History of Development of Injection Molding Machine Technologies and Future Perspectives

History of Developmentof Injection Molding Machine Technologies
and Future Perspectives
Hiromasa Uezono Katsuhiro Fujii Kiyoshi Ochi Takahide Omobayashi-SynopsisOver half of a century has passed since we began our injection molding machine business operations in technicalcollaboration with the German companies Ankerwerk in 1961 and Krauss Maffei in 1963. Injection molding machines have
evolved from being hydraulically-driven to become superior electrically-driven, energy-saving machines that provide
precise, stable molding conditions. In 2004, JSW introduced the J-AD series, its 4th generation of all-electrically-driven
injection molding machines. Thereafter, JSW continued to develop a number of specialty machines that met market needs,
such as the J-AD-USM ultra-high speed injection specification series of machines, and machines in collaboration withsubsidiary Meiki Co. in 2010. Now in the present, we have just released the 5th generation J-ADS series in March 2015.
Over the past 10 years we have also poured our efforts into the development of process technologies. We advanced our
proprietary DSI process technology to create the HP-DSI process, acquired a commanding market share in Japan for the
MuCell foaming molding process. Screw and barrel technology and control technology are the core technologies of injection
molding machines, and we have continued to develop, improve, and bring to the market these technologies along with thereleases of new machines to stand apart from our competitors. In order to develop into a Global Top 5 company, we must
develop differentiated technologies that impress our customers and continue moving the progress of technologicaldevelopment forward.

1. Preface
A quarter of a century has past since electricallydriven injection molding machines first entered themarket with slogans for stable high-precisionmolding as well as energy savings. Throughout these
25 years, we have seen advancements at a component
level, such as the capacity enhancement of servo
motors which are a core component, and high load
support in ball screws, but not technologicalinnovation in the injection molding machines
themselves. This has resulted in further
commoditization and even fiercer price wars,
especially in Japan. Therefore, we launched the J-AD
Series in the market in 2004 and have striven
thereafter to develop and improve our process
technologies, such as HP-DSI and MuCell that aimed
to differentiate this technology, while also developing
our own original control technologies. In addition, we
have worked to jointly developed machines, such as
the opposed 2M machine, to leverage a synergistic
effect with Meiki Co., Ltd. through a business
partnership in 2008 and acquisition as a subsidiaryin 2010.

This report introduces technological developments
after the J-AD Series entered the market in 2004
around the four aspects of machine development,
process technologies, screw technologies and control
technologies in addition to describing the J-ADS
Series, which is the fifth generation of electricallydriven injection molding machines released into themarket in March 2015.

2. Technological Development of
Injection Molding Machines
2.1 Series Shifts of Injection Molding Machines(Fig.1)
We entered into a technological alliance withtwo German companies -- Ankerwerk in 1961 andKrauss Maffei in 1963 -- to not only develop andmanufacture small- to large-size injection molding
machines but also accumulate technology. These
injection molding machines used hydraulics as adriving force while adopting a toggle mechanism
for the clamping unit and an in-line screw system
for the injection unit. This series established aconcrete base in the injection molding machine

Injection Molding Machinery Engineering Dept., Hiroshima Plant

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History of Development of Injection Molding Machine Technologies and Future Perspectives

industry. However, as times changed together withgreat demand for reductions in the environmental
impact, hydraulic injection molding machines had
a series shift from the Japan Steel Works andAnkerwerk V-series (Photo.1) to the N, NA, N-BII,
J-S, J-SII, J-E, J-EII, and J-EIII until the final
transition from shipments of vertical type electric
servo drive injection molding machines at the
beginning of 2012 to electrically-driven injection
molding machines.
We solidified development of electrically-driven
injection molding machines with superior
environmental performance, such as energy
savings and no hydraulic oil, before everyone else
in 1984 and released the J-EL series full electric
servo drive injection molding machine for sale four
years later in 1988. At the time, we were confronted
by a variety of technological challenges inmotorizing injection molding machines. However,repeated improvements and refinements led to therelease of the J-ELII series in 1995, the J-ELIII
series in 2000, and the long-selling fourth
generation J-AD series in 2004.

2.2 J-AD Series
The J-AD series became a rare long seller in theinjection molding machine industry. Behind thissuccess was a diverse line-up of products that
gradually released small- to large-size and verticalmodels, had machine specifications superior tocompetitors as well as offered a timely additionalline-up of injection molding machines with uniquespecifications that matched market needs.

Fig.1 Series Shifts of Injection Molding Machines

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JSW TECHNICAL REVIEW No.20

Photo.1 V-series

History of Development of Injection Molding Machine Technologies and Future Perspectives

2.2.1 Small-size J-AD Machines (Photo.2)
The small-size J-AD machine was developed totarget the thin-walled precision product field andadopted high-spec injection specifications as thestandard machine contrary to competitors.
A tta i n i n g s u f f ic ie n t p e r f o r m a nc e wi th aconventional control was difficult to meet the highspec injection specifications for the small-size J-AD
machine. Therefore, leveraging our strengths indeveloping and manufacturing control technologies
and circuit boards, we succeeded in the developmentof an optimal high-speed servo control circuit for
an injection molding machine. This control circuit
was built into the J-AD series as the SYSCOM3000
Controller (Fig.2). The SYSCOM3000 controller
realized the fastest control cycle in the industry at
62.5 μs, which is its greatest feature. This
innovation has contributed greatly to stable highprecision molding in the high-speed injection
molding machine industry. In addition, thesimultaneous multi-screen display allows avisibility and intelligibility to realize a control thatis easy to operate by adopting a vertical 15-inch
touch panel in the operational section of thecontroller.
The J-AD series also employs a unique JSW
injection control built-in standard to achieve evengreater stable high-precision molding. A wide

Photo.2 Small-size J-AD Machines

Fig.2 The SYSCOM3000 controller

range of control systems are built-in to use as
standard options only available in electricallydriven injection molding machines, such as the
IWCS control that stabilizes the density of molten
resin through screw rotation after plasticizing iscomplete, software control to prevent peak pressure
right before pressure transfer in the injection
process, and APC control to limit overshooting andundershooting in the pressure control during theinjection process.
Thereafter, the small-size J-AD machine built ahistory as a long seller with performance outshining
everything else even today.
2.2.2 Medium-size J-AD Machines
The medium-size J-AD machine was firstreleased in June 2006 with the J350AD machinethat has 350 tf of clamping force before completingits expansion into a four model series of mediumsize J-AD machines in March 2007. The mediumsize J-AD series includes machines that can beused more safely thanks to greater rigidity in theclamping unit and the bed based on improvements
to molding stability represented by the built-in
high-speed servo control cycle following theconcepts of the small-size J-AD machine. We create
optimal designs via FEM analysis technologies,
especially for the platen and the bed, to improvevariations in thickness for actual moldings of flat
plates by 17% as well as reduce vibrations ofstationary platens during high-speed opening andclosing at least 30%.
2.2.3 Large/Ultra Large-size J-AD Machines(Photo.3)
Large/ultra large-size J-AD machines completed
the expansion of the full electric servo drive
injection molding machine from 850 tf of clamping
force in October 2009 and 1,300 tf of clamping force
in January 2011 to the world’s highest clamping
force at 3,000 tf in January 2012. These machines
were developed around the keywords “high-cycle
molding,” “energy savings” and “molding stability”
to satisfy market needs from larger and thinnermolded products for industries from automobiles,
office equipment and appliances to general goodsin addition to offering even greater productivity
and molding stability.
In terms of high-cycle molding, this series hasrealized faster opening and closing speeds throughthe adoption of toggle-type clamping structures

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History of Development of Injection Molding Machine Technologies and Future Perspectives

with superior high-cycle molding and energy
savings in addition to the pursuit of optimal toggle
designs. We have also evolved the screw design todramatically enhance high-cycle performance bydeveloping screws that satisfy lower temperature
uniform plasticization, higher mixing and higher
plasticizing performance.
In terms of energy savings, this series has
contributed to reductions in power consumption
and CO2 emissions by adopting the optimal toggle
designs described previously in addition to power
regeneration systems similar to hybrid automobiles
to regenerate energy accumulated throughmechanical operations such as injection andclamping into electric energy.
In terms of molding stability, we have improved
the control cycle described previously in addition
to developing proprietary multi-axis synchronous
control technology able to move four ball screws
with four-axis servo motors that each movesynchronously. These technologies contribute tostable molding by making high-power and highprecision servo systems a reality.

Photo.3 Ultra Large-size J-AD Machines

2.2.4 Vertical Type JT-AD Machines (Photo.4)
Vertical type JT-AD machines began sales ofrotary machines with 40 tf and 70 tf clamping force
from November 2006 and a rotary machine withthe world’s highest clamping force of 220 tf wasreleased as a vertical type electric servo drive
injection molding machine in 2009 to complete thedevelopment in the series. Vertical type injection
molding machines often are installed in-line aspart of the manufacturing line to be a machine
primarily for insert molding and need to be low to
the floor to lower the pass line of molded parts.
Moreover, this was developed as a machine able tosatisfy the requirements for a more compact
machine size, faster opening/closing and tablerotation speeds to improve productivity.

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Photo.4 Vertical Type JT-AD Machines

2.2.5 J-AD-USM Ultra High-speed Injection
Specification Machine
The popularization of the Internet and theprevalence of portable devices such as cellular
phones, smartphones, compact gaming consoles
and notebook computers are marvelous. Thisevolutionoftechnology
sparkedgreaterminiaturization and weight savings. Machinesthat have good injection specifications for filling
responsivity of resin at high speeds and highpressures had become necessary to makecomponents such as light guide plates and media
cards used in these devices thinner.
To address these various needs, we completed
the J-AD-60H-USM machine that realized an 800
mm/sec high-speed and high-response injection
performance in 2008 by decreasing the low inertiaof the device and increasing the output of the motor
based on the mechanical structure of a standard
machine.
60H-USM machines improve start-up of theinjection speed (acceleration) by 2.5 times compared
to conventional high-speed injection compliant
machines to reach a maximum speed of 800 mm/
sec in 13.5 ms. (Fig.3) We further improved andrefined the machine thereafter to allow themachine to reach a maximum speed of 1,000 mm/
sec today. Furthermore, higher speed control was
also required due to the improved injection speed
start-up, but we were able to facilitate stabilized
injection performance through the high-speed
servo control technology described previously.
Thereafter, enlarging and thinning of devices
advanced, even for the light guide plates following
the enlargement of tablet terminals such as

History of Development of Injection Molding Machine Technologies and Future Perspectives

Netbooks, and large-capacity as well as high-speed
high-response injection performance became anecessity.
Therefore,
theJ-AD-180H-USM
machine was released as an additional model in2010. The J-AD-180H-USM machine required twoaxis ball screws and servo motors to secure better
injection performance than the 60H, but we wereable to develop and utilize proprietary high-speed
synchronous control technology.
The machines were also equipped standard withelectric toggle-type injection compression molding
as technology to mold thin products such as lightguide plates. The toggle-type molding offers highspeed compression specifications built-in standard
with increased capacity of the servo motors forclamping as well as optimized pulley ratio tosupport ultra high-speed injection in addition to
enabling control of the mold position with anaccuracy at least ten times that of direct pressure
molding. A unique [Injection Synchronization]function able to synchronize the screw position andclamping force (compression force) during injection
has been added to attain molding products free ofdistortions and thickness variations.

Korean vehicles.
The machine has a middle platen between thestationary platen and movable platen able tomount the molds on both sides as part of themechanical structure. The middle platen has arotation mechanism, and different types of resins
are injected from the stationary platen andmovable platen. The middle platen can create
moldings for multi-color products in one cycle andimproves productivity to act as a stack mold by
repeatedly inverting 180 degrees to execute
moldings and filling two times the total number ofcavities.

Fig.4 Opposing Multi Color Hybrid Injection Molding Machine

2.4 J-ADS Series (Photo.5)
The J-ADS series is the fifth generation ofelectrically-driven injection molding machinesdeveloped with the concept of “maximum peace ofmind for all of our customers.” Four medium-size
models were released in March 2015.

Fig.3 60H-USM machines improve start-up of the injection speed(acceleration)

2.3 Opposing Multi Color Hybrid Injection
Molding Machine (Fig.4)(JM1600AD-MR)
We established an alliance with Meiki Co., Ltd.
In February 2010 and released an opposing multicolor hybrid injection molding machine combining
special direct-pressure clamping unit technology
from Meiki Co., Ltd. and the technology of ourelectric servo drive injection unit in July 2012.
This machine targeted automotive component
manufacturers that specialize in head and taillight moldings. As needs for these products to be
uncoated and lineless grew, the technology wasdeveloped expecting growth in American andPhoto.5 J-ADS Series

2.4.1 Medium-size J-ADS Machines
The J-ADS series is a machine that adopts ahigh rigidity/high precision clamping unit, newly
developed energy-saving barrel and new
SYSCOM5000i controller in the pursuit of “peaceof mind” for our customers.
(1) High-rigidity/high-precision clamping unit
We introduced a multitude of improvements fora uniform amount of deformation for the entire

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History of Development of Injection Molding Machine Technologies and Future Perspectives

platen face and succeeded in improving thevariations in surface pressure of the moldparting roughly 55% in addition to implementing
the high-rigidity clamping unit from theconventional machine. This clamping unit
improves the thickness distribution of molded
products and is expected to solve problems withburning by gas.
(2) Newly developed energy-saving barrel
The barrels of injection molding machines needconsiderable strength to handle the highpressure. We developed barrel materials thathave a material strength 1.5 times conventional
materials and succeeded in decreasing the outerbarrel diameter. Stronger materials and asmaller outer diameter was able to improve theheat transfer efficiency and reduce the power
consumption during continuous molding 10%
while also improving the control of the resins
temperature, including an improved heating
cycle, while also attaining stable molding
performance.
(3) New SYSCOM5000i controller
We conducted development based on the belief
greater ease of use was our top priority, such as
the adoption of an intuitive and intelligibleinterface that uses many operation sensations
and pictographs similar to smartphones. The
new SYSCOM5000i controller is packed withvarious functions to improve customer
productivity and bring “peace of mind” to ourcustomers, such as a predictive and preventative
maintenancefunctionthatcalculates
replacement periods of consumables andnotifies users of inspection timings for ballscrews, cooling fans, and other components, aswell as a display for the power consumption anda molding assist function for users new tomolding.
2.4.2 Small-size J-ADS Machines
We introduced an additional line-up of six smallsize models on October 2016 after the release of themedium-size J-ADS machine.
We implemented a variety of available molds
and a new type of downsized clamping mechanism
to allow the application of even large mold sizes.
Adopting a second generation flat press platen andseparate platen as well as improving the surface

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pressure variations of mold partings is contributing
to reductions in the clamping force, improvementsin the molded product quality and lower moldmaintenance costs. In addition, we have been able
to further reduce running costs by employing a
SYSCOM5000i controller similar to the mediumsize J-ADS while also equipping an additional “EcoMode” that improves the energy-saving efficiency
according to the molding conditions.

3. Molding Process Technology
The Japanese manufacturing industry has along history calling for industrial hollowing, but
trends such as the return of production bases toJapan are rejuvenating Japan pushed by the
recent weaker yen. This is also true with the plastic
injection molding industry. Many companies are
manufacturing products in Japan to increase
added value in particular, except in regards tomass-production and mass-consumption products.
Following these trends in the molding industry, we
are focusing on greater efficiency in manufacturing
and emphasize the development of new molding
process technology and composite molding
technology to satisfy customer needs as a company.
This section describes some examples of thesetechnologies.
3.1 Die Slide Injection (DSI) Molding Method
Fig.5 shows the DSI process. The DSI process
molds the primary mold components first (halfpieces of hollow molded components) with theprimary injection, and then opens the mold. Molds
move to a position where the primary moldcomponents face each other with a die slide
mechanism built into the injection molding
machine. The mold is closed again and a secondary
injection of resins in a band-like layer bonds thealigned primary molded components to combine
them into a molded product. In this way, because
the two halves are fused in the mold without thetemperature dropping right after the primary
molding, a highly precise molded product can beattained without the concern of dimensionalchanges in the bonding surface due to thermal
contraction.

History of Development of Injection Molding Machine Technologies and Future Perspectives

Fig.5 DSI process

3.2 Hot Plate-DSI (HP-DSI) Molding Method
The DSI molding method is a breakthroughprocess to manufacture hollow molded products.
However, the bonded section when combining
these halves is only on the outside of the molded
product while the rib inside is difficult to fuse. In
addition, resins with low bonding properties cannot
be utilized in the DSI molding process. A process
able to solve these two issues is the HP-DSI
molding method. Fig. 6 shows the HP-DSI molding
process. The HP-DSI process molds the primarymold components first (half pieces of hollow moldedcomponents) with the primary injection, and thenopens the mold. Molds move to a position where
the primary mold components face each other witha die slide mechanism built into the injection
molding machine. The mold is closed up to the gap
set in the parting surface of the mold and a heater

is inserted to apply heat to fuse the surfaces. The
mold is closed again after removing the heater tobond and combine the pieces into a molded product.
The following describes the benefits of the HP-DSI
molding method.
(1) Reduces defects in the bonding quality withfewer adverse effects to integrate bonds insideof the molds right after molding.
(2) Reduces the number of processes to allow
molded components to be integrated inside of
the mold.
(3) Eliminates intermediate inventory of primarymolded components.
(4) Facilitates three-dimensional bonds on non-flat
surfaces.
(5) Facilitates bonds even on ribs inside of hollow
pieces.

Fig.6 HP-DSI molding process

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History of Development of Injection Molding Machine Technologies and Future Perspectives

Moreover, the HP-DSI molding method provides
strong bonds superior to other bonding methods
such as vibration welding methods. However, there
are still some challenges, including the need todesign dedicated heaters for each product geometry
and the inability to support complex rib shapes
such as those that cannot be reproduced with theminimum bend radius of the heater. A swing-type
heater is the solution to these challenges. Photo 6
shows an example of a swing-type heater. The
heater operates like a swing by driving the heater
forward and backward together with an eccentric
cam using servo motors. The swing operation of
the heater can apply uniform heat to the welding.

(3) The bubble nuclei that are produced grow, press
the plastic material against the sides of themold due to the internal pressure of formedgas, dilute, cool, and then harden.

Fig.7 MuCell injection molding process

Customers can expect the same benefits for
products as injection foam molding that uses achemical foaming agent, such as weight reductions
and fewer warps and sink marks, because the
MuCell injection molding method is a foam molding
process. However, the greatest feature of the
MuCell injection molding method is the use of
nitrogen or carbon dioxide in a supercritical state
as a foaming agent. This type of foaming agent is
expected to provide the following benefits as well.

Photo.6 HP-DSI swing-type heater

3.3 Decorative Molding Technology via
MuCell®and Laminated Molding
The MuCell® injection molding method is a
microcellular foam injection molding technology toachieve a plastic foam part that has isolated cellswith an outer diameter of 10 to 200 μm. This
technology is a physical foam molding technologythat uses nitrogen and carbon dioxide rather thana chemical foaming agent such as azodicarbonamide(ADCA). This process has gained attention due toreductions in the environmental impact andrecyclability. Fig.7 shows the MuCell injection
molding process.
(1) This process mixes the melted plastic material
by injecting nitrogen or carbon dioxide in asupercritical state to the melted plastic in thebarrel.
(2) In the process to fill the mold, nitrogen or carbon
dioxide dissolved into the melted plastic cannot
sustain a dissolved state and generates bubble
nuclei.

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JSW TECHNICAL REVIEW No.20(1) Benefits related to the molding process such asa reduction in injection pressure and clamping
force due to a dramatically lower viscosity
apparent in the melted plastic(2) Benefits related to a lower environmental
impact such as the ability to avoid harmful
effects of the plastic materials as well as
recyclability(3) Benefits related to superior versatility such as
the use of engineered and super engineered
plastics
The MuCell injection molding method also has
challenges inherent to foam molding, such as lower
strength in molded products and lower surface
quality, because it is a foam molding process. The
decorative molding technology via MuCell andlaminated molding processes introduced in thisreport is one method to address issues such as alower surface quality. Photo.7 shows the decorative
molding system via MuCell and laminated moldingthat was exhibited at the IPF2014. The system iscomposed of a SCF unit and gas sponge as well asa film installation stand to equip film for MuCell
molding in addition to the main injection molding

History of Development of Injection Molding Machine Technologies and Future Perspectives

machine and standard peripheral devices such as
the mold temperature controller and the producttakeout robot. The molding executed this timeequipped the installation stand with an ABS
plastic film that has a thickness of approximately
0.4 mm, the insert was seated in the mold by the
product takeout robot when opening the mold, andthen the MuCell injection molding was executed.
Photo.8 is a molded product molded with the actualmachine exhibited at the IPF2014. The molded
product molded using the MuCell injection molding
method are not very suitable for decorative
products that come into people’s view because thesurface quality is worse than standard molded
products. However, the surface quality of molded
products is improved by affixing a film to achieve alight, high-design decorative product. This processeven supports diverse products made in small lots
as well because wide-ranging designs can besupported by simply changing the film to insert.

synchronous decompression inside of the cavities
in each part compared to the standard short shot
method. This achieves a uniform foaming body as
shown in Photo.9 in addition to dramatically
improving the foaming ratio two to three times.

Fig.8 Expansion molding process

Photo.7 Decorative molding system via MuCell

Photo.9 Cell Observation Photograph of the Expansion Molded ProductPhoto.8 Decorative Molded Product by Lamination Forming

4. Development of Screws and Barrels

3.4 MuCell®and Expansion Molding
The foaming ratio is limited to roughly 1.1 times
low foam molded products in the short shot method,which is one type of foam molding. This type ofmolding cannot satisfy user requirements for a
20% to 30% weight reduction ratio. Conversely, theexpansion molding method allows a two to threetimes higher foaming mold. Fig.8 shows the
expansion molding process. The internal pressure
difference inside of cavities is small thanks to

The development of screws and barrels up until
now was conducted in conjunction with thedevelopment of new machine models. We havebeen working in the development of screws andbarrels in parallel with the development of J-AD
large- and ultra large-size full electric servo drive
injection molding machines since 2004, and we are
introducing newly developed screws to the market.
Recently, however, diversification of usable plastic
materials that aim to improve functionality of
injection molded products is accelerating and a lot

65

History of Development of Injection Molding Machine Technologies and Future Perspectivesof development is advancing without links to new
development of machine models, such as screws
dedicated to specific plastics.
This page introduces the MIII-D screw for thelarge-size J-AD machine as well as the energysaving barrel for the medium-size J-ADS machine
as examples of development advancing in
conjunction with the development of new machinemodels while the screw with an irregular pitch for
optical molding materials such as computer
plastics is introduced as an example of development
for a screw dedicated to a specific plastic. In
addition, as part of the factors causing screw wear,
the CL screw developed as a measure to not only
improve material quality but also address factors
making solutions in the melting process difficult
are introduced together with the visualized barrel
that realizes the visualization of phenomena
causing various defects in moldings which need tobe solved.
4.1 MIII-D Screw
The performance generally required in screws
and barrels is wide ranging. However, the newscrew for the large-size MIII-D machine has
adopted the advantages of the MIII screw employedin the older series to improve the performance as
distinct prescribed properties around five items;(1)high dispersion performance, (2)high plasticizing
performance, (3)lower-temperature plasticization
performance, (4)recoloring performance and (5)plastic compatibility performance. An outline
drawing of the MIII-D screw is shown in Fig.9.
This basic structure establishes a sub flight slightly
lower than the main flight between the pitch of themain flight of the compression zone and meteringzone.

Fig.9 An outline drawing of the MIII-D screw

4.2 Energy-saving Barrels
The barrels of injection molding machinesrequire wear and corrosive resistance able tohandle a variety of plastic materials as well as thestrength to endure the high pressure of several
hundred MPa. Therefore, our barrels have a twolayer structure composed of a base material layer
with superior strength and toughness as well as a

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JSW TECHNICAL REVIEW No.20

layer of lining with superior wear and corrosive
resistance. Energy-saving barrels have a smallerouter diameter than conventional products thanks
to the application of a new material with 1.5 times
the strength of conventional materials on the basematerial layer. The reduction of the outer diameterof the barrel is able to reduce the heater capacity to
attach, which has realized a 10% reduction in
power consumption compared to conventional
structures.
4.3 Screws with an Irregular Pitch
Screws with an irregular pitch were developed
for the purpose of limiting the occurrence ofmolding defects, including carbonization andyellow discoloration in optical molding materials
such as computer plastics. Fig.10 shows thedifference in the exterior of a standard screw and ascrew with an irregular pitch. Screws with anirregular pitch are designed to change following
the axial direction of the flight pitch and prevent
sudden changes in the channel cross-sectional area
to stop a high shearing force in plastic materials.

Fig.10 Difference in the exterior of a standard screw and a screw with anirregular pitch

4.4 Contact Less (CL) Screws(1)CL screws were developed as a measure tocombat screw wear caused by factors related to themelting process. Fig.11 shows a schematic diagram
for the stepped pad of the thrust axial bearing. The
CL screw applies the logic for this lubrication force
to the flight of the screw. Fig.12 shows the resultsof measurements taken of the outer screw diameter
before and after employing the CL screw in an
actual production plant. The validity of this screw
was confirmed by almost no wear in the screw
flight during molding over a period of two years
after employing the CL screw compared to theseveral millimeters of wear in the screw flight overthe same period of time before employing the CL
screw.

History of Development of Injection Molding Machine Technologies and Future Perspectives

Photo.10 Visualized Barrel （66mm）

Fig.11 Stepped pad of the thrust axial bearing

Fig.13 Example image of observation taken through an observation window(Upper: Visualized image, Bottom: Infrared image)

5. Control Technologies
Fig.12 Results of measurements taken of the outer screw diameter before
and after employing the CL screw ( 2 years, after 540,000 shots )4.5 Visualized Barrel(2)Over the last ten years, we have worked to bring
the phenomena causing defects in molds to light(visualization). Photo.10 shows the visualized
barrel developed by JSW. The diameter of thescrew is 66 mm and observation windows
extrapolated from sight glass are installed in fiveareas on the side of the barrel to allow the process
to be observed from the screw supply zone to themetering zone. An example image of observation
taken through an observation window is shown in
Fig.13.
The development of the visualized barrel also
makes the visualization of the behavior in the
back-flow prevention ring attached to the end of
the screw possible. There are several limitations in
the use of the visualized barrel such as the injection
pressure and barrel temperature, but use of thisbarrel is expected to be effective in providing
insight to various phenomena.

The advancement in full electrically-driven
injection molding machines from small- to ultra
large-sizes means the importance of electricalcontrol technologies is growing for mechanicaldrive performance, such as injection, plasticization,
responsivity of the open/close drive axis, high-cycle
molding and high load support capacity. In
particular, technology for our proprietary largecapacity servo system is being employed inmachines from the J2500AD (24,600 kN clamping
force), which is an ultra large-size full electric
servo drive injection molding machine. The exteriordrawing of the injection unit is shown in Fig.14
and a block diagram of the control system is shownin Fig.15. The structural components of the servo
system utilize the same structural components
both in the medium- and large-size machines. The
necessary thrust for ultra large-size machines isachieved through synchronous control of four-axis
servo motors. The multi-axis servo system isconnected through high-speed communication. The
entire machine is built upon a 13-axis servo system.
In addition, the system operates with energy
savings and minimal equipment capacity by

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History of Development of Injection Molding Machine Technologies and Future Perspectives

Fig.14 The injection unit is shown

service history, as a product customers can use
over the long term. Functions supporting lower
power consumption according to the molding
conditions have also been newly introduced tosupport energy-saving needs.
Synchronous heat control has been equipped forthe barrel temperature control since the J-AD
series to prevent burning and deformation ofplastics at the start of heating. However, a newtemperature control board accelerating the control
cycle ten times has been built into the J-ADS series
to ensure more highly accurate temperaturestability.

Fig.15 Block diagram of the control system
Fig.16 SYSCOM5000i

equippingalarge-capacity
high-efficiency
converter as standard as well as through a power
regeneration function to realize high power with aminimal power supply.
The J-AD series has our SYSCOM3000 built inas the controller and, since its launch into themarket in 2004, has received praise for its usability.
The J-AD series has built a long-standing trackrecord. Moreover, the SYSCOM5000i developedwith the objective of further improving usability
has been built into machines since the J-ADS
series released in 2015 (Fig.16). These
characteristics have been implemented for the firsttime as injection molding machines for multi-touch
operating systems used in a wide range of products
from smartphones to tablet terminals in order tocreate a user interface able to set molding
conditions easily as well as provide intuitive
operations of the machines. In addition, injection
molding machines have enhanced maintenancecapabilities, including functions to predict the
product lifespan as well as functions to display the68

JSW TECHNICAL REVIEW No.20

6. Conclusion
This report has introduced our technologicaldevelopment since 2004 by looking independently
at model development, process technologies, screw
technologies and control technologies. In March
2015, the new J-ADS machine entered the market
and differentiated itself with soft technology suchas the SYSCOM5000i at its core, and we believe
the current trend lacking advancement in
revolutionary hard technology will continue. On
the other hand, the demand for greater functionalityof plastic molded products such as metal
alternatives are growing in the market. There isalso a greater tendency to use engineered andsuper engineered materials for the plastic
materials. Molding machine manufacturers are
requiring molding process technologies compatible
with these products as well as the development oflong-lasting and cheaper screws and barrels that

History of Development of Injection Molding Machine Technologies and Future Perspectives

assume use of these plastic materials. Thisdevelopment is a pressing challenge for JSW.
Finally, we must realize the development ofdistinctive technologies as soon as possible thatare able to bring sensation to customers in order toescape a red ocean market where commoditization
is progressing. We will put all of our strength into
furthering
technical
development
without
compromise to become one of the top five companies
by 2020.

References(1) The Japan Steel Works Technical Review No.64(2013), p.93-94(2) Akira Yasue, Katsuyuki Araki, Kazuma
Nakagawa, Hideki Chiba: The Japan Steel
WorksTechnical Review, No. 64 (2013), p.75-78(3) Munemori T., Plastic Age 2009.2, p.75-78

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