individual batches, like woodblock
prints. The main feature of his system wasarranging metal type on a holding plate
instead of making individual wood blocks foreach page, which was a far more efficientsystem.
As the name “press” suggests, thisprinting plate was repeatedly pressed against
sheets to print them. The rotary printing press
was invented in order to do this continuously.
In this, the printing plate is wrapped around aroll rather than a flat plate, which is called theplate cylinder. Inking the plate cylinder androtating it over a sheet that moves at the same
speed will print an image on the sheet. Ifsheets are continuously fed from a roll andthe plate cylinder keeps rotating, images will
be printed continuously. In the 1950s, a flat

plate was made by first picking and arranging
metal type, then it was pressed against a thick,bulky piece of paper to form its replica,
which was called the paper mold. Lead waspoured into the mold to form a lead plate,which was then wrapped around a roll. Ink
was applied to the projecting parts of theplate that were the shapes of the letters. Thus
it was called letterpress printing. The mostinfluential change in newspaper printing wasfrom letterpress printing to offset printing,and this demanded a change in newsprint
quality.
In offset printing, the printing plate ismade in quite a different way. A photosensitive resin plate is exposed to light only
on the areas that are to be printed (areas to be
inked). The exposed areas harden and the rest
is washed away. The hardened areas arehydrophobic and the washed-out areas arehydrophilic. This plate is wrapped around acylinder, which is called the plate cylinder.
Water is applied to the plate by the waterroller. This water only remains on thehydrophilic areas. Next, the ink roller inks theplate, and this ink only remains on thehydrophobic areas, without water. Finally, theimage thus formed with ink on the plate istransferred to the blanket cylinder, and thenprinted onto paper.
Though offset printing requires more
complicated equipment than letterpress, itdoes not need laborious type-setting, allowing
significant cost savings. Due to this, rotaryoffset printing quickly became common
among newspaper printers, as will be shownin Chapter 5.

Fig. 4.11. Letterpress and offset press [2].
In offset printing, the area to print on thepaper is controlled through the use of water.
Paper, on the other hand, is very sensitive tomoisture and humidity changes, and stretches
Systematic Survey on Newsprint Production Technologies in Japan17

readily when it gets wet. This means that
paper that is as stable as possible is preferable.
If paper does not react equally to water acrossits cross direction (width), problems will
happen in printing. The paper surface needs
to be smoother compared with that forletterpress, in which the plate is pressedagainst the paper. As the ink is tackier, thepaper surface needs to be more resistantagainst being pulled by the ink. The use ofoffset printing enabled the printing process to
be rationalized, but it also required increased
quality from the paper.
Following the spread of offset printing,color printing became common. This affected
newsprint quality, which will be examined in
Chapters 5 and 6. For reference, this next
section will provide a brief outline of color
printing (color offset printing).
Color printing on newsprint is different
from ordinary color offset printing. The firstcolor printing system used for newsprint wascalled the satellite system, as printing rolls ofdifferent colors were positioned around thelarge cylinder like satellites.

Fig. 4.12. Satellite multi-color press [2].
Using this system, paper can be printed
with one color (usually black) on one sideand four colors on the other side. On thecolor-printed side, dampening water isapplied four times, so the paper has to be
more resistant to water. The system currently
in use is called a tower press, which can print
four colors on both sides.

18

Fig. 4.13. Tower press [2].
As dampening water is applied four times
on each side, for a total of eight times, thepaper quality must be higher still. Paper
quality has to be controlled more evenly in its
cross direction in areas such as basis weight,
thickness and moisture content, and its
surface strength also has to be improved.
4-3-3 Printing operation in newspaper
printers
This section will cover how newspaper
printers print. Newsprint rolls are delivered tonewspaper printers as what is called an A-roll,which is about 1.6 m wide, 13,000 m long
and weighs about 900 kg. One roll isequivalent to eight pages of that day’s
newspaper run. If a newspaper has forty
pages, as is common these days, five rolls areused to print it, one for every eight pages. In
normal operation, one rotary printing press
has five printing units and each unit prints
eight pages. After printing, the paper fromeach unit moves forward with precise timing
to be stacked up into a single copy, which isthen folded and cut separately. The operation
is a race against the shipping time. If a
problem such as a paper break happens in justone printing unit, then the whole operation
has to shut down. So newspaper printersdemand high reliability from newsprint rolls.
As printing speeds increase, these demands
grow more and more severe. Printer use theterm “sheet break frequency” as an index of

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

reliability, which means the number of sheet
breaks during printing per hundred rolls. Thisfrequency was 1 percent (one break per 100
rolls) in the 1970s, but in the 2000s, it was
down to less than one break per 1,000 rolls.
This issue has been one of the subjects oftechnological development in newsprint
manufacturing, and will be reviewed insubsequent chapters.

Bibliography[1] Supplied by Nippon Paper Industries Co.,Ltd.
[2] T. Naito, “Progress of newsprint
manufacturing over the last 60 years,”
Hyakumanto, No. 126, p. 25 (Paper
Museum).
[3] Preserving
andPublicizing
Technological Archives of the JapanesePaper Industry, “Four A-roll-capable
paper machine largest and fastest in Asia
(1960),” No. 6, p. 2, Oct. 13, 2004.
Chapter 4.1 drew on the following article.
K. Iida, “History, characteristics and ecologyof pulp and paper industry,” JAPAN TAPPIJournal, vol. 55, No. 4 p. 417, 2001.

Systematic Survey on Newsprint Production Technologies in Japan19

5 History of newsprint production over the last 60
years
The core technologies for manufacturing
newsprint were briefly reviewed in Chapter 4.
This chapter provides a chronological review
of how newspaper printers demands for
quality changed and how the paper industry
tried to meet these demands.
Prior to World War II, the Japanese paperindustry was prospering in Hokkaido and
Sakhalin where good softwood was available.
Following its defeat, Japan lost Sakhalin andthe paper industry lost its main pulp supply.
The paper industry was devastated in the
confusion following the war: production in1946 was only 210,000 tons, of whichnewsprint was only 75,000 tons: a quarter ofthe maximum output before the war, and justone fiftieth of the present production.
Post-war recovery had to start from this level.
Figure 5.1 shows some features of how
newsprint production increased in Japan. One
feature is that the number of copies publishedby newspaper printers increased at a constantrate. The other is that paper companies inJapan continued supplying newsprint,
protecting the domestic market frominternational rivals.

Fig. 5.1. Annual newspaper publication
numbers and newsprint consumption [1].
As this chapter is simply a general
overview, certain technical terms used here
have not yet been defined in this paper. These
terms will be explained in later chapters, suchas Chapter 6 for pulp and Chapter 7 for paper
machines.

20

1945–1955
Newspaper
printers
usedrotaryletterpress printers (single color), and theirprinting speed was about 80,000 copies perhour, four pages a copy. These printers werevery slow compared with modern offset press
printers that print four colors at 150,000
copies per hour, 40 pages a copy. The ink has
to be quickly absorbed into the paper inletterpress printing, which means paper needs
to be bulky, so the paper used during thisperiod had a basis weight of 52 g/m2.
Groundwood pulp and unbleached sulfite
pulp, both from domestic softwood, wereused in an 80–20 ratio (see Chapter 6 fordetails). The paper machines were the
Fourdrinier type, with a width of about 3.4 m
and a speed of about 300 m/min.
1956–1965
During the period of high economic
growth, demand for newspapers increased
and many new paper machines were installed(refer to the news chronology in Chapter 12).
However, this increased pulp demand caused
a softwood shortage, so instead of GP, CGP(manufactured from hardwood and lightly
treated with chemicals) was developed. The
typical pulp composition of newsprint at thetime was 60% GP, 20% CGP, and 20% SP.
However, CGP was later replaced by TMP
manufactured from imported softwood chips.
To improve productivity, larger and larger
paper machines were developed. In 1957, a
machine wide enough for three A-sizenewsprint rolls (about 5.4 m wide) was
installed, followed in 1960 by one that was
7m wide and ran at 600 m/min. Newspaper
printers also improved their technologies,
enabling them to print at rates up to 100,000
copies per hour, 16 pages a copy, and also
tested out color printing.
1966–1975
Major newspaper printers started to
publish copies with 24 pages, introduced a

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

small number of offset printing presses, andbegan to print advertisements in color. Paper
companies rushed to expand their capacity,with 21 new machines starting operation, twoof which had a width of 8.4 m, wide enoughfor five A-size newsprint rolls, and ran at
800 m/min. On the pulp supply side, studies
were started on changing over from the major
chemical pulp at the time, SP, to cleaner KP,
as pollution from its untreated effluent was
becoming a serious issue.
1976–1985
Both newspaper printers and paper
companies accelerated their technologicalinnovations. Newspaper printers rapidly
converted from letterpresses to offset presses,
bringing in the CTS system, in which every
page was edited on computer and displayedon monitors, and typesetting was done on
resin film the size of one page. The transferfrom lead plate to resin plate greatly
improved productivity in printing operations.
As productivity improved, printers required
further improvements in newsprint quality.
These requirements included a sheet breakrate of 1%, improved ink setting on the wireside of the paper (the side of paper that faced
the wire was inferior to the other side in termsof ink setting, due to the use of the
Fourdrinier machine), and improved opacity.
The second oil shock caused a rapid risein the price of imported softwood chips. To
cope with this, newspaper printers and paper
companies worked together to reduce thebasis weight of newsprint. This cooperation
was something that no other country
attempted, and it lasted until the 2000s,
gaining more and more traction. Specifically,
the basis weight initially went down from53 g/m2 to 49 g/m2, then to 45 g/m2 andfinally to 43 g/m2. As shown in Fig. 5.2, once
newsprint with a lower basis weight wasdeveloped, it very rapidly took over the shareof heavier types.

Fig. 5.2. Changes in basis weight shares ofnewsprint [1].
This reduction in basis weight required
even further technological developments innewsprint production. Newsprint qualities
such as strength, printability, opacity andbrittleness had to be maintained at a lower
basis weight, but not all quality requirements
could be satisfied with the machinery of thetime. Paper companies introduced such newtechnologies,
astwin-wire
formers,
conversion from SP to KP, the use of DIP,
and the use of oil-absorptive fillers like whitecarbon. These technologies will be further
explained in Chapters 6 and 7.
1986–1995
As offset printing and color printing
became increasingly common in thenewspaper market, paper companies wererequired to provide further basis weight
reductions. Offset printing uses tacky ink so itneeds paper with a high surface strength. In
multi-color printing, four different colors are
printed on the same paper surface, whichmeans even higher strength is required. In
offset printing, dampening water istransferred to the paper, so if the paper isunable to stand up to this, issues such as color
drift will occur. The lower the basis weight,
the more chance of problems.
To satisfy the demands for a lower basis
weight, Japan developed gate roll-type sizepress coated newsprint (see Chapter 7). With
this improvement, newsprint could be printed
at up to 150,000 copies per hour, 40 pages a
copy, with few sheet breaks (perhaps 1–2
times per 1,000 rolls). This superior quality
meant that there were almost no imports ofnewsprint rolls into Japan.

Systematic Survey on Newsprint Production Technologies in Japan

21

1996–2005
Color printing became more common,
and a new type of multi-color printing press
called the tower press was introduced, as
described in Chapter 4.3.
This press can print both sides of thepaper in full color. That meant thatdampening water is applied to the paper fourtimes per side, requiring stronger paper. This
meant that paper had to be more uniform
cross-wise in qualities like basis weight,
moisture and thickness. To make printed
images stand out more, the paper had to bewhiter. In fact, paper brightness had increasedby 10 points to 55% in the last fifty years.
Brightness is a term expressing the whitenessof paper, and is expressed as a ratio in thescale in which a black body is 0% andmagnesium oxide is 100%. As printingpresses capable of printing 180,000 copies
per hour were introduced and newsprint witha 40 g/m2 basis weight came onto the market,
newsprint performance demands became
even stricter, requiring sheet breaks of lessthan 1 per 1,000 rolls. Paper machines kept
evolving to cope with those demands. For
example, to improve uniformity in the crossdirection of paper machines headboxes wereconverted to consistency control methods (seeChapter 7) and soft-nip calenders wereintroduced to improve surface quality. In
addition, greater amounts of recycled pulp
could be used by refining the DIP process,and calcium carbonate could be used byconverting to neutral sheet forming (seeChapter 6).
These technological developments are
summarized in Table 5.1
Table 5.1. Technology changes over the past
50 years
Printing

22

Printing in the
1950s
Letterpress,
black only:
4 pages/copy
Printing speed:
320,000 pages/hour

Printing in the
2000s
Offset press, fourcolors:40 pages/copy
Printing speed: 6
millionpages/hour
Sheet break rate:
less than 1/1,000
rolls

Newsprint
Consumption
Pulp andadditives

PapermachineBasis weight: 52
2g/m
Brightness: 45%
500,000
tons/year
GP: 400,000
tons/year
SP: 100,000
tons/year

Basis weight: 432g/m
Brightness: 55%
3.75 million
tons/year
DIP: 2.6 million
tons/year
TMP: 0.75 million
tons/year
GP: 0.2 million
tons/year
KP: 0.2 million
tons/year
Calciumcarbonate
Surface sizing

Fourdriniermachine
3.3 m wide, 300
m/min
Acid forming

Twin-wiremachine
10 m wide, 1,800m/min
Size press
Neutral forming

The future of newsprint production
The Japanese paper industry has had todevelop a range of technologies to meet thedemands of newspaper printers for improving
their printing. Its success in this means thatJapan needs to import very few newsprintrolls. Though the newspaper industry in Japan
has grown steadily, supported by the homedelivery system each morning, the domestic
market is now saturated, which forces thepaper industry to look for new strategies.
The strict demands of newspaper printers
has left Japanese paper companies facing a
dilemma. Japanese newsprint meets the highquality standards demanded by newspaper
printers, which suggests that it would meet
any standard globally, but there are cost
factors to consider.
Paper companies have invested hugesums to modernize equipment in order tomake their products satisfactory to theirclients. This investment ends up making thepaper cost more. In fact, Japanese newsprint
is 40–50% more expensive than imported
newsprint, which raises the question of why
Japanese newspaper printers buy high-priced
domestic paper. Their operating style,running massive, high-speed printing presses
to ensure high productivity (see Chapter 4.3),
unlike the way it is done in most othercountries. Using imported newsprint would

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

cause sheet breaks at higher rates, such as
three per 100 rolls, and with the huge presses
that are used in Japan, this loss of
productivity would be quite significant: in theworst case they would need another entire
printing press to ensure they could ship thenewspaper on time. The high reliability levelsof domestic newsprint are able to offset theextra expense of purchasing domestic
newsprint.
Thus the apparent contraction of saving
money by spending more money actuallyworks to reduce the total cost. However, mostoverseas printing presses are not as fast, so
the high reliability of Japanese newsprint isless of an advantage. Japanese newsprint,
with its high prices but high reliability, isfinding it difficult to expand overseas, which
is a challenge that the industry is going tohave to deal with.

Links to subsequent chapters
The changes discussed in this chapter
form the essence of this paper. More detailsof the technological developments in pulp
supply will be explained in Chapter 6, and for
paper machines in Chapter 7, while thetechnological characteristics of the Japanese
paper industry will be explained in moredetail in Chapter 8.
The paper listed as [1] in the
Bibliography section was used as referencewith the kind permission of the author.
Bibliography[1] T. Naito, “Progress of newsprint
manufacturing over the last 60 years,”
Hyakumanto, No. 126, p. 25 (Paper
Museum).

Systematic Survey on Newsprint Production Technologies in Japan

23

6 Technological development part 1: pulp resources
6.1 History of pulp resource exploitation
6-1-1 Introduction
Japan’s demand for paper and paperboard
increased almost in proportion to its GDP.
The demand for newsprint increased in asimilar way, going from 700,000 tons in 1960
to 3.8 million tons in 2000, a five-foldincrease. As Japan lacked sufficient wood
resources, the most important topic for theindustry was how to secure the amount ofpulp demanded by this expansion. However,the Japanese paper industry was able tosuccessfully obtain a series of new resources
to meet this increasing demand, allowing theindustry to remain competitive againstinternational competitors and retain its gripon the domestic market. This history will be
reviewed in this section through a look at thechanges in the pulping process.
The basic quality requirements ofnewsprint were described in Chapter 4.2. At
the risk of duplicating that section, newsprintin the 1950s was made of chemical pulp thatgave strength to sheets, and mechanical pulpthat gave them opacity, stiffness andsmoothness. Both types of pulp were madefrom softwood, and blended in a ratio ofroughly 1 to 4. The quality of the newsprint
was controlled by subtly adjusting that ratio.
However, the search for candidates for
new pulp resources had to start, as softwoodforests were scarce in Japan and could not
keep up with the increasing demand. Fig. 6.1
depicts the types and amounts of pulp thatwere used for newsprint production in Japan.

24

Fig. 6.1. Amount of pulp used for newsprint
by grade.
(Abbreviations used in the figure are
explained in Chapter 4.1.3, but are cited again
for convenience.)
Chemical pulp group
KP: Kraft pulp
SP: Sulfite pulp
Mechanical pulp group
GP: Groundwood pulp
CGP: Chemi-groundwood pulp (madefrom hardwood)
TMP: Thermo-mechanical pulp
RGP: Refiner groundwood pulp
SCP: Semi-chemical pulp (made from
hardwood,
quality
betweenmechanical pulp and chemical pulp.)
Recycled pulp
DIP: Deinked pulp (Deinked recycled
pulp from waste paper)
Figure 6.1 is designed to show how thedifferent types of pulp used for newsprint
have changed over the past forty years.
Though still called “newsprint,” the present
composition of pulp is far removed from thatof the 1950s. Note that the values in Fig. 6.1
are calculated by the following procedure,
and are not actual data.
Newsprint production volume statistics
are shown in Fig. 5.1. The statistics of pulp
production as a whole are also available, butthere is no data to show the extent to which
different pulp types were used in newsprint
production. Therefore, the ratios of pulp

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

composition at every period were firstestimated from data in the literature andcorporate records, and shown in Fig. 6.2.
Then, using Fig. 6.2 and Fig. 5.1,
consumption of a given pulp type at a given
period was calculated as shown in Fig. 6.1.
Though Fig. 6.1 does not use actual statistics,
it gives a reasonably accurate depiction of
pulp consumption by type at a given period in
newsprint production.

Fig. 6.2. Pulp blend ratios for newsprint
manufacturing (estimated) [1].
6-1-2 1945 to 1955
As quality softwood for mechanical pulp
production became in short supply, red pine,
an endemic species of Japan, was usedinstead. Red pine contains a lot of pitch, andits tracheid cells, which are what becomes thepulp, have thick walls. These thick walls
means that its pulp is brittle and weak. The
high pitch content is particularly inconvenient.
In mechanical pulp manufacturing, the pitch
is dispersed in water during the grinding
process, allowing it to coagulate on themachinery or stick to rolls. Though theshortage of softwood forced manufacturers to
reluctantly use red pine, finding the necessary
expertise to do so was not an easy job. The
countermeasure adopted was seasoning,
storing the logs in water or on land for at least
six months. During seasoning, the pitch
undergoes chemical modification and is also
decomposed by microorganisms. Anothermeasure was to add an aluminum sulfate
solution, called “alum” in the paper industry,
to pulp slurry to adjust its pH to about 4.0 andprevent it coagulating on paper machines.
Numerous research papers were published inJAPAN TAPPI Journal during this period, as
this was the first post-war technologicalbreakthrough in the Japanese paper industry,and led to increased GP consumption, as
shown in Fig. 6.1. Storing large numbers oflogs for six or more months, then collecting
and transporting them to a plant in time
demanded high levels of mill management,
which in turn affected operating costs.
Developing and implementing this sort ofhigh-level mill management techniques
would become common in the paper industry.
A grinder for producing GP is illustrated
in Fig. 6.3. Parallel logs are pressed against
the surface of a rotating grinding stone about
2 meters in diameter, which crushes andgrinds them. In mill operation, logs about 20
to 40 cm in diameter and 1 to 2 m long are
floated along a channel. Ten or so logs at atime are picked up and inserted into what iscalled a “grinder pocket.” After the first batchof logs is ground, rotation is stopped and a
new batch is loaded into the grinder. It is alaborious, batch-based operation. The logs
must be straight and of similar diameters.
This grinder was replaced with a more
efficient refiner.

Fig. 6.3. Conceptual image of a grinder.
6-1-3 1956 to 1970
Further increases in demand caused
severe mechanical pulp shortages. The
limited amount of softwood available meantthat the use of hardwood was studied
worldwide, leading to the development ofChemi-groundwood
Pulp
(CGP)
and
Semi-chemical Pulp (SCP). In theseprocesses, chips (small pieces of woodcrushed from logs to a size of about 20 mm ×
20 mm × 5 mm) were lightly treated with
Systematic Survey on Newsprint Production Technologies in Japan25

chemicals and disintegrated using a refiner.
The advantage of using chips was that they
could be fed to the refiner continuously,
rather than in batches. Chips are continuously
fed into the refiner from a conveyor belt.
Chips are ground between two large disks
driven by a powerful motor, and continuously
discharged. Some modern refiners have disks
up to 2 m in diameter, and are powered by up
to 23,000 hp. The development of large
refiners led to development of pulping
processes such as RGP and TMP, increasing
options in the pulp supply.

Fig. 6.4. Conceptual image of disk refiner.
(Chips enter from the black arrow and arerefined between the disks, one of which isrotating.)
Hardwoods have higher densities thansoftwoods, making them difficult to bepulped using grinders. The resultant GP wasshorter, and only able to form weak paper.
Treating chips with chemicals before refining
dissolves some of the hemicelluloses in chips,
making them easier to refine and improving
pulp strength. The process was originallyinvented for the central corrugated cores,
called the corrugating medium, of corrugatedcardboard. In Japan, however, it wasdeveloped as a way to use CGP in newsprintin place of GP. There were two types ofcreating CGP: the first was to treat chips withsodium hydrosulfite at a neutral pH underhigh temperatures, and the second was to use
sodium hydroxide at room temperatures. The
former was suitable for white hardwoods like
birch and beech, while the latter was mainly
for brown hardwoods like oak. The resultant
pulp was bleached with hydrogen peroxide,
especially for brown hardwoods. (Limitations

26of room preclude a detailed discussion in thispaper, and readers are requested to pleaserefer to the bibliography at the end of thischapter.) This led to the manufacture ofnewsprint that consisted of SP, GP and CGP
in a ratio of 2:5:3.
During the same period, the Japanese
paper industry made fresh progress,
establishing a solid foundation by producing
kraft pulp from hardwood and using it tomake a range of printing paper types. Whilevery common these days, at the time making
quality paper from hardwood pulp, far shorter
than softwood pulp, was inconceivable. The
Japanese paper industry built up its expertisein paper manufacturer by trial and error. The
availability of hardwood as a pulp source
meant that large-scale mills could beconstructed. In general, paper mills
manufacture a range of paper products. Thismeans that, if a technological development
reduces costs for the mill as a whole,
newsprint manufactured in that mill will also
benefit, becoming competitive with imported
products. In this way, the technology used to
manufacture printing paper from hardwood
kraft pulp indirectly helped to reduce thecosts of newsprint production.
In terms of quality paper made of
hardwood kraft pulp, a special edition(September 25, 1952) of the Kokusaku
Tsushin (the Kokusaku Pulp Co. newsletter)reported on the reconstruction of the Ufutsu
Mill as follows: “Paper has been made therewith 100% hardwood since May 1952. This
was the first such trial in Japan, and one ofthe very few worldwide.” Ufutsu Mill waslater amalgamated into Sanyo-Kokusaku Pulp
Co., and now operates under Nippon Paper
Industries Co. The reason they wereinterested in hardwood appears to be due tothe abundance of birch around the mill(personal communication with the author). As
paper machines at the time had many “opendraw” parts, such as from the wire part to thepress part, there was a far greater chance of
sheet breakage than would be the case today.
It is also apparent that adjusting speeds at
different parts would have posed considerable
difficulties. One advantage of birch is that it
has relatively longer fibers compared to otherhardwoods, so that there would be lessNational Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

chance of sheet breakage. The short pulp
gave the paper a finer, smoother surface thansoftwood pulp, making it suited for printing.
This unexpected benefit accelerated the useof hardwood in Japan. The development of
the continuous digester (see below for details)
also drove this change. As making finequality paper from hardwood pulp has
become popular globally, the demand for
hardwood pulp has risen. This has given birth
to large-scale pulping industries based around
eucalyptus plantations, with the largest beingin Brazil.
Japan made one more contribution to theworld in terms of manufacturing kraft pulp
from hardwood. At the time, chemical pulps,
whether kraft pulp or sulfite pulp, were
produced using batch digesters. A typicaldigester was a pressurized vessel with acapacity of 20 to 30 m3. Chips were fed into
the top of the digester, the top was closed,
pulping chemicals were added to the digester,which was then heated using injected steam.
In the sulfite process, pulping required
heating at temperatures of 120 to 130°C for 7
to 8 hours, while in the kraft process, it was
170 to 180°C for 1 to 2 hours. After pulping,
the bottom valve was opened to flush out thepulp. In 1938, the Swedish company Kamyr
designed the continuous digester to improve
productivity, and save both energy and plant
space. The first test plant was installed in1946 at the Karsbrug Mill in Sweden, while
the first commercial plant, with a capacity of
50 AD tons per day for softwood, wasinstalled in 1950 at Fengersfors Bruks AB,
Fengersfors, also in Sweden. The second
plant was opened in 1951 at Cartiera Vita
Mayer & Co., Cairate (Italy), with a softwood
capacity of 90 AD tons per day. On January
29, 1953, the third continuous digester started
operation in Oji Paper Co.’s Kasugai Mill, inJapan. This digester was 2.5 m in diameterand 23 m in height, with a volume of 110 m3
and a capacity of 90 tons per day. Chips were
fed in at the top and pulped while moving
down the tower, then discharged from thebottom. Initially, there were numerous issues
to overcome, including a hammering at thehigh pressure feeder, unstable chip level inthe digester, scaling on digester strainers andimpregnating zone heaters, hanging, and air

bubbles during washing. Oji Paper recordedthat they were eventually able to achieve
stable operation after considerable effort [2].
It is believed that these efforts by Oji Paper
refined the equipment to allow its acceptanceworldwide. These days, digesters are
increasingly large, with the capacity of thebiggest being 5,000 tons per day.
For reference, the photo in Fig. 6.5-1
shows the digester being brought into the
Kasugai Mill building. Fig. 6.5-2 is a photo of
the latest large-scale digester. The size of
people in each photo gives a good example of
how large they have grown.

Fig. 6.5-1. Installing a continuous digester at
Kasugai Mill, Oji Paper Co. (Source: Oji
Paper Co.)At this period in history, there were twocompeting chemical pulping processes, thekraft and sulfite processes, which strove tooutdo each other in terms of technologicaldevelopments. This was a key era in theindustry, as it was also the first in which
environmental concerns played a decisiverole in the competition. Though a lot of
research work for modernizing sulfite process
was done, unfortunately in vain, I personallybelieve that it was a necessary step in orderfor the paper industry to become
environmentally friendly over the next few
Systematic Survey on Newsprint Production Technologies in Japan27

decades.
Though the kraft process could produce
pulp from a range of wood species by using amixed aqueous solution of sodium hydroxideand sodium sulfide, the resultant pulp was
dark brown, so it could not be used fornewsprint and printing papers in that state.
However, the technology of bleaching thepulp with chlorine dioxide to make it very
white was already available and the color of
the pulp was not the problem. Another point
was that the kraft process used expensive
sodium compounds, and these had to be
recovered from the waste liquor, although arecovery process had established by that time.
There were two mains problems: the badsmells generated from the sodium sulfide thatpermeated the air around mills, and the factthat mills needed to be big to be economical,
and therefore needed huge investments.

Fig. 6.5-2. Modern continuous digester(largest size)(Source: Metso Paper Japan).
The sulfite process, on the other hand,used a calcium hydrogen sulfite solution. Due
to using a calcium base rather than a sodium
base, the pulping solution did not penetrate
into the wood as easily, meaning that only afew species of timber could be pulped. The
waste liquor from pulping was discharged
into rivers without any treatment, polluting
the area around mills. One way to prevent this28

was to collect the waste liquor from pulping,recover the calcium base, and regenerate it
into pulping solution. However, thetechnology required was daunting, and would
be very costly, even if it were possible. The
other way was to use soluble bases likesodium, magnesium and ammonia instead ofcalcium. Using these would allow the waste
liquor from pulping to be recovered in thesame way as the kraft process, greatly
reducing pollution. This would also mean thatthe current pulping plants could be used, andthe pulp would be white enough to be used innewsprint and other low-grade printing
papers without bleaching. Scandinavian
countries, with an abundance of softwood
resources that were suitable for sulfite
cooking, were interested in converting theircalcium base to soluble bases. After carryingout extensive research and development, theycame up with modified sulfite processes suchas the Stora process, the Sivola process andthe Magnefite process, which were put into
practical operation in a few mills.
For example, Stora Co. built a new millin Nova Scotia (Canada) using its proprietary
Stora process that included the waste liquor
recovery process and a two-stage pulping
process using a sodium base. In Japan, Jujo
Paper Co. converted its calcium base tosodium bases in its Fushiki and Yatsushiro
mills in 1963, blending the resultant pulp
with newsprint, although they did not recover
the waste liquor. The Magnefite processoffered excellent quality pulp as a substitutefor SP in newsprint, with high whiteness,high yield, and more tree species supported,and so several newsprint mills in Japan
started using this process in their operationsin 1967.
The waste chemical recovery of thesodium base, however, was far more
complicated than that used in the kraft
process, which prevented it from becoming
broadly accepted. A magnesium base, though
it could be recovered easily, was not accepted
either, as its pulp was not as strong as kraft
pulp and it still could only be used withspecific tree species [3].
In Japan, where softwood was scarce, thekraft process was accepted quickly, as it
could produce pulp suitable for printing paper,

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)especially quality paper, from a wide range ofdomestic hardwoods, as shown in Figs. 6.6
and 6.7, though the problems of bad smells
and large-scale investments still remained.
Research on finding a replacement for kraft
pulping was still being carried out at thistime.

Fig. 6.6. Rapid growth of kraft pulp
production [3].

and hemlock, as well as Douglas fir
eventually, from the west coast of the UnitedStates using special carriers designed totransport wood chips. At the time, this was ahigh-risk venture, but its success opened up
new territories for the Japanese paperindustry, and imported chips have been theprincipal means of its livelihood ever since.
Like Columbus’s famous egg, after
someone did it for the first time, it seemed to
be nothing special. There still remained
numerous obstacles, including collecting
chips in the States, designing the chip carrier,handling chips to and from the carrier,transportation
andevaluatingthedeterioration of chip quality duringtransportation. I feel this should be recorded
as a technological heritage of Japan, but
fortunately Morimasa Hanaya, who promoted
the project with Toyo Pulp Co., has publisheda report [4].

Fig. 6.8. First chip carrier (Kure-maru) [4].

Fig. 6.7. Kraft pulp becomes the main pulp
used [3].
The problem of waste liquor recovery
eventually forced paper companies thatwanted to continue using sulfite pulp fornewsprint to convert to the kraft process.
The transition from sulfite to kraft was
the first case in the history of paper
technology where environmental concerns
played the decisive role.
6-1-4 1971 to 1980 (Part I: Changes inwood resources)
As newsprint consumption increased
steadily, new softwood resources were sought.
In 1964, Toyo Pulp Co. and Daishowa Paper
Co. tried to import softwood chips, mostly fir

The importing of softwood chips fromthe United States brought about a change inmechanical pulp production for newsprint.
The refiner developed for CGP had been
improved so that it no longer required
chemical treatment. If softwood was available,
there was no longer any need to manufacture
an inferior alternative from hardwood. This
meant that CGP was rapidly taken over by
RGP and TMP, both of which guaranteedhigh quality. As RGP was the transitional
stage to TMP, a short discussion of how TMP
was produced is in order. The microscopic
structures of wood were shown in Chapter 4.1.
In this case, the tracheid cells that became thepulp are cemented with a layer of lignin.
However, on heating to more than 100°C, thelignin layer softens and breaks under the
stresses of refining, while the tracheidremains stiff. This means that TMP
Systematic Survey on Newsprint Production Technologies in Japan29

mechanical pulp produced in this way
contains more undamaged fibers thanconventional GP. In mill operation, softwoodchips would be heated from 110 to 125°C for
several minutes before being refined.

Fig. 6.9. GP (left) and TMP (right) [5].
Figure 6.9 shows photos of thedifferences between GP (left) and TMP(right). Though they are both mechanical pulp,
they have different qualities. As Fig. 6.9
suggests, TMP has better strength and lessopacity than GP. Initially, TMP was seen as
an alternative to CGP, but with the technicalimprovements that will be described in
Chapter 6-1-3, such as the use of amorphoussilica, it was ended up being a substitute for
GP itself.
As demand for printing paper grewsteadily, domestic hardwood became in short
supply. To alleviate this, hardwood chips,
starting with eucalyptus, were imported. The
first imports of eucalyptus chips were fromold growth trees in natural forests, quite
different from those harvested fromplantation forests. At the time, eucalyptus
wood was considered likely to cause
numerous issues, and as of 1957, only one
small mill in Australia was using aged
eucalyptus. Planning large-scale KP plants
using bulk imports at this stage required thedecision to be made based on preliminary
surveys and research. The technology which
made this possible was available in Japan.
This import of chips was, without doubt, due
to a major technological development on thepart of the Japanese pulp industry.
Importing chips greatly affected theconcept and design of paper mills in Japan.
First, one criterion for selecting mill locations

30

changed. Until that time, the most favorable
locations were close to domestic forests, afact which is still standard in other countries.
However, if chips were to be transported byship, locations near major ports became
advantageous, both in terms of wood supply
as well as logistics such as supplies of the oiland coal which paper mills consumed in large
amounts, and shipping out mill products.
Second, freed from the restrictions oncollecting logs, mills could be as large asneeded. This gave rise to a number of mills
large enough to be competitive globally, suchas Oji Paper Co.’s Tomakomai Mill,
Mitsubishi Paper Mills’ Hachinohe Mill,
Hokuetsu Paper Co.’s Niigata Mill, Nippon
Paper Industries’ Ishinomaki Mill and DaioPaper Co.’s Mishima Mill. This unique styleof business, operating large mills in a country
with a limited wood supply, helped theJapanese paper industry be internationallycompetitive and laid the foundations for its
next expansion. The following statistics show
how indispensable imported chips were to theindustry:
Number of chip carriers in 2004: 84
Ratio of imported chips to total wood
consumption in 2004: Softwood 43%,
Hardwood 89%

Fig. 6.10. Wood consumption by origin [6].

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

working in cooperation with newspaper
printers, started a project to reduce the basis
weight of newsprint. This project, called“keiryō-ka” or “lightening,” was unique toJapan, and its successful outcome was shownin Fig. 5.2 in Chapter 5.
This keiryō-ka movement was not only
for newsprint, but could also be applied toother kinds of paper or paperboard. Figure
6.12 shows the changes to linerboard as an
example.
Fig. 6.11. Number of chip carriers [6].
These efforts also led to the new overseas
afforestation ventures that the paper industry
are currently promoting, which will be
discussed later.
6-1-5 1970 to 1980 (Part II: Improving
newsprint quality)
As discussed earlier, newspaper printers
also revolutionized their technologies during
this decade, converting from letterpresses tooffset presses. The Computer Typo-setting
System (CTS) was first installed at Saga
Newspaper Co. in 1968. In the CTS system, apage was edited and displayed on screen by acomputer, and the entire page was typeset ona film that was sent to be printed. This
technology changed how printing plates were
made, saving significant amounts of labor in
the printing operation. With major newspaper
printers starting to use this system in 1978,
they required ever-higher newsprint qualities.
The following requests were presented fromprinters in a meeting held between anewspaper printer and a paper company [1].
• A sheet break rate of 1% (one sheet breakper 100 rolls)• Better ink setting on the wire-side surface• Better opacity: newsprint should havesufficient opacity so that images printed on
one side should not show through on theother.
These demands forced paper companies
to change their pulp blending prescriptions
and even modify paper machines themselves,as will be described later in Chapter 7.
In addition, the second Oil Shock sent thepriceofimported
softwood
chips
skyrocketing, meaning that paper companies,

Fig. 6.12. Basis weight reduction inlinerboard [7].
Copy paper for PPC also reduced its basis
weight from 78 g/m2 to its present 64 g/m2.
If the basis weight of paper is reduced,
the resulting paper weakens and its opacity
lessens. To compensate for the loss ofstrength, stronger pulp should be used. We
have already looked at the two types ofchemical pulp, sulfite and kraft, and seen how
hardwood kraft pulp was already the main
pulp for printing paper. Softwood sulfite pulp,
however, despite its environmental problems,
was still used for newsprint production
because of its cost advantage, as it could be
used without bleaching. Kraft pulp, on theother hand, made stronger paper than sulfite
pulp. As stronger pulp was needed tocompensate for the strength loss, the small
amount of sulfite pulp remaining was finallyreplaced with kraft pulp. For mechanical pulp,
TMP was used instead of GP, as it wasstronger (see Fig. 6.1), despite the fact that
GP has good opacity, preventing images fromshowing through on the other side of thepaper, and gives a smoother surface. If GP is
replaced with TMP to get better strength, theprint shows through. To prevent this, ink
should be retained and less of it impregnatedinto the sheet. To achieve this, a pigment that
can absorb oil is incorporated into the paper.
Systematic Survey on Newsprint Production Technologies in Japan

31

Specifically,
amorphoussilicawasmanufactured at mill sites and added tonewsprint at a ratio of about 1%. The issue of
how to compensate for downgrades in quality
such as strength, opacity and stiffness due tothe basis weight reduction remains the mostimportant topic within the industry. This was
also the case when recycled pulp became themain pulp in newsprint over the coming
decades.
As the Fourdrinier machine drained water
through a wire mesh, the wire side of thepaper (the surface that faced the wire)
contained fewer fine fibers, making it coarser
than the top side of the paper. This resulted inrough printed images. When paper machines
were ran at higher speeds to increase
productivity, that difference increased,
worsening the printed images on the wire side.
This issue was overcome through theinvention of twin-wire formers, which will be
discussed in more detail in Chapter 7.
6-1-6 1981 to 2000
Until around 1975, newsprint andprinting
paper
outputsincreasedneck-and-neck. Then, as people started toenjoy better lifestyles, they demanded better
printed images. This trend increased thedemand for printing paper, and meant that
hardwood chips had to import from othercountries than Australia, such as the southern
United States or Chile. The sulfite pulp that
had only been used for newsprint was finallycompletely replaced by kraft pulp and was nolonger used, as the pollution problems it
caused were too great.
The next resource to gain attention as apulp source was recycled pulp. Waste paper
had been widely used as recycled pulp for
paperboard in Japan, and in fact, Japandeveloped its own linerboard made mostly ofrecycled pulp, which remains competitive
with linerboard made from kraft pulp
imported from the United States.
In 2006, 60.7% of the total pulp
consumption in Japan was recycled pulp.

32

Fig. 6.13. Recycled pulp and fresh pulp
categories (2006) [8].
Figure 6.14 depicts the ratios of recycled
pulp in paper and paperboard. The top line isfor paperboard and the bottom line is forpaper (newsprint and printing paper). The
general trend shows that reclaimed waste
paper was mostly recycled into paperboard.
The initial concept was to recycle waste
paper into newsprint and printing paper forpurely economical merits, rather than forenvironmental concerns, so there were noannouncements from paper companies about
their use of recycled pulp in newsprint, andwork on developing the technology
proceeded quietly. However, starting in the
1990s, the public started to see the use ofrecycled pulp as eco-friendly, and demanded
greater use of it.

Fig. 6.14. Ratio of recycled pulp in paper andpaperboard [9].
The first practical large-scale recycling
system was recycling old newspapers into
newsprint. However, as noted previously,
recycled pulp is obtained from the original
waste paper, so rather than being a specific
type of pulp, it contains different kinds ofpulp in essentially the same ratios as theoriginal paper. For example, recycled pulp

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

from old newspapers includes bothmechanical pulp and chemical pulp. As otherpaper, such as advertising leaflets, are usually
mixed in with newspapers when recycling,
the pulp thus obtained usually consists ofaround 40 to 50% mechanical pulp and 50 to60% chemical pulp. These two kinds of pulp
are used as pulp sources for newsprint.
As recycled pulp became the industry
standard, it affected the supply and demandof pulp sources. As mechanical pulp was
replaced with recycled pulp, the demand formechanical pulp deceased, which resulted in
declining softwood chips imports. In addition,
as recycling of high-grade printing paper
increased, the demand for the hardwood chips
used for them also plateaued.

Fig. 6.15. Mechanical pulp production by
year [10].

Fig. 6.16. Softwood consumption by year
[10].

Fig. 6.17. Hardwood consumption by year[10].
As had happened so often in the past, thediscovery of a new resource and thetechnological development that allowed its
use quickly changed the structure of theindustry.
Though the term “recycled pulp” is usedin this paper, technically it should be referred
to as “Deinked Pulp” (DIP). Waste paper,
when reclaimed, contains contaminants, andthe pulp fraction has to be separated fromthem, and then deinked. The technologicaldevelopments which allow deinking will be
described in Chapter 6.2. For the moment, theways in which this deinked pulp could
provide as much as 70% of the raw materials
for newsprint will be covered.
As has been noted multiple times in thispaper, newsprint needs both strength andopacity. Chemical pulp gives strength andmechanical pulp gives opacity. For example,
if DIP made up of a 4:6 ratio of mechanicaland chemical pulps is used as 70% of the raw
pulp for newsprint, it means that themechanical pulp accounts for 28% and thechemical pulp accounts for 42% of the final
product. If 25% more fresh mechanical pulp
and 5% more fresh chemical pulp is added tothat DIP, the final share of mechanical pulp is
53% and that of chemical pulp is 47%. The
pulp resulting from this blend provides ample
strength, but it opacity is not high enough. As
the trend in newsprint was towards lower
basis weights with higher whiteness to makecolor images look better, opacity became
increasingly critical, so as noted previously,
amorphous silica was added to improve
opacity.
Systematic Survey on Newsprint Production Technologies in Japan33

In the 2000s, the active use of inorganic
fillers in newsprint was tried. Traditionally,
between 10% and 20% of inorganic fillers
were commonly added to traditional printing
paper, giving it the opacity levels and surface
qualities required for printing. When printing
paper was recycled, these fillers were mixed
in with the resulting DIP. The filler most used
recently is calcium carbonate, which
decomposes in an acidic pH solution. The
problemwasthat
newsprintwas
manufactured at acidic pHs, such as pH 4, so
as more recycled pulp was used, calcium
carbonate would leach out from the printing
paper-sourced pulp that had been mixed inwith the newsprint. So the industry decided to
manufacture newsprint at pH levels close toneutral, such as pH 6, and actively add new
calcium carbonate to improve opacity.
Since the 1850s, paper had been
manufactured in at acidic pH levels, usingaluminum sulfate (called “alum” in the paperindustry). The use of alum meant that tracesof free sulfuric acid remained in the paper,
deteriorating it over extended periods of time:
paper would yellow and become brittle.
Libraries around the world were faced withthis issue, and it also became an issue inJapan during the 1970s. To cope with thisproblem, Japanese paper manufacturers
changed to producing paper at neutral pH
levels, without the use of alum. Neutral sheet
forming has greater chances of problems
during manufacture, such as generating slime
and sticky contaminants, and needs greater
expertise to operate the machinery thanordinary acidic sheet forming. However, it
does have the advantage of being able to use
calcium carbonate, one of the few fillers
abundant in Japan. As a result, these days
Japan is a world leader in neutral sheet
forming for printing paper, and thistechnology is also being actively applied tonewsprint manufacturing.
During printing, fillers adhere to printing
plates, making them dirty. To cope with this,printing paper is generally coated with a thinlayer of starch, using machines called sizepresses. Historically, these size presses were
not considered necessary in newsprint
machines, but the increasing speed of offset
printing for newspapers in the 1980s meant

34

that newspaper printers needed higher levelsof printability, demanding newsprint which
would cause less fiber piling on their plates.
As a result, paper companies in Japan
installed size presses, called gate roll coaters,in their newsprint machines (see Chapter 7.5).
This meant that newspaper printers could
print papers at a rate of 150,000 copies perhour, 40 pages a copy, with only a few sheet
breaks (perhaps 1 to 2 per 1,000 rolls), and so
there was almost no reason to rely on
imported newsprint (see Chapter 5). These
added gate roll size presses also made it
possible to add calcium carbonate tonewsprint, with the result that a new type ofnewsprint, formed at a neutral pH with added
calcium carbonate, is currently manufactured
in Japan. Its future market growth is a topic
of some interest.
6-1-7 Current state of global newsprint
production
This chapter has focused on Japan, but it
is also important to examine what was
happening globally at this time. Fifty years
ago, newsprint contained 70 to 80%
groundwood pulp, with chemical pulp
making up the rest. At present, Scandinavian
countries where softwood is still abundant
still use 100% TMP. This is because TMP’sbalance of strength and opacity make it well
suited for newsprint quality. In the U.S.,
environmental concerns regulate blending
with DIP, so the U.S. newsprint is a blend of
TMP and DIP. Canada, which exports
newsprint to the U.S., is also forced to blend
DIP with TMP in its newsprint for thatreason.
6-1-8 Future resources
In the belief that overseas plantation
forests will be the next key pulp resource,
Japan-based paper companies are engaged inafforestation in a number of countries
world-wide. In most cases, the land they use
is not suited for agriculture, or theafforestation is expected to improve theenvironment, so there is little competition
with agriculture for this land. Unfortunately,
limitations of space prevent more detail here.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

6.2 DIP for newsprint
6-2-1 Technological development
While Chapter 6.1 provided a brief
description of pulping equipment, readers are
urged to refer to other works, such as thoselisted in the bibliography, for more details.
However, as the development of DIP fornewsprint is unique to the Japanese paperindustry, more details on the process is and its
background is provided here.
The process starts with the collection ofwaste paper. Waste paper has historically
been reclaimed by paper collectors andclassified by quality, with any contaminants
such as metal and glass being removed. Aftersorting, old newspapers, along with the flyers
included in them, are baled and delivered toprocessing plants. Newspapers are relatively
uniform in quality, can be reclaimed in large
volumes (making them suited for the mass
production of pulp), and are printed using
poor quality offset printing, making the ink
easy to remove. A geographically compact
country with over 100 million residents who
consume paper at the rate of 240 kg/capita
per year is well suited for recycling waste
paper and developing sorting systems.
As described in Chapter 6-1-6, thetechnology of using waste paper for
paperboard had already been established.
However, it used waste paper to form thebacking layers of paperboard, most of the ink
was not removed, and small amounts ofcontaminants and undisintegrated pieces were
acceptable. For newsprint, contaminantremoval had to be improved, and most of the
ink removed from the pulp. Deinking was, ofcourse, practiced to some extent at the time.
However, it was only on a small scale, just a
few tons per day, and used what now appears
to be a very old-fashioned process: air was
injected into an open vessel and bubbles
containing the ink that lifted off were
skimmed out with a scraper. It required a lotof room, and the area around the vessel would
become dirty due to spilled ink.
This antiquated technology was refined inJapan into a new process in whichcontaminants are removed and ink isseparated from pulp at high levels of efficacy
on a mass production scale. This was madepossible thanks to the collaboration between

paper companies and equipment suppliers.
Historically, paper companies in Japan
installed equipment developed by foreign
suppliers at relatively early stages of theirdevelopment, and worked together with the
suppliers’ Japanese licensees to put them into
operation. The first installation of thecontinuous digester described above is an
example of this, as is the introduction of thetwin-wire paper machine that will be
discussed later. However, Japanese suppliers
like Aikawa Iron Works and Ishikawajima
Machinery Co. also played an important rolein developing the equipment for newsprintuse DIP. The surfactant is a key chemical in
the deinking process, and traditionallyordinary soap was used. However, chemical
suppliers in Japan (Kao Co., etc.) developed
high quality surfactants, helping spread thetechnology. These developments are detailed
below.
6-2-2 DIP production processes
Waste paper is immersed in water andseparated out to its original pulp fibers in aprocess called disintegration. Next, this pulp
slurry passes through a coarse screen to
remove larger-sized contaminants, as
although waste paper is sorted and classified
by the waste paper dealers, it still contains
contaminants such as metal, glass and plastic.
Disintegration is done in a device called a“pulper,” which is designed to disintegrate
the waste paper as far as possible while
keeping the contaminants as intact as possible.
In most cases, the pulp is heated up to
between 40°C and 50°C, and alkali is added
to help the disintegration. Some of the ink
peels off from the pulp during thisdisintegration process, but care is taken not tobreak down the ink into pieces that are too
small, as ink particles smaller than 10
microns in diameter are difficult to remove inthe succeeding floatation stage.
The resultant pulp slurry is moved to thescreening and cleaning part. Contaminants
are removed in stages, starting from the larger
ones and moving down to the smallest ones.
The first screen is the coarse screen, withround holes 3 to 4 mm in diameter throughwhich the slurry is passed. It then moves to afine screen which uses slits instead. If further
Systematic Survey on Newsprint Production Technologies in Japan

35

screening is needed, narrower slits are used.
However, the narrower the slits, the smaller
the output volume, and thus the higher thecosts. As newsprint quality restrictions
became increasingly strict, these slits became
narrower and narrower. This meant increased
energy consumption, so energy-saving
screens were developed. Next, the screened
pulp slurry moves to the cleaners. The
cleaners, which come in two types, one forheavy contaminants and the other for light
contaminants, use centrifugal force to remove
contaminants, based on their density
These steps have been traditionally usedin paperboard manufacturing. Recycled pulp
for newsprint has to be deinked after cleaning.
After being printed, ink particles adhere to
the pulp surface through the use of a binder, acomponent of ink shown in Fig. 6.18.

to the bubble surfaces, and float to the top.
They are scraped out mechanically, using apaddle. Early equipment was small-scale andopen on top, so the ink would splatter aroundthe equipment. But a series of new equipment
was later developed that had closed tops andoffered higher capacities. The soap that was
originally used as the surfactant was replacedwith highly-effective chemicals developed bychemical manufacturers.

Fig. 6.19. Deinking mechanism [11].

Fig. 6.18. Ink on paper surface [5].
By this stage, some of the ink has alreadycome off through disintegration, screening
and cleaning. Deinking targets any residual
ink. First, the pulp slurry is dewatered to aconcentration of 25 to 35%, and treated in akneader or disperser, inside which the pulp
rubs up against itself and the ink ismechanically rubbed off. In most cases, thepulp is heated to 50 to 100°C and alkali isadded. Care also needs to be taken to notbreak the ink up into excessively small pieces.
The slurry is diluted to a pulp concentrationof about 1% and the rubbed-off ink isremoved through floatation, the principle ofwhich is illustrated in Fig. 6.19. A surface
active agent (surfactant) is added to the slurry
and then air is blown into it, which produces
a lot of small bubbles. The ink particles
dispersed by the mechanical rubbing adhere

36

After deinking, the pulp is screened andcleaned again to remove any fine residual
contaminants. The next step is washing, inwhich the pulp is diluted and then condensed
so that the remaining ink particles are washedout from the slurry. Finally, the finished pulp
is bleached. The main bleaching chemical ishydrogen peroxide, and two-stage bleaching
is normally used to get sufficiently highlevels of whiteness. This allows DIP withbrightness levels of 60% to be manufactured,and this accounts for between 50% and 70%
of newsprint pulp. Figure 6.20 shows how arange of different equipment is installed inseries in a DIP plant.
As newsprint requires increasingly
refined DIP, engineering issues such as
designing plants which can produce
acceptable DIP at competitive costs become
increasingly important. Japanese paper
companies have developed their technologies
through trial and error, and created a systemthat is becoming a global standard. The
flowsheet of a typical DIP process is depicted
below.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Fig. 6.20. DIP plant flow sheet.
Bibliography[1] T. Naito “Progress of newsprint
manufacturing over the last 60 years,”
Hyakumanto, No. 126, p. 25 (Paper
Museum).
[2] Preserving
andPublicizingtheTechnological Archives of the JapanesePaper Industry, No. 7, p. 1, “First
continuous kraft pulp digester in Japan,”Oct. 13, 2004, JAPAN TAPPI.
[3] Preserving
andPublicizingtheTechnological Archives of the JapanesePaper Industry, No. 20, p. 1, “Thetechnology demanded by environmental
concerns (2): From sulfite pulp to kraft
pulp,” Oct. 10, 2007, JAPAN TAPPI.
[4] M. Hanaya, “Imported chips fromlumber waste helped global environment”
Tech Times, p. 113, May 10, 2007.
[5] Supplied by Nippon Paper Industries Co.
[6] Preserving
andPublicizingtheTechnological Archives of the JapanesePaper Industry, No. 13, p. 1, “Imported
chips helped growth of Japanese paperindustry,” Nov. 1, 2005, JAPAN TAPPI.
[7] Preserving
andPublicizingtheTechnological Archives of the JapanesePaper Industry, No. 16, p. 1, “Reducing
basis weight of linerboard,” Oct. 2006,
JAPAN TAPPI.
[8] Pulp and Paper, No. 694, p.14, Japan
Paper Association.
[9] Excerpted from Annual Report on Pulp
and Paper Statistics (METI).
[10] K. Iida, “Evolutional developments in
the history of the Japanese pulp andpaper industry,” Pulp and Paper
Symposium, Dec. 2003 (Pulp and Paper
Research Committee).
[11] Y. Irika, “Deinking technology for waste
paper,” JAPAN TAPPI Journal, vol. 58,
No. 7, p. 954.
Some references for pulping production
methods are listed below.
References
1. Handbook of Pulp and Paper Technology,
Jan. 30, 1992, JAPAN TAPPI.
2. Pulp
and
Paper
Manufacturing
Technologies, vol. 1 Kraft Pulp, May 1996,
JAPAN TAPPI.
3. Pulp
and
Paper
Manufacturing
Technologies, vol. 2 Mechanical Pulp, Nov.
1997, JAPAN TAPPI.
4. Pulp
and
Paper
Manufacturing
Technologies, vol. 4 Recycled Pulp, Aug.
2005, JAPAN TAPPI.

Systematic Survey on Newsprint Production Technologies in Japan

37

7 Technological development part 2: paper
machines
7.1 The basic concepts of paper making
The basic concepts of paper making andan overview of paper machine were provided
in Section 4.2. A model outline is shown in
Fig. 4.7. The key steps are, first, a 1%
concentration of pulp slurry is dewatered on a
wire
mesh
to
approximately
20%
concentration. The presses then increase thepulp concentration to 50%. Then, the dryer
dries the pulp web to just a 6% moistureconcentration level. These pulp to water
ratios are converted to grams of water pergram of pulp and summarized in Table 7.1.
Figure 4.9 in Section 4.2 shows an outline ofthe dryer part. Multiple dryers in sequence
are required to reduce the moistureconcentration to 0.94 grams of water pergram of pulp.
Table 7.1 The amount of water removed ateach section of paper machine

Wire
part
Press
part
Dryer
part

Stock
consist
ency
(%)

Water
content(g/pulp
g)

Inlet

1

99

Outlet

20

4

Inlet

20

4

Outlet

50

1

Inlet

50

1

Outlet

94

0.06

Water
removedin eachsection(g/pulp
g)
95
3
0.94

Standard paper machines 50 years ago
were 3.5 m in width and ran at 300 m/min,
while current machines are 10 m in width andrun at 1,800 m/min. This increase has been
made possible through the technologicaldevelopments that will be discussed in thischapter.

38

7.2 Wire part (Forming section)
7.2.1 Introduction
This section of the chapter will provide a
review of the technological developments inthe wire part. The wire part uses wire meshes,
which are usually made of plastic these days.
The purpose of this part is to form a wet webof pulp on a moving wire mesh and drainwater through it (see Fig. 4.7-1). Key
technological developments in the wire partare listed below.
(1) As paper machine widths increased, one
issue was how to distribute the incoming
pulp slurry uniformly over the full widthof the machine. The solution was a
distributor with multiple tapered tubes.
(2) The next issue was that the pulp slurry
had to flow out on the moving wire meshat the same velocity as the wire. In older
designs, the slurry was kept in an open
vessel (the head box) and was discharged
simply by pressure. As machine speeds
increased, this simple head pressure
became insufficient and improvements
were made, changing the head box froman open type to a closed pressurized type.
(3) When the pulp slurry flows out on thewire, the width of the flow-out gate
opening is controlled to get a uniform
sheet. As paper machines became wider,more precise control of opening width
was needed. The solution was to use“slice and lip control,” going fromlaminar flow to turbulent flow, and frommechanical lip adjustment to consistency
adjustment through dilution.
(4) Water must be drained from the pulp
stock on the wire as fast as possible. To
ensure this, a range of devices weredeveloped and installed under the wire,such as table rolls, suction boxes and foil.
(5) The wet paper web has to traverse a short
gap from the wire part to the press part
felt without any support (see Fig. 4.7-1).
As the wet web was weak and often

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

broke during this transfer, this was one of
the main issues to solve, and the solution
developed was the pick-up roll.
(6) Increasing machine speed meant that thewire part had to be longer to finish
dewatering, which resulted in making theengineering harder. This was because
water was only drained down through thewire. However, if the wet web wasplaced between a pair of wire meshes anddewatered on both sides, it would shorten
the total length of wire mesh needed.
This breakthrough from the old wire part
design is called a twin-wire former.
(7) Wire is moving under tension, so it
should move steadily and be resistant toabrasion from the supporting materials.
To make it move more easily andsmoothly, wire meshes changed frombronze wire to plastic wire.
(8) The wire mesh, like any textile, is woven
with weft and warp wires, on the surfaceof which the wet pulp web rests. Thismeans that any unevenness of the woven
surface is replicated on the web surface.
This unevenness has a significant effecton the final printed image. After studying
how the wire threads should be woven,they were eventually changed from plain
weave to multi-layer weave.
(9) As the pulp is very fine, about 40% of itends up passing through the wire alongwith the drainage water. This drainage isused to dilute more pulp, recycling it.
The question of how to improve theretention of pulp stock on the wire was a
problem that was dealt with using wet
end control.
As paper machines get larger and faster,these issues have been developed in order toallow the technology to stay one step ahead,
an issue the industry still faces. As issues oflength mean that it is impossible to review allof them in this paper, the first three items
shall be described in relation to each other,with the sixth item reviewed in addition.
7-2-2

Distributing pulp stock evenly acrossthe width of the paper machine
Pulp slurry at about 1% concentration istransported to a paper machine through asingle large diameter pipe, so the issue is how

to distribute it evenly across the width of thepaper machine. To allow this, a device calleda distributor was developed. Before paper
machines became as wide as they are today,
the pipe opening was simply expanded to thewidth of the machine in a fan shape. Later, abranched model was invented, in which thepulp slurry was fed through several small
pipes branching from the main pipe to thepaper machine. This branched pipeline wasfurther modified in different ways, including
adding cross flow and taper flow, and is now
the industry standard.

Fig. 7.1. Current distributor [1].
Figure 7.1 is an Opti-flow II head box
made by Metso. Pulp slurry coming
perpendicular to the paper machine is
distributed through multiple branched pipes
to the inner elements of the head box. The
upper half of the figure shows a photo of thehead box, while the bottom half is a computer
simulation of stock flow in the distributor.
In the next stage, pulp slurry is ejectedfrom the head box onto the wire at the same
speed the wire moves. The name “head box”
comes from it creating hydraulic pressure(head) within a box based on the height (h) of
the pulp stock. If a thin slit is opened acrossits width at the foot of the box, the pulp slurry
Systematic Survey on Newsprint Production Technologies in Japan39

is ejected at a theoretical speed of (2gh)1/2. Inpractice, some correction is needed,
depending on the shape of the outlet.
Operators also needed to know how to adjust
the angle (jet angle) of impingement of stockon the wire or adjust the difference between
the speed of the wire and the pulp slurry. At
speeds of less than 400 m/min, this initial
type of simple, open head box worked
perfectly well. However, as machine speeds
increased, increasingly taller heads wererequired, and eventually merely increasing
the head height could not provide enoughvelocity, nor could they fit within the millbuildings. Therefore closed and pressurizedhead boxes were developed. The paper
machine discussed in the case study in
Chapter 11 had one of the first such headboxes. Once the head box became pressurized,
it was freed from having to be considered abox, so a series of closed models wereintroduced by manufacturers.

Fig. 7.2. Open type head box [2].

Fig. 7.3. Closed type head box [3].
One characteristic all head boxes have incommon is that they have an air chamber as apressure damper. As keeping the pulp stock
well dispersed is needed to allow a uniform

40

flow, lamellar flow was maintained as muchas possible in the old style of head box. In
high-speed machines, however, the pulp stock
is dispersed with the addition of a strong
shear force.
Finally, the pulp slurry flows out onto thewire mesh, where final adjustments are madeto control the opening of outlet slit in the
cross direction. A number of pressure bolts
are fixed on the outlet at equal intervals
across the machine, and by controlling thepressure on these bolts, the openings underthem are adjusted to ensure that the flow
becomes uniform across the entire width.
These bolts are generally called “jacks” inpaper mills (see Fig. 4.7-1). In earlier years,
operators would observe the flow on the wire(such as uneven dewatering in the crossdirection) and control the bolts manually,
which meant that a considerable amount ofskill and experience was required. However,a device which measured basic sheet qualities
on-line as a profile of the cross direction wasinvented in 1969, bringing about a revolution
in paper machine operation (see Chapter 7.6
for details). As this made it possible tomonitor the moisture content and basis
weight of the web as cross-directional
profiles in real time on a monitor, finer
adjustment of the bolts became possible.
There was still one problem, however. Whena bolt was tightened, the opening underneathbecame narrower. If the basis weight was
reduced only at that position, adjustment
would be simple. However, as pulp stock is a
fluid, tightening one bolt affected the adjacentpositions, so multiple bolt adjustments wereneeded to correct a profile. Skill andexperience were still required. Nevertheless,the monitoring device was truly revolutionary,and cross-directional profiles were greatly
improved. The next move, then, was to feedback data from the monitor to adjust the boltpressure (lip opening) automatically, rather
than manually. This was a task in which
computer simulation excelled, and a model
for standardizing opening profiles wasdeveloped. This meant that a considerable
portion of the skill needed for operation was
taken over by computers. Though final fineadjustment was still done manually by theoperators, a significant part of operational

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

expertise was transferred to a controller, likea black box, and used widely as coretechnology. As opening profiles were
established as standard models, feed-forward
control became possible. Paper machines
would normally operate continuously, butwere sometimes stopped under circumstancessuch as replacing equipment or scheduled
shut-downs. When the machine was restarted,
it could be quickly adjusted to the mostfavorable condition registered in its controller.
This was a considerable merit for processindustries. At the same time, paper machines
were becoming larger and faster, andtwin-wire formers were now used, whichmeant that operators could no longer visuallycheck the pulp stock flow on the wire. Now,
all paper machines have to operate under thesurveillance of one of these on-line profile
monitors.
As paper machines became larger andlarger, controlling the opening became harderand harder, and was never an easy task. At
this point, the next innovation was created.
When an opening was pressed down by a bolt,
it affected the neighboring pulp flow.
However, if the pulp slurry was diluted withwater, then instead of pressing the opening,
the basis weight at the location could be
reduced without disturbing the neighboring
pulp flow. So the entire lip was divided into
parts 3–6 cm wide, and pulp stock sent toeach part independently, its consistency
adjusted by adding water as needed based on
the information monitored at the end of themachine. This meant that the basis weightprofile across the width could be controlled
without disturbing the neighboring pulp flows.
With this technology, the long-awaited
cross-direction automatic profile control
finally became available, and large paper
machines took advantage of it.
For reference, an example of a current
cross directional profile (basis weight) isshown.

Fig. 7.4. Cross-directional profile of basis
weight [4].
This series of technological developments
is typical of process industries, to which thepaper industry belongs. It took almost fifty
years, during which new materials were
invented and the process control was refined.
Thanks to these developments, equipment
increased in size, productivity improved, andproduct reliability was considerably improved.
On the other hand, however, skill andknowledge became less significant. In fact,
the process industries have been cooperatingwith equipment manufacturers to take a leadrole in technological developments of thiskind. Once a new technology was invented, it
was incorporated into the standard equipment
supplied to industry newcomers. In mostcases, these newcomers would installlarge-scale, cost-competitive equipment.
Though they may have lacked experience andskills, this improved equipment helped themproduce products that were generally
accepted by the market. That meant, however,that the inventor of the technology lost theiradvantage. While there remain differences inoperation level, this is happening to Japaneseindustries such as paper and steel which
manufacture basic raw materials, andmethods for dealing with this are a major
concern.
7.2.3 Dewatering
When making paper by hand, water isdrained through the wire mesh by gravity.
However, with the development ofcontinuous
sheet
forming
machines,hydrodynamics has been applied to efficiently
accelerate dewatering through the wire. In theearly stages, small rolls called table rolls wereset parallel across the machine to support themoving wire (Fig. 4.7-1). These rolls were
Systematic Survey on Newsprint Production Technologies in Japan41

not driven, but were rotated by the wire meshmoving forward over them. As the roll rotates,
negative pressure is produced at the back partof the roll, which sucks water from the web.
Table rolls were later replaced by foils, whichwere fixed in position, non-rotating. The
dewatering principles of table rolls and foils
are illustrated in Fig. 7.4 and Fig. 7.5
respectively. The difference is that the tableroll produces a spike-like suction while thefoil dewaters with gentler suction over alonger length.
Another device, called a suction box, wasalso developed, which used suction to
dewater.

Fig. 7.5. Dewatering using table roll [2].

Fig. 7.6. Dewatering using foil [2].
Installing these devices allowed paper
machines as wide as 7 meters to run at 700
m/min in 1960. The wire part of thesemachines was equivalent to a process unit
which dewatered at a rate of 20 tons/min. The
wire used for these machines was 7 meters
wide and 40–50 meters long, seamlessly
connected at both ends so it could keep
circulating on an infinite loopy. It was subject
to wear through abrasion, however, andneeded to be replaced once a month or so.
Physical and operational limitations meant

42

that the wire could not be made longer. This
meant that it seemed impossible to increase
machine speed further.
Though paper machines ran horizontallyand water was removed downwards (in the
direction of gravity), dewatering was actually
done by hydrodynamic forces such as
negative pressure and suction, rather than bygravitational pull. So, if a wet web could beheld between two wires and forcibly
dewatered on both sides, the wire would only
need to be half as long as for single-sided
dewatering. Moreover, it would not be
restricted to running horizontally, and could
run vertically, allowing the wire part, which
had an overall length of some 20 m, to be
shortened. This idea gave birth to thetwin-wire paper machine.
A set of wire meshes which hold pulp
web between them is pressed from one sidewith shoe blades or rolls to curve it like abow. The tension on the wire generated bythis curving presses the pulp stock andsqueezes water outwards through the wire.
The shoe blades pressed against the curved
wire work like table rolls or foils, draining
water to their side through the negative
pressure produced at their tips. This is thescientific principle, at any rate (see Figs. 7.7
and 7.8). However, the actual engineering
requires technology. In the old horizontal
paper machines, the wire was slowly shaken
crosswise to improve stock dispersion on thewire and made the sheet smoother. Thisdispersal effect could not be replicated usinga twin-wire system, so paper would have to
be made using the pulp distribution that cameout of the slice outlet. That meant that the
profile in the cross direction would have to be
more even than ever. In addition, though thelength of the wire mesh would be shorter, twosets of wires would be needed. This meantthat their lifespan would have to be longer
than ever.
In spite of those problems, the firsttwin-wire machine was commercialized in1968 by Black Clawson Co. But its machine,called the Verti-Former as it fed stock
vertically downwards, ended up seeing use in
only a few paper mills due to poor sheet
formation.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Fig. 7.7. Conceptual image of a
Verti-Former [2].
The Verti-Former was followed by the
Bel-Baie former, developed by Beloit
Corporation, which became standard innewsprint manufacturing. Pulp stock was
injected upwards and sandwiched between
two wires. The set of wires was curved byhaving shoe blades press on them, with thepressure of the wire tension removing water
outwards. The negative pressure produced at
the blade tips also removed water inwards.
The ratio of the amounts of water removed toboth sides was roughly 6 to 4, with the inside
being slightly greater.

commercially operate twin-wire formers.
Thoughthetwin-wire
formerrevolutionized newsprint production, it was
not accepted in manufacturing other grades of
paper. Most grades of printing paper haveheavier basis weights and demand higher
quality sheet formation than newsprint. As aresult, several types of hybrid former weredeveloped, which had the high productivity oftwin-wire formers and the quality sheet
formation of Fourdrinier machines. In thesehybrid machines, sheets were formed on aconventional wire part, over which a
top-mounted former was added to remove
some of the water from the upper side. Thesehybrid formers were suitable for many kindsof printing paper, so became commonly used
for such in mills. One model, the Duo-Former,
became essentially the de facto standard inJapan.

Fig. 7.9. Example of a hybrid former [6].

Fig. 7.8. Conceptual image of a Bel-Baie
former [5].
In this former, the shoe blades werepressed against the wire with higher pressuresthan that in ordinary Fourdrinier machines,
resulting in increased wire wear. Better wireand shoe blade materials had to be developed.
By then, wire meshes were already made ofplastic, not bronze, making their life much
longer. Developments in ceramics helped
create good quality shoe blades. These twodevelopments
madeitpossibleto

The concept of dewatering from bothsides brought about a revolution in sheet
quality. When water drains through wire, fine
bits of pulp stock also fall out. The watercontaining this fine pulp is recycled to diluteincoming pulp stock. In conventional paper
machines, water is only removed from one
side. As sheet forming is a type of wire
filtration, greater amounts of fine pulp remainon the top side of the sheet and lesser
amounts on the wire side. Despite a thicknessof less than 0.1 mm, the sheet has different
materials on the top and bottom. As paper isprinted on both sides, this two-sidedness
affects the printed images. In most cases, thetop side, which contains more fine pulp, has
better quality printing. This two-sidedness isalso a problem in printing operations, as it
makes the paper curl when moistened. In
addition, the faster the machine speed, theworse the conditions for drainage become andthe larger the two-sidedness grows.
Paper machines using two-side dewatering
solved this problem in an instant. At that time,newspaper printers were replacing their
Systematic Survey on Newsprint Production Technologies in Japan43

letterpress printers with offset presses, andincreasing the number of pages per copy. For
a newspaper with 40 pages, 5 newsprint rolls
would be set on a rotary press and printed
simultaneously on both sides. Every roll andevery side would be required to behave in thesame manner. This demand forced newsprint
manufacturers in Japan to install twin-wiremachines.
In this way, a major breakthrough inindustrial technology like the twin-wiremachine is accomplished not by an idea alone
but through a combination of the needs(improved productivity for the mill, changes
in quality demands due to client technologicaldevelopments)andthetechnologicalinnovations in related areas that make theseneeds possible (such as process control,
plastic wire and shoe blades).

7.3 Press part (Press section)
7-3-1 Overview
This section will review the engineering
issues in the press part. The purpose of thepress part is to squeeze out water from wet
paper web through mechanical force.
The word “press” is usually associatedwith machinery pressing a flat plate
downward, in a batch operation. In traditional
hand-made paper making, a number of wet
sheets were stacked and pressed exactly in theway the word suggests. In modern paper
making, however, pressing is used in adifferent concept, although the word is still inuse. The basic design is illustrated in Fig.
7.10 (refer to Fig. 4.7-1 as well).
Straight Through Press in about 1945

Fig. 7.10. Basic model of the press part [7].
When the wet paper web reaches thepress part, it is like tissue paper that has beensaturated with water (like wet wipes). This
paper is squeezed by passing it through tworolls pressing vertically against each other.

44

One large roll is called the stone roll and wastraditionally made of granite, and the other iscalled the rubber roll and is covered withrubber. As the wet web is very delicate, it iscarried on a bed of supporting felt (the actualmachines sometimes have the wet web on thebottom of the felt) that moves at the same
speed as the paper machine while the water issqueezed out by the pressure of the two rolls.
In most cases, the wet web faces the stoneroll. One set of rolls is not enough, so a press
part will have between two to four sets ofrolls.
Paper machines like that illustrated in Fig.
7.10, which were popular in the 1950s, ran at
300 m/min. The newest current machines run
at 1,800 m/min. This increase has been madepossiblethroughthetechnologicaldevelopments that will be discussed below.
(1) Water is squeezed from the wet web
through the pressing actions of the rolls,
and is absorbed into the supporting felt.
When a wet web is peeled from a pressroll, it absorbs some of this water backfrom the felt. To minimize this re-wetting,the rubber roll has been modified to
rapidly remove water from the felt. These
modifications are the use of grooved rolls(with grooves on the roll surface) or asuction roll (with a suction mechanism
inside the roll).
(2) Three to four sets of press rolls areneeded, but there have been attempts atusing fewer, such as going from astraight-through design to Twinver and
Tri-Nip designs.
(3) To prevent two-sidedness installing afourth press was found to make itpossible to make each surface of the web
contact the stone roll surface.
(4) The pressure produced by a roll is a typeof linear load. Pressure will be more
effective if applied on a surface as anarea rather than as a line. This idea, theshoe press, revolutionized press design.
(5) As paper machine speeds increased,larger diameter rolls were needed. Largerolls of uniform quality could not bemade from natural granite, so substitutes
were needed, leading to the developmentof the synthetic press roll.
(6) The press felt also had to be modified to

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)improve its performance, so new types offiber, needle felt and laminated felt weredeveloped.
(7) Adjustment of the roll crown to ensurethat the nip pressure was even in the
crosswise direction was another issue,
leading to the development of rolls withcrowns that could be controlled, called
crown controlled rolls (CC rolls).
(8) Finally, as quality demands grew everstricter, the development of heating
through steam boxes made it possible tohave uniform moisture profiles along thecross direction of the paper machine,especially at both ends.
Items (2), (4) and (6) will be reviewed
below.
7-3-2 Arrangement of press rolls
Until about 1960, press rolls werearranged as shown in Fig. 7.10, with ahorizontal series of roll sets. However, thisdesign required a fair amount of space, andthe weak wet web had to traverse long
distances between the presses, meaning that it
broke often in that area. This led to a more
efficient layout of the rolls, as shown in Fig.
7.11.
In this design, the No. 2 press (2P) andthe No. 3 press (3P) share the same stone roll(the dark-colored roll), saving one roll. The
same press suction roll (the darkish roll) isused for both the No. 1 press and the No. 2press. Reducing the distance of the wet web
run means less chance of sheet break, so thepaper run in the press part was greatly
shortened. Limitations of room prevent a
review of the long history of press rollconfigurations. However, efficient press
arrangements and the development of theshoe press, which will be covered in the next
chapter, mean that modern paper machines
are able to run at very high speeds.

1.

2.

Its dewatering and travel abilities were improved byinstalling No.3 press before the open draw.

Fig. 7.11. Tri-Nip press [7].
For example, a standard newsprint
machine has both No. 1 and No. 2 presses anda shoe press, as depicted in Fig. 7.12, andruns at 1,800 m/min.

1.

3P in old Twinver-Com+3P newsprint machine wasconverted to shoe press in 1990 (1200 m/min).

Fig. 7.12. Typical press part of modern
newsprint machines [7].
7-3-3 Shoe press
As noted earlier, rolls press the wet web
linearly, but higher pressures are needed tomake dewatering efficient. However, if
excessive pressure is applied, the formed
sheet is crushed, especially in paperboard
with a heavy basis weight (about 5 to 8 times
that of newsprint). In classical hand-madepaper, the wet sheet was pressed with a flat
plate in batches. This is surface pressure(plate pressing), not linear pressing. To
mimic this plate pressing in the modern
continuous process, the shoe press wasdeveloped. It consists of a shoe, which isfixed and concave along its top side, and arotating roll with a curvature that fits theconcave surface of the shoe. Rotating a rollagainst this fixed shoe surface mimics
pressing by a plate. To prevent the moving
paper web from being scratched on the solid
shoe surface, a belt runs over the shoe surface
at the same speed as the press roll. Thus, theroll, the web and the shoe belt are all moving
at the same speed relative to each other, andbetter drainage is possible at lower pressures.
The first model is shown in Fig. 7.13. It
was called an extended nip press, andsupposedly the width of the nip was ten times
greater than ordinary roll presses.

The Tri-Nip press was developed by adding 3P to the
Bi-Nip press in 1975.
Systematic Survey on Newsprint Production Technologies in Japan45

Fig. 7.13. Conceptual image of a shoepress [7].
Later, the closed type was developed, andthis is now used in manufacturing not only
paperboard, but also printing paper andnewsprint.

1.
2.

The closed-type shoe press was developed toeliminate the defects of the open-type ENP such as oil
spillage by enclosed the blanket end.
Use of the shoe press increased machine speed.

Fig. 7.14. Closed-type shoe press [7].
The other advantage of the shoe press isthat the wet web is pressed with less pressure
and is left bulkier. This bulk gives stiffness topaper that is supposedly proportional to thethird power of its thickness. This added bulk
is especially advantageous for newsprint, as
newspapers are expected to be able to be read
without the top falling over. In this sense, theshoe press was truly a revolutionary
development [7].

46

7-3-4 Technological developments in press
felt
Paper machines are different fromchemical plants, which, though they are atype of continuous process, are generally aclosed system, with every unit connected withpipes. Attempts to operate all the linked unitsof a paper machine at high speeds, however,will fail if the only strengthening ismechanical. Every part of the machine needs
to have upgraded design and performance,with the help of suppliers of tools andauxiliary equipment. When the wire part wasmade larger and faster, the demands for
improvements to the wire mesh, such as alonger working life, ease of replacement, andfewer wire marks on the sheet surface, were
each satisfied. The same sort of technologicaldevelopment has been applied to the press felt,
which is explained in more detail by Someya(2005) [8].
Water is squeezed from the wet web by
the press pressure and absorbed into the press
felt, where it is retained. When the wet web
leaves a press roll, it reabsorbs water from thefelt. This means that the press felt has to beable to absorb and retain as much water as
possible. When this felt is pressed against the
web surface, the uneven pattern of the felt istransferred to the web surface, leaving marks
called felt marks. It was important that thesefelt marks were kept to a minimum, and at thesame time, stable operation over extended
periods of time was also vital.
Felt was originally woven with a raised
warp and woof. Later, needle felt wasdeveloped, in which the butt (short fibers) isneedle-punched into a base cloth. The
availability of a range of butt and cloth types
allowed multiple combinations, accelerating
technical developments. In the base cloth
itself, multi-filament threads replaced yarn,
and recently have in turn been replaced bymono-filament threads as usage requirements
have become ever stricter. For the butt, amixture of wool and nylon fiber was initiallyused, then replaced by purely synthetic fibers.
Later, the fibers were chemically treated toincrease the abrasion resistance of the felt.
Modifications were also applied to prevent it
flattening as much under pressure (improving
its flatness resistance qualities). These days,

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

the quality of the butt is controlled throughmodifying its polymer structure rather thanthe use of chemical treatment.

The developments of press felt discussed
above are summarized in Table 7.2, alongwith the press part developments. Although
this table is based on fine paper machines, it
is also applicable to newsprint machines.
There are many technical terms used in
the table, but they will not be defined here, as
the purpose of this table is to allow readers tounderstand the role and contributions of press
felt in improving performance in the press
part as a whole. Note, however, that the term
“NMC” used in the table refers to the lifespanof the felt expressed as numbers of nip passes,
one million passes being a unit. The tableshows how this NMC value has been growing
steadily, despite the increasingly severe usage
conditions.

Fig. 7.15. Example of laminate felt [8].
In recent year, the increasingly strict
requirements for felt have led to thedevelopment of new products. For example,
laminated felt consists of two different clothtypes to improve the surface quality at thesame time as ensuring good drainage.
Another new product has a special sheet or
film inserted to prevent rewetting. Press felts,
in most cases, are delivered as endless forms,
but there is one type, the seam type, that canbe joined at its ends. These new functionoriented products are expected to be theindustry standard in the future.

Systematic Survey on Newsprint Production Technologies in Japan47

Table 7.2. Felt quality changes to meet developments in press part [8]Paper machine
Press section

Year

Type of press
1804

Roll or shoe

Forward press

Plain press

Reverse press

Suction press

1931

Dual press

1950

Straight-through press

Functions required for felt
Fine paper machine
Total
Speed
MNC
Pressure
m/min
kg/cm

TravelSqueezingabilitySurface
AntiAntiquality abrasion flattening

Type of felt

Woven felt

Twinver press
1960√

Grooved√√Needle felt
(BOB)

Uni-press

Suction G√√

Weftless felt√

BOM single

1970√

Multi-nip press

1980

Extended nip press

800

270

1.7

900

370

1.8

1000

370

2.0

1300

410

2-3

1500

410

2-3

Monofilament for weft

√

√

√

BOM double

√

√

√

Laminate felt

√

√

√

Laminate felt

√

√

√

√

Super-fine laminate

√

√

√

√

Multi-nip+4P
Nipco rollFlexiso-nip press

Shoe press

Intensa-press(closed)Press for carton board

Dina-rock

Distributed type

SimZ-roll

1990
Shoe press for newsprint
Shoe press for printing paper

2000

No-draw press

2000

√

Closed transfer press
Single nip press48

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

What has been discussed here is the barebones of the felt technological development,
in which a great number of prototypes andtests were repeated again and again. For
example, roll manufacturers are responsiblefor developing the different materials used for
different rolls. As the press felt absorbs andthen expels water, it becomes contaminated,
and therefore needs to be washed during
operation. This washing unit and the washingchemicals are also developed by specialists.
In this way, a wide range of specialist
manufacturers all contribute to efficient
operation in just the press part alone.

7.4 Dryer part (Dryer section)
7-4-1 Introduction
Following the press part is the dryer part.
The wet paper web is put into contact with aheated rotating dryer to dry it. As one dryer isusually insufficient, the wet web passes
through multiple dryers until it is completely
dried, as shown in Fig. 4.7-2. There areusually several dozen dryers. The wet web isunsupported when it passes from one dryer tothe next, meaning that there is a high risk ofsheet break. Minimizing sheet breaks is aperennial issue for the dryer part.
The physical actions in the dryer part are
as follows (Fig. 7.16). When the wet web
contacts a heated dryer cylinder, inside which
low pressure steam is injected, it is heated up,
causing some of its moisture to evaporate
from the back of the web. The web thenleaves the first dryer cylinder, moves forward
to the next cylinder, and is wrapped around it.
During this free transverse between cylinders,more of its moisture evaporates and the web
can cool down. The amount of water
evaporated during this transfer stage is quite
significant, totaling roughly half of the total
evaporation, so efficiency here is very
important. Once in contact with the next
cylinder, the web receives more heat and its
temperature goes up again. This cycle isrepeated at every dryer cylinder.

Fig. 7.16. Conceptual image of dryer.
The basic layout of dryer cylinders is asshown in Fig. 7.17. Cylinders are laid in a
zigzag pattern, and the wet paper web moves
from the upper cylinder to the lower one thenback up again to the upper one. As the web
travels a relatively long distance in total, it
must be kept taut, without flapping or snaking.
To achieve this, two sets of dryer canvas, one
for the upper dryers and the other for the
lower dryers, move over the cylinders topress the web against the cylinders, as shownin Fig. 7.17.

Fig. 7.17. Conceptual image of dryer canvas(seen from the side) [9].
The problems to be solved for the dryer partwere as follows.
(1) The steam injected in to a cylinder to heatit remains as drainage water inside thecylinder. As this drainage water interfereswith the heat transfer to the cylinder shell,draining it from the cylinder is importantfor improving heat efficiency. This
becomes more critical over machine
speeds of 1,000 m/min. The solutions
developed include the rotary siphon,stationary siphon and the spoiler bar.
(2) Evaporating as much water as possible
Systematic Survey on Newsprint Production Technologies in Japan

49

from the wet pulp web while it istraversing between cylinders (this iscalled the dryer pocket) has been a major
issue. Ventilation in the dryer pockets has
been improved, and heating the wet web
itself is another approach. The technology
developed for this includes blow rolls, hot
air ducts and infra-red heating.
(3) As paper machines grow wider and faster,
the wet web in the dryer part becomesincreasingly unstable, with greater
chances of flapping and snaking whenusing a conventional canvas layout.
Modifications have been developed toovercome this, such as the single canvas
system, the single deck system andequipment for helping steady web
running such as Uno-run.
(4) The quality of the canvas has been asubject of research and development, andimprovements include needle canvas andhigh-permeability canvas.
(5) The steam evaporated from wet web has
enthalpy which can be recovered toincrease energy efficiency by, forexample, enclosing the dryers in a hoodor drying at a high dew point.
This paper will discuss items (2) and (3).
7-4-2 Evaporation in dryer pockets
Evaporation of moisture from the wet
web in the dryer pockets is very important,and research has been undertaken on methods
for increasing the amount evaporated by
reducing humidity within the pocket. Until
around 1980, the dryer canvas ran on the wet
web, pressing the web against the dryer
cylinder to prevent web snaking, as in Fig.
7.17. This type of canvas circulation meantthat a dryer pocket became a space enclosed
by wet web on both sides, as well as thecylinder and canvas, so had only two
openings at either end widthwise across thepaper machine. Water vapor that evaporated
from the web accumulated in the pocket,
increasing humidity and restricting further
evaporation. To counter this, a system calleda blow roll was developed, in which dryheated air is blown into the pocket, purging
the vapor through the openings and reducing
humidity. The support rolls for the canvas are
perforated to allow the air to be injected.

50Fig. 7.18. Conceptual image of blow roll [9].
However, in this design, the air purged
from the side ends is very humid, andnegatively affects the moisture profile of the
web in the cross direction, especially at bothends. To counter this, the blow box, as shownin Fig. 7.19, was developed. In this system a
box blows air into the pocket at the point
where the web leaves the cylinder and sucks
humid air from the pocket through the canvas.
The box is partitioned horizontally every
meter, allowing the air flow to be controlled
for every section.

Fig. 7.19. Conceptual image of blow box [9].
With these modifications, machines canrun faster with better moisture profiles in the
cross direction.
7-4-3 FlutteringWhenmachinespeedsexceed1,000 m/min, wet web fluttering within the
pocket grows worse, making the web very
susceptible to breakage. To counter this, thesingle canvas system was developed.
Normally, the wet web would flutter as it
moved unsupported within a pocket, but

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

using canvas that ran on the top and bottom,
it could be supported against fluttering bychanging its layout.

ended up removing all that saved length inmachine design. Refer to the earlier Fig. 4.9
for details. Even today, breakthrough ideas
like the Condebelt design are sought for thedryer part, but so far these remain at the
research stage.

7.5 Size press

Fig. 7.20. Conceptual image of single canvas
system [10].
Wet web is placed on the moving canvas
and they are run together through the dryerpart, as shown in Fig. 7.20. At one dryer, thewet web contacts the cylinder surface, and at
the next dryer, the canvas contacts thecylinder surface. This layout inevitably
results in lowered heat efficiency. However,air ventilation at the pockets is easy, as they
are not enclosed. While a rather forced
concept that would appear to be a step
backwards in terms of energy efficiency, in
actual use it worked fairly well. In addition,
as existing dryer systems could be modified
without much remodeling, the system spread
rapidly worldwide due to the lack of a patent.
The canvas was also modified to suit it better,such as increasing its permeability.
The next idea was a dryer layout with nofree-run zones. The zig-zag layout of thedryers means that there were areas called“free runs” left between them. However, if
dryers are arranged in a single stage, rather
than two staggered ones, as in Fig. 7.21, there
would be no free runs. This layout is called
the single deck system.

Fig. 7.21. Conceptual image of single deck
system [10].
Though the single deck system requires
more space, recent high speed machines needsteady operation more than space, so thissystem is adopted.
The developments in the wire part andpress part worked to save space. However,the dryer part, which had already been long,

A paper machine consists of three mainparts or sections, as reviewed above. In
newsprint manufacturing, one other piece ofequipment, called a size press, has played an
important role (see Chapters 5 and 6). Paper
has to have some degree of water repellency
to control the penetration of printing ink, so
sizing agents have been used commonly inprinting paper production. The equipmentthat applies sizing agent to the paper is called
the size press. The “press” part of its names
originates from its roll layout, where two rollspress against each one, rotating in opposite
directions. The sizing agent is added to thespace between the two rolls at the top, the“nip,” to form a small pool or “pond.” Paperpassing through this pond absorbs the sizing
agent, which is then pressed into the paper as
it passes through the nip between the rolls.

Fig. 7.22. Conceptual image of size press(conventional) [2].
As high-speed multi-color offset printing
became popular for newsprint printing, thedemands for newsprint surface strength
became increasing strict. As discussed in
Chapter 4.3, offset printing uses damping
water, which removes small fibers from theweb surface, which then accumulate them on
the printing cylinder. This can cause blank
Systematic Survey on Newsprint Production Technologies in Japan

51

areas to appear in the printed image. This alsomeans that the printing machine has to be
shut down for cleaning. To prevent this, asize press has commonly been included in
paper machines producing most grades ofprinting paper, applying a thin layer (1 g/m2
on each side) of starch, and this technology is
now applied to newsprint machines.
The size press is located after the dryerpart, which means that paper has to be
rewetted. This rewetted paper is dried again
by a dryer called the “after dryer,” which
consumes additional energy. To avoid this,considerable effort was applied to
manufacturing newsprint good enough foroffset printing without the use of size presses
by controlling pulp quality and fine-tuning
machine operation. However, the problems
could not be solved this way, so the use of asize press is now standard in the industry.
Newsprint machines usually run fasterthan machines for printing paper. As their
speed increased, however, problems arosewith stable operation for pond-type sizepresses, as shown in Fig. 7.22. Attention
focused on the gate roll coater, which had notbeen particularly popular in Japan until then.
Using this gate roll coater instead of a sizepress greatly improved paper quality andsatisfied the strict demands of Japanesenewspaper printers. This means that atpresent there are almost no imports ofnewsprint rolls.

Fig. 7.23. Gate roll-type size press [2].
With the gate roll coater being revived to
improve the surface quality of newsprint, newversions which were more suitable for highspeed operation were also developed. The
gate roll coater also found a new applicationin producing high-quality coated paper. The
chemical agents on the surface, called thecoating color, were once simple starches, but

52

are now acrylic latexes that offer functional
advantages.
Installing a size press requires additional
investment costs and extra thermal energy.
The reasons why it offers better cost
performance are as follows. While theaddition of a size press increases the costs ofmachine operation, it also offers more choice
for selecting the types of pulp to use, which
in turn reduces pulp costs and allows machine
speed to increase, leading to higher
productivity. The most important factor,
however, is that newspaper printers can run
their printers with higher efficiency due toless accumulation of fiber on the printercylinders and thus less-frequent washing. The
overall productivity gain is quite significant,more than offsetting the increased cost for
paper manufacturers. In Japan, bothproducers and printers could share theseadvantages. In other words, the end users
agreed to pay the additional amount to cover
the cost increases in production. This
demonstrates that if cost merits gained byusers is greater than the cost increases borneby producers, the change will be acceptablefor both of them. This mutual trust between
them has been an indispensable part of theindustry in Japan.

7.6 Process control
Process control technology has beenheavily involved in order to operate theequipment efficiently and obtain high quality
products.
(1) Widthwise profile control in paper
machines
For modern paper machines, widths of 10
meters are common, and their widthwise
variations in basis weight are as small as±0.7 g/m2, as shown in Fig. 7.3. This sort ofsmall variation in the width direction isachieved by monitoring paper properties suchas basis weight, moisture and thickness in the
cross direction online and feeding this databack to machine operation. One major
contributor to this is the BM monitor (atrademark of Yokogawa Electric Co. that has
been genericized in Japan). The use of BM
monitor data has greatly advanced equipment

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

for controlling cross directional profiles likethose at the slice lip (mechanical adjustment
as well as consistency control), at the press
part (CC roll and steam box) and at the dryer
part. These days, other properties of paper,
such as its ash content and fiber orientation,
can also be monitored. In addition,
monitoring is now done at the wet end orother positions on the machine other than thedry end.
The configuration is shown in Fig.
7-24-1.

Fig. 7.24-1. BM monitor [11].

machines, even older and smaller ones.
(2) Controlling machine speed
It should be obvious that synchronizing
the speed in each part is very important.
Unfortunately, limitations of space prevent
speed control from being discussed in thispaper.
(3) Mill-wide control systemsWiththepopularity
of
DCS(decentralized control systems) along with
BM monitors, the concept arose of optimizing
mill operation as a whole through real
operational data. Due to the wide range ofequipment that must function in cooperation
with each other in a mill, understanding
exactly what is happening within the mill isanimportanttool
forincreasing
competitiveness.
An automatic diagnosis system iscurrently being developed as a further stepfrom localized operation control to betteroverall mill management. Preventive
maintenance is a subject of great concern formill operation, and Japan’s high operational
efficiency is due to this having become partof the basic culture of mills. This newautomatic diagnosis system points the way tofuture mill management systems.

7.7 Equipment
contributions
technology

Fig. 7.24-2. Conceptual image of calendar.
A sensor head attached to a frame
traverses back and forth across the width ofthe paper web without contacting it (oneminute per traverse). As the paper web ismoving under the sensor, data is picked up
diagonally, not in a true width direction.
However, statistical analysis can allow
reliable width profiles to be calculated. In
addition, the monitor not only provides real
profiles, but also stores data tracked over timeand can display this data as needed. The BM
monitor has revolutionized paper machine
control, and so is now found on almost all

development
andfromJapaneseA range of different technologicaldevelopments, some of which are not coveredin this chapter, have helped to create andmodernize paper machines. As the scope andscale of these technologies suggest, the paperindustry has not created all thesedevelopments alone.
In Japan during the 1950s, paper
companies took the initiative in developing
equipment, which was actually manufactured
for them by five or six iron works. However,as paper machines became increasingly
sophisticated, fewer and fewer companies
were able to manufacture them. In addition,some of Japan’s most important equipment
manufacturers such as Mitsubishi Heavy
Industries and IHI Corporation became
licensees of European or Americancompanies, so, starting in the 1960s, their
Systematic Survey on Newsprint Production Technologies in Japan53

focus switched to bringing in overseas
equipment to Japanese paper companies. This
final section will examine how Japaneseequipment manufacturers and Japanese paper
companies
contributed
toworldwide
technological development.
Japanese equipment manufacturers had
always been able to deliver reliable products
and comprehensive after-sales services totheir customers. As a result, Japanese paper
companies, trusting them, installed this
newly-developed equipment before overseas
companies followed suit. They were also
capable of evaluating the possibilities of thisnew equipment, and applying it in milloperation, taking on the risks of thisinvestment. For examples, while twin-wireformers and hybrid formers were developedin Europe and America, it was Japanese paper
companies and equipment manufacturers that
contributed to them operating successfully inmills. The experience and expertise theygained was then spread to other countries(while there are no quantitative records on
this topic, discussions with related parties
have suggested this was the case). Even then,Japan was already the world’s second-largest
paper producer after the United States, and its
paper consumption was increasing in stepwith its dramatically increasing GDP. This
meant that there were plenty of opportunities
for both investing in new equipment anddeveloping expertise in their operation.
Recently, however, there has been an
increasing trend towards an oligopoly ofequipment manufacturers, and now there are
only two paper machine manufacturers, both
European, remaining in the market, both ofwhom are increasing their dominance intechnologicaldevelopments.
Moreover,investment in Japan is stagnating, which
results in fewer chances to actively try out
new technologies and less contribution to
global technical developments.
As equipment manufacturers leaddevelopments, the question arises as to whatpart of these developments the paper industry
has been responsible for. In other words, thetechnological abilities that have allowed theJapanese paper industry to retain its
international competitiveness. This questionis one of the main themes of this paper.

54

The answer can be summarized in three
categories: exploiting a succession of new
fiber resources as discussed in Chapter 6,
operating equipment with the world’s highest
levels of productivity, and maintaining
product reliability that is far superior to world
standards. Productivity and reliability will be
discussed in Chapter 8.
Japan’s international competitiveness has
been accomplished through cooperation
between many paper companies andmanufacturers(bothequipment
manufacturers and chemical and auxiliarymaterials manufacturers), providing thetechnological strengths of the paper industry.
Paper companies realized what they neededin terms of technology, and informed
manufacturers of what they wanted,
occasionally urging them to develop better
technology. The manufacturers in turnpursued these possibilities, cooperating withpaper companies as they saw fit. This
indispensable relationship of mutual trust
through technological development withrelated industries, rather than simple
equipment, is what has powered development
in Japan.
It is possible that technologicaldevelopment based on this sort of mutual
trust is one of the characteristics of theJapanese system, seen not only in the paperindustry but also in other large-scale processindustries. It also can be seen in other typesof industry, such as the automotive industry,
which works with component manufacturers
to makes cars that have some of the best
reputations in the world. A single genius may
advancescience,buttechnologicaldevelopment is the sum of all the energy of
all the people involved.
Bibliography[1] Supplied by Metso Paper Japan.
[2] Pulp and Paper Manufacturing
Technologies, vol. 6 Paper Making, p.
56, Dec. 1998, JAPAN TAPPI.
[3] Supplied by Voith IHI Paper
Technologies Co. Ltd.
[4] Supplied by Nippon Paper Industries
Co.
[5] T. Naito, “Progress of newsprint
manufacturing over the last 60 years,”National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Hyakumanto, No. 126, p. 25 (Paper
Museum).
[6] Supplied by Voith IHI Paper
Technologies Co. Ltd.
[7] M. Iijima, “Theories of dewatering andthe history of press felt,” in Preserving
and Publicizing the Technological
Archives of the Japanese Paper
Industry, No. 8, p. 1, April 25, 2005,
JAPAN TAPPI.
[8] H. Someya, “History of press partconfiguration and press roll design,” in
Preserving
andPublicizingtheTechnological Archives of the JapanesePaper Industry, No. 8, p. 15, April 25,
2005, JAPAN TAPPI.
[9] M. Ashida, “History of the dryer partand its future,” in Preserving andPublicizing the Technological Archivesof the Japanese Paper Industry, No. 1,
p. 1, Feb. 2004, JAPAN TAPPI.
[10] M. Sumiyoshi, “History of dryer

canvas,” in Preserving and Publicizing
the Technological Archives of theJapanese Paper Industry, No. 1, p. 36,
Feb. 2004, JAPAN TAPPI.
[11] Supplied by Yokogawa Electric
Corporation.
Some references for paper-making technology
are listed below.
References
1.
Handbook of Pulp and Paper
Technology, Jan. 30, 1992, JAPANTAPPI.
2.
Pulp
and
Paper
Manufacturing
Technologies, vol. 6 Paper Making, Dec.
1998, JAPAN TAPPI.
3.
Pulp
and
Paper
Manufacturing
Technologies, vol. 10 Process Control,
April 1992, JAPAN TAPPI.

Systematic Survey on Newsprint Production Technologies in Japan

55

8 Technological Development Part 3: Production
Technology and Mill Operation Culture
8.1 Production Technology: Productivity
and product reliability
This paper has presented a typical modelof technological development in the paperindustry through the history of newsprint
production. There is no doubt that production
technology is one of the factors making theindustryinternationallycompetitive.
Production technology is the provision ofhigh productivity equipment (equipment
productivity) that is operated efficiently(operating efficiency) to manufacture
products
thatarereliableandcost-competitive (cost performance). This
chapter will analyze the production
technology of the Japanese paper industry
from these three points.
8-1-1 Equipment productivity
In Japan, the price of paper in general has
been largely constant, without major pricehikes, over the last forty years, a situation
which was forced by international
competition. Meanwhile, the amount of
production has increased fourteen times, andthe costs of raw materials and labor have also
increased. Despite these factors, the price has
been kept almost the same by increasing
productivity, such as installing larger andfaster equipment that requires less labor. This
is of course not limited to the paper industry,
with other industries like steel having done
the same. As discussed in a previous chapter,the first continuous kraft plant was installed
in 1953, with a capacity of some 100 t/day.
Modern plants now produce up to several
thousand t/day. Similarly, the widest andfastest paper machines in the 1960s were 7 mwide and ran at 600 m/min, and now they are
10 m wide and run at 1,800 m/min.
Japan once led the world with this sort ofinvestment in high-speed, large-scalemachinery. Now, however, it lags behindcountries like China and Brazil. As a result,Japan currently operates medium to large,56

rather than the largest, paper machines, butdoes so with high efficiency to produce paperwith high reliability. In Japan, production
technology is developed to allow the country
to remain internationally competitive. The
other characteristic of Japanese industry is its
investment methods, different from that ofscrap and build. While investing in new, large
paper machines, the industry is still operatingolder, smaller machines. This combination
machine sizes serves to supply the range of
products demanded by the domestic market,
which is sensitive to quality. But thesesmaller, older machines and equipment aredestined to disappear soon.
8-1-2 Operating efficiency
One characteristic of the Japanese paperindustry is that it operates a range ofmachines, from large to medium, at highefficiency: their overall efficiency is morethan 90% in most cases (see Chapter 11), a
rate which is very seldom seen overseas. For
example, the figure quoted by machine
manufacturers in their leaflets is 70–85%. In
the process industries, high operating
efficiency means that, as a direct return, total
sales against investment are improved.
However, there is an additional meaning. In
paper mills, the running efficiency of thepaper machine (the final stage of material
flow) has a major effect on total millefficiency. When a sheet breaks in a paper
machine, operation must be restarted as soon
as possible. Until the machine is restarted,
pulp stock keeps getting fed to the machine,
but as it cannot be used, it has to be returnedto the storage tank. There is also a lot of
wasted paper around the machine. Thus,
every time a sheet breaks, steady operation
has to stop, and product quality fluctuates(causing defective products) until normal
operation resumes, causing total losses far
greater than just time. Moreover, the waste
paper stuck to the machine has to be cleaned
off, which is a very labor-intensive task.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

The frequency of sheet breaks is quite
low in Japan, averaging about several times amonth, a tenth of the world average. Thismeans that the operating efficiency is veryhigh. Conversely, should there be no sheet
breaks at all, all production lines leading to it
would be steady and there would be no needfor emergency action. Utilities like power andsteam would also be able to be operated at
optimal efficiencies. Product quality would
be stable and yields would be maximized.
This means that production costs would be
minimal while the volume produced will be
maximal. This creates greater revenue thanjust increasing production.
This technology is noted for an
operational management that is dependent on
a highly-skilled workforce.
Operating efficiency means that paper
machines must be good, but their efficiency
will only increase when the mill as a whole isproperly managed. In Japan, operation of amill as a whole in this sense is based onwell-established expertise. The issue for the
next generation will be to systemize thatexpertise in the form of Japan’s uniquemanagement routines. This topic will be
discussed further in Chapter 9.
8-1-3 Product cost performance
While not isolated to the Japanese paperindustry, one of its characteristics is that its
products offer high cost performance, whichlets domestic products remain competitive
against imports. For example, newspaper
printers are vulnerable to sheet breaks during
printing, so count the frequency of sheet
breaks per 100 rolls as an indicator.
Newsprint produced in the United States
breaks several times (perhaps 3 or so) per 100
rolls as an average. In Japan, however, thesheet break rate is less than one per 1,000
rolls. This difference is not due to thephysical strength of the newsprint (as might
be measured in a test lab), as the physicalstrength of the Japanese product is no greaterthan that of the American. The difference isdue to careful operation, such as reducing
defective spots in the sheet by removing
foreign matter and maintaining even property
profiles across the paper width and movement
direction.

This falls under a type of operating
expertise, using the latest process control
technology, which undeniably improves
product reliability. Product reliability does
need a certain level of investment to improveit, and this investment does increase the costof the products. This is why domestic
newsprint is more expensive than imported,
as significant money has been invested tomodernize newsprint production (these ways
include strengthening contaminant removal,
converting machines to twin-wire types,
introducing size presses, and installing thelatest profile control for consistency
adjustment). For printers, however, reliable
newsprint gives them higher printing
efficiency with less labor, and in some cases
they could reduce the number of printing
machines they needed. If the gain fromreliable products is greater than the cost
increase of buying it at higher prices, thenprinters will choose buying the reliable
product despite its high price. This is theconcept of cost performance. To supply
products with high cost performance means
to improve the efficiency of the social system
as a whole. This high cost performance for
products is what has supported industry inJapan as a whole, the paper industry amongthem.
8-1-4 Future issues
Equipment manufacturers have recently
developed an interest in production
technology, and are now supplying
equipment controlled using automatedsystems based on operating expertise. This
operating expertise is one of coretechnologies by which Japanese industries
has been able to become globally competitive,
and is now incorporated in manufacturer
systems, akin to a “black box”, for supply toanywhere in the world. As an example of how
this back box system works, China, alatecomer in terms of modern paper
manufacturing, currently does quite welloperating some of the world’s largest andnewest paper machines, despite their lack ofoperational experience. This has meant asignificant erosion of competitiveness forJapan, which is an issue the country must
now face.
Systematic Survey on Newsprint Production Technologies in Japan

57

8.2 Mill operation culture
8-2-1 Image of a large paper millThis section will present an image of alarge pulp and paper mill that manufactures
3,000 tons of newsprint and printing paper aday. Each paper roll weighs about one ton,and so each day 3,000 rolls are shipped out
by truck from the mill.
The mill covers about one million square
meters of land, meaning that vehicles areused to move around it. It consumes about
4,000 tons of fiber sources (wood chips andrecovered waste paper) a day, along with
1,200 tons of coal and 500 kL of oil. Water isa vital part of paper making, and this milluses about 300,000 cubic meters a day. All
these materials need to be brought into themill every single day, and there is also an
additional week’s worth of each stockpiled in
the mill. In the wood yard, wood chips are
piled and stored in different areas, based on
their tree species and country of origin. These
chips are mixed in accordance with
instructions from the pulping section and sentout to be pulped. Waste paper, anotherimportant resource, is also stockpiled
according to quality, and sent on to therepulping plant as needed. There are usually a
few pulping lines for pulp and repulping, witheach line producing pulp with particularqualities, and these different types of pulp are
distributed continuously to multiple paper
machines. Each paper machine blends thispulp with other additives to produce its own
type of paper, based on the mill management
plan. In other words, pulping lines and paper
machines are coordinated with each other,allowing them to change the quality of their
output in accordance with instructions fromthe mill management. The manufactured
paper rolls are stored in a warehouse andshipped out when an order comes in.
Normally, this warehouse would stock about
one week’s production.
8-2-2 Mill operation culture and millmanagement cultureAn
indispensable
part
of
mill
management is to coordinate all operations,from bringing in stock to delivering products.

58This is especially necessary in large-scale
process industries. This efficient operation ofa plant as a whole is something Japan
typically excels at. The same applies to paper
mills in Japan, and their operating efficiency,
an indicator of how well coordination iscarried out, is outstanding (see Chapter 8.1).
There is no particular secret behind thishigh level of coordination; no special
equipment nor extraordinary genius. The
equipment is simply maintained as it shouldbe, and the workers acknowledge the sharedobjective of the mill. The mill being kept
clean and tidy is also due to the shared cultureof the mill. However, this system cannot bebuilt in a day: it takes a long time to establish
a culture like this. Prior to writing this paper,
the author interviewed a number ofexperienced paper mill engineers, who agreed
with this understanding. While some readers
may wonder if this is a type of technology, it
could well be so, as it helps to improve theoperating efficiency of the mill. The famous
just-in-time system, the “Kanban system,”Toyota invented is certainly a type oftechnology, as it improves efficiency andproduces profit, and establishing an operating
culture is the same.
8-2-3 Introducing operating culture overseas
Could this type of technology, which at
first glance appears to be Japanese culture, be
introduced overseas? This is a difficult
subject to evaluate qualitatively, and so what
follows are from the author’s experiences andfrom discussions with acquaintances.
Historically, the management systemused in Japanese paper mills has been
introduced to Taiwan and Korea throughpersonnel exchange. Most paper mills in
Taiwan are managed similarly to Japanesemills, and carry out small group activities andmeetings just as in Japan. From about 2000,
China started to install large paper machines,
expecting huge future demand. Taiwan
provided a large number of managers tomanage these mills and technicians to operate
their machines, thus bringing over Japanesemill management systems to China as well.
The author visited one large paper mill in
China in 2006. Its managers were from
Taiwan and the mill looked like one in Japan;

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

it was kept clean and had a poster showing
the mill’s small group activities; its operating
efficiency looked to be close to that of Japan.
The next Chinese mill visited was run using
Finnish investment, with a Finnish manager,
and the mill looked like one in Europe
In Canada and the United States, mills
supportedbyJapanese
investment
incorporated Japanese management systems,
and showed improve performance as a result.
Some of these mills include Norpac Co.
(Nippon Paper Industries Co.) and How
Sound Pulp and Paper Co. (Oji Paper Co.). In
other parts of the world, Hokuetsu Paper Co.
provided support for APP Co.’s Indah Kiat
mill in Indonesia, which reports say isoperating smoothly.
In this way, the mill management systems
developed
in
Japan
are
becoming
management culture in other parts of theworld.
The technological developments innewsprint manufacturing have been discussed
in Chapters 6 through 8. Newsprint
manufacturing competitiveness depends bothon those technological developments and also
on the capability of the mill as a whole inother technical areas, a topic which will be
discussed in Chapter 9.
Bibliography[1] K. Iida, “History, characteristics andecology of pulp and paper industry,”
JAPAN TAPPI Journal, vol. 55, No. 4 p.
417, 2001.
[2] K. Iida, “Technological developments in
the Japanese paper industry,” JAPANTAPPI Journal, vol. 61, No. 4, p. 393,
2007.

Systematic Survey on Newsprint Production Technologies in Japan59

9 Other technologies in the paper industry
Newsprint manufacturing is only one ofthe operations carried out by mills, so thelevels of technologies in areas other thanpaper-making have a considerable impact on
the cost and quality of newsprint produced
there. For example, energy costs are about 10
to 20% of the total cost in newsprint
production, so if the mill’s energy unit pricecan be reduced, newsprint will cost less to
manufacture. In addition, effluent and exhaustgas disposal, while not directly related tonewsprint production, has to be managed
properly to ensure steady mill operation. For
these reasons, the levels of these secondary
technologies also need to be kept as high as
possible in order to make newsprintcompetitive. This chapter discusses thetechnological developments in these areas.

9.1 Energy-saving technologies
The idea that the paper industry, one of
the larger process industries, consumes a lotof energy is not actually based in fact. Whatfollows is a breakdown of energy
consumption per sector in Japan as of 1997
[1].
Industry sector: 49 %Public and household sector: 26%
Transportation sector: 25%
The industry sector is broken down as follows.
Chemical industry: 13%
Steel industry: 12%
Cement industry: 3%
Pulp and paper industry: 3%
Other: 18%
Of these industries, the paper industry
utilizes energy in a unique way.
Manufacturing plants in general are poweredby electricity, which is generated by steam
produced from fuel. In this case, less than
40% of the potential energy of the fuel isconverted to electricity. Paper mills have theirown power plants, so they can generate
electricity to operate their equipment and use
the remaining low pressure steam to dry

60

paper using the paper machines. This meansthat the total rate of energy utilization is very
high, around 70%. In addition, when woodchips are chemically pulped, about 50% of
the wood (biomass) becomes pulp and therest is recovered as waste liquor. This waste
liquor is condensed in evaporators and thenburned in recovery boilers to recover thechemicals. This combustion, done at hightemperatures and pressures, produces
high-pressure steam that is used forgenerating electricity. Thus the energy
produced from the unused parts of wood(classified as biomass energy) provides abouta third of the industry’s total energy
consumption. This means that the paperindustry is characterized by both a high rateof energy utilization and effective biomass
utilization. Nevertheless, saving energy has
still been an important issue in the industry,
and much effort has been devoted to thedevelopment of this technology category.
Japan’s energy utilization is very
distinctive when compared to that of othercountries. Though comparing electricity
prices directly is difficult due to fluctuations
in exchange rates, power in Japan is generally
more expensive. As a result, technicaldevelopments in the energy sector have been
aimed at lowering power consumption.
The Japanese paper industry has beenworking on reducing both energy prices andunit energy consumption. A rough estimationsuggests that the Japanese paper industry
produces paper using two-thirds of the unit
energy consumption in the United States.
This has been made possible not throughrevolutionary technologies, but throughsteady efforts to reduce energy consumption,
as detailed below.
(1) Investment by management
A range of different investments havebeen made to reduce the unit price ofelectricity. These include increasing
power self-sufficiency in mills by
installing power plants (big mills arealmost 100% energy self-sufficient),

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

promoting co-generation (effective use of
low pressure steam), and installinghigh-efficiency recovery boilers (better
utilizationofbiomass
energy).
Manufacturing equipment has also been
replaced by equipment which consumes
less energy. These investments were notjust about saving energy, but also ensurethat equipment was modernized at thesame time, leading to mill operations
becoming increasingly stable andefficient: a change, which, needless tosay, also saved them energy. Inverter
controls were also added to every large
electric motor as a way to improve theunit energy consumption of equipment.
This trend towards equipment investment
was further driven by the high cost of
mains electricity.
(2) Energy-saving efforts in mills
Minor savings at the small group activity
level accumulate to major savings for themill as a whole. To give an example, theprocess from pulping to paper making isa continuous process, and to ensure
steady operation, the process involves anumber of pulp slurry storage tanks inthe process. Those storage tanks areagitated by a stirrer, and so keeping thelevel of stock in a tank as low as possible
saves circulation energy. After the firstoil price hike, every mill started doing
this for all its storage tanks. Overall millefficiency was improved as a result,though it required careful, detailed
management. Reducing the volume ofstock in the tanks also meant that
impellers could be made smaller, further
saving energy. These sorts of actions
eventually added up to the developmentof energy-efficient mills, allowing themto maintain competitiveness.
JAPAN TAPPI has published statistics forunit energy consumption at every stage of
operation in 1979 [2], 1989 [3], and 1999
[4]. Unfortunately, there is little data
available from other countries, so theycannot be compared.

9.2 Technology

topreserve

theenvironment
Japan is a densely packed country inwhich the Japanese paper industry produced
the second-greatest amount of paper andpaperboard in the world, until China's output
exploded several years ago. Mills are located
all over the country, with many of them close
to urban areas.

Fig. 9.1. Mill in an urban area [5].
This creates a different environment toother countries. Historically the paperindustry caused a number of environmental
problems, but during the years from 1970 to1990 the industry invested huge amounts ofmoney in protecting the environment, andnow it meets the world’s severest restrictions
in categories such as effluents, gas emissions
and noise. The industry provides a model ofsustainable development in a crowded
country with so many people producing
goods to create the second-highest GDP in
the world. Japan just manages to stay aheadin protecting the environment, and so is far
from lagging when it comes to these issues.
The Japanese paper industry is the mostecological in the world. Its unit energy
consumption for paper manufacturing isbelieved to be the smallest in the world,which means that the least amount of carbon
dioxideisemittedduringpaper
manufacturing. The recycle rate of waste
paper, more than 70%, is probably in theminimum zone of environmental load
predicted by LCA (life cycle assessment).
Systematic Survey on Newsprint Production Technologies in Japan

61

The Japanese paper industry started
treating effluent somewhat earlier than othercounties, reducing SS, COD and BOD
discharges. As a result, Japan is the only oneof the major paper producing nations that did
not suffer from dioxin pollution, while
Scandinavian and North American countries
were, forcing them to prohibit fishing andwarn against eating fish from polluted areas.
While there are differences in the production
processes, Japan was able to remain
unaffected by this problem thanks to thesignificant investments in environmental
conservation its paper industry had been
making since the early years.

Fig. 9.2. Financial investments inenvironmental conservation [6].
Dealing with environmental problems,
however, has not been so scientific, and wasdone through installing equipment largely topass targeted numerical levels of pollutants.
Recent environmental problems are moredifficult to tackle, however, as they areintertwined with other phenomena that affectdaily life such as global warming andhormone-disrupting chemicals. Rather thansimply setting acceptable values, scientificproof and evidence are required to deal with
them.
These technological efforts have helped
mills to operate efficiently, making the paperindustry globally competitive. They also
represent some of the characteristics ofJapanese industry as a whole.

9.3 Research and development
62

Though the Japanese paper industry did
not develop equipment that was noticeably
innovative, it managed to expand its output
through creatively improving what it could, inspite of its handicaps in terms of fiber andenergy sources. Newsprint production
provides a typical example, suggesting thatJapan has some degree of research anddevelopment capability, and has provided
enough manpower to carry it out. Though thisstatement is based on personal information
rather than firm data, it does appear thatJapanese paper companies assign more
manpower to R&D than paper companies inother countries, and it is probably this greater
manpower in R&D that has enabled theindustry to expand and grow.
Japanese companies have made investingin improving the quality of their product(paper) their first priority. To show an
example, the fierce competition in the coatedpaper market in Japan means that four paper
companies have their own high speed pilot
coaters, while only one coater is available inlaboratories in Scandinavia and probably
none in North America (based on informationfrom 1998: more recent information isunavailable). Japanese companies are also
leading in developing high quality thermal
and inkjet printing paper products. The efforts
put into satisfying customers’ sometimes
extreme requests have improved the cost
performance of products in general and madethem competitive against imports. Newsprint
production in Japan is a typical case of thiseffort.
Japanese paper companies are, however,trimming technical staff now. If thiscontinues, there are serious concerns thatJapan’s technological capability will be
negatively affected, which would mean thatnew product development and international
competitiveness will be weakened, andfinally the paper industry itself will be indanger. The issue facing the industry is how
to increase the efficiency of its technical staff.
Another question is how many
researchers there are in public institutions anduniversities compared to other countries.
Each year, JAPAN TAPPI surveys theresearch topics carried out on wood chemistry

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

and other areas by public institutions anduniversities and publishes the results in its
journal. Quite a number of researchers are
involved in this area. However, there are few
topics that are related to the paper industry,and research on the paper making process isquite rare [7]. Moreover, universities are now
officiallyclassified
asindependentadministrative corporations, and university
researchers note that it is difficult to obtaingovernment research funds on subjects
relating to the pulp and paper industry. Thereis a problem in terms of coordinating researchamong government, academia and industry
here, which is not managed as well as in
Finland, for example. An analysis needs to be
carried out on the reasons why it does notwork, and this area remains a major topic forstudy.

9.4 Education and training
Newsprint production in Japan has beenable to remain internationally competitive dueto the advanced technological capabilities ofthe mill as a whole, rather than relying solely
on the latest equipment. Technical educationand training have played an important role
here. It is the understanding of the author thatJapanese mills have more technical staff andmaintenance crews than mills in othercountries. As every mill manufactures its own
range of products, it is difficult to comparethem on a simple basis, especially as thesestatistics are not published. However, more
manpower in technical jobs means higher
labor costs. The question then arises, ofcourse, of the return on these higher costs.
It is the author's belief that the large
number of technical staff in mills is one of thecharacteristics of the Japanese system; onethat has definitely produced returns. As
mentioned in the discussion of newsprint
production, business circumstances such as
requests by clients, fiber source supplies andequipment renewal are always changing, and
it is how they have been dealt with that hascreatedtheindustry’s
international
competitiveness. For example, when a milldecides that it must use more waste paper,
each mill has to have its own supply network,
depending on its location. They have to plan

what type of waste paper they should collect,
and how much they should collect; the typeof equipment they should select and what its
capacity should be. They need to evaluate
how the fiber from waste paper affects both
paper machine operation and the final productquality; determine how to deal with any
effects this has and how to proceed with trial
operation or test printing by the user before
investing in equipment. In most cases, these
are new initiatives without any existingmodels to refer to as they forge ahead into
new areas. This is precisely what happened
with newsprint production in Japan, and it
happened for other paper products as well.
The force behind all this has been thetechnical staff in the mills.
Operating a mill efficiently requires
maintenance staff who are both capable andresponsible for maintaining equipment. Thisis different from mills overseas, where
maintenance work is usually outsourced.
The large numbers of technical staff inmills means that R&D can be done throughcoordination with suppliers such as
equipment and chemical companies. The
cases described in Chapters 6 and 7 areexamples of successful cooperation.
Technical staff are trained by theircompanies in a range of ways. Information is
also exchanged among mills extremely
frequently. From the standpoint of
information exchange, the high number ofmills in a relatively small country like Japanis advantageous, as the cost of exchange is far
less than in countries like the United States,
Canada or China, where mills are located allover the country. For example, if a
conference is held in Tokyo, participantsfrom all over the country can arrive in Tokyo
in just two hours, something which is
impossible in the United States or China. Thisis an advantage for Japan that cannot be put
into hard figures.
Technical education and training in Japan
has been developed in a uniquely Japanesemanner, based on the country’s traditional
lifetime
employment
systemandgeographicalcharacteristics.
This
employment system is changing now,
however, and so the education system may
have to change as well.
Systematic Survey on Newsprint Production Technologies in Japan63

Bibliography[1] A. Takahashi, “Energy situation of thepulp and paper industry in 1997,” JAPANTAPPI Journal, vol. 53, No. 4, p. 64,
1999.
[2] Energy Committee, JAPAN TAPPI,“The first survey on energy consumption,”JAPAN TAPPI Journal, vol. 33, No. 1, p.
110, 1979.
[3] Energy Committee, JAPAN TAPPI,“The 6th survey on energy consumption,”JAPAN TAPPI Journal vol. 44, No. 5, p.
447, 1979.
[4] Energy Committee, JAPAN TAPPI,“The 7th survey on energy consumption,”JAPAN TAPPI Journal, vol. 55, No. 5 p.
573 and vol. 55, No. 6, p. 737, 2001.
[5] Supplied by Nippon Paper Industries Co.

64[6] Pulp
andPaper
Manufacturing
Technologies, vol. 12, Environment, p.
13, May 2002, JAPAN TAPPI.
[7] Wood Science Committee, JAPANTAPPI 2006, “Research projects ofuniversities and government research
institutes,” JAPAN TAPPI Journal, vol.
61, No. 5, p. 584, 2007.
The following article was also referenced incompiling this chapter.
Reference
1. K. Iida, “Technological developments in
the Japanese paper industry,” JAPANTAPPI Journal, vol. 61, No. 4, p. 393,
2007.
.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

10 Summary: International comparison of paperindustry business models
Finally, this chapter covers the businessmodels of paper industries in other countries
as a way to better understand thecharacteristics of the Japanese paper industry.
(1) Brazil
In Brazil, eucalyptus trees are planted invast plains and harvested before being
replanted, in a seven or eight year cycle much
like growing crops. The chips from thiseucalyptus wood are pulped in some of theworld’s largest digesters (5,000 tons per line
per day, as shown in Fig. 6.6) to produce
bleached kraft pulp. This is sold to paper
companies around the world which lack theirown pulp sources. These eucalyptus
plantations were planned from the beginningto supply wood to pulp and steel
manufacturing. The decision-making behindsuch a large project is definitely a type oftechnology.
(2) The U.S.A.
With its ample resources, the UnitedStates is the world’s largest paper producer.
Its advantage comes from having developed aunique form of wood use that producestimber and makes pulp from waste wood.
While Canada has excellent softwood fornewsprint production, such as spruce and fir,softwood in the United States, such as
Douglas fir and pine, is not suitable fornewsprint. However, these species grow fast
and are widely used as housing timbers.
Douglas fir forests can easily be planted andharvested in the United States, and theresulting logs are sawn to timber first, withthe residual waste chipped for kraft pulping.
The kraft pulp is then sheeted to form
linerboard. Linerboard made from Douglas fir
kraft pulp is rigid and strong, and is the bestmaterial for the linerboard of corrugatedcontainer. As a result, American linerboard
currently predominates worldwide.
(3) Finland
Finland has abundant, good quality
softwood, which it is using to expand
worldwide. Up until the 1980s, their mills

were small, and Finland was not a majorpresence in the industry. However, following
the depression of the 1980s, the country
formed a national policy of supporting
industry, academia, and government links topromote R&D, and also promoted scrap andbuild in mills to make them suitable forlarge-scale production. They use their
top-quality spruce to manufacture products
such as lightweight printing paper and coatedpaper. Thanks to smoothly-functioning
industry, academia, and government R&D
coordination, they sell the machinery andequipment they developed to customers
around the world.
(4) Germany
Early in the 20th century, Germany was
the largest paper producer in Europe, boasting
the most advanced technology of the time.
One of the German technical journals for pulp
and paper at that time published around 4,500
A4 pages a year during this time. Germany
used fir forests as their pulp source and had a
big market in Europe. However, due toenvironmental concerns, they prohibited theconstruction of kraft plants in the country.
The kraft process was notorious for its smell,and no countermeasures were available at thattime. This decision prevented Germany fromexpanding as much as other countries, and its
former glories were lost.
In this way, every country developed its
own unique business pattern, using its
circumstances as best it could. In comparison,
Japan could be summarized as follows.
In the 1950s and 1960s, paper
consumption in Japan was about 3 million
tons a year, a tenth of the present
consumption, and only domestic wood wasused as fiber sources. Mills that could
produce some 100 to 200 tons a day werelocated in different areas around the country
to utilize the wood growing near the mills. As
demand increased, companies increased theircapacities. This had the result of reducing thewood supply, and the price of paper went
Systematic Survey on Newsprint Production Technologies in Japan65

down due to competition caused by excess
capacity. In addition, import duties on pulp
and paper were gradually removed. This
meant that competing against imported
products became a common issue for theindustry as a whole, so R&D was started forsurvival reasons. One technology which had adecisive influence on the Japanese model wasto transport chips from overseas to Japan
using specially-designed ships. Freed from areliance on the domestic wood supply, mills
could now use large-scale machinery andequipment, and integrate all stages, from
pulping to paper making, in a single plant. As
a result, mills for newsprint and printing
paper were sited near ports large enough forbulk carrier vessels to berth at, and huge mills
were constructed, as big as any in the world
and with capacities in excess of 3,000 tons aday.
With over a hundred million people
living on relatively little habitable land, andone of the highest consumption rates per
capita (240 kg/per capita) of any country,
there was a massive amount of waste paper
generated, which could be collected easily.
After 1980, the industry was interested inusing more waste paper as a source fordinked recycled pulp, a change which madethe industry even more competitive.
Technological breakthroughs such as large
coastal mills and the use of waste paper
demonstrated the technological capabilities
which have allowed the Japanese paperindustry to remain one of world’s largest.
In addition to this resource management,
technological capabilities in manufacturing
have helped the Japanese paper industry.
These manufacturing technologies include theinstallation of highly productive equipment(equipment productivity), efficient operation(operating efficiency), and the provision ofreliable, cost-competitive products (productcost performance). The first to be discussed
here is productivity. Many of Japan’s major
equipment manufacturers became licensees ofEuropean and American paper machine
manufacturers during the 1960s, after whichmachinery and equipment developed overseas
was brought into Japan, earlier than othercountries. The Japanese paper industry’s
willingness to bring in new equipment ended66

up renovating their machinery and improving
its efficiency. For example, in the 1950s,
paper machines in Japan were about 3.5
meters wide and ran at about 300 m/min.
Now, in 2000, there are machines that are 10
meters wide and run at 1,800 m/min. When
new machines were brought in, the abilities toevaluate this new equipment and put it into
operation were needed, as was the
management will to take these risks. In thecourse of these innovations, the paperindustry worked with manufacturers on
modifying and improving the equipment,
rather than merely being passive users. There
have been many techniques developed inJapan through this cooperation with
manufacturers that are now common
worldwide. This process shows the level ofsincere trust between manufacturers andusers.
One of the characteristics of Japan’s
technology is that equipment operation ishighly efficient. It is quite normal in Japan tooperate paper machines at an overall
efficiency of more than 90%, which rarely
seen elsewhere in the world. That figure ispossible thanks not to just the efficient
operation of paper machines but by properly
managing a mill as a whole, including otherprocess equipment, based on a culture thathas been nurtured in mills over many decades.
This mill culture is gradually becoming more
and more common overseas through the useof technology exchanges and direct
investment overseas.
The other characteristic is productreliability. As mentioned before, newsprint isa good example. While newspaper printers inJapan have stricter demands for productquality than other countries, the Japanese
attitude of prioritizing customer satisfaction
has encouraged R&D and produced a reliable
product that is unique in the world. As aresult, while newsprint is an internationalcommodity, very little is imported to Japan.
In this way, the Japanese paper industry
has built itself a unique place in the world,
but it is now confronted by a new problem.
Paper consumption (including newsprint) inJapan increased in pace with the GDP, andthe paper industry was focused on ensuring
footholds in the growing domestic market.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

However, as the domestic market is notexpected to expand much from this point, theindustry will be forced to expand
internationally to grow. For this to be a
success, Japan needs new technologicalcapabilities which will both satisfy the strict
demands of domestic customers and alsodeliver
products
atinternationallycompetitive prices.
Bibliography[1] K. Iida, “Evolutional developments in thehistory of the Japanese pulp and paperindustry,” Pulp and Paper Symposium,
Dec. 2003, Pulp and Paper ResearchCommittee.

Systematic Survey on Newsprint Production Technologies in Japan67

11 Operational data for a typical newsprint
machine11.1 Introduction
This chapter will discuss the operational
data for a single newsprint machine over a
forty year period. When it was installed in a
Japanese mill in 1960, this paper machine
was one of the biggest in the world at thetime. Since then, paper machines havebecome increasingly wider and far faster, but
this paper machine is still in operation today,
fitting in as a medium size machine under thepresent standards, but is run at the highest
levels of efficiency, allowing it to produce thefinest quality newsprint rolls. The operational
data of this paper machine over the past forty
years has been made public by courtesy of themill management to show how technologies
were developed in newsprint production.
This paper machine is the No. 6
newsprint machine in Nippon Paper
Industries Co., Ltd.’s Kushiro Mill. When themachine was installed, its design wasconsidered revolutionary, as can be seen fromthe materials supplied by its manufacturer,
Mitsubishi Heavy Industries Ltd [1]. The
operational data has been summarized fromthree viewpoints: (1) machine modifications
history, (2) production efficiency history, and(3) product quality history.

11.2 Machine modifications history
Historically, the Japanese paper industry
modified then ran older paper machines inparallel with the installation of large,
up-to-date machines to cope with steadyincreases in demand. Modifications used thenewest technologies of the time to improve
productivity and product quality, andmaintaincompetitiveness.
Repeated
modifications, which required relatively small
investments in general, allowed the industry
to react quickly to the market’s changing
requests. It was quite a Japanese way, being
quick and adaptable in nature, and different
from that of Scandinavia, which was mostly a68

scrap and build style.
Actual examples are provided byDocument 1 (Machine Modifications History).
The newsprint machine was frequently
remodeled through the installation of what
were then new technologies. Auxiliarymaterials, such as wire, felt and canvas, werealso modified, and the pulp types fed to themachine also changed as pulp resources
diversified. These facts suggest flexible andadaptable management of operation on thepart of the mill as a whole.
In terms of specific figures, the machine
was designed to run at 606 m/min, but was
remodeled to 1,200 m/min through upgrades
to the drive unit, allowing it to run at 1,050
m/min. The records show when newtechnologies were put into practice and, at thesame time, the characteristics of technology
development in Japan.

11.3 Production efficiency history
Document 1, which contains the yearlynewsprint output of the machine, shows that
there was a drop from 1991. One reason forthis decrease was that products other thannewsprint were also produced on thismachine, and their volumes are not includedin the figures. The other reason was the trend
towards newsprint with lower basis weights,
which resulted in a lower tonnage output forthe same square area. For these reasons,
Document 2 (Production Efficiency History)
can more reasonably be seen as the
productivity history. The machine’s speed
increased gradually, jumped up after major
modifications
andthenincreased
incrementally. This gradual increase wasachieved by continuous, steady developmentin operational expertise, one of thecharacteristics of Japanese mill management.
Also note the number of operators (Document1). When the machine was first put into use, it
had a total of 48 operators in a three shiftsystem, consisting of 13 operators per shift

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

plus 3 assistants per shift. However, by 2008,
it only required a total of 20 operators in afour shift system with 5 operators per shift.
This reduction was greatly helped by the
introduction of mill automation, such as inwinder operation, and these efforts to increase
reductions are ongoing.
The overall efficiency of the machine asshown in Document 2 is also noticeable.
Overall efficiency is the ratio of the volume
produced with acceptable quality against thevolume which should be produced within theplanned operating time. This ratio exceeded
90% within three years after start-up (1963),
and reached 95% by 1977. Paper machines inJapan are commonly referred to as being run
with high efficiency, but no data has everbeen published to demonstrate this. This is,therefore, the first case in which data,
especially dating from when the machine was
first started up, has been made public, andsubsequent access to this data should be ofgreat value to future researchers.

6.1), dramatically improving opacity andbrightness. It will be interesting to see where
this trial, unique to Japan, will end up.
The most important measure for quality
is the sheet break rate announced bynewspaper printers. This rate cannot simply
be explained by the physical strength of paper
as measured in test labs. As discussed
previously, the expertise in operating mills
such as maintaining steady operation andreducing accidental defects in rolls plays animportant part. In addition, the appearance ofthe printed image is also an important index.

11.5 Summary
These specific operational records can beanalyzed from various perspectives and will
be helpful in studying the history oftechnology.
Copyright of Documents 1, 2, and 3
remains with Nippon Paper Industries Co.,and no use or reproduction is allowed without
the company’s consent.

11.4 Product quality history
Document 3 (Product Quality History)
show how a certain level of quality has been
maintained throughout despite the frequentchanges of pulp sources and the steady
reduction of basis weight. At one stage there
were specifications on paper strength agreed
on with newspaper printers, but these werediscontinued in the 1980s, and replaced as anindex by the sheet break rate on the printingpress.
As newsprint became lighter, sheet
thickness, density and opacity were also
being reduced. Opacity was greatly improved
through the neutral sheet forming describedin Chapter 6-1-6, while paper strength
increased through greater use of DIP, whichcontained kraft pulp to give better strength. It
is clear how the sheet properties that were
measured changed to suit newspaper printers’
shifting quality demands. The reason that thecoefficient of friction was listed under quality
control is that this coefficient measured thedegree to which newsprint was prevented
from slipping during handling.
One influential change was theconversion to neutral sheet forming (Chapter

Documents: History of the No. 6 paper
machine at Nippon Paper Industries Co.’s
Kushiro Mill
1. Machine Modifications History ········p. 71
2. Production Efficiency History ··········p. 72
3. Product Quality History ·················p. 73
Bibliography[1] “Newsprint machine capable of four A
rolls installed in 1960,” in Preserving andPublicizing Technological Archives ofJapanese Paper Industry, No. 6, p.1, Oct.
13, 2004.

Systematic Survey on Newsprint Production Technologies in Japan69

Acknowledgements
I would like to offer my thanks to all those people without whom this paper could not havebeen completed. In particular, Mr. Tsutomu Naito, Manager of the Environmental Department at
Nippon Paper Industries Co. for his assistance with Chapter 5; Mr. Noboru Hasegawa,
Executive Vice-President of Nippon Paper Industries Co. for his assistance with Chapter 11; andMr. Tetsu Nakayama, General Manager of Nippon Paper Industries Co.’s Kushiro Mill, andeveryone else from the mill who prepared the materials. Finally, I would like to thank Mr.
Kunitaka Toyofuku, Executive Director of JAPAN TAPPI, for all his understanding and supportof the necessity of organizing this report.

70

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Started in June

Systematic Survey on Newsprint Production Technologies in Japan

Year

Age

71

1,050 m/min

Multi type

6 operators

Flat mono type

Replaced soft calender (hot soft nip)
Changed to stationary siphon for all dryers

Piled mono +single mono

NBKP
startedReplaced stock inlet (Mitsubishi to Metso)
Upgraded drive system

Multi typesingleUpgraded BM monitor

Multifilament

Changed to stationary siphon at pre-dryer#2 ? ? ?
LL 2.5 layer

Installed automatic winder spacer

9 operators
TT 3.5 layer

SS 2.5 layer

5M/C ended

Installed double doctor at the top roll of #3 press
Press center roll converted to ceramic
Installed double doctor at the top roll of #3 press

13 operators/shift(+ 3
assistants/shift)
10 operators/crew(introduced a 4crew 3 shiftsystem)

4M/C
ended

Installed belt for sheet transfer
Installed automatic splicer in winder operation
Installed automatic core feeder in winder operation

Spun type1,010 m/min

Upgraded start-up/shut-down instrumentation

Cotton yarn
1,000 m/min#1 LL 2.5 layer

Installed wire outside roll

1958 -

Installed Aquato-roll in dryer part (moisture profile control)
Replaced screen in front of machine (Iruha to Rameau–Aikawa)

Plastics (single)
Hyke (Germany)

Short-term
operation

Installed spot detector (contaminates on sheet)
Installed calto-roll for calender
Replaced head box

Pulp

Installed
Newsprint
imported from
NorpacInstalled size press (gate roll type)Installed rotary siphon in dryers
Upgraded BM monitor
Upgraded winder

Pulp
composition

8M/C
startedReplaced Fourdrinier with Twin Wire (Bel-Baie)
Installed automatic reel change system
Introduced start-up/shut-down instrumentation
Replaced screen in front of machine (Iruha)

Number ofoperators

7M/C
startedCalender rolls modified to CCR

Woven felt

Woven canvas

Labor-saving modifications
BM monitor installed
Press rolls modified to CCR

Felt

Canvas

Improved foil arrangement in wire partBronzeNipponFilcon Co.

#3 press modified to Venta-nip

700 m/minWire

Inlet slice lip replaced
Modification to No. 1 dryer part2

Basis weight (g/m )Production (1000 tons)

Mill
TopicsScreening system modified (Yanson screen installed)
Calender rolls modified (increased diameter)
Heat recovery system modified (dryer hood fully enclosed)

Auxiliaries
Drive

Machine speed: 660 m/min (May)

Modifications to machine

Document 1.
Machine modifications history of the No. 6 newsprint machine in Nippon Paper Industries Co., Ltd.’s Kushiro Mill
Neutralsheet
forming

Revised on Jan. 29, 2008

Ended in Oct.

Ended in June

Ended
Ended in Dec.

Installed
Installed
Installed
Installed

LTT 3.5 layer
TT 3.0 layer
1,200 m/min

Piled mono +Piled mono
Flat mono type(all)
Fused type (piled
mono + piled mono)

5 operators

Document 2.

72

Production efficiency history of the No. 6 newsprint machine in Nippon Paper
Industries Co., Ltd.’s Kushiro Mill

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Document 3.

Product quality history [1] (Kushiro Mill, Nippon Paper Industries Co. Ltd.)

Nominal basis weight
Machine No.
Sheet formingYear
Specification

MoistureBasisweightThickness
DensityTearstrength

H (51.8 g/m2)
4
Acid
1978
1978
Average Specification Average Specification
7.5 6-8
6.9 7.0

S (48.4 g/m2)
L (46.2 g/m2)
SL (42.8ｇ/m2)
6
4
6
8
8
6
6
6
6
Acid
Neutral
Acid
Acid
Acid
Acid
NeutralNeutral
Acid
Acid
1978
1978
1989
1989
1989
1989
2001
2006
1989
1990
2001
2001
2006
2006
Average Specification Average Average Average Average Average Average Average Average Average Average Average Average Average
7.5
7.4
8.7
8.4
8.5
8.6
8.4
8.6
9.0
8.1
8.4
8.4
8.4
8.4

%

6-8

g/m2

52-55

53.1 52-55

52.9 53±1

53.3

49.1

49.1

46.6

46.6

47.0

46.1

45.9

43.5

43.0

43.2

43.6

44.2

44.5

μm

82-92

83.0 82-92
0.64

84.5
0.63 0.62↑

85.5
0.63

81.0
0.61

74.5
0.66

75.0
0.62

75.0
0.62

79.5
0.59

70.0
0.64

71.4
0.62

75.0
0.58

69.5
0.62

74.7
0.56

74.6
0.57

74.3
0.58

72.6
0.60

28.6

24.0

24.4

25.0

CD

28↑

29.3 28↑30.2 30↑

32.4 30↑

31.6

42.0

35.3

37.0

40.0

42.8

37.0

36.5

42.5

41.3

43.4

38.1

38.8

kgf

MD

2.7↑

2.85 2.7↑

2.82

2.37

2.12

3.22

3.63

3.62

3.75

3.53

3.81

3.40

3.27

3.74

3.79

4.04

4.06

Sheet
quality Elongation %

CD
MD
CD

1.01

1.12
1.29

1.24
1.42
2.28

1.24
1.42
2.18

1.33
1.41
1.21

1.50

0.73
1.39
2.54

1.16
1.36

1.32

1.59

1.57

0.73
1.36
2.39

0.74
1.36
2.48

71

55

62

42

77

42

53

61

34

35

27

33

Tensilestrength

g/cm3
gf

Smoothnesecss (F)
Smoothnesecss (W)
Brightness %Opacity%
Frictioncoefficent
Oilsec
absorptionAsh%content
Print%
through
Mechanica%l pulpPulp blend
Deinked
ratio
%
pulp
Kraft pulp %

48.4

MD

1.22

1.12

1.11

Ave.
Ave.

40↑

55 40↑

52 50↑

55

70

51

52

37

65

43

46

67

26

26

22

29

F
W

52↑

53.3 52↑53.2 50↑50.7 52↑52.6

91.9 93↑

94.4

91.8

52.3
52.2
88.9

51.5
51.5
89.3

94.4

56.3
56.1
95.5

51.8
51.9
88.6

51.5

91.4 89↑

51.8
52.0
89.4

54.7

89↑

51.8
51.8
91.6

86.2

53.8
55.4
93.3

53.8
55.4
92.6

54.8
55.2
95.2

54.9
55.2
95.5

0.47

0.52

0.57

0.57

0.55

0.58

0.54

0.56

0.55

0.55

0.57

0.58

57

47

57

25.0

47

39

71

65

65

68

88

63

76

59

70

80

58

60

3.5

3.1

3.2

2.3

3.3

2.9

6.2

11.5

2.7

1.8

5.6

5.1

11.9

12.0

F

84.6

87.5

85.3

91.2

W

83.5

86.1

84.8

90.8

3.0

85-10085-100

83-84

82-84

46-51

38-42

33-47

24-25

70-80

70-80

48-60

48-60

22-34

20-32

15-25

15-25

0
0-15

0
15

0
16-17

16-18

19-59
16-19

17-48
27-28

33-35
23-29

34-42
25-40

18-25
2-4

18-25
2-4

20-33
20-22

20-33
25-27

60-70
6-8

60-70
8-12

65-80
8-10

65-80
4-10

Systematic Survey on Newsprint Production Technologies in Japan73

12 Evolutionary chart and chronological table
Historical development of newsprint production technologies in Japansaving74

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Chronological table of technological developments in newsprint production* Indicates a specific year; Years without asterisks (*) indicate an approximate year.
Year (last two digits only)
Newsprint
Production(10,000 tons)
Basis weight
Brightness

Production followed demand
increase
Increasingly less

50

*16

55

60

65

70

75

*73

*115

*115

*188

*206

2

80

*259
2

49 g/m52 g/mIncreased to improve image appea45% min.

85

90

*270

*358

2

00

*340

*370

2

46 g/m50-52%

Sheet break rate Goal: extreme printing efficiency

95

40g/m255%

43 g/m

1/100 rolls

1/1,000 rolls

during printing
Newspaper
printing
technologies

Lead plate to resin plate
Mechanization
CTS to C to P

Letterpress

Single color printing

Offset press

High speed color offset printing

Typical pulp blend Softwood

Initial innovation
Era of mechanization
Teletype for kanji characters
Automated type picking
Single color, 4 pages a
copy and 80,000 copies
per hour16 pages a copy and 100,000
copies per hour
Color printing started

Second innovation*Introduction of CTS
Lead plate to resin plate

24 pages at major newspaper printers
Color ad started

SP 20%SP 17%KP 3%
CGP 4%
GP 76%SP 15%KP 3%
CGP 10%GP 66%
RCP 6%SP 10%KP 10%
CGP 10%GP 55%RGP 15%

DIP (deinked recycled fiber)
Hardwood

32 pages,
8 in color

40 pages, 16 in color
48 pages, 24 in color

Offset printing gradually comes into use
Tower press*73 offsets out of 1,024 rotary printing presses*294 offsets out of 1,219 rotary printing presses*Offset ratio:35%
Offset ratio:92%

GP 80%

Resource
exploitation

Computer to Plate(Plate preparation directly from computer)*CTS at major newspaper printers

SP 3%
KP 17%KP 10%KP 5%

GP 45%
TMP+RGP 25%
DIP 10%

GP 13%
TMP+RGP 34%
DIP 43%

GP 5%
TMP 20%
DIP 70%GP from red pine
*Chip imports using carriers started
RGP started

Imported chips

TMP in operation

CGP used

End of CGP

DIP KP from SP

DIP started

DIP becomes the main pulp

KP from SP
Improving opacity
Paper machine
Fourdrinier type Wide, high speed*2 A-roll width, 300 ｍ/min.

*21 newsprint machines installed, 43 in total*3 A-roll width*4 A-roll width, 600 m/min

twin-wire type

Auxiliary

twin-wire

Improving productivity andquality

Ca l ci um
ca rbona tea ddedWhite carbon added*5 A-roll width, 800 m/min*Introduction of twin-wire machines*Most newsprint produced by twin-wire machines*4 A-roll width*5 A-roll width, 1,100 m/min

Introduction of BM monitor

Gate roll size press*5 A-roll width, 1,800 m/min.
*9 m wide, 1,700 m/min
Profile control using
consistency adjustment

Systematic Survey on Newsprint Production Technologies in Japan75

Chronological table of core technologies in newsprint production(Data provided by the corporations that developed the technologies)(Excerpts from "Chronological table of technological developments in the Japanese paper industry" by JAPAN TAPPI (May 2004 and June,2005)
Year (last two digits)
Pulping and stock
preparation

55

60

65

70

75

80

85

90

95

00

*Continuous liquid stage digester (Kvaerner)*Super-refiner type 150 (Aikawa Iron Works Co.) for stock preparation*Deluxfiner type 100 (Aikawa Iron Works Co.) for stock preparation*Double disk AW-20 (Aikawa Iron Works Co.) for stock preparation*Topfiner A type (Aikawa Iron Works Co.) for stock preparation*Screen B type 1000 (Aikawa Iron Works Co.) for machine approach*High consistency pulper (Aikawa Iron Works Co.) for DIP preparation*Floatator box type (Aikawa Iron Works Co.) for DIP preparation*Doctor type DST (Aikawa Iron Works Co.)
*Doctor double type (Aikawa Iron Works Co.)
*Poseidon type PPM200 (Aikawa Iron Works Co.) for effluent treatment

Paper machine

Wire, felt and canvas*Newsprint machine (4 A-roll width)(Mitsubishi Heavy Industries)*Newsprint machine (5 A-roll width, 1000m/min.)(Mitsubishi Heavy Industries)*Paper machine for newsprint and telephone directories (Bel-Baie II, converflow head box) (Mitsubishi Heavy Industries)*Duofomer D (paper machine) (IHI Voith Paper)*Duofomer D (paper machine) (IHI Voith Paper)*Gate roll size press (Mitsubishi Heavy Industries)*Symsizer (Sumitomo Heavy Industries)*Penta-nip press (Mitsubishi Heavy Industries)*Controlled crown roll (Mitsubishi Heavy Industries)*Aquato-roll (Honeywell)*Thermato-roll, zoom profiler (Honeywell)*Steam box (Sumitomo Heavy Industries)*Extended-nip press (Mitsubishi Heavy Industries)*Uno-run blow box (Sumitomo Heavy Industries)*Edge flow control (Sumitomo Heavy Industries)*Automated basis weight profile control (IHI Voith Paper)*High dew-point closed hood (Sumitomo Heavy Industries)*Full-automated roll wrapping (Kawanoe Zoki Co.)
*Automatic winder changer (Mitsubishi Heavy Industries)*Vari-roll winder (IHI Voith Paper)*Dryer canvas using synthetic fiber (Shikishima Canvas Co.)
*Plastic canvas (Shikishima Canvas Co.)
*Needle canvas (Shikishima Canvas Co.)
*Full automatic canvas washing (Kawanoe Zoki Co.)*Multi-filament wire (Nippon Filcon Co.)
*Mono-filament double woven wire (Nippon Filcon Co.)
*Seamless felt (Ichikawa Co.)
*Belt for shoe press (Ichikawa Co.)76

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Instrumentation*1936 Automatic control valve (Yamatake Sangyo Systems)*Electromagnetic flowmeter (Yokogawa Electric Corporation)*Electromagnetic flowmeter (Yamatake Sangyo Systems)*Online basis weight monitor (Yokogawa Electric Corporation)*Analog BM monitor (Yokogawa Electric Corporation)*Digital BM monitor (Yokogawa Electric Corporation)*B/M7000XL (Yokogawa Electric Corporation)*Photodiode spot detector (Omron Corporation)*CCD camera spot detector (Omron Corporation)*CCD system streak detector of (Omron Corporation)*Defect imaging system (Omron Corporation)* System 2000(Honeywell)*Decentralized Control System (DCS) (Yokogawa Electric Corporation)*YEWMAC (Production line control system) (Yokogawa Electric Corporation)*Large-scale DCS system (Yokogawa Electric Corporation)*Large-scale DCS system (Yokogawa Electric Corporation)*Fully-automatic cutter sorter (Omron Corporation)

Non-chlorine bleaching agents*Hydrosulfite at Tokyo plant (Mitsubishi Gas Chemical Co.)
*Hydrogen peroxide through self-oxidation at Yokkaichi plant (Mitsubishi Gas Chemical Co.)
*Hydrogen peroxide by self-oxidation at Kashima plant (Mitsubishi Gas Chemical Co.)

Sizing agents

Starches*Cationic polymer as sizing agent for internal surface sizing (Arakawa Chemical Industries)*Rosin-derived emulsion sizing agent for internal sizing (Arakawa Chemical Industries)*Rosin-derived neutral emulsion sizing agent for rinternal sizing (Arakawa
Chemical Industries)*Neutral rosin sizing agent for internal sizing (Harima Chemicals Group)*Cationic starch for internal sizing (Oji Cornstarch Co.)*Starch for surface sizing on newsprint (Oji Cornstarch Co.)
*Polyacrylamide modified by mannch reaction for internal sizing (Harima Chemicals Group)

Deinking agents*Anionic surfactant for deinking (Kao Corporation)*Deinking system using unsaturated-fatty-acid/nonionic detergent, licensed from West Germany (Kao Corporation)*Deinking system using saturated fatty acid/foaming agent, good for floatation (Kao Corporation)*Deinking agent using higher fatty acid with AO addition (nonionic) (Kao Corporation)*Deinking system using fat with AO addition/saturated fatty acid/foaming agent (Kao Corporation)*Deinking agent using refined alcohol with AO addition, standard as of 2005 (Kao Corporation)*Deinking agent for paper recycling (Harima Chemical Industries)

Systematic Survey on Newsprint Production Technologies in Japan77

Chronological table of pulp and paper industry news items
Excerpts from "Chronological table of news in the pulp and paper industry," prepared by JAPAN TAPPI, June, 2004.
Names of Japanese paper companies are given in the Roman alphabet as pronounced rather than in their English names, as some companies no longer
exist and their English names are not available.
Names of companies other than paper companies that no longer exist are given phonetically in the Roman alphabet, not in their English names.
Chips
1949

Pulp
Kanzaki, Kanzaki Seishi: No. 1 grinder. Kofu Pulp:
started GP.

1950
1951

Ishinomaki, Tohoku Pulp: Kamyr drum
barker.
Yatsushiro, Jujo Seishi: multi-blade
chipper.

1954

78

Kitagami Seishi: first chip CGP.

Fushiki, Jujo Seishi, Wood Machinery ring grinder(Canada).
Tomakomai, Tomakomai Seishi: magazine grinder(2,690 kw).
Iwakuni, Sanyo Pulp: Foxboro automatic controller
for digestion.
Akita, Tohoku Pulp: Foxboro automatic controller
for digestion.
Marusan Seishi: first SCP production.
Nihon Seishi: SCP (1,020 t/month).
Fuji, Honshu Seishi: first Kamyr grinder (1,100 kw,
870 kw, 1,120 kw).
Kokura, Jujo Seishi: Kamyr-type double piston ring
grinder (8 units).
Toyo Pulp: refiners instead of beaters.
Kushiro, Jujo Seishi: SP (10 t digesters).

1953

1957

News

Osaka, Osaka Seishi: No. 1 machine(1,880 mm)

1952

1955
1956

Newsprint

Hardwood use increased since 1954
due to softwood shortage: 1.11 million
m³ in 1956, 13% of total consumption.
Test import of pulp wood from USSR,
5,600 m³.

Osaka, Osaka Seishi: paper machine(1,880 mm)

Nihon Seishi: newsprint only with
SCP

Kawanoe, Maruzumi Seishi: paper
machine (1,960 mm)

Tomakomai, Oji Seishi, continuous digester for
SCP by Hitachi Zosen (70 t/day).
Nishinippon Pulp: SCP.
National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Tomakomai, Oji Seishi: 3 A-rollnewsprint machine (5,280 mm).
Sakamoto, Jujo Seishi (3,160 mm).

MITI required a certain amount offorest to be planted for new pulp
capacity. MITI required theChips1958

Increase in use of scrap wood chips

1959

Sharp increase of scrap wood chips (4xprevious year's volume).

1960

1961

1962

1963

Scrap wood chips from Douglas fir

1964

First import of chips from North
America using Toyo Pulp's Kure-maru
chip carrier .Daishowa Seishi's
Daishowa-maru (chip carrier) went into
service.

Pulp
Iwakuni, Sanyo Pulp: SCP (globe digester 33
t/day), using acidic SCP from hardwood fornewsprint.
Nikko, Takasaki Seishi: SCP by continuous KP
process.
Ishinomaki, Tohoku Pulp: magazine grinder (750kw, 15 t/day, No. 1 & 2)
Fuji, Daishowa Seishi: magazine grinder (15 t, No.
6)
Ishinomaki, Tohoku Pulp: magazine grinder (15t/day).
Kanzaki, Kanzaki Seishi: additional SCP.
Mishima, Daio Seishi: new SCP.Kushiro, Jujo
Seishi: CGP (Bauer 40 t/day).
Ishinomaki, Tohoku Pulp: CGP (Bauer 34 t/day).
Ishinomaki, Tohoku Pulp: magazine grinder (15 t).

Newsprint
Mishima, Daio Seishi (3,610 mm,
No. 10).

News
curtailing of some operations.

Ishinomaki, Tohoku Pulp: 3,610 mm.
Kushiro, Jujo Seishi: 3,610 mm.

Edogawa, Honshu Seishi:
problems with Urayasu
fishermen's union regarding SCP
effluent.

Shiraoi, Daishowa Seishi: SCP (75 t), CGP (126 t),
magazine grinder (117 t) for newsprint.
Kushiro, Jujo Seishi: additional CGP (Bauer).
Tomakomai, Oji Seishi: Cold soda CGP (152 t).
Mishima, Daio Seishi: CGP.
Ishinomaki, Tohoku Pulp: magazine grinder (15 t),
CGP (Bauer 6 m³, 40 t/day × 3 units).
Hardwood CGP, 3× volume produced in theprevious year.
Nichinan, Nippon Pulp: conversion to KP.
Fushiki, Jujo Seishi: bleach plant (80 t).
Yatsushiro, Jujo Seishi: CGP (Sprout-Waldron 67
t/day).
Nakatsugawa, Chuo Itagami: SCP.
Yatsushiro, Jujo Seishi: 2-stage SP. Number ofmills using 2-stage SP increasing

Kushiro, Jujo Seishi: No. 6 (4 A-rollmachine, 6,960 mm).
Ishinomaki, Tohoku Pulp (5,280mm), Tomakomai, Oji Seishi (5,280mm).
Shiraoi, Daishowa Seishi (5,400mm).

Fushiki, Jujo Seishi, RGP (DDR 600 kw × 2 units),
first in Japan. RGP installations continued.
Tomakomai, Oji Seishi, RGP (117 t/day), cold soda
CGP (146 t/day).
Ishinomaki, Tohoku Pulp, new SP for newsprint
from Japanese cedar.

Tomakomai, Oji Seishi, N-1 machine(6,960 mm)

Asahikawa, Kokusaku Pulp (6,960
mm).
Kawanoe, Maruzumi Seishi:
newsprint (3,700 mm).

Capacity: paper 22,261 t/day,
pulp 17,537 t/day. Production:
paper 6.38 million t/year, pulp
4.577 million t/year (data for June
1993).

Systematic Survey on Newsprint Production Technologies in Japan

79

1965

Chips
Daishowa Seishi chip carrier docked at
Shimizu Port.

1966

1967

1968

1969

Chip carriers into service: Tokai Pulp,
Honshu Seishi, Daio Seishi, Maruzumi
Seishi.
Chip carriers into service: Oji Seishi,
Jujo Seishi, Sanyo Pulp

Kojin: mangrove chip production at
Sarawak. Tokai Pulp: imported chips
from New Zealand. Use of old-growth
eucalyptus.

1970

1971

80

Pulp
Fuji, Daishowa Seishi: RGP (84 t/day).
Kushiro, Jujo Seishi: CGP (Asplund 160 t/day).
Niigata, Hokuetsu Seishi: BGP (66 t/day).
Kanzaki Seishi: conversion from Ca-SP to Na-SP.
Kushiro, Jujo Seishi: CGP (Asplund continuous
digester).
Hachinohe, Mitsubishi Seishi, CGP (Asplundcontinuous 615 m³, 55 t/day).
Headquarters, Koyo Seishi, DIP plant.
Shiraoi, Daishowa Seishi, CGP (Asplund 156
t/day).
Kushiro, Jujo Seishi: magnefite process.
RGP: Kushiro, Jujo Seishi (170 t/day), Tomakomai,
Oji Seishi (59 t/day), Fushiki, Jujo Seishi (45t/day).
SCP: Okayama Seishi.
CGP: Yoshinaga, Daishowa Seishi (150 t/day),Tomakomai, Oji Seishi (120 t/day)Mishima, Daio Seishi: CGP (Asplund).
Kawanoe, Maruzumi Seishi: RGP (120 t/day,Verti-finer).
Ishinomaki, Jujo Seishi: CGP (150 t/day, Asplund).

Tomakomai, Oji Seishi: RGP (448 t/month).
Fushiki, Jujo Seishi: additional RGP (90 t/day).

Ishinomaki, Jujo Seishi: chip imports
from Tasmania using 2 carriers. Sanyo
Pulp: expansion of Iwakuni harbor
facilities (berths for 40,000 ton chip
carriers). Agreement on chips between
Japan and USSR (for development inSiberia). Honshu Seishi: JANT PTY

Kokusaku Pulp, Oji Seishi and Carter (New
Zealand): RGP and lumber.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Newsprint
New newsprint machines: Fuji,
Daishowa Seishi: 3,710 mm,
Kushiro, Jujo Seishi No. 7 (6,960
mm).

News

Tomakomai, Oji Seishi: N-2 machine(6,960 mm)

Futatsuka, Tonami Seishi: No. 2(3,710 mm).
Mishima, Daio Seishi: No. 15 (3,610
mm).
Yoshinaga, Daishowa Seishi:
Verti-former (3,700 mm), first inJapan.
Iwanuma, Daishowa Seishi (86,900mm), widest in Japan.
Tomakomai, Oji Seishi: N3 (5 A-roll,
8,640 mm), largest newsprint-onlymill in the world.
Mishima, Daio Seishi: No. 16 (3,610mm).
Osaka Seishi: No. 5 (3,610 mm).
Kawanoe, Maruzumi Seishi (3,700mm).

Third liberalization of capital in
pulp and paper manufacturing.
Edogawa, Honshu Seishi: SCP
shutdown. Fuji, Honshu Seishi:
clarifier (31 m) × 2 units.

Water Pollution Control Act
enforced nationwide (daily
average: COD and BOD 120 ppm
each, SS 150 ppm. Max.: 160
ppm each and 200 ppm).

Chipsfor New Guinea development.
1972

1973

Rapid increase in chip carriers (20carriers in the 35–50,000-ton classscheduled). Medium-sized paper
companies become interested inoverseas resources.

Pulp

Newsprint

Tomakomai, Oji Seishi: CGP (Asplund 270 t/day),
RGP (168 t/day).
Ishinomaki, Jujo Seishi: DIP (30 t/day)
Recycled paper centers established in Tokyo andOsaka. 13 companies in Kansai established astockpile company for waste paper. MITI studied
paper recycling systems. Demand for waste paperin 1973: 5.9 million tons (10.8% increase, recovery
rate: 38.8%). MITI organized a study group for
dissolved pulp demand. MITI proposed a center forrecycling paper and paper products.

Tomakomai, Oji Seishi: N4 (8,690mm).
Mishima, Daio Seishi: N3 (8,600
mm)

News

Dispute over sludge pollution in
Iyo-Mishima; 13 mills ordered to
improve. Third sludge treatment
in Tagono-ura. Agreement on
pollution prevention among
Yamaguchi Prefecture, Iwakuni
City, Sanyo-Kokusaku Pulp and
Nihon Shigyo. Daio Seishi:
agreement on pollution
prevention with local district.
Toyo Pulp: agreement on
numerical-based odor pollution
prevention. Tomioka, Kanzaki
Seishi: introduction of pollution
fund system. Kitakami River:designated as water quality
standards classification. 57 millsin Fuji district converted fromheavy oil to city gas. Wakayama
Prefecture implemented severest
add-on regulations. Suzukawa,
Daishowa Seishi: work on
preventing KP stenches (350
million yen). 6 mills in Ehime
Prefecture ordered to stop
operation. 17 mills in Shizuoka
Prefecture ordered to stop
operation. Hachinohe, Mitsubishi
Seishi: PDP series for white water
recovery.

Systematic Survey on Newsprint Production Technologies in Japan

81

1974

1975

82

Chips
Toho Wara Pulp imported straw from
Korea and Taiwan. Marubeni,
Daishowa Seishi, Sanyo-Kokusaku
Pulp: started study on resources inChile. Honshu Seishi: chip productionin New Guinea (150,000 m³/year). Fivecompanies (Jujo, Kojin, etc.): chips
from mangroves. Chip carriers now
number 51 ships.

Pulp
Oji and Jujo: policy to introduce TMP.

Excessive chip imports from the U.S.
caused problems in Japan.

Kushiro, Jujo Seishi: started TMP. Fuji, Honshu
Seishi: DIP plant (30 t/day) to replace LBKP.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

Newsprint
Iwanuma, Daishowa Seishi:
Duo-former started. Honshu Seishi
ordered drive system using Thyrista
from Toshiba (high precision andlong life). Kushiro, Jujo Seishi and
Shiraoi, Daishowa Seishi: returned to
coal.

News
Investment in the paper industry
in 1974: 251.5 billion yen (28.6%
of which was for pollution
control). Kushiro, Honshu Seishi;
strict agreement with Kushiro
City (Sox, soot and dust andeffluent). Iwakuni,
Sanyo-Kokusaku Pulp: pilot plant
for treating bleach plant effluent(300 t/day). A cooperative in
Ehime Prefecture tried toincinerate sludge incineration andproduce active charcoal.
Standards for sulfur oxides
became severer. Ehime
Prefecture: snap inspection of 80
mills. Kasugai, Oji Seishi: facility
for recycling water (BOD 70ppm). Ishinomaki, Jujo Seishi:
No. 4 Clarifier (diameter: 106 m).
Kawanoe, Iyo-Mishima andTakaoka, Fuji had their own joint
incinerators for PS. 73% ofeffluent in the paper industry
treated with coagulation system(MITI data).
15 companies in Fuji city:
cooperative union for solidifying
PS. Completion of Fujinomiya,
Fuji Film Co., flue-gas
desulfurization equipment. 8
levels for Sox in flue gas. Planned
investment for pollution control in
1975: 63.3 billion yen (30.6% of
the total investment). Revision of
Air Pollution Control Act.
Okayama Seishi started full-scale
operation of treating paper sludge
with earthworms. Daido Sanso
industrialized pure oxygen
aeration process.

1976

Chips
Chip Carrier Issues Committee
launched (13 companies, 65 ships).

Pulp
Major paper companies interested in wastepaper.
Settsu Itagami: hot dispersion system from
Kobayashi Engineering Works.

1977

1978

Dramatic increase in ratio of DIP in newsprint(64,000 tons/month).

Newsprint
Jujo Seishi and Weyerhaeuser (U.S.):
joint venture for newsprint
production (210,000 tons/year), 50%
of production imported into Japan.
Iwanuma, Daishowa Seishi: moved tolower basis weight (from 53 g/m² to
49 g/m²).Kushiro, Jujo Seishi: B/M
CENTUM from Yokogawa Electric
Corporation (overall control systemof paper machine)

Paper companies testing lower basis
weight.
Kushiro, Jujo Seishi: No. 8, Bel-Baie
II (324 t/day).
Mishima, Daio Seishi: N-4.
Light basis weight newsprint rapidly
increased share (41.7% in Sept.).
Mishima, Daio Seishi: computer
control of in-house power plant.

1979
1980

1981

Aikawa Iron Works: introduced DIP technology
from Rameau (France) and Feldmühle (Germany).
Waste paper recovery rate: 46.2% (highest ever).

Tomakomai, Oji Seishi: N-5 (8,950
mm, Bel-Baie, 530 t/day).
46 g/m² newsprint: 93%/46 g/m²
newsprint undergoing R&D.
Yokogawa Electric Corporation:"B/M 80" BM monitor.

News
Clean Japan Center makes
progress. Cooperative of pulp
companies in Ehime finishedactivated sludge plant. Mishima,
Daio Seishi/Nichinan, Nihon
Pulp: finished work for odor
control. Pulp sludge in
Tagono-ura increased by 200,000
m³ in a year. 2 million m³ of pulp
sludge on the seabed at
Iyo-Mishima. Otake Shigyo:
agreement with Hiroshima
Prefecture on pollution
prevention. Mishima, Daio Seishi:
facilities for pollution control.
Fushiki, Jujo Seishi: equipment
for flue-gas desulfurization (thefourth in the company).
Kure, Toyo Pulp installed
activated sludge facility (11,000
m³/day).

Takahagi, Nippon Kako Seishi:
cleared the prefecture's additional
regulations of 20 ppm BOD byusing an activated sludge process.
Investment for pollution
prevention over the 6 years from1972 was 183.3 billion yen,passing its previous peak.
1.46 million tons of pulp sludge
in Tagono-ura treated since 1972.
Hachinohe, Mitsubishi Seishi:
duct-type gas holder for odor
control.
Sludge problem in Tagono-ura
cleared up (6.8 billion yen, 1.82
million tons).

Systematic Survey on Newsprint Production Technologies in Japan

83

Pulp
Toyo Pulp: additional DIP (15,000 tons/month).

Newsprint
Sanshu Seishi: smallest Bel-Baie
former in the world (70 t/day).
Tomakomai, Oji Seishi: N-2
converted to twin-wire. 46 g/m²
newsprint share reached 42%,
re-named to "lightweight" from oldname of "super-lightweight."
White carbon output: 2,000 t/month.

1984

Mishima, Daio Seishi: doubled CTMP capacity.

Oji Seishi: on-site manufacturing ofwhite carbon. Light weight grade up
to 55%. Mishima, Daio Seishi: N5(300 t/day). Mishima, Daio Seishi
finished the first stage of mill-wide
computer control of production.

1985

Waste paper recovery: 9.63 million tons, recovery
rate: 50.5%, 93.4% for newspaper in particular.
Tomakomai, Oji Seishi: DIP 750 t/day in total, 30%
of its pulp consumption.

1982

1983

1986

1987

84

Chips
Chip manufacturers decreased (downby 1,600 in a year from 6,305 mills).

Reconsideration of domestic chip
supply (chip carriers down to 48 from69 in 1976).

Nagoya Pulp: new chip yard in Handa
city for Australian eucalyptus.
Tomakomai, Oji Seishi: new PGW.

Tomakomai, Oji Seishi started PGW.

Mishima, Daio Seishi: 207 m tallchimney. Kushiro, Jujo Seishi:
powdered coal boiler.

Mishima (new), Daio Seishi: additional PGW.

Mishima (new), Daio Seishi:
Duo-former F (newsprint total:
60,000 tons/month). Iwanuma,
Daishowa Seishi: converted No. 3 to
Bel-Baie. Kushiro, Honshu Seishi:
converted to newsprint from liner
board in No. 2 machine. Ishinomaki,
Jujo Seishi: powdered coal boiler andturbine, and roofed coal yard (13.4
billion yen).

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

News

Mihara, Mitsubishi Heavy
Industries: pilot paper machine(500 mm, 1200 m/min).
Mitsubishi Seishi opened R&D
centerDaishowa Seishi started
manufacturing BCTMP (250t/day) for its Iwanuma mill at
Quesnel River Pulp Co. (joint
venture with Daishowa), andacquired Port Angeles (U.S.) for
80 million dollars.

1988

Chips
15 paper companies founded a joint
venture company with for developing
eucalyptus in Thailand. Daio Seishi:chip carrier (35,700 t).

Mishima, Daio Seishi: PGW (4,400 kw × 2
units).Mishima, Daio Seishi: DIP (6,000 t/month,
Voith), bleached to high brightness.

1989

Data not available from 1990 to 1992.
1993 Oji Seishi: chips from South Africa
and Brazil.

1994

1995

1996

1997

Pulp
Yoshinaga, Daishowa Seishi: DIP (100 t/day) for
newsprint.

Tomakomai, Oji Seishi: additional TMP and newhydrogen peroxide bleaching. Kasugai, Oji Seishi
used thiourea dioxide for bleaching.
Mitsubishi Gas Chemical Co. marketed in-houseproduction system for thiourea dioxide.

Nippon Seishi and Mitsui & Co.:large-scale plantation forest inAustralia. Mitsubishi Seishi and
Mitsubishi Corporation: joint
plantation venture in Tasmania.
Daio Seishi and Kawatetsu Shoji:
plantation in Tasmania.

Nippon Seishi and Mitsui & Co.:
eucalyptus plantation in Australia(10,000 ha, 100,000 GDT/year).
Chuetsu Pulp, Hokuetsu Seishi,
Maruzumi Seishi and Marubeni

Newsprint
Tomakomai, Oji Seishi: large-scale
modification to No. 11, newsprint
capacity increased to 1,500 t/day.
Futatsuka, Chuetsu Pulp: No. 3 (400t/day). Maruzumi Seishi: Bel-Baie III(600 t/day). Mishima, Daio Seishi
completed N-7 machine.
Mishima, Daio Seishi: N6 (5,730
mm, 1,400 m/min). Oji Seishi
planned Howe Sound (newsprint,
200,000 tons/year, starting 1991).
Iwanuma, Daishowa Seishi, will
finish No. 4 (9,000 mm, 1,500m/min, Bel-Baie III) in 2001.
HSPP (joint venture with Oji Seishi)
produced newsprint at 43 g/m²
(super-lightweight) with gate rollcoating.
Iwanuma, Daishowa Seishi: gate rollcoater on No. 4 machine. Kawanoe,
Daio Seishi: gate roll coater on No. 2
machine.

News

Daishowa Seishi: joint venture fornewsprint in UK with Reed Pack.
Nippon Keizai Shimbun
promoted lowered basis weightnewsprint (from 46 g/m² to 43g/m²) to publish at 40 pages a
copy.
Nippon Seishi, Honshu Seishi,
Mitsubishi Seishi, Nihon Shigyo
and Daishowa Seishi establishedtheir environmental charters.
Hokuetsu Seishi licensed
production technology toThailand Paper (Siam Cement
Group).Nippon Seishi guided
operation work at Barito Pacificpulp mill (Indonesia).

Fuji, Daishowa Seishi: gate rollcoater on No. 11 machine (3,255 mm,
168.3 t/day).

Fuji, Daishowa Seishi: DIP (200 t/day). Futatsuka,
Chuetsu Pulp: DIP (50 t/day, started in September).

Yatsushiro, Nippon Seishi: newsprint
machine (240,000 tons/year,
scheduled to start in 1998). Daio
Seishi: new mill for paperboard andnewsprint in Iwaki, Fukushima
Prefecture (scheduled to start in late1997).
Tomakomai, Oji Seishi ordered apaper machine (9,150 mm, 1,800m/min.) from Mitsubishi Heavy
Industries, scheduled to start Oct.
1998. Iwaki, Daio Seishi: ordered a

Chuetsu Pulp supported
state-owned paper mill in
Vietnam. Daio Seishi trained 8
staff from Vietnam's largest
newsprint maker.

Japan Paper Association
formulated a voluntary action
plan on environment and a
voluntary management plan on
toxic air pollutants.

Systematic Survey on Newsprint Production Technologies in Japan

85

1998

1999

2000

86

Chips
Corporation: plantation in New
Zealand (acacia, 400 ha, expected to
expand to 10,000 ha in the future).
Paper companies enlarged theirplantations. Oji Seishi, C. Itoh,
Dengenkaihatsu and Kodansha:
plantation in Australia (10,000 ha 10
years later).

Daio Seishi enlarged plantation in
Chile (to 100,000 ha from 64,000 ha).
Ratio of chips from plantation
increased to estimated 30% of
softwood chips and 50% of hardwood
chips.

Pulp

Newsprint
paper machine (12,000 tons/year,
using only DIP).

Iwaki, Daio Seishi: DIP (300 t/day).
Nippon Seishi: expansion of DIP to 2,700 t/day(increased by 700 t/day).
Nichinan, Oji Seishi: DIP for printing paper (270t/day).

Iwaki, Daio Seishi: newsprint
machine in operation (12,000
tons/year using only DIP).

Nomachi, Chuetsu Pulp: DIP (100 t/day). Fuji,
Daishowa Seishi: DIP (200 t/day).

Mishima, Daio Seishi started N5(Duo-former, 5,210 mm, 380 t/day).

In 1997, 96 DIP facilities, 4.039 million tons.

National Museum of Nature and Science: Survey Reports on the Systemization of Technologies Vol.10 (March 2008)

News

Mitsubishi Heavy Industries
developed 2,000 m/min.
newsprint machine. World's
largest paper company formed
from a merger between Enso
(Finland) and Stora (Sweden): 13
million tons/year.

Nippon Keizai Shimbun used
ultra-super-light basis weight (40g/m²). Ratio of super-lightweightin Jan.: 94.8%.

List of Candidates for Registration as Newsprint Manufacturing Technology
No.

Name

1

Fourdrinier-type
paper machine

2

World’s firstcontinuous
paper machine

3Type ofarticleModel

Location

AddressYear

Comment

Paper
Museum1-1-3, Oji, Kita-ku,
Tokyo

1960

Model

Paper
Museum1-1-3, Oji, Kita-ku,
Tokyo

1955

CylinderYankeetype paper
machineKamyr-type
continuous
digester

Model

Paper
Museum1-1-3, Oji, Kita-ku,
Tokyo

1952

A model of the newsprint
machine installed in 1960 as
the No. 6 machine in theKushiro Mill, Jujo Seishi. At
the time, this was one of themost advanced in the world.
1:30 scale (36 × 352 × 25 cm)
A model of the firstcontinuous paper machine,
invented by Louis Robert in1798 1:2 scale (70 × 111 ×
77 cm)A model of a cylinder Yankee
paper machine 1:10 scale (60× 106 × 75 cm)

Model

Paper
Museum1-1-3, Oji, Kita-ku,
Tokyo

1974

5

Equipment
drawings

Actualitem

2-1-1 Oji-machi,
Tomakomai,
Hokkaido

1963-6

Equipment
drawings

Actualitem

Tomakomai
Mill, Oji
Paper Co.
Ltd.
KasugaiMill, Oji
Paper Co.
Ltd.

1, Oji-cho,Kasugai, Aichi

1953-

7

Qualityspecifications

Actualitem

AsahikawaMill,
NipponPaper
Industries
Co. Ltd.

505-1, Parupu-cho,Asahikawa,
Hokkaido

1973-

8
9

(Deleted from original paper due to inaccuracy)
Product sample
ActualKishu Mill, 182, Udono,
book
item
Kishu
Kiho-machi,
Seishi Co.
Minami-muro, Mie
Ltd.

4

1980-

A model of the Kamyr
continuous digester installedin the Kushiro Mill, Honshu
Seishi, in 1974. Created forthe construction work. 1:25
scale (67 × 140 × 167 cm)
Equipment drawings and flow
diagrams of pulping facilities
and paper machines datingback to 1963.
The drawings and layouts ofevery item of equipment
installed in the mill since
1953, when the mill started
operation. They are stored inledgers as well as in digitalform. Total: 40,000 items.
Quality specifications on
production control, quality
control and unit requirements.
These were used as thecompany standards since its
inception as Sanyo-Kokusaku
Pulp. Those from 1973 to2005 are stored as paper
media, while those from 2005
are stored as digital files.
Product sample books forcolored fine paper dating backto 1980.