Injection molding was king at JP 92 Osaka.
Two suppliers introduced new all-electric injection molding machines. Toyo Machinery & Metal (represented here by Maruka Machinery Corp. of America, Pine Brook, N.J.) introduced a compact "all-in-one" injection molding machine cell with 11-ton clamp. The servo-electric Plastar TIC-10 accommodates peripheral equipment, including "hopperless" direct material feed, mold-temperature controller, parts extractor, chute, and conveyor, directly onto its frame. Toyo also has expanded its TU servo-electric line with an 88-ton unit, increasing the tonnage range from 5.5 to 88 tons. (CIRCLE 75)
JSW Plastics Machinery (Bell, Calif.) introduced an 55-ton all-electric servo machine, the J50EL. It's said to be capable of molding at ultra-low to high injection rates, with smooth changeover between the two. (CIRCLE 76)
Besides all-electrics, Toyo introduced a hybrid TIS-180, said to combine energy savings with "precision fast cycling." The unit is equipped with a servo motor on the screw, a gas accumulator to build injection pressure, and a hydraulic pump to perform mold opening and closing. The three movements are tied together with a 16-bit computer. (CIRCLE 77)
Nissei (Anaheim, Calif.) introduced a new hybrid MM40 machine, combining a hydraulic mold clamp and servo-electric injection unit with closed-loop control. This combination reportedly provides stable repeatability and precise control of the clamp plus high-precision injection. The machine requires only 9 liters of hydraulic oil, significantly reducing energy consumption. The injection unit is said to provide excellent position and speed control, with repeatability achieved over a range from extremely low speed and pressure to high speed/high pressure. (CIRCLE 78)
Mitsubishi displayed its MSP series molding machine, combining a straight hydraulic clamp with AC inverter screw motor. (The MJ series, a similar version now offered in the U.S. by MC Machinery Systems, Inc., Wood Dale, Ill., incorporates a Vickers hydraulic motor on the screw.) One advantage of the MSP series is that it performs plastication during mold opening and closing, resulting in fast cycles. In addition, the company demonstrated its MM 450-II machine also equipped with a servo motor on the screw. (CIRCLE 79)
Several machines designed for specialized jobs were also on hand. Meiki (Elk Grove Village, Ill.) demonstrated its quick color-change system on a 55-ton machine. The Liquid Coloring System injects liquid colorant directly into the plastication cylinder. Changeover from one color to another is accomplished in about 10 shots without the need for purging. (A similar approach was shown at JP 90 in Tokyo by Nissei; see PT, Jan. '91, p. 63). (CIRCLE 80)
Meiki also demonstrated an insert molding machine, Model M-60B-VR, with rotary table and horizontal injection unit. Insertion accuracy is said to be |+ or -~3 microns. (CIRCLE 81)
An in-mold labeling system, called Simpac, was demonstrated by Sumitomo Heavy Industries (SHI Plastics Machinery, Norcross, Ga.) on its SG150U fast-cycle machine with a special four-cavity mold. PP labels were fed into the mold cavities by an auxiliary feeder and held in place by vacuum inside the mold. PS cups were then molded directly onto the labels in 7.2-sec shots. Labels completely surrounded each cup 360|degrees~. The mold was supplied by Sumitomo and jointly developed by Sumitomo and Yushin.
JSW showed off its J50E-C5 injection-compression machine for molding optical disks. It boasts highly accurate injection control at ultra-low speeds, highly accurate temperature control, and highly rigid clamping unit. (CIRCLE 82)
Nissei introduced a new 80-ton rubber injection machine, based on its FE series. It features a special controller with a number of panels, each of which is for exclusive use in presetting the venting position of the screw. (CIRCLE 83)
SPACE-SAVING VERTICAL UNITS
A number of vertical injection presses were also on hand. Nissei introduced a small pneumatic model AP10-1. It combines vertical plunger-type injection and vertical 11-ton pneumatic clamp, and is said to be suitable for minimum space requirements and small production runs. It reportedly maintains constant clamp force, with minimal air consumption. (CIRCLE 84)
Nissei also demonstrated its new ST10S2V small vertical-clamp machine, developed by combining various modular components into a molding machine with clamp force up to 16.5 tons. The model can be configured with either vertical or horizontal injection mechanisms and three different mold-handling mechanisms--fixed-position, sliding, or rotating. (CIRCLE 85)
A new JT40E-55V vertical machine was demonstrated by JSW Plastics Machinery. It includes a new S-50 screw for high plasticating capacity, and new control with LCD display. A compact take-out device built into the machine is available as an option. (CIRCLE 86)
Two novel "tilt" insert molders were on hand from Sanjo Seiki (distributed by Pentel of America, Torrance, Calif.). These are vertical-clamp, vertical-injection units of 57 and 93 tons. To make loading inserts easier, the bottom mold tilts upward to a 45|degrees~ angle. It returns again to a horizontal position for injection, and tilts upward again to facilitate part removal. Also shown by Sanjo was the Sanjection 15 (16.5 tons), in which the mold shuttles back and forth on a tray between the vertical injection unit and ejector station. (CIRCLE 87)
NEW CLAMPING MECHANISMS
Nissei also introduced a large machine with a new clamping mechanism. The 610-ton PH560S unit is said to adapt Nissei's hydromechanical clamping system to achieve shorter cycle time, lower cost, and a smaller footprint. Opening and closing of the mold is executed with the mold clamping rod connected to the moveable platen in an unlocked position. The locking mechanism on the front of the clamping piston provides high-pressure clamping with the mold clamping rod in the locked position. Advantages of the new clamp are said to be 10% reduction in floor space and more than 20% reduction in oil usage as compared to conventional machines. Mold-opening force has also been increased by 57% over that of current comparable models. (CIRCLE 88)
Mitsubishi also showed a hydromechanical clamp on its MM 450-II (495-ton) machine. Previously, the hydromechanical clamp, which uses less space and is more energy efficient, was available only in larger tonnages. (CIRCLE 89)
OPTIMIZED INJECTION UNITS
A number of machine builders announced new injection units claimed to optimize injection pressure vs. velocity, resulting in prevention of short shots and reduced risk of warpage and residual stress. Nissei demonstrated its 18D-type injection mechanism, which is said to fine-tune flow and pressure to achieve stable molding of thin-wall and intricate parts. It consists of a primary cylinder and two supplementary cylinders, the combination of which permits selection of any one of six stages of different injection characteristics.
A similar idea was employed by Niigata on its NN-MI series of hydraulic machines. (Niigata is represented by Daiichi Jitsugyo America Inc., Elk Grove Village, Ill.) The system makes use of three injection-cylinder combinations for a total of five possible injection profiles ranging from low pressure/high velocity to high pressure/low velocity. The NN-MI series ranges from 33 to 495 tons, including new 82-, 244-, and 495-ton units. (CIRCLE 90)
Similarly, Toshiba's Binary Low Pressure Injection System uses three injection cylinders to optimize injection pressure and speed in four possible stages. Toshiba also introduced two double-flighted screw designs said to improve temperature and pressure stability. The SRB and SDB double-flighted screws reportedly improve productivity by 20% over full-flighted screws. (Toshiba Machine Co., America, Elk Grove Village, Ill.) (CIRCLE 91)
In other developments, Nissei appears to have engineered more simultaneous functions than ever into its FE series machines in order to speed cycles. The machine achieves dry-cycle times of about 4 sec by combining movements such as metering during mold opening/closing, ejection and nozzle forward during mold opening, nozzle backward during metering, and opening and closing of the shutoff nozzle during injection.
Shinwa Seiki (rep. by Methods Plastics Machinery, Sudbury, Mass.) extended the clamping range of its CN series hydraulic machines to 400 tons. It also installed an automatic pressure sensor, eliminating the last limit switch on the machine. A third new enhancement is a "clamp-tonnage back-off" feature, which reduces holding pressure during the cooling cycle to save energy. (CIRCLE 92)
A new KM-C2 series of toggle-clamp machines with a new type of controls was introduced by Kawaguchi (rep. by Tomen America Inc., Buffalo Grove, Ill.). The series extends from 55 to 716 tons. It's said to be mid-range between the KM-B (CRT controls) and KM-C (LED) lines. (CIRCLE 93)
JSW introduced a 16.5-ton horizontal, hydraulic-clamp machine (J15E) with highly rigid clamping unit and wide spacing (8.8 in. square) between tiebars. (CIRCLE 94)
In hot-runner systems, Seiki Corp. introduced a Spear System multi-tip edge-gating bushing (contact Spear System, Camarillo, Calif.). The SI system is configured so that the multiple nozzles point down at an angle of up to 30|degrees~. Thus, they contact the part at an angle. This is said to optimize flow and minimize gate marks. (CIRCLE 95)
Not all of the news was in hardware. Toshiba showcased its latest generation Injectvisor controls on its relatively new IS-F series of hydraulic injection machines. The IS80FPB, a 91-tonner, was equipped with Toshiba's new high-end VL touchscreen control, with features suitable for automatic and unmanned production. Among the VL control's standard features are: six-speed, five-pressure profiling; three-step, closed-loop programmed control of mold two-step programmed control of ejection; RA-PID control, said to minimize overshoots and provide faster response to temperature conditions; and preventive-maintenance and self-diagnostic packages.
Useful options on the VL control include a Moldlyzer, which performs multi-point sampling of the shape of the injection-pressure or cavity-pressure curve during filling for an automatic quality check, and also controls changeover from filling to holding. A Prestrol option performs injection-compression by means of programmed clamp-pressure control in order to prevent warpage of thin-walled parts and breakage of thick-walled products. In addition, a Plastlyzer option performs multi-point sampling of the shape of the screw backpressure or retraction speed, aiding in the detection of feed irregularities and viscosity changes. (CIRCLE 96)
Ube Industries (Ann Arbor, Mich.) presented a new "Software Servo" enhancement to the PZII controller that was first shown last year at NPE. The software servo controls injection velocity by use of both time and screw position. When an injection velocity setpoint is entered through the control panel, the controller defines where the screw position should be at each end of 1-millisec time slots. The defined parameters are then applied to actual operation with a closed-loop correction system, which has both feedback and "feed-forward" features.
The software servo is said to provide tighter control than conventional closed-loop devices, which can only adjust the next shot to make up for the error on the last shot (feedback function). The software servo, on the other hand, can predict what will happen on the next shot from the trend of past shots, and thus bring the next shot closer to the desired value (feedback plus feed-forward functions). In trials, 530-g shots of PP showed an average deviation of only 0.05%. Benefits of the software servo control are greatly reduced random interference and high repeatability of the injection velocity profile, because any deviation is instantly corrected. Steep acceleration/deceleration can be accomplished without overshooting or undershooting, and high stability is provided at both high and low speed. The feature will be offered as an option on PZII series machines from 385 to 990 tons. (CIRCLE 97)
Toshiba presented information on its "Expert System" for improving product quality. The system determines initial machine settings based on product, resin, and machine data. It then corrects the settings during automatic operation to enable quick improvement of product quality. The user can add his own molding and material knowledge to the basic data base.
Nissei introduced its CD-Factory Automation system, which molds 8- and 12-cm CDs in 5.5 sec, and includes an automatic stamper change. The system consists of an injection-compression molding machine, automatic stamper quick-change device, and automatic stamper carrier all tied together with an NC-NET control. The system was demonstrated molding 12-cm CDs, completing the whole operation from molding up to stamper change in about 2 min.
NC-NET is a new central control, which monitors and regulates all operations, such as QC, production control, injection conditions, and any changes in the molding conditions. In another factory automation example, it integrated all operations of three small molding machines off site.
Hama Corp. (Hama USA, Three Bridges, N.J.) demonstrated the HM2800, a combination gate-cutting and casing robot configuration that formerly required two separate units (see PT, June '91, p. 153). Cutting force is adjustable, and the unit includes a static electricity remover. A programmable controller adjusts cutting and casing functions.
A high-speed robot and a palletizing device were demonstrated by the Sailor Pen Co. (rep. by Automated Assemblies Corp., Clinton, Mass.). The RZ200F has a cycle time of just 4.3 sec; take-out time is 1 sec. The RZ200M3 is a three-axis, servo-driven, six-cavity take-out and stacking unit. In the demonstration, it alternated the stacking configuration to pack parts more densely.
Yushin (Warwick, R.I.) developed a high-speed version of its Absoliner VA robot line. The VA-200-S-HS version is equipped with a larger AC digital motor, capable of quick response, for overall dry cycles of 3.8 sec. Yushin also added new insert capability to its five-axis, traversing take-out robot, VA-200DL-IN. The unit is capable of performing combined take-out and insert molding functions under the control of a programmed magnetic card. (CIRCLE 98)
Harmo (rep. by Conair Martin, Agawam, Mass.) introduced a five-axis servo robot, HE-150G-SSS. Harmo combines servo and pneumatic operation on its new model HE-150GW-1CC model. Also new is the new EX(F) series of pneumatic robots for machines of 25-500 tons. (CIRCLE 99)
Three new robots were on hand at Ichikoh Engineering (contact Ichikoh Manufacturing, Shelbyville, Ky). The WB series are three-axis, electric-driven robots with extended vertical range, capable of placing parts below the nozzle center. Also introduced were CZ series three-axis pneumatic types and a small ITR model with three servo axes and two axes on the wrist for very precise positioning. (CIRCLE 100)
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|Title Annotation:||plastics molding machinery featured at trade fair in Japan|
|Author:||De Gaspari, John|
|Date:||Jun 1, 1992|
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