Paper Technology JournalInterview:
World record in Braviken.
A special event:
Hosting the european paperindustry.
News from the Divisions:“Pole position” for Voith Sulzer
shoe presses.

4

Corporate News:
Joint Venture in China –Liaoyang.
Newspaper hoaxes:
The ingenuity of journalists.

Contents

Foreword

1

Interview:
World record in Braviken

2

A special event:
Hosting the european paperindustry

10

News from the Divisions
Stock Preparation: Screening –a tool for stickies removal

22

Stock Preparation:
Stickies removal in flotation

30

Paper Machinery: “Pole position”
for Voith Sulzer shoe presses

34

Paper Machinery: Web and tailtransfer systems in board andpackaging paper machines41

Finishing: Janus – a new technology
for old calenders?

49

Finishing: Calender rebuild to Janus –economical aspects
56
Service:
Potential in Europe

61

Corporate News
China: Joint venture in China –Liaoyang

66

Great Britain:
A new home for Nipco

70

USA: Voith Sulzer Paper Technology –rooted in the history of North American
papermaking
72
Newspaper Hoaxes:
The ingenuity of journalists

Cover picture:
Janus calender rolls (see page 49).

78

1

Dear customers, dear readers!

Hans Müller,
President and CEO,Voith Sulzer Papiertechnik GmbH & Co. KG

Paper and board are and remain important communication media, in spiteof all the diverse electronic media available. The demand for paper andboard is increasing annually at a rate of 2.3 to 2.5 percent and all theleading experts are of the opinion that this trend will continue well into
the 21st century. One region in particular exhibits a double-digit rate of
growth compared with the rest of the world: Asia, with its expanding
economy. This development is confirmed both by the excellent overall
order situation for Voith Sulzer Paper Technology’s third business year
and also in our specific deliveries to the Asiatic region. Compared to ourcompany’s first two years of business, in which the proportion of orders
from the Asiatic region was approximately 20 percent, we expect a
distinct increase for the current year.
Not surprisingly it is the innovative, forward-looking companies andregions in which our products and services are most successful.
Wherever there is progress, leading-edge technology is at the forefront.
The most recent example is the PM 53’s world record in Braviken with
1672 m/min or more than 100 km/h in continuous operation – a successwhich points the way forward. For more information, please read thereport on the following pages.
In the light of an increasingly global market it is quite clear just how
important it is to improve the level of cooperation and to arrive at evenbetter technological solutions and efficiency; this was confirmed during
the first customer congress of our Stock Preparation Division in Ravensburg (see page 10). Only by working together with our customers andthrough the exchange of concepts, ideas and visions will it be possible tocreate meaningful and practical improvements. We hope that you will findmany points of interest in our latest twogether customer magazine tofurther this dialogue.

Yours sincerely,

Hans Müller

2

Olle Svensson and Per Bjurbom(bottom): “We have invested in theright technology. PM 53 is quite simply
a very, very good paper machine.”WORLD RECIN BRAVI

3

ORD
KEN

With this “mile-a-minute”
newsprint machine inBraviken, Voith Sulzer has
set a world record yet
again: in February 1997,
the machine operated at amean speed of 1672 m/min– more than 100 km/h –for more than 24 hours.
Peak speeds reached1703 m/min.

4

MN: Why did

To start with we managed this growth

MN: What kind of raw materials do you

you make thiswithout investing in new machinery, untiluse?

large investment

at the beginning of the nineties our stan-in Braviken?

dard newsprint capacity was not enough

OS: Currently we are using a mixture of

to meet demand. Our decision for the new

40% DIP and 60% TMP on PM 53. 40% ofdays

PM 53 then not only gave us additional

the waste paper furnish comes fromwe have to offer

capacity of 300,000 tpa, but also allowed

Sweden, and the rest from Norway,

our customers afurther developments toward improved

Germany and Britain.

wide

newsprint production.

OS: These

Marion Nager,
Corporate Marketing,interviewed Braviken
Mill Manager Olle
Svensson and PM 53
Production Manager
Per Bjurbom.

varietyofpaper grades. Let

Naturally our final target was also higher

MN: What paper grades do youme tell you some-profitability through economies of scale

manufacture on PM 53, and how flexible

thingwith larger production facilities.

is your production programme?

about

the

background:
OS: We think our PM 53 gives us theHolmen Paper has
always been a big

MN: What was the order of magnitude ofgreatest possible flexibility – we can makenewsprint produc-

this investment?

a whole range of different newsprint type
grades.

er. In recent years we have been very successful in upgrading to improved news-

OS: Total investment for the entire pro-

We started off of course with standard

print qualities, mainly in our Hallsta mill,

duction plant amounted to 2040 billion

newsprint paper at 45 g/m 2 , but it has

particularly with regard to brightness.

SEK. This included a complete paper

become very clear already that PM 53 is

Apart from this, our output of newsprint

machine, two winders, a wrapping line,

also an excellent machine for the lower

and telephone book paper has steadilyextension of our stock preparation with abasis weights now in growing demand on

grown. Today are Europe’s biggest pro-second deinking line, and a new TMP pro-

European markets. We have already pro-

ducer of telephone book paper.

duction line.

duced 40 g/m 2 and 42 g/m 2 grades suc-Interview

5

MN: What made you choose Voith Sulzer

Technical data of PM 53
Wire width

9650 mmCut web width

8950 mm

Rated operating speed

1800 m/min

Basis weight range

40-48,8 g/m 2

Capacity

986 t/24 hPaper Technology for your project?
OS: With PM 51 and PM 52, we have ofcourse already had two large and highly
efficient Voith machines in Braviken. So in
1988 we started discussions with Voith on
new technology to keep us competitive

Features
GapJet 2
Headbox with ModuleJet 2

well past the turn of the millennium.

DuoFormer 2 CFD
Gap-Former with JetCleaner

What we wanted was a paper machine

Duo-Centri 2 press section with NipcoFlex shoe press, blind-drilled QualiFlex press
sleeves and DuoSteam blow box

cy while keeping operating costs as low as

Single-tier dryer section with DuoStabilizers and DuoCleaner dryer fabric cleaning

papermaking system on the market; aSoft calenders: (2 x 1 nip) with Nipcorect rollspress section comprising only 3 nips, with

Pope reel with Center Wind

no open draw and high dryness, a com-

2 DuoRollers

pletely closed web run through the entire

with highest possible production efficienpossible. And we also wanted the bestdryer section, and a soft calender.
cessfully, and are currently considering

allows line forces up to 380 kN and tem-making even thinner grades down toperatures up to 200°C. We still have to

We soon came to the conclusion that a

34 g/m 2 . With the soft calender on PM 53

prove this in practice, however. The

DuoFormer CFD would be the best solu-

we shall also be in the position to produce

degree of flexibility of course also de-tion. In the press section nowever there

rotogravure printing papers, because it

pends on variations in furnish qualities.

seemed to be only one way of reaching

10

HOSTING THE EUROP

Hans Müller, Chief Executive Officer of Voith Sulzer Paper Technology(photo left), welcomed the guests on the first evening. Karl Turobin-Ort,
Vice President Stock Preparation Systems, Dr. Lothar Pfalzer, Head of theVoith Sulzer Stock Preparation Division, and Herbert Holik (picture above,from left to right), opened the programme of specialist papers.

11

EAN PAPER INDUSTRYThe Stock Preparation Division had sentout invitations and some 250 experts
from 15 European countries attended thefirst Customer Conference to be held by
Voith Sulzer Paper Technology since thecompanies merged in this business area.
The conference took place under a radiantblue sky and at spring temperaturesin Friedrichshafen on Lake Constance,
Germany.16 reports on the general topic of“Preparation of Waste Paper as a Valuable
Secondary Raw Material for New Papers
in a Wide Range of Qualities” were thehighlights of this event.

12

Dr. Lothar Pfalzer (right) presented the structure(Fig. 1) of Voith Sulzer Paper Technology, withparticular reference to the Stock Preparation
Division and its COC (Centre of Competence)in Ravensburg.

In his address of welcome at the start of theconference programme,
Dr. Lothar Pfalzer, Headof the Voith Sulzer Stock
Preparation
Division,drew attention to thelong-standing and traditional
links
betweenRavensburg
andthepaper industry, as one ofthe oldest papermaking
centres in Europe with ahistory dating back 600
years. He laid emphasison the fact that, since themerger of the Voith andSulzer Paper Technology
operations, many of thesynergy objectives havealready been attained.
The highly satisfactory
progress of business
confirmed the decision tomerge the two
tradi-

VOITH SULZER PAPER TECHNOLOGY
H. Müller
Dr. L. Pfalzer

Dr. H. Jung

Dr. H.P. Sollinger Prof. Dr. F. Silbermayr Dr. D. Kurth

Stock
Preparation

Paper Machines
Graphic Papers

COC

B+G

meri

Ravensburg

Euskirchen

MunichPaper Machines
Board and Pack.

Vaassen Tolosa
NL

Spain

Finishing

R. Hall
Service

Schio Appleton Mansfield

Sao
Paulo

Tokyo

Italy

Brazil

Japan

USA

USA

1

tional companies.
“We wish to thank you here and now forremaining loyal customers in this merger
period, despite the problems encountered. Your confidence is both an encouragement and an obligation for us. Our
combined resources now offer you a wide
range of benefits. For instance, with themerger we have combined both researchexpenditures with no cutting corners”.

A special event

13

Welcome relaxation after the concentrated
presentation of technical information was

Where does the young company stand
today with its extensive experience inthe field of stock preparation? The first
customer conference brought a convincing answer to this question. Dr.
Pfalzer began by presenting the structure of the company with particularemphasis on stock preparation (Fig. 1).
Stock preparation is one of the fivedivisions of Voith Sulzer Paper Tech-

nology. Management of the various facilities with their independent business units
for stock preparation in Europe, Americaand Asia is now controlled from Ravensburg, the headquarters of Voith Sulzer
Stoffaufbereitung GmbH & Co. KG.
Research and development, patents andlicencing as well as marketing functions,serving all the divisional sites, are also
centralized in Ravensburg for all worldwide operations. The special structure of

14

Fig. 2:
From woodyard to packaging the finished paper,
Voith Sulzer Paper Technology supplies
everything from a single source.

Clothing

Paper machine

Slitting

Wrapping,
Transportation,
Storage

Approach flow

Supercalendering
Soft calendering

Waste paper preparation

Stock preparation

2

Air
technology
Coating

Chemical pulp preparation

Coating
Calendering
Winding

Pulp mill

CTMP, TMP
Mechanical pulp

Woodyard

Single source supply

Paper finishing

Voith Sulzer Stock Preparation

Voith Sulzer Paper Machines

Andritz Actiengesellschaft

Voith Sulzer Finishing

B+G FördertechnikAppleton Mills

meri Entsorgungstechnik

the division – concentration on the one
hand and global diversification and presence on the other – ensures that customers can find a qualified Voith Sulzer
discussion partner anywhere in theworld, whether for complete plants orindividual machines. Fast and expert service assistance is readily available. Afterall “stock preparation is the foundation of
successful papermaking”.

Sales and nearness to customers
Under this heading, Karl Turobin-Ort
went on to discuss the worldwide growthof paper production from the present figure of 280 million tons per year to
around 450 million tons by the year
2010. He made it clear that this growth
will be unevenly distributed; in the immediate future, it will be concentrated
primarily on Asia where massive investments are being made in high technology
machinery. Asia is now advancing tobecome a major power on the world
paper market. From the European angle,
it is important to follow carefully the
influence of this Asian pressure on the

global structure of our industry and on
the familiar cycles in our industrial development. With its worldwide market presence and familiarity with the global paperindustry, Voith Sulzer Paper Technology
offers its European customers an intensive dialogue over their investments,from initial talks to final implementation.
Apart from know-how, Voith Sulzer Paper
Technology with its partners is able todeliver “everything from a single source”,
not just in stock preparation but also
from “the woodyard right through topackaging the finished paper”. We believe
this will prove to be a particularly valuable asset (Fig. 2). Quoting the example
of Voith Sulzer’s six European contact
partners in Sweden, France, the Netherlands, Great Britain and Spain, together
with the service and spare parts centres,
Karl Turobin-Ort explained what the division understands today by nearness to its
customers.

How does our service function?
This question was answered by Werner
Brettschneider who conceded that not all

customer expectations had been satisfied in
the accustomed manner in the recent past –due to the merger of the Voith and Sulzer
Stock Preparation Divisions to form a single
division at the Ravensburg facility. 20 tonsof documents and 180,000 drawings had tobe moved, to say nothing of production
machinery and stocks of spare parts. This
phase is now behind us. “The new Voith
Sulzer service can be put to the test”.
Service to customers comprises telephoneadvice around the clock, fast on-site intervention, short delivery periods because supplies of many wear parts and spares are heldA special event

15

Fig. 3:“The new Voith Sulzer Service can be put to thetest”.
We Keep Your Production Plant Going:
Advice / customer service
Stockholding

Ser v

ice

Parts manufacture and repair

Express workshop

Custom-tailored service contract3

Just-in-time
delivery contract

in stock and the newly fitted-out express
manufacturing facility for emergencies.
A hot line has been set up to answer
particularly urgent problems. In addition,
tailored solutions can be offered tocustomers to safeguard production efficiency, for instance, call-off and maintenance contracts or special rebates(Fig. 3). In the service area, nearness
to customers is the aim, too. In Europe
and beyond its borders a dense networkof own companies, representations,licensees and group companies has
been set up.
The two-day event was rounded off by a visit to
the recently extended Research and Technology
Centre in Ravensburg with a comprehensive
exhibition of state-of-the-art system components,
particularly for waste paper preparation.

16

The situation is somewhat better with themeasurement of macrostickies. Admittedly, no generally acknowledged measuring
technique exists as yet, so that statements on absolute values and degrees of
efficiency must first be examined todetermine how they are arrived at.
However, Voith Sulzer Stock Preparation
now offers an improved measuringmethod representing real progress in

Newsprint Concept Utilizing 100% Waste Paper

Stickies relevant process stages: Loop 1: MC-Screening
Flotation I
Cleaning
Fine screening✓

QUALITY

Paper machine

LC-Screening // 0,35Disc filter

Flotation II

Bleaching, ox.

Disc filter
HC-Press

Dispersion

HW-Cleaner

PM-Loop

Loop II
LC-Screening //0,15

HW-Cleaner

Flotation I

Pulping system

Loop IMC Screening ø1,2

The following is a summary by Herbert
Holik of all the technical papers
presented during the Stock Preparation
Division’s Customer Conference.
On request, the full text of the contributions with all illustrations isavailable directly from Voith Sulzer
Stoffaufbereitung GmbH & Co. KG,
Ravensburg.

the measured values. Holik highlighted
the existing difficulties. No method is yet
in view for quantitative measurement of
microstickies.

Protector system

Stock cleanliness – an important
objective in stock preparation
With this presentation, Herbert Holik,
Head of Voith Sulzer Stock Preparation
Research and Development, opened theseries of technical papers. Stickies andthe optical impression are important criteria today in terms of product quality
and efficiency for papermakers of bothwhite and brown grades. The more exacting requirements placed on cleanlinessnot only demand more complex processing systems but also equally exacting
measuring technology – for instance toensure adequate statistical reliability of

✓✓✓
✓✓✓✓
✓
✓ ✓ ✓ ✓✓ ✓ ✓Loop 2: Dispersion
Flotation II✓ ✓ ✓ ✓✓ ✓✓ ✓ ✓ ✓✓

PM
Loop:

✓
✓

Cleaning
Screening“Stickies – a challenge for the entire process
technology”, was the title chosen by Michael
Schwarz for his presentation.
He began with the wide range of substances
found in the papermaking process. As a function of the different particle sizes, he explained
the corresponding technical processes by which
undesirable particles can be removed from thesuspension. In addition to mechanical separation of macrostickies in the stock flow, fine tuning of chemical additives in the entire system,
optimization of water management and the sepThe author:
Herbert Holik,
Research andDevelopment
Stock Preparation
Division

As a guest speaker on behalf of Haindl Papier,Germany, Manfred Geistbeck had prepared his
presentation entitled “Stickies removal inflotation” jointly with Horst Wiese, also of
Haindl Papier, as well as Martin Kemper andaccuracy, practicality and economy. The
procedure is also faster than previous
Voith Sulzer methods. Herbert Holik, whochaired the conference and led the discussions, stressed the importance of an
intensive exchange of information
between papermakers and suppliers at atime when the pace of developments is
becoming faster and faster. The customer
conference objective was to provide
information on the “tools” which Voith
Sulzer Stock Preparation can offer its
partners today. At the same time, Holik
stressed the need for early indications of
future requirements by the paper industry
to secure the appropriate ongoing development of these tools.

aration of microstickies from the filtrate flows
are the main tools used to control stickies.
Quoting one example of a process, he illustrated
the steps for controlling stickies in stock preparation for newsprint made from 100% recycled
paper. Many members of the audience perhaps
heard for the first time that flotation II after dispersion makes an important contribution to
reducing macrostickies. The benefit of dispersion is not solely that the stickies can be rendered harmless by reducing their size, but that
this process step apparently permits betterflotation of the stickies. However, screening still
remains the most important method of removing stickies.
Quoting the example of two testliner system
concepts, he went on to show that single loop
systems with screening in the approach flow
represent a cost-effective solution. On the other
hand, the possibility of choosing the rather
more complex two loop system should be carefully considered, too. Stock storage, separate
loops and locating the screening stage up front
in the stock preparation ensures high paper
machine productivity.

Thomas Martin of Voith Sulzer. Laboratory tests
have shown that stickies removal in the flotation
stage of the Schongau waste paper preparation
plant can be further enhanced. See page 30.

A special event

α1 > α2α2α1α1Efficiency [%]Screen with surface profile(profile angle α)α(Measurement with standardized stock)

Influence of Slot Width and Screen Surface Profile

0.10 // ; profile angle α10.15 // ; profile angle α10.15 // ; profile angle α2Rel. reject [%]Conclusion
WHAT

WHERE

Dist. components
finecoarseConsistency

Multi
Family

thin

thick

ScreeninggentleScreening efficiency [%]Screening Efficiency as a Function of Screening Area
100
90
80
70
60
50
40
30
20
10
0

LC slots

MC- + LCslots

LC slots
extendedsystem

LC slots in long fibre line
MC slots
MC holes0

For particles with at least one dimension smaller
than the screen basket openings, the removal
probability reduces with each screen basket contact. One important result of many studies wasthat as regards screening efficiency, the slot
width must always be seen in context with thebasket surface profile. For instance, with a slot
width of 0.1 mm, screening efficiency is, in fact,
lower than with a slot width of 0.15 mm, if at thesame time the profile angle is reduced. Witheasily deformable stickies, removal efficiency is

In the second presentation in the trilogy “Screening – a tool for stickies removal”, Reimund
Rienecker dealt with the subject of “machines”.
He stressed the importance of carefully matching
the individual components and their combination
to the particular screening task.
For instance, velocity, together with pressure andvacuum pulses differ widely from one rotor toanother (foil, step, bump and lobed rotors) as
does their throughput limit, screening efficiency
for foreign substances in general and for stickies
in particular. Another important factor is theinfluence which the slot width has on the thickening factor (i.e. the ratio of overflow to inlet
consistency): diminishing slot widths lead to an
over-proportional rise in the thickening factor.
Minimum slot widths of 0.1mm, which are thesubject of great controversy today, are particularly sensitive: even the smallest deviations in slot

HOW
powerful

The next three contributions dealt with “Screening – a tool for stickies removal”. As the first
speaker, Samuel Schabel examined the “fundamentals”. Size, geometry and deformability ofthe stickies have a decisive bearing on their suitability for removal. The design of screen housing,rotor and basket determine fluid dynamics andthe forces applied to the suspension.

1
2
3
4
5
Total screening area [m2/100 t/24 h]

67Peter Schweiss was the third speaker on the
topic of “Screening – a tool for stickies
removal”. He discussed “systems”. From thevarious machine and system parameters, a whole
range of general concepts can be derived to handle the different screening tasks, e.g. slot screening for medium and low consistencies, slot
screening in the approach flow representing theonly use of fine screening or in addition to that instock preparation. In a summary, the various
arrangements of screening stages (forward, fullcascade, partial cascade and series) were compared. The thickening factors in a screening

17

lower than with more rigid particles. Removal
efficiency decreases with increasing shear andcompression forces in the screen.
For these sensitive screening tasks, the screensshould be run at low consistencies, moderate
rotor speeds and low pressure differences
across the screen basket. Schabel used two
diagrams to emphasize the fact that the mean
screen throughflow velocity cannot be used asa criterion for evaluating different types ofscreens.
The diagrams showed the measured screen
throughflow velocities during one rotor revolution for two different rotors. Both the local peakvalues of the flow velocities – up to a factor often times the mean value or more – and theshape and length of the pressure and vacuum
phases showed wide differences.

width or in profile angle (e.g. caused by wear)
result in significant changes in plant operating
conditions and in technological results. Operating reliability, screening efficiency and specificthroughput are significantly increased if theflow is uniform over the entire area of thescreen basket. This is achieved by the “MultiFamily” with its flow-optimized housing and the“fish mouth” shape of the accepts outlet.
The Multi-Family includes the MultiSorter, theMultiFractor and MultiScreen. Careful selection
and combination of the individual modules
ensures a tailored machine for every screening
task and production capacity. The range covers
high and low consistency screening, applications in stock preparation and in the approachflow as well as fractionating and screening
tasks in mechanical and chemical pulp production.

system depend very largely on the slot width.
This was illustrated by the example of slot
widths of 0.1 mm and 0.15 mm in a system with
two and three stages. A size comparison of theslot opening of a C-bar screen basket with thefibres and fibre bundles of a wood-containing
deinking stock illustrated this conclusion.
Various system variants for a deinking plant
were also discussed, with particular reference
to their screening efficiency: low consistency
slot screening, as favoured by Voith Sulzer,
medium consistency slot screening, medium

18

Water and Filtrate Clarification, WSR Subsystem Modules
Inlet
Elephant filter / Thickener

10000 ppm

1000 ppm

Wire filter(Gamma filter)
Microflotation(Deltapurge)

Spray filtration(Trenner)

Beispielprozeß für Zeitungsdruck aus 100% AP
LC-Sortierung //0,35

ST-Cleaner

PM

Flotation II

Scheibenfilter

Auflösesystem

Scheibenfilter
PresseLC-Sortierung //0,15

ST-Cleaner

MC-Sortierung ø1,2

Flotation I

Bleiche, ox.

Sticky-relevante Prozeßschritte: Loop 1: MC-Sortierung ✓ ✓ ✓✓✓✓✓Flotation I✓
Cleaner
Feinsortierung ✓ ✓ ✓ ✓ ✓ ✓ ✓Sandfilter(Omega)Clarified water

PM-Loop

Loop II
Dispergierung

100 ppm

Protectorsystem

Loop I

10 ppm✓QUALITÄT

Loop 2: Dispergierung
Flotation II✓ ✓ ✓ ✓✓ ✓✓ ✓ ✓ ✓✓PMLoop:✓✓Cleaner
Sortierung

100 ppm

Inlet

CoarseFine fraction
fraction
1000 ppm

10000 ppm

consistency followed by low consistency slot
screening and the series variant with low consistency slot screening. An overview of screening
systems in brown stock plants was given. This
included the recommended low consistency
screening and the different designs of medium
consistency slot screening, medium consistency
and subsequent low consistency slot screening
with fractionation as well as low consistency slot
screening in the approach flow. In each case typical layouts and the resultant screening efficiency
were presented. With brown stock, effective
deflaking is necessary to minimize fibre losses.
With high dirt concentrations, intermediate

screening using a Rejectsorter or Combisorter
must be installed to protect the deflaker against
excessive wear.

In his paper entitled “Dispersion – an important
process stage for reducing stickies problems”,
Wolfgang Mannes called attention to a trend in
the brown stock sector. The first plants with low
consistency slot screening without dispersion are
already operational.

perger or kneading disperger handle stickies andwhat are the best operating conditions for them?

Fine screening in the low consistency range
offers the benefit that the screen baskets withfine slot widths are more effectively protectedagainst wear, since the particles causing wear
can be removed more efficiently. The fact that
improved screening efficiency generally also
necessitates greater expenditure was illustratedby showing screening efficiency plotted over therequired total screen area of the complete
screening system.

However, dispersion is likely to continue to bejustified in certain market segments because of
the variety of raw materials and the different
product criteria such as optical impression,
hygiene and strength.

In extensive tests, both in the Ravensburg
R & D facility and in commercial operation, it
was found that the disk disperger is more efficient than the kneading disperger as far as
stickies are concerned. Despite intensive studies, it was impossible to show that stickies areagglomerated by the kneading disperger or byother kneaders, as has frequently been argued
in the industry.

For white products, the trend is now towards low
consistency screening with slot widths of 0.1 mm
to 0.15 mm. In all cases, residual stickies are
extremely detrimental to product quality andpaper machine runnability. That is why dispersion
will no doubt remain indispensable in future forwhite paper production. How does the disk dis-

As to the effectiveness of stickies treatment,
this increases with stock consistency and temperature; a specific dispersion energy of 60 to
80 kWh/t is normally sufficient. Cast fillings are
beneficial and a maximum peripheral speed of
50 to 60 m/s is optimum. This avoids unnecessary wear problems.

The contribution on “Microstickies – troublemaker in water loops” by Lucas Menke concluded the papers on stickies. Menke is the Managing
Director of Meri Entsorgungstechnik, Munich, a
joint venture of Meri Anlagentechnik and Voith
Sulzer. He explained that stickies problems
necessitate a detailed examination of the water
system. Micro-stickies are evenly dispersed in thewater. Their concentration depends essentially on
the specific water consumption of the process.
Initial chemical treatment must first agglomerate
microstickies into flocs.

the different dosing concepts and chemicals
were given. Upgrading results taking the example of a newsprint mill were presented.

They can then be removed in the microflotation
system. Filtrate flows with a minimum load of any
other solids should be chosen to keep the chemicals consumption and losses in valuable solids as
low as possible. A recipe on how to select thebest chemicals and a summary and assessment of

The importance attached nowadays to optimum
water, sludge and reject treatment was
explained. First, typical WSR (water, sludge,
reject) sub-systems were presented for a deinking plant and a brown stock preparation plant.
The individual components for water and filtratecleaning and their optimum application depending on solids contents in the inlet and in theclarified water were then explained.
The various machines for sludge dewatering,
their capacity and attainable final consistency
were described. Finally, the machines for efficient reject handling and reject dewatering were
presented.

A special event

Voith Sulzer Laboratory Flotation Cell
Fibre consistency = 1% (standard)
Rel. air colume= Mill operation

Reject rate
Reject compos.

= Mill operation= Mill operation

Air supply
Foam discharge= Automatic= Automatic

Effectivity of Process Modules in Removing
Disturbing Components

opticalProcess module Screen- Flo- Wash- Centrif. cleaning Disper- Bleachinging
Disturbing
tationing
sion
heavylightoxid. red.
weightweightcomponents
Conventional–
printing inks
Non-impact inks–

Lacquers–

Flexo inks–

Fibres with undetached
inks

–

–
–

–

–

–

–

–

–

–

–

–

–

Coloured fibres

–

–

–

–

–

–

Medium

Low

–

–

–

–

–

–

Unbleached fibres

High

–

–

Opening his introduction to the problems of“Optical cleanliness”, Herbert Holik defined
the criteria for its determination: dirt specks,
mottling, brightness and lightness, together withchromaticity values.

19

brightness of very grey stocks. Laboratory flotation is generally used to determine the maximum brightness achievable for a particular
stock.

Here, too, there are problems with measurements, e.g. in the measurement of dirt specks
with different methods measuring different size
spectra or the unsolved problem of measuring the

Recognizing the importance of laboratory flotation as a standard reference, Voith Sulzer has
developed a new laboratory flotation cell, which
operates under conditions close to thoseencountered in practice.

Harald Selder entitled his presentation “Improving the cleanliness of secondary fibre stocks”.
He examined the optical, chemical, colloid-chemical and microbiological cleanliness. These threefactors have assumed very great importancetoday, in food packaging and in other areas. He
began by illustrating the size ranges of opticalinhomogeneities and the efficiency of processmodules in eliminating them.

followed by indications as to which process
steps are the most successful for their removal.
The main process step here is washing withsuitable treatment of the filtrate, and flotation.
A second list, this time of relevant microorganisms, described their effect on the paper
production process and on the consumer. An
integrated process module for sterilization was
proposed here.

Flotation is the leading technique for this purpose. However, dispersion, too, makes an important contribution by reducing the size of printing
ink specks to below the visibility limit and making
toner particles flotatable. Quoting the example ofa three loop system, he showed how a secondary
fibre raw material similar to chemical pulp quality
can be produced from office waste. A list of
detectable chemical contents with an indication of
their origin and problems created by them was

To eliminate problems caused by inadequate
colloid-chemical cleanliness, these substances
are nowadays frequently fixed on the fibres
using polymer fixing agents and leave the production process with the finished product. However, it is strongly recommended that the stock
be dewatered to a high consistency ahead of thepaper machine. The colloidal substances should
then be removed from the filtrate.

In his presentation “Flotation deinking – a key
technology for brightness and cleanliness”,
Herbert Britz began by describing the various
principles in flotation and their resulting benefits
and drawbacks.

distinct reduction in fibre losses in the secondary stage are achieved. Controlling the overflow from the secondary stage ensures economic fillers removal from the suspension. The
largest plant delivered to date is designed fora capacity of 675 t/24 h.

–– No effectFor instance, centrifugal force in flotationachieves higher brightness than conventional
flotation cells because the spectrum of particle
sizes to be removed is moved downwards. On theother hand, the range of the spectrum is considerably reduced so that the removal efficiency withlarger particles falls dramatically.
The EcoCell, as a synthesis of the former E cell
(Voith) and CF cell (Sulzer) combines the operating and technological benefits of both its predecessors. The technological benefits come intoplay in both primary and secondary flotation.
Here, high dirt speck and stickies reduction, aconsiderable increase in brightness as well as

The heart of the EcoCell is the 4 stage selfsuction micro-turbulence generator. It permits ahigh flow ratio of process air and suspension
and includes areas of different microturbulence,thus generating a wide spectrum of air bubble
sizes. This in turn results in a broad size spectrum of particles which can be removed.
A retrofit kit is offered for converting existing
E cells or tubular cells to the EcoCell specification. This improves the technological results orincreases the capacity of existing plants, while
fibre losses and energy consumption can be
reduced.

20“Dispersion – the process stage for improving
optical properties” was the title of the presentation by Volker Niggl. He explained the wide rangeof tasks assigned to the dispersion system: residual dirt specks and stickies must be rendered dispersable or flotatable, printing ink still adheringto the fibres must be detached, bleaching agents
mixed in, catalases destroyed, the germ countreduced, fibres treated technologically and inspecial cases coating grit has to be dispersed.
The disk disperger and kneading disperger are
suitable for these tasks. Both machines are highly
efficient as far as reduction of dirt specks is concerned. For conventional printing inks, the disk
disperger has slight advantages, while the kneading disperger is better for laser printing particles.
The dispersion effect of both machines rises withincreasing specific energy. In the disk disperger,
this is determined in advance by the choice offillings and consistency and is controlled byadjusting the gap between the fillings. With thekneading disperger, the number, arrangement andgeometry of the teeth as well as consistency
influence the specific energy absorbed. This canbe readily adjusted by a throttle on the outlet

Bleaching Plant in the System Technology Centre Ravensburg
Ascendingscrew

Plug screw
Heating screw
Distribution screw

High temp. dispersion
Conventional bleaching
MC-oxygen bleaching
HC-oxy. blea. (in preparat.)

Disperger
Ascending
screw

High
consistency
tower
25-35%

Kneading
Disperger

Rotaryvalve

O2

Digester
Repulper
O2
Pump (MC)Mediumconsist.
oxygentower
10-12%High shear
mixer

Volker Gehr wound up the presentations on thesubject of optical cleanliness with his paper entitled “Bleaching of secondary fibre stocks – what
can white magic achieve?”.
He indicated as the main task of oxidative bleaching techniques an increase in brightness by lightening the fibres, while reductive bleaching controls chromaticity coordinates and increases
brightness by colour stripping. He illustrated thegain in brightness, the general effect, operating
parameters and the machines for conventional
chlorine-free bleaching of secondary fibres.
Harmful decomposition of the peroxide bleaching
agent is caused by heavy metals, catalases,
reduction agents and COD. Possible solutions
were indicated for each of these problems.
Taking the example of two-stage, oxidative
followed by reductive bleaching, a preparation
system for upgraded newsprint was discussed
and the importance of water loop separation highlighted. The sequence reductive then oxidative
bleaching was illustrated by the example of athree loop system to make market pulp grades of
equivalent quality to chemical pulp from officewaste. In this case, strict water loop separation isvital for the technological success and for good
economics. As regards “unconventional” bleach-side. Both machine types are designed for a
maximum motor load of 2,500 kW with a maximum production of 700 t / 24 h each. Only thedisk disperger can also be used at temperaturesin excess of 100°C. However, for cost reasons
heating should be kept to the absolute minimum, as underlined by a diagram of the operating costs from different dispersion units. The
higher the process temperature, the greater the
reduction in dirt specks in dispersion while
breaking length diminishes. The disk disperger
is operated at temperatures in excess of around
85°C, while the kneading disperger can also be
run “cold” since it treats the fibres more gently,
even at lower temperatures.
The disk disperger and kneading disperger are
similar in their removal of printing inks andmixing in of bleaching chemicals for increasing
brightness. In the summary, attention was
drawn once again to the strong points of thetwo types of dispergers, their typical operating
conditions for the individual applications werelisted and recommendations given for their use
in stock preparation systems.

ing of secondary fibres with oxygen, typical
process parameters and the anticipated results
were indicated. Vastly different results occur
with wood-containing and woodfree raw materials. Different technological results are obtained
when operating modes are employed such as
high alkaline charge and simultaneous hightemperatures or modes with low alkaline charge
and low temperatures with simultaneous addition of peroxide.
For secondary fibre bleaching with ozone,
brightness can be increased by up to 20 points,
but this effect is confined to virtually woodfree
raw materials. On the other hand, ozone is themost effective of all chlorine-free bleaching
agents for colour stripping and for deactivatingbrighteners or to reduce the effect ofunbleached kraft fibres.
In the Voith Sulzer R & D plant, conventional
bleaching can be performed with peroxide,
dithionite and FAS in both the high and medium
consistency ranges. Oxygen and peroxideenhanced oxygen bleaching in the medium consistency range is also possible. A further extension of the plant to include high consistencypressurized bleaching is planned.

A special event

Chemical oxygen demand [mg/l]

Newsprint System: COD in Relation to Water Loop Separation
COD reduction in the PM loop
5000

Integrated HC pressat the end of stock preparation

Loop I

Loop I

Loop II

Loop II

4000

Countercurrent water
management

3000

Reduction in specific effluent
with constant COD levelin the PM loop

2000
PM Loop1000
PM Loop0

Carry over consistency to PM loop
12.0%
30.0%
Specific effluent: 5.0 l/kg

Loop 1 process water withhighest COD level tobiological clarification

Today’s Stock Preparation

Improved paper quality
Advantages in converting
Reduced cleaning costs on the PM

PM 4/7

LC Screening ø1,6 mm

Storage tower

Bleaching, red.

Dispersion

HC Thickening

Washing

LW Cleaning

LC Screening //0,15 mm

HW Cleaning

Flotation

MC Screening //0,20 mm

MC Screening ø1,2 mm

HD Cleaning

HC Pulping system

We expect:

HW Cleaning

PM-Loop

Loop I21

Two papers then specifically dealt with “Systems”. The first, by Dietmar Borschke, presented
the interrelationship between the individual
process stages discussed earlier in the day. At
the beginning of his paper on “System designs –a complex puzzle for the entire process technology”, Borschke defined the different technological objectives for white and brown stock systems.
He went on to present a plant concept for upgraded newsprint and illustrated the progress incleanliness (stickies area, dirt speck area andbrightness) right through the process. In theprocess water loop, the COD was presented as afunction of specific waste water discharge. To
reduce COD in the paper machine loop, high consistency thickening is recommended at the end of
the stock preparation, as well as consequent
application of the counterflow principle throughout the water loops. The process water is thenremoved from the loop with the highest COD(loop 1) level for biological clarification. Plants ofthis type are operated nowadays with a specificeffluent rate of 8 to 10 l/kg and show a COD ofaround 1,000 mg/l in the paper machine loop. As
an example for packaging paper production, aplant design with a two loop system for the
preparation of testliner stock was presented.
The change in stickies area and dirt specks was
illustrated throughout the process.

The second guest speaker Helmut Berger ofWepa Papierfabrik, Giershagen, Germany, wound
up the conference with his contribution “Leadingedge technology for soft products – translating
practical experience into system design in atissue mill”.

brightness, dirt specks, strength and bulk. The
stock preparation must be sufficiently effective
to produce a finished stock product with tightly
defined, high quality standards from waste
paper raw materials with a very wide range ofproperties. The improvements included more
efficient screening in the medium consistency
range. Here, the screen basket holes werereduced from 1.6 mm to 1.2 mm and an additional slot screening stage with a slot width of
0.2 mm installed. Furthermore, the slot widthsof the screen baskets in the low consistency
fine screening were reduced from 0.25 mm to0.15 mm.

After describing the group’s mills and the Wepa
initiative for “recycled paper with a 100% closed
circuit”, he defined the reasons for Wepa’s
ongoing development work in stock preparation:
adaptation to changes in waste paper quality,
enhancement of paper machine productivity andreduction in converting problems.
He named stickies reduction as one of the maintasks, although no direct measurable relationshipexisted between such problems on the one hand
and the stickies area in the finished stock on theother.
The new stock preparation design on PM 4/7 was
prepared by analysis of the existing 4/7 plant,
evaluation of experience from plant 5 and selective trials in the R & D facility at Voith Sulzer inRavensburg. Criteria for the finished tissue stock
are high, on the one hand as a result of theexacting runnability requirement of the tissue
machines and converting plant, but above all dueto the required end product properties such as

A comparison of the more complex two loop
system with a lower cost single loop system
resulted in the recommendation to choose thetwo loop system and to operate a screeningstage in the approach flow purely as a safeguard measure. With the two loop system,
product quality and the process itself are easier
to control from both the technological and technical point of view. The higher investment andoperating costs are more than offset by
improved paper machine efficiency. In conclusion, the following statements were made covering the water loops and specific effluent rates
for testliner and fluting systems: closed waterloops operate satisfactorily from the point ofview of manageable plant conditions and good
product quality if around 3 to 4 litres processwater per kg finished stock are treated in an
integrated biological clarification plant and theresulting COD is less than 10,000 mg/l.

A VarioSplit of the latest design ensures anincreased removal of fillers and fines and hence
a further improvement of product quality. Further expectations included even better paper
quality, advantages in the converting sector andreduced cleaning requirements on the paper
machine itself.
The upgraded plant 4/7 was restarted in March’97. The author was able to report a successful
start-up. Initial results confirmed that thisinvestment has lived up to the high expectations
placed on it. For instance, the reduction in
stickies area improved from 88% to 97%.

22

NEWS FROM
Stock Preparation Division:
Screening – a tool for stickies removal

The authors:
P. Schweiss,
R. Rienecker,
Product Group
Screening,
P. Respondek,
Dr. S. Schabel,
R&D, Stock
Preparation

Screening is an important

Fundamentals

Most stickies are deformable. They areprocess step in stock

The size of particles screened is a direct

more difficult to handle than non-preparation, particularly

function of screen hole or slot size. In the

deformable particles, because they can bewith regard to stickies

case of stickies, however, not only theirforced through the basket slots and evenremoval. This article

size is important but also their geometry

desintegrated. Upstream machines andillustrates the main(stickies particles are predominantly flat

the screen itself must therefore be

aspects of screening,rather than spherical) and their deforma-designed and operated to minimize stick-

starting with an examina-

bility. These three parameters of stickies

ies deformation or desintegration. Thistion of fundamentals.

size, geometry and deformability must bemeans that the shear forces and pres-carefully analyzed for effects on screen-sures acting on particles in the machines

Afterwards, the Voithing. To improve screening, increasingly

must be kept as low as possible.

Sulzer modular screen

finer screen slots are used in order toconcept is described,

remove the smallest possible particles.

Fig. 2 shows the effect of consistency onwhich covers a wide

Since stickies and fibres are more flat

shear forces in a screen. The zone where

variety of applications.

than spherical, their orientation in theshear forces are likely to break down ton-

Finally, ways are dis-flow path through the screen is an impor-

er and stickies particles is shaded in red.

cussed of solving as

tant factor.

For a typical medium consistency screen-

many screening problems

As shown by the test results in Fig. 1, dif-ing configuration, this means greater

as possible by well-ferent slot widths and screen basket sur-deformation and breakdown of stickies atthought out integration of

faces can give the same screening effi-

consistencies higher than about 2.5%,

screens in the systemciency. Slot width and screen basket sur-with a corresponding deterioration ofconcept.

face profile affect screening efficiency andscreening efficiency.

the maximum possible specific flow
through the screen in any particular case.

The pressures in a screen are due above

They also influence operating reliability.

all to the rotor. With a new method for

All these parameters have to be taken into

3-dimensional measurement of local slot

account when selecting the optimum

velocities at a high spacial and temporal

screen basket.

resolution, we can now gather detailed

Stock Preparation

23

M THE DIVISIONS
Fig. 1:
Influence of slot width and screen basket surface
profile.
Fig. 2:
Shear stress in screens.

information on local pressures during
screening. Typical results using this

α2
α1
α1

α1 > α2method are shown in Figs. 3 and 4, wheremean slot velocities are plotted per single
revolution for a foil rotor and a step rotor.

Efficiency [%]α

In the latter case, throughput velocities
for the same volumetric flow are significantly higher than with the foil rotor.
0.10 // ; profile angle α10.15 // ; profile angle α10.15 // ; profile angle α2

Screen with surface profile(profile angle a)

Machines
These basic considerations and theoperating limits must therefore be taken

Rel. reject [%]into account in the design and manufac-(Measurement with standardized stock)1

ture of screens. “Classical” waste paper
stock screening can be divided into the10following subsystems, each of which

Increasing disintegration of toner andadhesive particles

must have a tail screening stage tailoredto the specific requirements:

Shear stress [N/mm2]

1

I Prescreening in the medium consisten-

10 -1

cy range with hole and slot screens
I Fine screening in the low consistency

10 -2

range with fine slots
I Approach flow screening, where high10 -3

paper machine runnability is the main
requirement. Here, both hole and slot

10-4

screening are used, but the trend is
1

2

2

3

4
Consistency [%]5

6clearly towards fine slot screening.

24

Fig. 3:
Dimensionless slot velocity with foil rotor.
Fig. 4:
Dimensionless slot velocity with step rotor.

Product quality is chiefly determined byfine screening using fine slots. Such finescreens can only be operated with stock

20

which has been suitably deflocked, since15

ual fibres can pass through the fine slots.

10

This fluidization process can be carriedout either by screening in the low consistency range, or by medium consistency
screening which requires a high energy
input.

Dimensionless velocity [–]this is the only way to ensure that individ-

5
0
-5
-10

As mentioned previously, however, high-15

energy input with high resultant turbu--20
0

lence and shear stress has a negative50

effect on stickies removal.

100

150

200

250

300

Rotors360
Angle [°]

3

We carried out extensive tests on various
different rotors under the same operating
conditions to find out their effects on
throughput (Fig. 5) as well as on energy

20

consumption and screening efficiency
nants is shown in Fig. 6 for a bump rotor
and a foil rotor. Contaminants removal by
the bump rotor was impressive, almost as
high as the flow-optimized foil rotor. The
results for stickies clearly show that theirremoval is governed by other laws than

15
Dimensionless velocity [–](Fig. 6). Removal of stickies and contami-

10
5
0
-5
-10

those applying to relatively rigid particles.
By contrast with the foil rotor, stickies
removal with the bump rotor is far lessefficient than contaminants removal. Thisis due to the high tip speed required forthe bump rotor in the medium consistency range. Here again, this clearly confirms

-15
-20
0

50

100

150

200

250

300

360
Angle [°]

4

Stock Preparation

25

Fig. 5:
Throughput limits of various rotors as a functionof peripheral speed.
Fig. 6:
Influence of turbulence on various characteristics
of disturbing components.
Fig. 7:
Rotor types.

that deformable particles such as stickies

250
Foil

Blade

Throughput [t/24 h]

200
150

Throughput limit =blockage limit
minus 15%

cannot be efficiently screened out in the

For the same percentage reject rate,
screen basket andconsistency

with the finest slots, as shown in Fig. 2.

100

medium consistency range (> 2.5%), even

Screens not only have to remove stickies.
This fact is illustrated by the wide applica-

50
Step

Bump

0
10

14

5

18
22
Peripheral speed [m/s]2630

Different rotors
require very different
peripheral speeds
to achieve the same
throughputstion range of Voith Sulzer rotors shown in
Fig. 7:
I Lobed rotor (medium consistency
screening):
A rotor for coarse screening, primarilyhole prescreening.

Screening efficiency h [%]

100

6

Foil

80

Low consistency
CI 0.94 %

60

rotor

(medium

consistency

screening): Mainly used for medium
consistency slot screening, this gives
relatively high efficiencies but requires

Bump

40

20

Medium consistency
CI 3.15 %0Same reject rates for
all measurements

high tip speeds.
I Step rotor (medium consistency
screening):
Suitable for both hole and slot screen-

Contaminants

Lobed rotor
7

I BumpStickies area

the downstream stages.

Number of stickies

Step rotor

ing, this also helps relieve and protect

Bump rotor

Foil rotor

26

Fig. 8:
Influence of slot width on thickening factor(fractionation effect).
Fig. 9:Influence of different surface profiles on
operating performance and screening efficiency.
Fig. 10:MultiSorter housing
Left: Conical housing.
Right: “Fish mouth” accept outlet.

I Foil rotor (low consistency screening):

1.8

Used for fine screening and in the
gentle screening with very low energy
consumption.
Screen baskets

Thickening factor[–]approach flow, this allows extremely

1.7

1.7
1.6

1.55
1.47

1.5

0.09
0.10
0.11

1.4
1.3
1.2

Fibre losses and fractionating effects

1.1

depend very much on screen basket slot

10width and surface profiles. Measurements
taken on a deinking plant show that with

0.05

0.1

0.12

0.15

0.2

0.25
Slot width [mm]Reduction in slot width results in an over proportional increasein the thickening factor (reject consistency to inlet consistency)

decreasing slot width, the thickening fac-

Finest variations in slot widths lead to dramatic changes insystem performance and technological results

tor increases disproportionately (Fig. 8).

8

Even the smallest changes in slot width
for the same volumetric flow rate have adramatic effect on reject quantities. Thesechanges in slot width can be within theorder of magnitude of tolerances for the
profile bars (> 0.01 mm).

Screen basket // 0.25 mm: new

The finer the slot, the more important theThickening factor =surface profile for efficient screening, andthe greater the sensitivity to wear, as the

CR
CI

worn
1.12

1.45

Reduction in stickies area

69.3 %

79.9 %

Reduction in number of stickies

48.5 %

65.6 %

example in Fig. 9 demonstrates.
This shows the surface structure of the

A worn profile changes operating performance by reducing throughput and increasing the
thickening factor (higher reject rate) and screening efficiency
9

same screen basket in the new condition,
and after several months of continuous

Housing

through the screen basket. Hence, “meanoperation on a stock with a high sand con-

Another important screen component ishole or slot velocity” is a purely theoreti-tent. While the surface becomes worn, thethe housing, the effect of which is usually

cal parameter which has little or nothingslot width remains unaltered.

underestimated.

to do with practice. In actual fact, local

As a result, the thickening factor rises

As shown by our flow measurements onvelocity, depending on inlet and outlet

under otherwise completely identical con-screen baskets, the usually cylindricalgeometry. Even reverse flow from theditions, and the stickies removal increas-geometry of most conventional housings

accepts side can occur at other points. It

es dramatically.

results in widely varying flow velocities

goes without saying that such conditions

velocities can be up to ten times the mean

Stock Preparation27

10

are not conducive to optimum screening

thus also helping to even out the flow. As

widely varying requirements of raw mate-efficiency.

a result, “gentle” rotors can be used orrials and finished stocks, a custom-tai-correspondingly high throughputs arelored solution is required in every case.

Using extensive computer simulations

possible.

based on the latest test results, Voith

Thorough system analysis is necessary on

Sulzer has therefore developed a new

As already mentioned, the MultiSorterone hand for optimum screening efficien-style screen housing which significantly

housing is part of our new modular screen

cy, and on the other hand to ensure oper-

contributes to evening out the flow pat-concept – the “Multi” family. If we consid-

ational reliability, particularly with theterns through the screen basket. In future,er the various medium and low consisten-finest slot sizes. Fig. 11 shows fibre char-this new housing will be used for all ourcy screening applications: approach flow,

acteristics from the overflow of a firstscreens, both in the low and medium con-fractionation, mechanical and chemical

screening stage at 0.1 mm slot width in asistency ranges. It forms the basic mod-pulp screening as well as tail screening,

deinking plant for wood-containing DIP

ule of our new MultiSorter family and isand additionally the wide range of sizes

stock. On the same scale, a C-bar screen

already well-proven in the approach flow

and speed alternatives, more than 150 dif-basket section with 0.1 mm slot width isas the MultiScreen MSA. The design

ferent versions are available – without

also shown. Clearly, the large fibre bun-ensures virtually even flow velocities

taking into account all the various screen

dles can hardly pass through these finethroughout the accepts zone. This verybaskets. With this carefully designed

slots, thus resulting in a substantial frac-demanding construction from the fabrica-

modular system, a wide range of possibil-

tionation effect. These large fibre bundles

tion point of view serves as a model forities can be realized without excessive

originate mainly from the TMP component

the new generation of pressure screens.

outlay or negative effects on technologi-

of newsprint, but similar fibre sizes arecal performance.

also found in brown stock.

conical housing, which widens toward the

Systems

Consequently, the system layout and thebase so that the greatest housing volume

The design of screening systems, bothminimum possible slot width have to be

is at the level of the accepts outlet. This

subsystems and complete systems, has toselected not only with regard to dirt

has a “fish mouth” shape with a very large

take account of numerous technologicalremoval, but also taking account of fibrecross-section where it joins the housing,and plant-related conditions. Due to thecharacteristics.

Fig. 10 shows the main features of the new

28

Fig. 11:Size comparison of wood-containing DIP andC-bar profile.
Fig. 12:
Overview of screening systems in deinking
plants.

Screen baskets with 0.1 mm slot width
can nevertheless be used with woodfree

1.0 mm

DIP stocks, however, as shown for example in a large European DIP plant where a
0.1 mm slotted Voith Sulzer screen is in
successful service.
If such fine slots are not possible because

Wood-containing fibres 1

Wood-containing fibres 2of the fibre characteristics, optimum efficiencies can only be achieved by appropriate system layouts, in principle byusing several screening stages in series.

0.1

mm

We have investigated numerous com11

binations and analyzed the resultant datawith computer simulations, particularly
MC holeswith regard to stickies and fine slots,
since efficiency is a function of the kind of

Low consistency
slot screening

particle as well as machine layout.

h ~ 77%
B 1.4
MC holesPrincipally, high efficiency can only be
assured through greater outlay. A cascade

it ensures higher overall screening effi-

whole, this is a very important factor inoperational reliability.

AF holes/slots
h ~ 55%

B 1.4
Medium and low
consistency
slot screening

MC holesA-B
low consistency
slot screening// 0.2
MC slots

LC slots

AF holes/slots
h ~ 79%B 1.4

ciency. And together with the subsystemlayout and integration into the system as a// 0.15
MC slots

Medium consistency
slot screeningor A-B type layout costs more than a simple forward-flow system, for example, but

AF: Approach flow
AF holes/slots

LC slots// 0.2// 0.15
LC slots

MC holesA
B 1.4

B// 0.15

AF holes/slots
h ~ 81%h = screening efficiency

Fig. 12 shows an overview of typicalscreening systems today for deinking

comprises 0.15 mm slot screening ortency, maximum screening efficiencies

stock. All deinking plants include medium

even finer in special cases.

can be attained for all kinds of stickies.

removal of coarse contaminants as a pre-Our preference for stickies screening isFurthermore, the sensitive screen baskets

condition for effective slot screening. The

low consistency slot screening, because

can be protected against wear by anactual stickies screening stage, however,by using gentle foil rotors at low consis-

upstream low consistency cleaner stage.

consistency hole screening for efficient

12

Stock Preparation

29

Fig. 13:
Screening efficiency as a function of screening
area for the various screening systems.

cates that high stock quality can only be100

ensured by high system outlay.
LC slots90

Screening efficiency [%]8070

MC + LC slots

This means that various compromises are

LC slots
extended system

usually made because of the widely diver-60

sified requirements on the finished stock.

50

This applies just as much to DIP as tobrown grades, but as a basic principle,

40

quality can be improved by connecting

LC slots in long fibre line

30

medium and low consistency screening

MC slots
MC holes20

systems in series. Another way of improv-

10

ing quality is to connect low consistency

0slot screens in series – in fact, this kind of
0

13

1

2

3
4
5
Total screening area [m 2/100 t / 24 h]67

so-called A-B system is not only simpler
to install but enhances screening condi-

For stickies screening in brown stock sys-

low consistency slot screening attains

tions as a whole. It costs the most intems, basically the same relationships

surprisingly high efficiencies. This shows

terms of machine investment, but screen-

apply as in deinking plants. An additionalthat although MC slot screening needs

ing efficiency is the best: the higher the

point must be taken into account, how-less investment outlay, it is not appropri-

outlay, the higher the efficiency. Very sim-

ever: after hole prescreening, the stock

ate for high quality finished stock.

ple systems such as slot screening in theapproach flow only, or medium consisten-

contains much higher stickies concentrations than in deinking plants, together

Likewise for brown stock preparation sys-

cy slot screening, are only appropriate forwith various abrasive contaminants suchtems, we recommend low consistency

lower quality stocks. And greater atten-

as sand and glass, and it also has a highslot screening for maximum stickies

tion has to be paid to operating condi-

flake content. Depending on the raw mate-removal, preceded by a cleaner stage totions, particularly when slot screening isrial, there might also be a considerable

reduce screen basket wear. As we have

only used in the approach flow.

proportion of long, stiff fibres, which areseen so far, the numerous system alterna-

highly susceptible to fractionation in slot

tives differ significantly with regard to

Conclusions

screening.

investment outlay and attainable efficien-With the flexible screen modules now

cy. Fig. 13 summarizes the efficiency

available, it is possible to remove contam-

The same kind of fine slotted screen

ranges of various system configurations

inants and stickies from stock very effi-baskets used for low consistency screen-

as a function of total screening area. The

ciently and cost-effectively, with reliable

ing are also used in our medium consis-

latter is a relatively direct measure of sys-

operation. Optimum results can only betency machines. As regards the complete

tem investment outlay. Despite substan-

attained, however, if a wide variety ofstickies spectrum, however, screening

tial differences in their details, all thefacts and findings are taken into accountefficiencies are not so high here – butscreening systems in this diagram lie onin the design and operation of the screen-

passing the accepts through subsequent

an asymptotic curve. This clearly indi-

ing systems.

34

Paper Machinery Divisions:“Pole position” for Voith Sulzer shoe presses

100
90

46

5

80

Number of installation

22

22

70

60
50

10

40

1

30

1

20
10

6
1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1

1999

MarketIntensa-S press were integrated into theindisputably market leader in modern

In the first decade after launching the

new NipcoFlex press. Thanks to the sum

shoe press technology.

enclosed shoe press in 1984, a total of

total of Voith and Sulzer know-how and

42 Voith and Sulz-

the

er

Wyss

patent restrictions, the resultant product

Technology

shoe presses went

offered papermakers substantial benefits.

The NipcoFlex shoe press is outstanding

Eschereliminationofcounterproductive

into service (seeThe author:
Wolfgang Schuwerk,
NipcoFlex Technology

for its uncomplicated and absolutely

Fig. 1). The Voith

So far more than 85 customers in

dependable technology. The shoe is lubri-

Sulzer Paper Tech-

28 countries have recognized the techno-

catednology merger inlogical advantages and cost effectivenessensures an optimal line force profile (see

1994

a

of the NipcoFlex press (see Fig. 1). In theFig. 2). This is characterized by a steep

symbiosis of thesefirst 30 “twogether” months alone, orders

pressure rise prior to dewatering, fol-

two very success-were booked for 60 shoe presses, and at

lowed by a very gentle increase during the

ful systems – thethe time of writing, 83 Voith Sulzer shoe

dewatering process to a relatively low

best features ofpresses are in service worldwide. With

maximum pressure. The pressure drop in

the Flexonip press

300 years of collective experience andthe nip outlet is steep again to prevent

andmore than 100 units sold, Voith Sulzer isrewetting. This shoe press comprises a

brought

theNipco-

entirelyhydrodynamicallyandPaper Machines

35

Figs. 1:
Voith Sulzer shoe press sales growth andregional representation.
Fig. 2:
NipcoFlex press nip.
Fig. 3:
Effect of pressure pockets on line force profile.

I

II

III

Nipco-P rollPressure

Pressure

Fig. 4:
Cross-section through a NipcoFlex press.

NipcoFlex rollTime

Pressure2

NipcoFlex shoe presses are pressed
Distance

Distance

against the maiting roll by a single row ofhydrostatic elements (Fig. 4). This elegantly simple pressing mechanism is pos-3

Hydrostatic shoe

Hydrodynamic shoesible because thanks to the patented
asymmetrical arrangement of the rollconcave upper part and a rigid lower part,tion involved (= pressure x flow rate), oilsleeve, the shoe is displaced toward theseparated by an insulation layer – afeed pockets have two serious drawbacks.

nip inlet relative to the pressing direction.

patented compound construction which

They generate pressure plateaus (Fig. 3)

A symmetrical shoe arrangement would

largely prevents thermal deformation ofwhich at constant line force unavoidably

either generate an undesirably symmetri-

the shoe due to cold zones in the nip

cause steeper pressure gradients due tocal line force profile, or require the extra

intake and hot zones in the outlet. Thesethe equal areas under the pressure

outlay of a double row of pressing ele-

are unavoidable in a lubrication nip

curves, at the same time leading to higher

ments to ensure an optimal profile as inbecause of oil heating. In other designs,

maximum pressures. Operating experi-

Fig. 5.

cold hydrostatic oil is fed directly to theence with pocket-type oil feed shoe press-

nip via pockets in order to limit thees has also shown that the press roll

The NipcoFlex loading elements aretemperature differential between inlet andsleeve can easily be damaged from withinarranged quasi as a single zone over theoutlet. Apart from the energy consump-when wads pass through the nip.

roll width, and supplied with oil pressure4

36

Fig. 5:Longitudinal section through a NipcoFlex press.
Fig. 6:Voith Sulzer QualiFlex press sleeve.

by a common lead (Fig. 5). Smaller elements are only fitted at the roll ends totake account of any variations in web

Nipco-P rollwidth. Within the approx. 150 mm wide
end zones, the line force and moistureprofile can thus be varied considerably.
Thanks to the flexibility of the shoe, theshoe press in any case applies an ideallyequalized line force over the nip width,
without any additional error. The result isan absolutely uniform CD moisture profile. Here again, experience in practice has
shown that no zonal correction is necessary with NipcoFlex presses. With unequal line force distribution – for example
to compensate in advance for CD moisture
NipcoFlex roll

profile alterations in the dryer section –felt characteristics change unequally dur-5

ing service life and thus cause additional
production problems.
Another advantage of the NipcoFlex shoepress is the positionally stable Nipco-P
maiting roll (Fig. 5). Since the roll shell isdirectly supported in the bearing distance,
its position is unaffected by the unavoidable beam deflection and thus ensures

Longitudinal yarns

Circumferential yarns

Blind holeconstant conditions for the press sleeveadvance and docters. Since the hydrostatic loading elements of the Nipco-Proll have the same area as those of the

QualiFlex S (smooth)QualiFlex B (blind drilled)shoe press, control is very simple and

The NipcoFlex press and associated Quali-

embedded in polyurethane (Fig. 6) arereliable, with no risk of damage to the roll

Flex press roll sleeves comprise a very

breaking world records in service life,

shell or bearings. Furthermore, the direct

cost-effective solution – thanks to out-measured both in terms of nip passes andforce transmission between rolls via

standing press sleeve life, for example.

operating days. In the 3rd nip of a paper

patented links allows an extremely com-Blind-drilled QualiFlex sleeves with end-

machine for copy papers, for example, apact design.

less nonwoven reinforcement yarns fully

QualiFlex sleeve running at 1180 m/min

6

Paper Machines

37

Fig. 7:
QualiFlex Top Ten running times.
Fig. 8:Change of strength properties after installing a
NipcoFlex press in a testliner machine.
Fig. 9:Tandem NipcoFlex press on a 7250 mm wide
paper machine for linerboard.
Rank
1
2
3
4
5
6
7
8
9
10
7

Installation
Neusiedler
VP 4-Melbourne
PerlenHoya
VP 6-Sydney
Cardella
VP 6-Sydney
Neusiedler
BravikenZülpichCountry
A
AUS
CH
GER
AUS
I
AUS
A
S
GER

Speed (m/min)
1190
580
1140
500
800
520
780
1090
1500
900

Sleeve Life (Days)
303
370
175
516
239
354
235
231
161
263

Nips (Millions)
95
75
70
68
64
62
62
62
60
58

reached 95 million nip passes – corresponding to 303 days of operation. Another QualiFlex sleeve ran for 516 days in alinerboard machine. And as shown by the
top ten list in Fig. 7, these extremely long
operating times are no exception by anymeans.
The dependability of the NipcoFlex/QualiFlex system protects operators today

Change after rebuild [%]

115

110

NipcoFlex press,
double-felted

against unplanned roll sleeve changes,

Testlinerused at the highest possible operating

100% waste paper
Basis weight:
140 - 300 g/m2

105
Dry content increase
after rebuild: 9%and enable this type of shoe press to be
speeds.
Applications
The first shoe presses were used in board
and packaging paper machines. They covered practically the whole operating range

100
8Density

Burstpressure

RCT

Plybondstrength

Tensilestrengthboth of narrow and wide machines as well
as slow and fast machines. Operating
results with NipcoFlex shoe presses in thelast nip of packaging paper machines
show increases in dry contents up to 15%
or even above in some cases. Final dry
contents of 51 to 54% are possible onlinerboard machines. This kind of dry content increase naturally brings considerably higher density, so that burst pressure, tensile strength, RCT and plybond
strength are likewise improved significantly (Fig. 8). Suitable concepts forkraftliner, testliner and corrugated board
are Tandem-NipcoFlex presses (Fig. 9),
which apart from the aforementioned
increase in dry content also bring the9advantage of closed and extremely reli-38

Fig. 10:
Press section results on Perlen PM5 before andafter rebuild.
Fig. 11:
Press section of a paper machine for wood-freecopy paper.

able web run, from the wire section

For packaging paper machines, shoepresses are state of the art. Their flatpressure

gradients,

long

50
4

1.5

48

dewatering

times and low line forces also make them

20
46

1.0

ideal for board and sack kraft. It is precisely with these grades, which are particularly sensitive to compression, that gen-Cobb oil absorption[g|m 2]

PPS roughness
[µm]

Bulk
[cm 3/g]Dry content[%]

through both presses to the dryer section.

3
15

44
0.5

tle dewatering brings higher quality andgreater economy. The latest application

420

for NipcoFlex presses is in pulp dewatering machines.

10

2
TS BS

Before rebuild

TS BS

TS BS

TS BS

After rebuild

10

NipcoFlex shoe presses have long proved
their technological advantages and costeffectiveness for writing and printing
papers as well. Our one hundredth shoepress – a NipcoFlex – will be installed in a
recently ordered newsprint machine.
There are two main reasons why theseshoe presses can be installed in fastmachines: replacement of granite rolls byceramic rolls and the high quality of flexible press sleeves with long operating life.
Excellent references in writing and printing paper machines bear witness to theeminent suitability of NipcoFlex shoepresses in this field.
I The world’s first shoe press in a newsprint machine has been operating sinceLine force
Operating speed
Dry content after third nip
Thickness
Delta roughness (TS/BS)[kN/m][m|min]
[%]
[µm]
[%]

Before rebuild

After rebuild

70 / 70 / 90
900
43,5
104
-12

70 / 90 / 550
1150
50
104
-10

11

volume, smoothness, oil absorption

from 43.5 to 50% and outstanding

and 2-sidedness (Fig. 10).

sleeve service life have proved its cost-

1994 with great success. Expectations

I The second shoe press for writing andhave been exceeded not only by theprinting paper has been operating in a

I The third Voith Sulzer shoe press in the

27% production boost, but also bymachine for wood-free copy paper

writing and printing paper segment

quality enhancements with regard tosince 1995. A dry content increase

represents a real quantum leap: de-effectiveness (Fig. 11).

Paper Machines

39

Fig. 12:
DuoCentri NipcoFlex press on a 9650 mm wide
newsprint machine.
Fig. 13:
Effect of shoe press on characteristics of woodfree coated paper.

sured by the NipcoFlex press, the drycontent of these mark-sensitive grades
can easily encreased by 3-4% (Fig. 13).
One of the most impressive aspects
here is that the NipcoFlex press is basically very simple and reliable despite
its high technological level. The problems only too familiar with conventional presses – such as irregular moistureprofiles or felt barring due to vibration
feedback – just do not occur with thisdesign.
Totally eight shoe presses now operatingin writing/printing paper machines, an12

other twelve are currently on order.

50

Cobb oil absorption[g|m 2]

PPS roughness
[µm]

Bulk
[cm 3/g]Dry content
[%]
1,4

7,8

54

1,3

7,4

50

Cost-effectiveness
Apart from the technological advantagesof the NipcoFlex shoe press, one of its
greatest benefits is cost-effectiveness.

48

The higher dry content enabled by thispress allows considerably greater output.

46
1,2

7,0

1,1

6,6

Even a 2% runnability increase, for exam-

46

ple, increases annual production from
250,000 to 255,000 tonnes. So assuming

44
42

an overheads contribution of 600 DM/t fornewsprint, the overall contribution in-

42
0

TS BS
Before rebuild

creases by 3 million DM per year. And

38

6,2
TS BS

TS BS

TS BS

After rebuildwith production increases around 20% or
more, the cost-effectiveness of the Nip-

13

coFlex shoe press becomes indisputable –signed for a speed of 1800 m/min, thisclosed web run with high dry content inpromising a really fast return on invest-

press holds the world speed record at

the first open draw, thus ensuring

ment.

excellent runnability.

The cost-effectiveness of this press is not

1672 m/min. And with a wire width of9650 mm, the production is 270,000 t/y.

I Equally good references are available in

only due to increases in output, however:

The DuoCentri NipcoFlex press withthe wood-free coated paper sector. Giv-

NipcoFlex shoe presses also reduce spe-shoe in the third nip (Fig. 12) enables

en an optimal line force profile as en-cific production costs.

40

Fig. 14:
Production cost savings by a DuoCentri
NipcoFlex press compared with a conventional
4-nip press.
Fig. 15:
DuoCentri NipcoFlex press (left).
Duo NipcoFlex press (right).

This is well illustrated by comparing a
DuoCentri NipcoFlex press with a conven-

Newsprint 46 g/m2, 1500 m/min
3,5% dry content increase with NipcoFlex
Steam cost: 30 DM/t; power tariff: 0.123 DM/kWhtional 3-nip press followed by straight7

through press. At only 3.5% higher dry

6content, the DuoCentri NipcoFlex press inm/min saves DM 5.20/t in steam costs,
and DM 0.80/t in electrical power due toelimination of the fourth press. Furthermore, with a total of only three felts, it

5
Cost savings [DM/t]a newsprint machine operating at 1500

4
3
2
1

saves DM 0.90/t in clothing costs. Like-0

wise roll cover and trimming costs are-1

reduced by DM 0.70/t (Fig. 14). Including-2

the cost of new press sleeves, the Duo-

Steam

Power

Roll covers/
trimming

4th feltPresssleeveTotal

Centri NipcoFlex press brings overall sav14

ings here of about 6.20 DM/t. This result
is further improved by lower investment
costs in the press section, and in somecases lower investment costs due to ashorter dry section.

NipcoFlex

NipcoFlex

Future outlook
Although today’s shoe presses meet current demands very well, new concepts areunder development for further improvement of technological results – in particular for printing and writing papers.
Future requirements are already clear:closed web run, highest possible dry con-

Nipco-F(70 kN/m)

NipcoFlex(200 kN/m)tent, good structural and surface charac15

teristics with the least possible 2-sidedness. At the same time, the design must(Fig. 15). This concept enables extremely

is limited, but the dewatering rate is highbe compact and reasonable priced. An

gentle dewatering from beginning to end,

here in any case. Apart from higher dry

innovative solution in this direction is thethus improving paper quality still further.

content due to the higher line force in the

Duo-NipcoFlex press – a 3-nip press with

The maximum line force of such a shoeother nips, above all characteristics suchshoe presses in the first and third nippress in the first nip against a suction rollas curl and cockling are improved.

Paper Machines

41

Paper Machinery Divisions:
Web and tail transfer systems in board
and packaging paper machines

web threading

tail threading

web

tail

1

Sheet transfer is

A significant step towards enhancing the

fer systems and methods used in the

an increasingly

runability of a paper or board machine isdifferent positions.

important factor

the installation of a system safely trans-

in advanced board

ferring the sheet from one section to theFundamentals

and packaging

other. Such a transfer system is not only

The two basic transfer methods are: web

paper machines.

an economic solution but it also adds totransfer, tail transfer.

Many paper andthe safety of the machine crew.

board producers

The author:
Peter Haider,
Paper Machinery
Division Board
and Packaging

Tail transfer is used if the web itself is toocurrently tend to

Sheet transfer is becoming an increasing-heavy to get it through to the next posi-

optimize existing

ly complicated process. Faster and fastertion. For this, an approx. 20 cm wide tail is

machines andmachine speeds with a continual reduc-cut from the web and moved to the next

improve theirtion of basis weights and the increased

position. Then, the tail is widened out torunability rather

use of waste paper make the use of closed

full width.

than to order new

transfer systems without open draws nec-

machines.

essary. This article gives a short overview

Strength development as a function ofof the most important transfer positions

dryness

in state-of-the-art board and packaging

Every transfer operation is determined topaper machines and it presents the trans-a large extent by the strength of the web

42Fig. 1:
Web transfer versus tail transfer.
Fig. 2:
Relative sheet strength in a paper or board
machine.
Fig. 3:
Combi Tandem NipcoFlex press.

or tail. Fig. 2 shows the relative strengthof the web/tail from the beginning to the100

end of the production process.

90

After the wire section, the dry content is

80

approx. 20%, which corresponds to a relrelative strength (%)

70

ative strength of less than 1%. In otherwords, paper strength in this position is60

less than 1% of the final strength of the50

web. As the dry content increases, the40strength of the paper web increases aswell. In spite of that, relative strength

30

after the press section is not more than20

4%. Due to these low strengths, transfer
100

in these positions has to satisfy particu0

10

20

30

40

50

60

70

80

90

100

larly high requirements.

dry content (%)
2

Another critical point in every paper
machine is where the paper is threaded
through the Speedsizer or size press.
Since the web absorbs moisture andtherefore loses strength as it passes
through the size press, there is anincreased risk of web breaks.
Transfer systems at the wet end of alinerboard machineTransfer from wire to press section
At basis weights of up to 300 g/m 2 , safe
transfer is ensured by closed transfer systems utilizing a pickup roll for transferring
the web from the wire section into thepress section. Higher basis weights may
cause sagging of the web or web edges.
The web transfer approach used on Tandem NipcoFlex presses without a bottom

3

felt in the last press Fig. 3 offers a closed

Paper Machines

43

Fig. 4:
Tail transfer from press section to pre-dryer
section.
Fig. 5:
Transfer systems at board machine wet end.

● open tail threading● tail threading

pickup with
rapid trap box(> 300 g/m2)

threading doctor + blow tablefelt blow pipe

tail doctor

blow pipe

45

web run through the press section. The

I transfer of web into pre-dryer section.

web is picked up at its full width by thethreading doctor and a blow table are

pickup roll and carried through the press

The advantages of this method are:section without open draws.

I constant web width travelling throughTransfer sequence:
I full width goes into broke pit
I cutting of 1st edge trim by means ofedge spraying device
I transfer of web without 1st edge trim
with pickup roll onto pickup felt
I closed web run through press section
I full width goes into press pulper after
last press

used (see Fig.4).

the press, independent of shrinkage

First, the full width runs from the smooth

and web widthbottom press roll into the press pulper. To

I permanent position of edge spraying
devices
I constant setting of web width at
pickup roll (no transfer zone required)I uniform strain on felts across thetransfer the paper, an approx. 20 cm wide
tail is cut from the web and blown into thepre-dryer section by means of air nozzles
integrated in the threading doctor and theblow table.

width
I constant edge relief setting in the shoepress.

I loading of presses
I cutting of 2nd edge trim (sizepress roll into the pre-dryer section, aTransfer systems at the wet end of aboard machineTransfer from wire to press section

Transfer from press section to pre-dryer

For basis weights larger than 300 g/m 2 ,adjustment) and transfer tail by means

sectionopen tail transfer is used. A slotted blow-of travelling squirt

For tail transfer from the smooth bottom

pipe located behind the wire lifts the44

Fig. 6:
AP-Shur.

blown by integrated air nozzles onto thenext press felt. When the tail has beentransferred, the tail doctor is lifted off the
felt.
web

press roll
1st dryer

Tail transfer from last press intopre-dryer section
The rope nip can be placed upstream or
downstream of the last press. In the firstcase, the advantage is that the tail cansimply be taken by hand and inserted into
the rope nip before the last press nip; atthe same time, the loose end has to be

AP-Shurtorn off at the cleaning doctor of thesmooth roll.
Placing the rope nip after the last press
makes the design less complicated but

6transfer at high speeds becomes verytransfer tail from the wire and directs it

Tail transfer between presses

towards the pickup roll (see Fig. 5). The

Due to the open press configuration in ahigh-vacuum transfer zone integrated inboard machine the tail has to be taken

Closed web transfer from press section

the pickup roll carries the tail into thefrom the felt after each press and directed

into pre-dryer section using an AP-Shurpress section.

to the next position. This can be donepress felt

The pickup roll is used as a suction guidemanually with blow pipes or automatically

The AP-Shur press felt permits web trans-roll, which upon web transfer is moved

with tail doctors.

fer without open draws from the last press

into its operating position. It is notdifficult since a blowpipe has to be used.

into the pre-dryer section. The press felt

absolutely necessary to force the roll into

If it is done manually, the tail is slightly

is wrapped around the first dryer (seethe wire. With a distance of 2-3 mm thelifted by means of the blowpipe arranged

Fig. 6). The heated felt improves theopen draw is so short that the stiffness

under the felt (see Fig. 5) and directed bytransmission of heat between press felt

ratio of the board becomes very small.

other blowpipes to the next position.

and paper and increases the dry content

The MD/CD ratio changes with increasing

Transferring the tail manually requiresof the web. This approach is preferred in

speeds and decreasing basis weights, andgreat skills of the machine crew.

double-felt presses. During transfer, thein these cases the “real” pickup roll gives

web passes through the last press nip, isbetter results. It is to be expected that forWith an automatic system, the tail doctor

slightly lifted by the top felt and only thensmaller basis weights the “real” pickup(see Fig. 5) is forced 2-3 mm into the felt,

drops onto the bottom felt. As the paperroll will become first choice.

then the tail is taken from the felt andweb is slightly lifted from the bottom felt,

Paper Machines45

Fig. 7:
Tail transfer systems in a linerboard machine
dryer section.

single tier section

double tier section

7

an air cushion forms between the felt andTail transfer in the dryer section of awith a doctor, which may either be a

the paper web, which prevents remoisten-linerboard machine

conventional design or a special transfer

ing of the paper.

Basically, there are two ways to thread thedoctor with a width of approx. 1 m.

paper tail through the dryer section of a
Benefits:

paper machine:Single-tier dryer section

I no open draws - less web breaks

I rope transfer

2 blowpipes are mounted on each doctor.

I less CD shrinkage

I ropeless transfer

The first blowpipe is used for picking theI higher strength (burst, SCT CD )tail up from the dryer. The air jet is direct-

I higher dry contents

Since tail transfer utilizing ropes is a well-

ed towards the doctor blade. The second

I vertical entry of the web into the pre-known method, this article will focus on

blowpipe, designed as a slotted blowpipe,

ropeless tail transfer. In a ropeless tailplaces the tail onto the vacuum-assistedtransfer system, every dryer is provided

reversing roll (see Fig. 7). The reversing

dryer section
I suitable for all basis weights

46

Fig. 8:Web cutter for ropeless transfer.

In practical applications, ropeless tailknock off
device“A”

view “A”

transfer is the approach adopted for basis

DSweights up to 180 g/m 2 and machine
speeds over 470 m/min. Solutions forextending the use of this transfer method
are currently under development at Voith
Sulzer.

web

Cutting devices in ropeless transfer
systems
The two types of cutting devices are thetail cutter and the web cutter:
The tail cutter is a blowpipe installed on
the tending side. This blowpipe is set to acertain position relative to the tail andknock off
deviceTS8cuts the tail by means of an air jet. The
time when the tail is to be transferred isdetermined manually (pushbutton). The

roll has a transfer zone on the tending

mounted on the doctor, blow the tail into

tail cutter is installed at the first vacuum-side to ensure safe tail transfer around thethe nip between the top dryer and the top

augmented roll in the dryer section.

roll. The blowpipes at the individual dry-

dryer fabric. The asymmetric arrangement

ers are actuated in groups. 4 dryers at aof the guide rolls and the use of BS stabi-

A web cutter has knockoff blowpipes

time are supplied with air, air supply to

lizers aid in the transfer of the tail. The

mounted both on the tending and on thethe next group of 4 dryers is started withindividual blowpipes are supplied with air

drive side (see Fig. 8). The blowpipes teara delay. The air rate of each blowpipe canin the same way as those in a single-tierthe web from the side and the web tension

be set separately. To reduce air consump-configuration.

ensurestion the blowpipes are operated in a pulse

full

separation

acrossthemachine width. The web cutter can bemode, which means that the air is

The advantages of ropeless tail transfer

activated either manually with a pushbut-

switched on and off every 0.5 seconds.

are:ton or automatically by means of photo-

Double-tier dryer section

I reduced transfer times

is located at the last reversing roll of a

In contrast to tail transfer in a single-tier

I enhanced runability (no changing of

single-tier dryer section. This configura-cells (in the dryer section). The web cutter

dryer section, in a double-tier configuration the tail is directed into the nip
between the bottom dryer and the dryer
fabric (see Fig. 7). 3 blowpipes, also

ropes or rope pulleys)
I less maintenance (no lubrication ofrope pulleys)
I reduced risk of accidents

tion prevents the paper from piling up in
the double-tier dryer section in the case ofa sheet break.

Paper Machines

47

Fig. 9:Tail transfer systems in the area of the
Speedsizer, calender, and pope reel.

● rope threading● ropeless threading
view “A”

tail cutting device

knife

vacuum transfer conveyer

“A”

air

9

Tail transfer in the dryer section of a

how to transfer the tail and it shows where

mass of paper is blown into the rope nip,board machine

the units are installed. Also here, there iswhich will repeatedly interrupt produc-

In the dryer section of a board machine,

the ropeless approach using vacuum

tion. To solve this problem, Voith Sulzer

the tail is transferred with 3 ropes: one

transfer belts on the one hand and the cut-has developed a new cutter design, theinner and one outer supporting ropeting devices using rope systems on the

EasyCut. The design and operation of theand a central clamping rope. As inother.

EasyCut are described in the last chapter

board machines basis weights are highof this article.

and speeds are low, hardly any prob-

Tail cutter with rope transfer

lems occur in tail transfer.

A pneumatic cylinder swivels a knife

Ropeless transfer

towards a stationary knife. The stationary

For ropeless tail transfer in the area of theknife is screwed to a frame. The knife

pope reel and the calender, the vacuum

Tail transfer systems in the area ofedges have to be set so that a small clear-transfer belts mentioned before can be

the size press, calender, and pope

ance is left between them. The tail is cut

used.

reel

by the two knives and blown by air into the

In these areas, ingoing dryness and,downstream rope nip (see Fig.9). How-

This transfer device consists of a tail cut-consequently, relative paper strength isever, at high speeds (1000 m/min =ter, a vacuum-augmented transport belt, ahigh, which is a great benefit in the

16.6 m paper/second) the paper will pile

blower, and a separate drive for the trans-

transfer process. Fig. 9 shows two ways

up at the knives, so that an uncontrollable

port belt (see Fig. 9).

48

Fig.10:
EasyCut.
Fig.11:
Installation position EasyCut.

11

10

The transfer tail is picked up by the doctor

cutting and transfer systems observed in

the tail. At the same time, the integrated

from the dryer, cut by the cutting device

practical applications a completely new

blowpipes are charged with air and imme-

and placed onto the approx. 15 cm wide

device was development. One of the key

diately blow the tail into the rope nip. As

transport belt. The transport belt is vacu-

issues was to solve the problem of paper

the speed of the roller is slightly higher

um-supported. As the belt moves fasterpile-up and tail cutting at the cutting

than that of the paper and the knife isthan the paper machine, there is no sag-device. Another focus was on the safe

positioned in an optimal manner, no paper

ging of the tail. Air nozzles are installed attransfer of the tail into the rope nip at any

will pile up in this area. Upon completion

the belt end, which induce sufficient ener-

basis weight.

of transfer, the movable part automatical-

gy in the tail to move it to the next posi-ly returns into its initial position.

tion. In complicated transfer configura-

The EasyCut Fig. 10 works along the fol-tions, it is possible to arrange several

lowing lines: The web is picked up by

The EasyCut offers the following advan-

belts one after the other or use a pivotedmeans of the doctor from the dryer andtages over conventional tail cutters:

design.

runs vertically into the pulper Fig. 11. The
approximately 20 cm wide transfer tailI guiding of paper tail to the cutting

runs down between the clamping and thepoint – no pilling-up of paper

EasyCut – a new tail cutting and tansfer

guide rollers. During transfer, the mov-

I roller speed larger than paper speed

deviceable part of the EasyCut is pivoted

for maintaining tension in paper tailThe EasyCut, a recent development madetowards the tail. The roller mounted on

I can be used for any basis weightbyTechnology,

the movable part (guide roller) directs the

I flexible adjustment – space-saving

ensures simple, automatic cutting andtail towads the clamping roller and main-transfer of the paper tail. Based on a col-tains tension in the tail. The knife now

lection of the drawbacks of conventional

moves out of its waiting position and cuts

Voith

SulzerPaper

designI reduced risk of accidents due toretracted knife.

Finishing

49

Finishing Division:
Janus – a new technology for old calenders?
The modular Janus concept was developed right from the beginning for using
newly designed elements in existingsupercalenders and soft calenders (seeFigs. 1 and 2).
Of course not every paper grade benefits
from the Janus concept – although applications range from improved newsprint
through coated and uncoated rotogravure
printing

paper

to

variouswood-free

grades (see Tab.1).
1

A cost/benefit analysis of Janus calendering technology soon shows that the highest quality paper
gradesnaturally

benefit the most.
As shown in Table
2, not only theclassical

surfaceparameters

such

as

gloss

and

smoothnessareimproved, but also
The author: Franz Kayser,
Marketing Manager,
Project Development,
R&D, Finishing Division2

opticalparame-ters.

Particularly

new technology.

with the faster output. Thirdly, offline cal-black

calendering

Fig. 3 indicates the various possibilities

endering can now be integrated into thewithin this direction. First of all, the speed

papermaking and coating line.

rotogravure printing papers – which had

increase allowed by upgrading two exist-

to be accepted as non-improvable ining supercalenders to Janus makes itsupercalenders so far – are now a thing

unnecessary to install a third one. And

In this latter connection, Fig. 4 showsof the past. Apart from quality enhance-

when

coating

how a soft calender with its limited tech-ment, however, calendering speed andmachine speeds are increased, an extra

nology was replaced with a 6-roll Janus

efficiency can also be improved by thiscalender is not required for catching up

calender – without discarding expensive

problems

papermachineand50Fig. 1:
Existing supercalender for double-coated papers.
Fig. 2:
Existing soft calender.
Fig. 3:
Rebuild possibilities: supercalender ⇒ Janus.
Fig. 4:
Soft calender rebuild to online Janus calender.

Table 1: Paper grades suitable fora rebuild from supercalender / soft
calender to JanusI SC-C (improved newsprint)
I SC-B (upgraded newsprint)
I SC offset
I SC-A (natural rotogravure)
I SC-A (natural rotogravure +)I LWC offset
I LWC rotogravure
I 2-sided coated wood-free
I 1-sided coated wood-free3

Table 2: Technological grounds fora rebuild from supercalender / soft
calender to Janus
Higher calendering speed with sameor better printability and compressibility, through:I higher gloss
I higher smoothness
I less brightness loss
I less opacity loss
I less volume loss
I far less “ black calendering”
I few missing dots in rotogravure
printing
I greater surface strength for offset
printing

4

main components. This kind of upgrade

Airstream technology brings uncompro-

main advantage here is not only reutiliza-

represents considerable progress towardmisingly high quality results in this con-tion of the steel roll core, but above all

optimal supercalender quality.

nection.

the resultant optimization of the line
force profile in the calender. Fig. 6 shows
a comparison between a conventional

One of the basic modules of the Janus

On the left in Fig. 5 is a normal super-

plastic

concept is the plastic-coated roll used incalender cotton-covered roll. On the right

Airstream roll.

this technology. For multiple-roll super-is the same roll rebuilt with plastic covercalenderand Marun Airstream components. The

rebuilds

toJanus,

Maruncovered

roll

and

a

Marun

The screwed or welded journals required

Finishing

51

Fig. 5:
Cotton-covered roll conversion into a Marun
Airstream roll.
Fig. 6:Comparison of line force distributions.

with conventional rolls always cause line
force profile deformation extending into

Cotton-covered roll

Marun Airstream roll

the web width. This is due to the stiffening effect of the roll journals, which prevents the oval deformation in the rollcentre from extending to the roll ends inthe nip. Since the Marun Airstream roll is
supported over its entire length on theshaft, deformation variations and line
force profile errors are eliminated. Furthermore, these rolls are designed for5

automatic cooling, which prevents thethermal deformation otherwise affecting

Conventional roll

Marun Airstream rollplastic rolls (see Table 3).

In fact the Marun Airstream roll is one of
the main elements allowing existingsupercalenders to be upgraded to Janus
technology. It forms the basis for all the

The calender roll surface, particularly ofLine force

various Janus roll cover qualities.

heated rolls which do most of the work inensuring gloss and smoothness, is par-WOB

6

ticularly important in the Janus concept.
As shown in Fig. 7, the roll smoothness
is transferred completely to the paper
surface gloss.
In order to upgrade an existing calender
to this kind of quality, a particularlysmoothandglossyrollsurfaceisrequired which is also wear-resistant. On
the other hand, the heated roll must also
ensure a temperature high enough for the

Table 3:
Advantages of the Marun Airstream rollIConstant deformation over entire
widthIResult: constant line force
IAutomatic interior cooling
INo heat build-up
ILonger cover life
ICounterbalanced weight:
no interference with deformationnecessary calendering quality.
Wood-free paper with a well plastifiablesurface coating does not require such ahigh temperature, for example, as uncoated natural rotogravure paper. The
surface even of an existing roll can easily
be upgraded to the required smoothness
with the SumaCal-GD-03 coating specially developed for this purpose. Since most52

Fig. 7:The calender roll surface smoothness is fullytransferred to paper gloss.

existing supercalenders use water heating with a limited temperature range,
however, it may be necessary in somecases to raise the temperature, for example by installing single-zone inductive
heating using the Power-Coil system.

In other cases is may be possible toattaintheinstalling

requiredanewtemperaturebysteam-heatedroll(Fig. 8).

For many years all supercalender operators have been continuously suffered“W-profile” and its effects. One of the7main reasons for this line force profile
error is the overhung calender rollweight, which can only be counteredeffectively and above all on a long-termbasis by installing counterbalance bearings. The Janus counterbalance bearing
modules can easily be retrofitted to existing calenders, as has already been donein several cases (Fig. 9).

The opportunity can also be taken here
for eliminating other problems, such as
roll nip guard plates. These have to be
fitted extremely closely to meet today’ssafety requirements, but unfortunately
this not only leads in many cases tocolossal time delays, but may also causeroll surface damage. By installing a new
7

Janus calender, this problem is eliminat-

Finishing

53

Fig. 8:Heated rolls.
Fig. 9:Leversupported bearings on all rolls.

Heated rolls:
Further utilization of existing rolls
I Upgrading of existingheating/cooling system
I Power Coil installation

8

ed by installing one rope threading sys-

cover demands only 72% of the powertem for the web – a method which canrequired by a blue denim roll filling.

also be used for rebuilds.

Compared with cotton-filled rolls, only
about half the drive power is required.

As mentioned, one reason for a rebuild toJanus may be higher operating speeds –Fig. 11 shows power measurements on awhich immediately raises the question ofsupercalender 8.7 m wide for LWC paper

existing drive capacities. Fig. 10 shows

using blue denim roll fillings.

how drive power requirements are affected by web compressibility. Drive power
requirement rises roughly linearly withAs shown in the diagram, the proportion

basis weight increase.

of energy consumed by paper compression is relatively low due to the low basis
weight. The great majority of power

Drive power requirement is also affected(almost 250 kW) is consumed by the blueby roll fillings or roll covers, however,denim roll fillings. According to Fig. 10,

and in this respect the Janus plastic rolltherefore, about 70 kW less power would

9

54

Fig. 10:Comparison of drive power consumption
by paper and roll cover compression.
Fig. 11:
SNC Timavo. Filling material: blue denim
F Q = 54 g/m 2; Q UW = 310 N/mm.
Fig. 12:Janus Maastricht. Cover material:
Janutec F Q = 250 g/m 2; Q UW = 340 N/mm.
Drive energy consumption by
paper compression

Drive energy consumption bycover compression

P Pap

PNip

F G3 > FG2

crown compensation rolls. This also has
to be taken into account for a rebuild toJanus, irrespective of the existing tech-

CottonFG2 > FG1

nology or roll supplier.

Blue denim

FG1

Janutec

All kinds of Voith Sulzer rolls can be usedv

– such as S-rolls, Hydrein rolls or Nipcovrolls – as well as other makes, although⇒ Power demand rises

Blue denim⇒ Janutec

approx. linear to basis weightPNip 72%

Cotton⇒ Janutec

technical modifications may be required48%

to the rolls or control system.

10

Drive power

400
300

Paper
web

200

Cover

100

500
Drive power kW

Drive power kW

500

Energy consumption by top +bottom rolls

Energy consumption by top +bottom rolls

Drive power

Attempts have been made for many years
toward automatic cross-profile regulationof web thickness, gloss and smoothness
on multi-roll supercalenders – but nearly400

all these attempts ended in failure,

300

Paper
web

200

because the rolls used in supercalenders
get deformed after long periods underload and produce exactly the opposite

100
Cover

0

0

200

400

600

800

1000

0

0

200

Speed m/min

400

600

800

effect.

1000

Speed m/min

11

12

Since the Janutec plastic roll covers usedin Janus calenders eliminate this undesir-

be required after a rebuild to higher

was reduced by Janutec covers on anable characteristic of conventional roll

speed using Janutec plastic rolls. Since

existing Janus calender for wood-freematerials, optimal cross-profile regula-

every supercalender drive is designed forcoated paper with basis weight 250 g/m 2.

tion is now possible for the first time inworst-case conditions – new filled rollIn this case the relatively heavy web con-multi-nip calenders, including supercal-

condition with maximum diameter, lowest

sumes most of the power, while roll cov-enders rebuilt to Janus. Table 4 shows

hardness and thus highest power con-er energy absorption only accounts fortwo examples of this.

sumption – reserve power capacity in thisabout 100 kW.

case is at least enough for speeds wellover 1000 m/min.
Fig. 12 shows how power consumption

With most Nipco rolls, retrofitting is posDiagrams 11 and 12 also show the powersible for 2 x 12 = 24 zones in one typecomponent due to the top and bottom

and 2 x 30 = 60 zones in the other. For

Finishing

55

Fig. 13:
Existing supercalender (3) for SC papers.
Fig. 14:Janus calender rebuild from supercalender.

Table 4:
Possible number of zones for rollrebuild to Nipcorect
Nipco rolls
I Additional zones by inserting new
tube bundle
I Maximum number of zones depends
on dia. of central bore, e.g.:
90 mm dia. ¿ max. 12 zones
130 mm dia. ¿ max. 30 zones(per side)

13

Hydrein rolls
I Additional zones by inserting tubes
in each boring
I Old rolls ¿ 4 x previous numberof zones
I New rolls ¿ 2 x previous numberof zones

Hydrein rolls, the maximum number ofretrofittable zones is generally limited to
24. The resultant overall zone width gives
a substantial quality gain over the crossprofile, however.
14

Fig. 13 shows one of three supercalen-

one calender be shut down straight away,

ure papers.

ders for SC papers in a German mill.

but the other two still have substantial

All in all, our title question can therefore

Fig. 14 shows how these calenders would

reservebe answered in the affirmative – Janus

look after rebuilding, using all the Janussmoothness

modules.

would increase by 7 points at 50% of thecapacity.
after

With

comparable

calendering,gloss

speed increase, with significantly higher
opacity, appreciably higher volume – andThe calendering speed possible after

a dramatic reduction of the black calen-rebuilding is so high that not only candering effect affecting natural rotograv-

technology can definitely be used for oldcalenders, with excellent results.

56

Finishing Division:
Calender rebuild to Janus –economical aspects

The author:
Richard Meuters,
Marketing andDivision Coordination,
Finishing Division

Now that the Janus

employees and European representatives

In this article the general costs/benefits

concept is so wellon calender conversion to the Janus con-

to be considered are explained systemati-

established that it

cept. For our customers in the paper

cally. Main emphasis here is not on

is always consid-

industry, we are holding further work-

cost/benefit analysis for a specific case,

ered

the

shops worldwide where rebuild possibili-

since such an individual approach doesplanning procedureties will be explained in detail to calender

not deliver generally valid results.

for new finishing

operators. Response to our first work-

plants, apublicity

shop of this kind in Krefeld for German-

The economic benefits of the Janus con-campaign

entitled

speaking customers was overwhelming.

cept are therefore examined here on the“Calender

rebuild

toduringJanus”

basis of categories and criteria. Further-wasApart from technical and technologicalmore symbols are introduced to show
favourable or unfavourable effects.

thefeatures, one of the most important deci-

beginning of 1997

sion criteria of rebuild possibilities forfor existing superexisting calenders are of course the eco-calenders and soft

nomical aspects involved.

launchedatCategories

calenders. With 2-phase mailings to morethan 1600 decision-makers in the paper

The main questions to be answered in

The cost-effectiveness of calender rebuild

industry worldwide, the feedback rate ofthis connection are as follows:

to Janus greatly depends on whether thepaper manufacturing process is altered

more than 10% shows the enormousinterest in this promising concept.

I Whatcustomerinvestment
Apart from these mailings, the campaign

bring?

was launched with a „Rebuild sympo-

I Whichsium“

toinformFinishing

Division

aspects?

inbenefitstheanthereby. In contrast to the classicalconcept

supercalender concept, Janus calenders

does

Janus

can be installed offline as well as online
are

the

main

cost/benefit

in the paper machine or coating aggregate.

Finishing

57

Calendering can therefore remain offline

Symbols

calender not only involves additional

despite supercalender rebuild to the

The customer benefit of a rebuild tospace requirements (if structurally possi-

Janus concept, or be converted thereby

Janus is not presented here in terms ofble), but also additional infrastructure

into an online process. Furthermore an

cash figures but symbolized as follows:

costs such as crane, supply piping, spareparts, etc.

online soft calender can be converted
into an online Janus calender. The threerebuild categories are as follows:

A rebuild to Janus is also much morefavourable with regard to operating costs– all the extra energy required for the$ $Category 1

$ $

$ $

third calender is saved. And Janus calenders run on low-cost primary energy:

offline to offline

Favourable

NeutralUnfavourable

steam heating instead of water. So thelosses associated with converting electri-

Category 2

offline to online

Category 3

online to online

cal or fossil energy are eliminated.
Category 1: offline to offline

Despite the modest extra power consumption due to higher operating speed,

Example: In a mill with two supercalen-

the overall energy savings are a very

ders, a third calender is required due to agood reason for a rebuild to the Janusplannedconcept.

increase

in

paper

machinespeed. Alternative: rebuild the two superCriteria

calenders to Janus!

Among the numerous cost/benefit criteria
for investment assessment, the three

der operation are significantly reduced byCase analysis based on the above criteria:

most important ones are listed below:
Investment costs
I Direct
I Indirect
Operating costs
I Energy
I Human resources

The human resources required for calenconversion to Janus. On one hand theextra shift otherwise required for the

A rebuild naturally involves direct invest-

additional supercalender is not needed.

ment costs. Apart from the purchase

And on the other hand far fewer person-

price procurement – which may wellnel are required than for two convention-exceed the purchase price of a third

al supercalenders thanks to the greatly

supercalender – standstill costs must

reduced roll changing frequency (mark-also be considered, although these canresistant plastic rolls instead of conven-be significantly reduced by successive

tional rolls) and the threading devices

conversion.

used in the Janus concept. Furthermore,
the Janus concept eliminates compo-

Production and pricing
I Output
I Prices

With regard to indirect investment costs,

nents requiring high operating and main-

however, a rebuild to Janus is clearlytenance outlay, such as spindles and nip

more favourable. Installing a third super-

guards – again reducing labour costs.

58

Fig. 1Furthermore, indirect investment costs
Category 1

offline to offline

arise since the dry section must be converted (shortened) or the pope roller
repositioned to make room for the Janus

Cost-effectiveness
Investment costs

DirectOperating costs

EnergyProduction and prices

Output

$ $
$ $

$ $

IndirectLabourPrices$ $$ $calender.
The great advantage of this rebuild again
lies in the resultant energy cost savings.

$ $Apart from the aforementioned costadvantage of steam heating instead of$ $ResultCustomer benefit thanks to cost savings

water, winding and unwinding power
consumption is entirely eliminated. And
with continuous online operation, theAs far as production output is concerned,der. This is because of the cost reduc-substantial energy wastage due to accel-the cost-effectiveness of a rebuild invest-

tions possible, above all operating costs.

eration and braking of an offline calenderment is just as favourable. Althoughis also eliminated. The entire process

speed increases are limited if existing

Another example in this category is alsoheat from the paper machine and coating

main drives are not replaced, Janus tech-interesting: by converting one of his twoaggregate can be utilized, so that calen-

nology allows significantly higher calen-

supercalenders to Janus, a paper manu-

der heating requirements are significantly

dering speeds. This not only eliminates

facturer may be able to shut down the

reduced.

the need for an additional supercalender,

first one entirely. In the same way as in

but generally gives capacity reserves forthe previous example, the advantage here

Personnel requirements for an online

increasing paper machine and calenderlies in a substantial reduction of operat-

Janus calender are minimal. Calender

speeds later on.

ing costs.

operation and maintenance are generally
taken over by the existing paper machineWith regard to paper quality and attain-crew, thus reducing labour costs enorCategory 2: offline to online

mously.

Example: In a mill with two offline super-With regard to production output, Janus

calenders or a 3+3 roll offline soft calen-

calenders are generally compatible with

Fig. 1 shows how criteria are met for

der, a Janus calender is installed online

today’srebuilds in category 1.

with the paper or coating machine.

speeds. Furthermore, a rebuild to online

Results:

All in all, an offline to offline

Here again, apart from direct investment

question of finishing capacity for future

rebuild gives greater customer benefit

costs standstill outlay is involved, whichneeds on existing paper machines andthan installing an additional supercalen-

negatively influences cost-effectiveness.

coating aggregates.

able market prices, there are no significant differences between supercalenders
and Janus technology.

paper

and

coating

machineJanus deals very effectively with theFinishing

59

Fig. 2The critical parameter when a supercalender is replaced with an online Janus

Category 2

offline to online

calender is calendering quality, whichbasically depends on the number of nips.
In the past, the inadequacy of multi-nip

Cost-effectiveness
Investment costs

Director more 2-roll stacks.

Operating costs

EnergyThanks to Janus technology, this prob-

Production and prices

Outputcalenders for online processing was why
online soft calenders were limited to one

$ $
$ $

$ $

$ $

Indirect$ $LabourPrices$ $$ $lem is now a thing of the past. Due to themodular concept, a wide variety of roll

Result$ $Customer benefit thanks to cost savings

configurations – from single nip to 8-nip
operation (2 x 5 rolls) – is not only possible but already realized. The flexibility

without increasing production costs sig-

Here again, energy costs are substantiallyof the Janus concept thus ensures thatnificantly.

reduced. The soft calender with its“open” heating rolls radiates thermal

the quality attained by an offline calendercan be reached by an online Janus for the

Fig. 2 summarizes assessment results forenergy continuously. The heating energy

majority of paper grades.

rebuilds in category 2.

required for single nip calendering is par-This means that attainable market prices

Results: Likewise rebuilds to Janus in theare equal to those with offline qualities –offline to online category bring substan-

Radiation losses therefore cause highbut production costs are much lower

tial customer benefit, thanks to operating

costs, last but not least in view of resul-

than prior to rebuild.

cost reductions.

tant shop heat which has to be removed

ticularly high – and expensive.

through the

air-conditioning system –An important point in this connection iswhich also requires energy. It is not bythat the Janus concept also allows

chance that this type of calender is often
Category 3: online to online

referred to as an “energy killer”.

number of nips can be individually con-

Example: A 2+2 roll online soft calender

By converting online soft calenders to thetrolled for any desired gloss and smooth-is converted into a 1 x 6 roll Janus calen-

Janus concept, these excessive costs are

ness, whether 1-sided or 2-sided. Thisder.

reduced in two ways. First of all the rollgreater calendering flexibility. Whatever
the configuration, single nips or any

surface temperature is lower, so that here

allows fast and flexible adjustment ofmarketApart from the direct investment costs

again, steam heating can be used instead

demands. In recessive times, competitive

already mentioned, there are no indirectof oil or electricity. Secondly, the heating

chances can thus be improved throughcosts in this case since space for theroll diameters are much smaller and heatsuperior quality of standard paper grades

online calender is already available.

two nips at the same time. And since theproduct

qualitytochanging

60

Fig. 3

terms of higher prices due to higher
Category 3

product quality at the same manufactur-

online to online

ing costs.
Cost-effectiveness
Investment costs

DirectOperating costs

EnergyProduction and prices

Output$ $$ $good many are now underway – has its
special features which affect individual$ $Labour$ $Every rebuild project in practice – and a$ $Indirect

aspects of the general economics investigated in the above.

$ $Prices

The reals scope of rebuild varies accordResult$ $Customer benefit thanks to higher prices

ing to existing calender equipment, likewise local energy and labour costs affectthe breakeven point. For operators ofcalender rolls are covered with paper

In this case, for example, annual turnoverdouble and triple calender configurations,anyway, heat radiation is much less.

would rise by more than 1 million DM for

however, the advantages of a rebuild to

one paper machine alone! Since thisJanus should be checked.

Rebuilding an online soft calender toextra income – thanks to the Janus con-online Janus has practically no effect on

cept – is possible at about the same

In summary, all existing calenders can bepersonnel requirements or production

costs as for online production of stan-converted to the Janus concept – soft

output.

dard grades, the financial advantages arecalenders as well as supercalenders. And

obvious.

this applies not only to Voith Sulzer

The critical parameter for cost-effective
conversion from online soft calender tocalenders but also to all other.
Fig. 3 summarizes results for category 3.

online Janus is calendering quality. As

By the way: during the course of 1997

mentioned, Janus calenders achieve theResults: In contrast to the other cate-

three supercalender rebuilds to Janus willsame gloss and smoothness results asgories, customer benefit with an online to

go into operation.

supercalenders, depending on the num-

online rebuild lies not in cost savings but

ber of nips.

in value added – and therefore in higher
product prices.

So in the present example a newsprint
soft calender can produce SC-B grades orAfter investigating all three categories,

better after conversion to Janus (andthe original question as to rebuild cost-suitable paper machine modifications). A

effectiveness can be answered as follows:

glance at a paper price list is enough to

Whatevershow what this means in terms of finan-

investment is always worthwhile. Either

cial returns.

in terms of operating cost savings, or intherebuild

category,

the

61

Service Division:
Potential in Europe
plant

lems – 365 days per year round the clock.

In addition, further Service Centre loca-

availability and op-

According to our strategy “global re-tions are planned in Scandinavia andtimal paper quality

cources – local response”, the Service

Southern Europe.

– two major goals

Division is represented in the main paperof the pulp andproducing regions.

Maximum

paper

impressively comprehensive. They in-industry
often

Apart from the various Service Centres include complete servicing of all plant andhard to achieve. So

North and South America, Europe’s large

machine components, whatever the makemany factors af-

pulp and paper industry is supported byor type. And whether for maintenance or

fect the production

Voith Sulzer Paper Technology Service

repair, conversion or modernization: to-process that new

Centres in the following strategic loca-

gether with the customer and other Voith

problems,

tions:

Sulzer Paper Technology Divisions, ourwhich

The author:
Kirsten Kolvenbach,MarketingService Division

The services offered by these centres are

are

both

specialists always work out the optimallarge and small,have to be solved

Düren Service Centre (Germany)solution according to specific needs.

every day in routine maintenance as well

Heidenheim Service Centre (Germany)

as emergencies.

Ravensburg Service Centre (Germany)

For efficient problem-solving, thoroughWeissenborn Service Centre (Germany)

analysis by appropriate measuring meth-

The Voith Sulzer Paper Technology Ser-

St. Pölten Service Centre (Austria)

ods is indispensable. Apart from trou-

vice Division is on standby for such prob-

Kriens Service Centre (Switzerland)

bleshooting, a plant condition analysis is62Fig. 1:Service Centres in Europe.
Fig. 2:A large paper machine roll for balancing.
Fig. 3:
Machining the centre seating of a suction rollsleeve.

Weißenborn
Düren

Heidenheim
Ravensburg

St. Pölten

Kriens12carried out or possibilities are investigat-

short time. Likewise for field thermal

ed for optimizing the production processspray coating, our modern equipment

and product quality. Furthermore, perma-

guarantees absolute uniformity. And withnent condition monitoring enables pre-our special-purpose vacuum extraction

ventive maintenance measures, thus pre-equipment, environmental hazards andventing consequential damage.

human risk are eliminated.

For plant conversions or modernizing in-

Through the Voith Sulzer Paper Technol-

dividual components, our service special-ogy Service Division, customers profit

ists can be called in right from the outset

from the entire Group resources in know-

in an advisory capacity. They bring withhow and manufacturing facilities – justthem not only outstanding know-how, but

contact your nearest service centre.

also the latest machining equipment. Even
the largest rolls can be ground and resur-

To find out more about the facilities of3

faced – because the range of service centre facilities is just as wide as the variety

fered by our European Service Centres,
read on:of roll diameters, widths, materials, sur-Likewise for field repairs, our Service

face finishes and weights. From balancing

Centres are equipped with the very latest

Düren Service Centre

to journal repairs, our roll services are ful-in mobile facilities. For example: in-situ

The Düren Service Centre people have aly comprehensive.

roll grinding on the paper machine can be

reputation for fast and personal help in

carried out to high precision in a very

emergencies. One of the latest examples

Service

63

Fig. 4:
Suction roll test rig.
Fig. 5:
Polar coordinate display of balancing
characteristics.

45of this was a breakdown caused by roll

Heidenheim Service Centre

tremely smooth running and outstanding

sleeve damage in a high-load press.

Located directly at the centre of compe-

operational behaviour, even at the highest

Shortly after the customer called at 10

tence (COC) for printing/writing paper

speeds.

a.m. on a Sunday morning, our service

machinery, Heidenheim Service Centre

centre specialists were on the spot with all

can access the latest findings to the bene-

the equipment required for roll disman-

fit of customers. For refurbishing suction

Ravensburg Service Centre

tling. At the same time a reserve roll was

rolls, for example, modern developments

Monitoring systems at the Ravensburg

prepared in the Service Centre and trans-

can be put into practice right down to theService Centre are the latest way of keep-

ported to the mill for installation in thelast detail: conical cover seatings for re-ing check on the production process andpress. At 6 p.m. on the same day the pa-

duced dynamic loading, oil lubricatedplant condition. These systems, which

per machine went back on line withoutsuction box bearings for greater reliabili-

can be individually configured to suitproblem.

ty, etc.

plant needs, enable systematic problem
analysis and diagnostics as a basis for

Another example: the Düren Service Cen-

After suction box overhaul, a test run iscondition based maintenance. The ulti-

tre offers grinding capacities up to almost

made on a special rig to check the sealing

mate goal is to optimize paper quality and

100 man-hours per day, so that several

bars in particular. This ensures optimal

maximize machine availability.

rolls can be refurbished simultaneously

running of the reinstalled roll. Dynamic

with relatively short downtimes. Thebalancing in three planes with graphicalInstead of completely replacing tissue andDüren facility and know-how can handle

display of results is another service at the

MG cylinders, the Reshelling procedure

all roll sizes, from the smallest to the

Heidenheim Centre. Thanks to modern

recently developed at the Ravensburg

largest.

balancing machines, this results in ex-

Service Centre refurbishes only the shell

64

Fig. 6:
Machining a JANUS CONCEPT roll.
Fig. 7:
Condition monitoring system.

6

7and if necessary the inner condensate

plemented successfully for some years

fan balancing and conditional monitoringdrainage system.

now in various paper mills.

of roller bearings during operation.

In addition to general maintenance and

The Weissenborn Service Centre also re-

St. Pölten Service Centre

overhauls, the Ravensburg Service Centre

pairs and installs all kinds of paper ma-

The world record paper machine in

specializes in NIPCO rolls. To ensure fullchinery components, including pipework

Braviken is equipped with an importantfunctionality of these rolls after refurbish-and pumps. Services range from diagnos-

component emanating from the St. Pölten

ing, a NIPCO test facility is available fortics to final condition assessment after

Service Centre: the GR roll cover of the fu-

checking operation and sealing. The mod-the completion of repairs and installation.

ture. As an alternative to granite rolls orsynthetic covers, ceramic covers are ideal

ern CNC grinding machines here enableoptimal high-precision grinding, even of

For customer support in case of planned

for all press types and all kinds of furnish

the coated SUMEcal GD rolls used in the

shutdowns, the Service Centre carries out– including those with high waste paper

JANUS CONCEPT.

pre-checkups. Three or four weeks priorcontent.

to shutdown, the condition of key components is checked. Based on results, rec-Thanks to its outstanding characteristics

Weissenborn Service Centre

ommendations are then made for system-– such as significant reduction of paper

Apart from detailed services such as roll

atic repair or optimization measures.

tension and tearing – the GR roll covercan stay in service for many years without

grinding or component repairs, the Weissenborn Centre also undertakes complex

Technical diagnostic methods round off

grinding. If required, the St. Pölten Ser-long-term service orders for total plant

the services provided by the Weissenborn

vice Centre can supply GR covers com-maintenance. This strategy has been im-

Centre, enabling details such as on-siteplete with roll.

Service

65

Fig. 8:
Grinding a GR ceramic roll coating.
Fig. 9:On-site thermal spray coating.

8

9

The St. Pölten Centre also provides on-

The Kriens Centre also provides services

machinery and spare parts deliveries tosite coating services for poperollers andsuch as roll balancing and complete over-works servicing or on-site overhaul.

reels, using portable sandblasting andhaul or repair of plant components.

thermal spray technology equipment. Forintermittent removal of deposits from rollIn the case of suction rolls, for example,

surfaces, multiple sand blasting can be

the customer can select the service ele-

carried out. The type of surfacing is opti-

ments required for his specific needs –This summary of the services provided bymized according to paper grade, thus en-

from bearing diagnostics to comprehen-

our individual centres gives some idea ofsuring maximum grip and longest possi-

sive overhaul and repairs, including new

the vast potential of the Voith Sulzer

ble service life of the raw surface by

paintwork inside and out.

Paper Technology Service Division.

This results in uniform winding hardness

Likewise customers outside the paper in-

Whatever your needs, it is only necessary

and structure.

dustry are served by the Kriens Centre, re-to contact the nearest Voith Sulzer Paper

spraying with extremely hard materials.

sulting in valuable synergies from the ex-

Technology Service Centre. You will then

Kriens Service Centre

perience and know-how gained in thisbenefit from the know-how and potential

Customer support services in Kriens in-connection.

not only of our service division, but of theclude not only expert consulting and trou-

entire Voith Sulzer Paper Technology

bleshooting, but also well-versed paper

Another product of the Kriens Service

machinery erection staff to assist plant

Centre is the well-proven BELL line of vac-personnel during planned shutdowns

uum pumps and compressors. Services in

and/or conversions.

this connection range from complete

Group.

66

1

China:
Joint venture in China – Liaoyang Voith
Sulzer Paper Machinery Co. Ltd.
The close cooperation between Voith

The Liaoyang Paper Machinery Works

Sulzer companies and Liaoyang Paper(LPMW), as it was then called, was rec-

Machinery Co. Ltd, in the north-east Chi-ommended as most suitable partner.

na province of Liaoning, started in 1986.

The authors:
Mr. Zhao Juntal,
Chairman of theBoard, LVSC;
Heinz Appenzeller,
GeneralManager LVSC;
Walter Müllner,
Voith Sulzer
Paper Technology,
chief representativein Beijing.

At that time J.M.Voith AG, St. Pölten/Aust-In 1987 LPMW signed a licence agree-

ria – responsible then for Group paper

ment with J.M. Voith AG for manufactur-

machinery marketing in the P.R. of China

ing packaging paper and board machinery– was looking for a joint-venture licensee

components in the People’s Republic ofamong leading Chinese paper machinery

China.

firms.
From 1986 to 1997, no fewer than nine
Negotiations were held with the Ministrylarge orders were completed on this basisof Light Industry, the Ministry of Foreign

for the Chinese paper industry, with

Trade

Cooperationequipment made in China worth around(MOFTEC), and the China National Import

250 million RMB (30 million US$) andand Export Corporation (CNTIC).

imports worth around 50 million US$.

and

Economic

Corporate News

67

Fig. 1:
Liaoyang city centre.
Fig. 2:Multi-fourdrinier board machine in Zhuhai.
Fig. 3:Dryer roll, 1500 mm dia.

These orders included the first DuoFormer H for Jin Cheng paper mills, alinerboard machine for the Wuhu Dong
Fang paper mill, several cylinder mould
former carton machines, and multi-fourdrinier board machine for Hongta Renhang mills in Zhuhai.
Based on these positive results with
LPMW and in view of Chinese market
development potential for packaging andboard machinery, Voith Sulzer Paper
Technology approved a joint venture in
1994 between J.M. Voith AG and Liaoyang
Paper Machinery Co. Ltd for marketingand manufacturing dryer sections androlls. Apart from the expected growth of
2

paper

consumption

in

the

People’sRepublic of China and the associatedimport of very large production aggregates, a decisive aspect here was theurgent need for modernizing or replacing
small to medium size machinery at reasonable cost.
Clearly this need could only be met
through adequate production of paper
machinery components in China withmodern know-how. Negotiations therefore started in 1994, and the new joint
venture was signed in March 1996.
After the necessary permits and businesslicence had been granted by Voith Sulzer
Paper

Technology

and

the

Chineseauthorities, this joint venture agreement
3

finally came into force on March 20, 1996.

68

Fig. 4:
Dynamic balancing machine.
Fig. 5:
Vertical boring mill.
Fig. 6:
Press section of a board machine in Zhuhai.

J.M. Voith has a 60% share in this joint
venture, with total assets around 17 million US dollars.
The LVSC headquarters and plant buildings are set up on a 25,000 m 2 site rightnext door to Liaoyang Paper Machinery
Co. Ltd. Apart from a small administrationbuilding for the company management,
sales department, financial and technicaldepartments, the three machine shops
cover an area totalling 10,000 m 2 .
One shop is equipped for machining dryerrolls and other heavy workpieces up to
32 tonnes (max. casting weight 25 t).
Rolls up to 8000 mm wide and 2200 mm
dia. are machined and dynamically bal-4

anced here, likewise small tissue rolls up
to 3600 mm dia. and 3800 mm wide.
In the second machine shop press rolls
and pope rollers are machined in diameters up to 1250 mm and widths up
to 12,000 mm, depending on diameter.
Here again, maximum workpiece weightcapacity is 32 tonnes.
The third shop is for works assembly anddispatch. Raw castings for dryer cylinders
are supplied by the LPM Co. Ltd foundry,
which is being modernized and expanded
to improve quality and enable rollcastings up to 1800 mm diameter and8000 mm wide. After expansion work iscompleted, the foundry and roll machine
shops will have a mean capacity of 5

6

Corporate News

69

Fig. 7:
The Liaoyang Voith Sulzer Paper Machinery
Co. Ltd. team.

7

420 dryer rolls per year (depending on

as key component suppliers, the LVSC

permanently located at LVSC headquar-

diameter and width).

joint venture can deliver complete paperters, and if necessary they can be sup-machines.

ported by additional personnel according

These shops can turn out up to 150 castto specific requirements.

rolls and 250 to 300 pope rollers. The

The importent role played in future by

Liaoyang Voith Sulzer Paper Machinerysales department of Liaoyang Voith Sulzer

LVSC in connection with large Voith Sul-

Co. Ltd. has received tender inquiries forPaper Machinery Co. Ltd. (LVSC) works

zer Paper Technology contracts in China

projects in China, Korea, Iran (in connec-

closely with the Voith Sulzer Paper Tech-

will included the placing of local produc-tion with Chinese development aid) andnology office in Beijing and with the sales

tion which cannot be handled by LVSC orfrom an Austrian/Chinese joint venture.

departments of Voith Sulzer Paper Tech-

LPM Co. Ltd.

The first small orders have already been

nology companies.

booked, and further orders are expected
According to current planning, humanby the time the production plant starts

Particularly important in this connection

resources will be expanded to 221

operating in mid-1997. This new company

is that with our Chinese partner and/or

employees in the final phase. Two Voith

is clearly going to reach its ambitious

Voith Sulzer Paper Technology companies

Sulzer Paper Technology managers aretargets.

70

Great Britain:
A new home for Nipco
Since the announcement in September
last year that the NIPCO roll business is tobe transferred to Voith Sulzer Finishing,
Voith Sulzer Manchester has been undergoing somewhat of a transformation to
become the Centre of Manufacture and the
new home for NIPCO.
In order to successfully co-ordinate these
efforts, Voith Sulzer Krefeld became theCentre of Product, responsible for designand development. Teams were immediately established in both Manchester andKrefeld to organise the transfer of the
NIPCO business activities from De Pretto
Escher Wyss in Schio, Northern Italy.
Thiscomplexmove

involves

taking1

onboard the technicalknow-how,extensive technical knowledge gained by

the test rig transfer – can take place. To be

re-siting the com-

Voith Sulzer Krefeld during manufacture

fully operational in the Manchester plantponents and spareof the Hydrein roll, which was previously

by the end of September, the new installa-

parts stock, pat-marketed in competition with NIPCO.

tion will allow comprehensive dynamic

terns, tooling, test

testing of the largest of rolls, some of

rig and of course,

Current NIPCO roll production in De Pret-

which already form part of the orders now

the manufacturing

to is now tailing off and with completionin hand since commencement of produc-

technology.

of the existing contracts planned for Junetion in Manchester (refer to table).

of this year, the final piece in the jigsaw –In becoming the
The author:
Nigel Ashworth,Finishing Divisioncentralmanufac-

Quantity

Customer

Diameter
mm

Face
mm

Type/Sizeturing base for all
deflectioncom-

3 Rolls

Hansol, Korea

610

5120

F/6

pensatingrolls,

6 Rolls

Port Hawksbury, Canada

980

9680

KLCR/15

2 Rolls

Braviken, Sweden

905

8950

F/13

1 RollHylte, Sweden

1035

8780

F/15

7 Rolls

N. N.

1003

9970

F/15

Manchester will draw on over thirty yearsof experience in the design and manufacture of the Swimming roll (now known as
Econip). It will also benefit from theCorporate News

71

Fig. 1:
The new assembly bay under construction.
Fig. 2:
Expansion programme will include the
manufacture of wider NIPCO calenders.
Fig. 3:
The Dedicated NIPCO Design Team.

2

The contract for Port Hawksbury in Cana-

Being accredited to the ISO 9001 quality

da is arguably one of the most technicallymanagement system for over 6 years,

demanding of roll designs built so far.

Manchester will continue to meet interna-

With a total of 54 zones each, these six

tionally recognised quality standards for

NIPCORECT rolls will be installed in two

the design and construction of all deflec-

new Janus concept calenders. They eachtion compensating rolls and finishing

employ the latest state of the art Load-equipment.

ContRoll system for monitoring and identifying disruptive forces in the calender

In addition, Manchester will also co-ordi-

roll stack.

nate NIPCO roll quotations, tenders and3This undertaking by Voith Sulzer Man-order handling together with the centralisation of spare parts and service arrange-

chester, forms part of its expansion pro-start-up planned for September, 1997.

ments. Extensive component stocking

gramme which involves a new 1000

Clients will be able to run a wide variety ofwherever possible, will ensure a fast andsquare metre manufacturing bay withpaper grades under the most arduous ofefficient turn-round of spare part orders.

cranage capacity of 80 tonnes for theoperating conditions to meet the neverassembly and testing of rolls. The new bay

ending demands of todays paper makerA team of service engineers are on hand towill also be used to build larger ECOSOFT

for continuous improvements in end

offer crucial support around the world andcalenders as a result of extending the

product quality.

enable the Voith Sulzer Paper Technology

range and widths of units supplied out ofservice centres to continue to offer unpar-

the Manchester centre. The commitment

Basic design parameters will be:

to manufacture these wider machines will

Specific nip pressure:

be backed up by a new customer trial

Speed:

1500 m/min

facility and paper testing laboratory with

Surface temperature:

220 deg C

50 N/mm 2

alleled customer care in a most competitive market.

72

USA:
Voith Sulzer Paper Technology – rooted in
the history of North American papermaking

1800

1900

1950

VALLEY IRON WORKS

1960

1970

ALLIS CHALMERS

1929-VOITH LICENSE

MORDEN MACHINE CO

1980

85

87 88 89 90

1993

1994

VOITH
ALLIS

VOITH MORDENVOITH INC.

1967-ESCOFARREL
1968-USM

MANCHESTER MACHINE CO
1964 DIAMOND INT.

1976-EMHARDEW
MAN

SULZER ESCHER WYSSBIRD MACHINE COBEW
SULZER
PAPERTECKLEINEWEFERSHUNT & MOSCROPThe story of Voith Sulzer Paper Technology is deeply rooted
in the development of the North American pulp and paperindustry. The origins of most of our products and divisions
date back to the end of the last century. Todays presence isbuilt from the vast resources of all our domestic and international founding companies. Ultimately all their talents,
knowledge and expertise were combined to form Voith Sulzer
Paper Technology North America, a recognized leader in oneof the largest industries on this continent.

The author: Ralf G.
Sieberth, Market &Business Development,
Voith Sulzer Paper
Technology North
America, Appleton

Our history is deeply rooted in the economic development andpioneering spirit that made the paper industry a dominating
industrial force.

Bird Machine Company
George Washington was only halfway
through his second presidential term in
office when George Bird opened his
paper mill in Walpole, Massachusetts.
The small mill located southwest of
Boston manufactured printing and wrapping paper. The quality of Bird’s mill
eventually made them the sole supplier ofUnited States banknote paper.
During the late 1800’s, George Bird’s
grandson, Charles, traveled to Europe
and returned with a German papermaking
screen. It was the first in America, and it
was a great success. By 1909 the Bird

Corporate News73

Fig. 1:
Bird screen. Built 1936 for Nekoosa Paper,Port Edwards .

Fig. 3:
1978. Preassembly of a press section
at Manchester Machine Company.

Fig. 2:
Voith Sulzer Paper Technology in Mansfield, MA,
today – originating from the previous Bird MachineCompany.

Fig. 4:Voith Sulzer Paper Technology in Middletown,
OH, today – the successor to Manchester
Machine Company.

1

3

2

4

Machine Company secured a license to
manufacture the screen and became aleading supplier of screens and cleaners
to the American paper industry. In 1987
Sulzer Escher Wyss of Ravensburg, West
Germany entered into a joint venture with
the Bird Machine Company to form Bird
Escher Wyss (BEW). BEW, now located in
Mansfield, Massachusetts, would soon
become one of the most comprehensive
stock preparation suppliers in the world.
Two years later, Sulzer Escher Wyss purchased BEW, making it an integrated
designer and manufacturer of paper
machinery and stock preparation equip-

ment. It also became a major parts andservice center.
Manchester Machine Company
The Middletown, Ohio operation wasstarted in 1860, when manufacturing
boomed along the Great Miami River insoutheastern Ohio. It manufactured
machinery for the paper and tobacco
industries, and is one of the oldest continuously operating businesses in thearea. In 1949 the company was named
Manchester Machine Company.
Manchester Machine Company became
known worldwide for its Manchester For-mers, used to manufacture containerboard and folding boxboard. Manchester
Machine Company also built smaller
paper machines and components, including suction rolls, headboxes, presses,
calenders and winders.
The present facilities in Middletown, justnorth of Cincinnati, were built in 1959. In
1964 it became part of Diamond International Corporation, best known in the
United States as a manufacturer of safety
matches. In 1980 Sulzer Escher Wyss
acquired a minority interest in Manchester Machine Company and it was renamed
Escher Wyss Manchester. The name was

74

Fig. 5:
Grinding of a Yankee dryer in the early twenties
at Farrel, Ansonia, CT. Today roll grinder manufacturing and service are provided by Voith Sulzer
in Appleton, Wl.

changed to Sulzer Escher Wyss in 1983
when Diamond International sold theirremaining shares.
Kleinewefers and Hunt & Moscrop
Kleinewefers, founded 130 years ago, hadlong been known as a supplier of calenders to the paper industry. The successful German company was a leading force
in supercalender technology worldwide,with a large market in North America.
They had also been advancing softnip
calender technology since the early
1980’s. The 65 year-old British firm of
Hunt & Moscrop had focused their manufacturing on supercalenders, and later
helped develop softnip calenders. Kleinewefers acquired Hunt & Moscrop in 1985.
In partnership with Kleinewefers, Hunt &Moscrop continued to advance softnip
and hardnip calender technology. For thelast three decades they have been amajor supplier of swimming rolls to theworldwide paper industry.
When Sulzer Escher Wyss purchased
Kleinewefers, the Hunt & Moscrop North
American office in Atlanta, Georgia was
moved to the Middletown facility. The
Ohio Sulzer Escher Wyss product line
now included the original Manchester
paper machinery, Bird stock preparation
technology and Kleinewefers, Hunt &Moscrop paper finishing machinery.
In 1993 the Sulzer Escher Wyss namewas changed to Sulzer Papertec to reflect
the acquisitions of the Kleinewefers, Hunt
& Moscrop and Bird product lines.
Morden Machine Company
Morden Machine Company was formed in
1929 by C.W. Morden in Portland, Oregon. Mr. Morden had developed and5patented one of the first conical pressurized refiners, and later developed the firsthigh-shear pulper for the reclamation ofwood fibers.
Morden Machine Company became aleading supplier of refiners and pulpers
to the paper industry throughout North
America. While Morden continued todesign and patent machines, they werebeing manufactured in Washington, Oregon and Oklahoma.
The company was operated and controlled by the Morden trust until 1967,
when the company was purchased by
Esco Corporation, maintaining the Morden Machine Company name.
The German Voith family purchased amajority interest in Morden MachineCompany from Esco Corporation. The
name was changed to Voith-Morden andit continued to operate from the Portland
office.
In October of 1979, the company’s principal place of business was moved from
Portland, Oregon to Appleton, Wisconsin.
The company was reincorporated in theState of Wisconsin in May, 1982 as
Voith-Morden, Inc. At the end of 1988, allshares held by the Voith family and Esco
in Voith-Morden, Inc. were purchased by
J.M. Voith GmbH of Heidenheim, West
Germany.
Farrel Company
In the 1840’s Farrel Company of Ansonia,
Connecticut was manufacturing machine
tools for a variety of industries. During
the early 1900’s, Farrel began manufacturing roll grinders for the growing North
American paper and steel industries.
In 1968 the Farrel family sold the company to U.S.M. Corporation. U.S.M. was alarge diversified conglomerate that
owned companies involved in plastics,
gears, shoes and bottle manufacturingmachinery. When U.S.M. began to divest
their holdings, the Farrel Company wassold to the Emhart Corporation. Throughout the 1970’s and 1980’s, the Farrel
Company became the leading supplier ofroll grinders in North America.
Voith-Morden purchased the Farrel Company roll grinder division in 1987, andintegrated it into the existing Voith single-wheel roll grinder product line being
manufactured in Appleton, Wisconsin.

Corporate News75

Figs. 6 and 7:
Two views of a headbox from Valley Iron Works,
Appleton, WI, for Chillicothe Paper Company,
Ohio. Primary material was cypress wood.
Fig. 8:Valley Iron Works, Appleton, in 1843. It started
as a machine and blacksmith shop and today
Appleton is the North American headquarters
of Voith Sulzer Paper Technology.

6

7

8

Valley Iron Works
Valley Iron Works was started in 1883
as a small machine and blacksmith shop
in Appleton, Wisconsin. Its primary
products were milling machinery, waterwheels, and other machinery. An interesting historical fact: In September 1882,
Appleton was the location of the firsthydroelectric central station in the world,
installed to provide electricity to com-

mercial and residential customers. Valley
Iron Works was incorporated in 1900 anddeveloped into a manufacturer of pulp
and papermaking machinery to serve thegrowing Fox Valley paper industry. Until
about 1930, the firm’s principal products
were beating, screening, and refining
equipment.
In the early 1920’s Valley Iron Works
became the licensed builders of the Voith

Inlet, a specialized design of headbox
headers, an important part of fourdrinier
type paper machines. Up to this point,
the company had produced primarily
components for cylinder paper machines.
This machine concept began to fall fromfavor, bowing to the more productive
fourdriniers.
In 1945 Valley Iron Works began to produce its own inlet and headbox combina-

76

9

10

11

Corporate News

77

Figs. 9, 10 and 11:
Voith Sulzer Paper Technology North America inAppleton, WI, today. Aerial view (with the
Recycling Technology Center in the background)and machine shop.

tions. The Valley Headbox continues tobe so popular that today over 1,200
headboxes in North America bear theValley nameplate.
Valley made these and other papermachine sections until it was decided in
1958 that the organization was ready tomarket its first complete machine. The
first order, received late that year, went
to Nicolet Paper Company of West
DePere, Wisconsin, and the firm continued to produce complete paper machinessince that time.
Valley Iron Works changed its name after
the purchase by Allis-Chalmers of Milwaukee, Wisconsin in 1959. The change
in names continued until 1974, when
Allis-Chalmers entered into a joint venture with J.M. Voith GmbH, creating theVoith-Allis Corporation. Only three years
later, Voith purchased the remaining
shares from Allis-Chalmers and the organization became Voith, Inc., Appleton.
Voith, Inc.
With the incorporation of the Voith, Inc.,a new office and manufacturing facility
was built in Appleton’s Northeast Industrial Park, to meet the increasing
demands for paper machinery. The primary products of this greenfield facility
were the new generation of Valley headboxes, and the widely known Voith Wtype hydraulic headboxes. Within a shorttime, the company had expanded from aservice center to a highly successful, fully equipped engineering, manufacturing
and service organization.
In 1988, after eleven years of steady
growth and several major expansions, theVoith Inc. paper machine business was
combined with Voith-Morden. The addition of the Voith-Morden stock preparation and roll grinding divisions meant
Voith Inc. could now offer their customers a complete line of products, fromfiber treatment through papermaking andfinishing, from one company.
All Twogether Now
On October 1, 1994, J.M. Voith GmbHand Sulzer AG merged their paper
machinery businesses into a joint venture, named Voith Sulzer Paper Technology. It was the culmination of a process
and the realization of a new global company that crosses cultural and geographic boundaries to deliver the highest quality products and service to our customers. The enterpreneurial spirit of theNorth American paper industry pioneers
was successfully merged with European
technology for the benefit of a concentrated, more effective North Americanpresence.
Today, complete paper machines andcomponents are manufactured primarily
at two locations, Middletown, Ohio and at
the Voith Sulzer Paper Technology North
American headquarters in Appleton, Wisconsin, which is located only a few miles
from the original Valley Iron Works site.
Many of the technologies developed byBird and Morden Companies are still
incorporated into our stock preparationequipment. The merger of the productlines and research facilities provides
Voith Sulzer customers with the mostcomprehensive line of pulping and deinking systems in the world.
In keeping with the combination of extensive experience and a long time traditionof technological innovations from both

Farrell and Voith Sulzer designs, our roll
grinders continue to be developed as wellas manufactured in Appleton, Wisconsin.
Advanced technology design permits fullautomation, including automatic rollloading. These machines have retained
their leadership position in both theworldwide paper and metals industry.
The Voith, Sulzer Escher Wyss, Kleinewefers and Hunt & Moscrop technologies
have been combined to deliver theworld’s finest finishing equipment toVoith Sulzer customers.
An efficient network of five service centers span the North American continent.
Each center is fully equipped to perform
all types of repairs and service. This
includes roll and machine component
rebuilds, as well as the maintenance andrepair of pulp processing and stock
preparation components.
10
Together, these operations are Voith
Sulzer Paper Technology, one of thelargest suppliers and service providers to
the pulp and paper industry on this continent. Continuing growth in North America
will see an addition of a 41,000 sq. ft.
manufacturing area along with a 14,000
sq. ft. office space in Appleton, and a
15,500 sq. ft. additional expansion in
Middletown, Ohio.
“We’ve come to where we are today
because of our past … and our past is
the key to our future,” said Werner Kade,
President of Voith Sulzer Paper Technology North America, Inc. According toKade, “Our future will continue our tradition of drawing on the vast North American resources and talent, in a spirit ofcooperation with our European partners,
to deliver the greatest benefits to ourcustomers.”
11

78

NEWSPAPER HOAXESThe ingenuity of journalists

The Ingenuity of Journalists

On November 9, 1874 the owner of the
New York Times ran out into the street,heavily armed, and stalked his way carefully through the city, overcome by fear
and terror, in order to complain at the local police station about a severe lack of
information. He had just read an article in
the rival newspaper The Herald, which tohis horror reported the escape of a whole
series of wild animals, including extremely dangerous big cats, from Central Park
Zoo. Witnesses claimed to have seen
these animals attack and kill at least
27 people, and a list of these unfortunates was printed. About 200 injuries
were reported, with some of the victims
horribly mutilated. Most of the wild animals were still on the rampage in theFifth Avenue area, with only 59 of themso far recaptured or shot at the time of
the Herald going to press. The danger tothe populace at large was not yet over.
A story line which could just as easily
come from the Jurassic Park film – andindeed the story was just as fictional! The
owner of The Times, who really shouldhave known better, was completely taken
in by the story. Fear and terror had madehim forget the journalist’s unwritten law:read the story exactly and read it to theend. Like many of his contemporaries, healso failed to read the last sentence,
which stated: “The entire story given
above is pure fabrication. Not one wordof it is true.” In other words, it was deliberately intended to mislead uncriticalreaders, an ingenious ploy thought up by
the journalist with the laudable aim ofdrawing attention to the safety risks at
the New York zoo. This type of nonsenseis quite far removed from the vision
Johannes Gutenberg had when he revolu-

tionised the printing process with his interchangeable metal type. “Truth”, he no
doubt thought approximately 450 years
ago, “yes, truth will now reach out into
the last corners of the world.” One ofGutenberg’s first printed works was the
Bible. The official Truth was now available to everyone, the Word of God could
now be read without having to rely on interpretations from the clergy. One looked
reverently upon the printed book andplaced one’s faith in the written word.
Those black letters pressed onto white
paper with the entire weight of heavy
metal had begun their advance.

79

hanced undoubtedly by a faith in authors
who declared their intention of writing
down in the new medium nothing more
nor less than that which actually occurred in the world. “The Public Newspaper” appeared to upright thinkers to be
the “organ which preaches to the people
and the voice of truth which penetrates
not only the palaces of the mighty, but also the huts of the lowest.” Someone who
believed in this within the finest meaningof enlightenment was the German writer
Karl Philipp Moritz, who in 1784 was editor of the “Vossische Zeitung”.

This sacred trust was quickly shatteredby cunning counterfeiters and their resourceful counterparts, the authors.
These sharp-witted minds caught on immediately to the fact that paper in its
naive innocence will accept anything thatthe printing press delivers. Some choose
to create new worlds, others took to writing documents, reports and news articles
in order to control worldly things.
“Maneggiare la realtá” – in English: totouch upon reality, or in more modern
terms: to manage the world – was in
Machiavelli’s time quite common, a period in which some of the most famouscounterfeiters carried out their trade under the cloak of secrecy. They bore false
witness and let the black letters on theprinting block proclaim it to be the truth.

But with the newspaper was born an unpleasant twin, a tiny Beelzebub: thenewspaper hoax, known in Germany andFrance as “die Ente”/”le canard” (duck)
respectively. The hoax – a cunning bird –is full of deceit and constantly changes
its form. It creeps across the white paper(which nowadays quite often has a grey
tinge) as a full-scale deception, or surfaces as a confident lie in the garb of apolitician. Sometimes it appears in a respectable disguise, sometimes it’s loudand vociferous, sometimes it emerges
from the mouth or pen of an author’s
foolish henchman. For uncritical professionals and readers, the hoax is usuallydifficult to detect. Excellent bloodhounds
are needed, who with inborn criminological instinct can hunt down and expose
even the most elegant of yarns.

The belief in “black ink on white paper”
was finally shattered with the onset ofnewspapers, which took to the world’s
stage in the 17th century in the form ofpure “news sheets”. Widespread distribution of these printed articles increased
the power of the men-of-action, en-Karl Philipp Moritz had only to turn his
attention to Prussian Berlin to see that
his vision of the newspaper was alreadybeing questioned. An extremely honourable nobleman, the renowned Prussian King Friedrich the Great, a few centuries earlier, had had his fun and games

80

with his contemporaries’ faith in thenewspaper. He personally set one or two
hoaxes in motion, just to see which dizzyheights of persuasion they would finallyreach on their journey through the Berlin
newspapers of the day. One of his misdeeds has been handed down to us,
namely from March 5, 1767. He placed areport in the paper stating that roughly
one week previously, a devastating hailstorm had raged over Potsdam – a strategic hoax with the aim of providing the
population with a topic of discussion thatwould take the place of the forthcoming
military campaign which up till then had
been on everyone’s tongues.

The newspaper’s ambition to provide
people with detailed facts so that they
could comprehend the machinations of
the world better and by doing so finallymaster superstition, actually succeededin calling a new form of gullibility into
being. It can be briefly described in thisway: the newspapers state what is goingon in the world. Therefore, what is printed there – in black and white – must ac-

tually have happened. The grey sheetssoon became the Bible for the enlightened professions. Berlin’s newspaper
readers, and similarly the readers of the
New York Herald, firmly believed theprinted reports of catastrophes, an obviously rock-solid dogma on which politicians and even the “Yellow Press” in our
so-modern century can continue to rely.
Even today, honourable institutes use thenewspaper to stage their foolish pranks.
April 1st has become the ideal day in theWestern world to make fun of the readers
in a non-punishable manner and to draw
attention to oneself by means of sophisticated but harmless hoaxes. In 1986, theBritish Energy Ministry placed full-pageadvertisements in the London-based daily
newspapers The Times and Guardian inorder to play a fully-fledged governmental hoax. Disguised as a “Government Announcement” and filled with diagramsand details of powerful scientific credibility, it announced to the British populationthat they should put on their T-shirts at
11:00 Central European Time, due to thefact that a shift in the Earth’s axis would
move the British Isles extremely close to
the equator. The same day’s edition of
The Times contained an advertisement
supported with relevant diagrams by theGerman car manufacturer BMW, which
promised British car owners a rosy futurewhen driving on the European continent:
apparently the steering wheel could be
mounted on the right-hand side of the carby performing just one or two simple operations. BMW: the first car with left- andright-hand drive. Two hoaxes withjester’s caps on, although it has to besaid that they were not only highly inventive but also honourable, since they re-vealed their true identity at the end of theadvertisement.
Hoaxes such as these were very common
in the 19th century in the columns of thebooming newspaper industry. Newspapers were springing up everywhere andwere soon desperate for circulation, so
they had to be filled with interesting stories. The hunt for sensation was up andrunning; the race against the competition
was on. All these contenders for readership attempted to buy in the best news
articles and stories – some of which unfortunately were not verified before being
printed, due to the keen rivalry between
newspapers to be first. Among those who
assisted in producing exciting copy were
famous minds such as Mark Twain, whowrote for the Virginia City Territorial
Enterprise, or Edgar Allen Poe, whoearned his money working for various“dailies”. Poe, that master of the perfectly constructed horror and criminal story,
announced on April 13, 1844 in the New
York Sun that a captive balloon, albeit

The Ingenuity of Journalists

unintentionally, had crossed the Atlantic
from Europe. Equipped with a propeller,
it had been on the way from London to
Paris with the famous Monck Mason on
board. Unfortunately, the propeller had
broken down and the aeronautical vehicle
was no longer controllable. After 76 hours,
believe it or not, it landed in Charleston,South Carolina, driven all the way by aneasterly wind. Of course, not a word of it
was true! But people asked themselves if
a science-fiction hoax which fitted ideally
into the progressive thinking of the century, could not perhaps be justified in aworld where so many fantastic things
were indeed possible.
It was all quite harmless really: the entire
collection of foolish hoaxes had no permanent or tangible after-effects for thepeople who had fallen for them. However,a joke can indeed have a lasting effect,
and a simple newspaper article cansometimes turn into a document withdramatic consequences. In Chicago in
1899, a group of reporters, each one employed at one of the four local daily
newspapers, came up jointly with what
they thought was a brilliant idea. They all
filed a report stating that the Chinese had
decided to tear down the 2,450 kilometre-long Chinese Wall. The planning andexecution of this gigantic project had
been placed in the hands of American engineers, who at that very moment justhappened to be staying in Chicago. This
turned out to be a newspaper hoax with
diplomatic consequences, a hoax whichbecame entangled in the network of
American-Chinese relations. The Asians
suspected an act of United States aggression, and it was even suggested in various quarters that the hoax had con-tributed in a small way to the Boxer Rising (though this was never corroborated.)
In spite of all this, the hoax just described is well on its way to exchanging
its jester’s cap for a spiked helmet. Thiswar helmet was most definitely a featureof the so-called Emser Depesche. The
German “Reichskanzler”, Otto von Bismarck, received a telegram in 1870 inwhich His Majesty the King reported ontalks conducted between himself and theFrench Ambassador. The King also mentioned that it was no longer necessary toreceive the ambassador any more as they
had discussed the matter at hand fully.
Bismarck abbreviated the text ingeniously. His version then gave the impressionthat the King no longer wanted to receive
the Ambassador. The wily statesman hadtaken the relevant words out of context
and allowed them to appear as a categorical rebuke. He passed his version on to
the press and got his sought-after war
with France, which he needed urgently to81unite the German states under Prussian
rule. His manipulation of this information
went into the history books as a monumental piece of written “reality management”. Today, this type of information
manipulation is quite common. We nolonger refer to these “half-hoaxes” which
are usually to be found in the politicalarena, as lies, but as public relations oradvertising.
So newspapers do indeed tell lies; it’s all
there to see in black and white, and theinnocent paper to which we are all too
prone to allocate the role of the accomplice is crushed by the mendacious type
fonts. Information and news reports
don’t describe the world as it is, but
could be said to reinvent it. And there are
prizes awarded these days for doing so, as
the example of the reporter Janet Cooke
will illustrate. An article which appearedin the Washington Post on September 28,
1980 claimed to relate the horrendous
story of a boy who was already addicted

"twogether" is published twice annuallyin German and English. Contributions by
independent authors do not necessarilyreflect the opinion of the publisher.
Please address all correspondence andinquiries to the editor.

Published by:Voith Sulzer Papiertechnik GmbH & Co. KG
Editor:Dr. Wolfgang Möhle, Corporate Marketing,
Voith Sulzer Papiertechnik GmbH & Co. KG,
P.O. Box 1970, D-89509 Heidenheim
Tel. (++49) 73 21 37 64 05
Fax (++49) 73 21 37 70 08

Paper Technology Journal

Editorial coordinator:
Manfred Schindler, D-73434 Aalen

Newsmagazine for theinternational clientele,
partners and friends of

Design, layout and typesetting:
MSW, P.O. Box 1243, D-73402 Aalen

We owe the entertaining review of newspaper
hoaxes to Dr. phil. Hans-Joachim Grautner,
author, free-lance journalist and essay writer in
the arts, culture, literature and radio drama areas,
who is also a contributor to the Stuttgarter
Zeitung newspaper.

to heroin at the tender age of eight. For
this, she received the Pulitzer Prize. True,
she only bathed in the glory of this award
for a short time, until the mask of deception was finally torn away. Her reportturned out to be a clever and brilliantly
written hoax – pure fabrication.
Reporters and journalists are equal in
every way to those who write works offiction. But time and time again, to ourgreat good fortune, it is their very own
colleagues who put a stop to this misguided creativity. A weekly magazine published in France is particularly uncompromising in its treatment of hoaxers. The
satirical publication known as Le Canard
enchaîné, whose only purpose in life is toput “hoaxers” in chains (enchaîné). The
magazine tends to hunt mainly over others’ estates, despatching its henchmen to
flush out the hoaxes in other newspapers
and media. Quite a few politicians havealready tripped up over their own hoaxes,
which the uncompromising hunters havegathered in and given a prominent placein their publication, causing the victims’
careers to falter.
Thus is the honour of the newspaper
publisher re-established. Veracious, upright journalists do everything they canto ensure that their pages are kept freefrom the work of the crafty hoaxer and toprotect the readers from the consequences of a hoax actually making it into
print. In the case of our zoo story at the
beginning, the originators of the story
were fully aware of their responsibilities.
Not only was the article intentionally
written as a hoax and declared as such inthe paper, but the Herald editor took action immediately after seeing the chaoson the streets of New York, and put astop to any further distribution of thatparticular issue.

Correction:
Although we cannot claim this as a “newspaper hoax” – our customer journal twogether
is not entirely immune to the misprint gremlin. Unfortunately, in the last issue, No. 3, twoerrors have crept into the text. The article“GR cover – next generation performanceleader” should read as follows on page 53:“Since the cover has a minimum thickness
limit .010”, there is ample material for multiple regrinds.”
In addition to this, some of our customers received a German copy instead of an English
one or vice versa. All those who contacted us
in this connection were subsequently suppliedwith the “correct” language.Please let us know
if there were any more cases of confusion. We
will naturally supply a copy in the required
language.

7/97/20 SDZ. Printed on chlorine-free bleached paper manufactured with Voith Sulzer Paper Technology machinery.

Copyright 7/97:
No part of this publication may be
reproduced or copied by any means
whatsoever without the express permissionof the editor.