K '98: Molding technology innovations

Molding technology of all types will be on display at K'98. Many manufacturers are planning exhibits around medical product manufacture because there is a special Medical Technology focus this year (see Sept. 1998 IMM, pp. 124-126). Multicomponent molding, especially the overmolding of a rigid material with a soft one, is another exciting topic. And micromolding-molding parts that weigh a fraction of a gram-is the focus of more than one exhibitor.

Automation will be everywhere-not the large automatic mold changing systems of past years, but purpose-built automation that surrounds a molding machine with not only part handling functions but also orientation, assembly, and packaging for a specific product type. In fact, many of today's hot products will be made right on the floor-smartcards, compact disks, DVDs, bottle preforms, syringes, thin-wall parts, and more.

While many manufacturers like to wait until K to announce their new products, a number of them have provided IMM with advance information. So while this will not be all-encompassing, the news here will be representative of what you can see. And, as always, our postshow coverage will bring even more news.

Medical Molding
In keeping with the medical theme of K'98, a cleanroom production cell on the Demag stand will make PC blood-collection containers in a mold from Medigate of Singapore. The clamp end will be enclosed in a cleanroom tent. From Ferromatik Milacron, a new 300-ton Elektra will mold medical syringes on fast cycles. Built on a new "global platform," the all-metric design delivers 10 percent more clamp force in a smaller footprint. There is a new injection unit, direct-drive clamp, and an open-architecture PC-based control.

Netstal's medical demonstration will be a 60-ton SynErgy machine making soft PVC pull-rings in an 8-cavity hot runner mold from Swiss moldmaker Schöttli. The mold also features fluid heating. The cycle time will be short, aided by robotics from Hekuma of Germany. Medical products will also be molded by Nissei's Elject ES3000, an all-electric machine with 155-ton clamp.

A 50-ton model of Battenfeld's new TM Series (Toggle Modular) injection molding machines will operate at K'98 making PP medical syringes in a 16-cavity mold. BM Biraghi is showing the latest advance in its Sintesi line of injection machines: an injection unit for high-speed applications like thin-wall medical parts. Another Demag cleanroom cell will mold polycarbonate cannulas in a Demag cleanroom enclosure as part of the K'98 Medical Technology Special to be seen in the Congress Centrum.

Multicomponent Molding
The largest press on the Demag stand will be an 800-ton Ergotech multicomponent unit molding TPE onto tank covers, and a multicomponent cell based on a 60-ton unit will be making a component of the BMW central locking system, encapsulating a metal insert in two separate injections of polyacetal and ultimately packaging the part.

From Arburg, the S series will be shown in a two-component configuration. A 100-ton two-color Elektra from Ferromatik Milacron will mold toothpaste tube shoulders of HDPE and PET. These two normally incompatible materials are joined geometrically, and Ferromatik will have information on its new technology using a rotating middle plate in a stack mold for shorter cycle times. The technique permits machine selection primarily by clamp tonnage rather than for tiebar spacing, as has been the case with rotary table presses.

Netstal's multicomponent technology, demonstrated on a 60-ton Synergy machine, will make a PC/ABS adjustment wheel for automotive ventilation devices. The mold, by Weber of Germany, is 2+2 cavities with hot runners and the shot size is 8.8g. Two new configurations of NPM's Unyka-2 multicomponent machines will be at K. One features the second injection unit mounted above the first to minimize melt turbulence and avoid pressure loss. The second new Unyka-2 has one injection unit mounted traditionally and the other entering the press area from above. It is ideal for moveable inserts or two-material work, and the second unit can be removed for normal single-material molding.

PET Preform Systems
In the PET preform area, Husky will be running a 90-ton model of the Index machine introduced last year with a 16-cavity mold, which means four sets of 16 cores on the rotating turret. It will cycle at about 9 seconds.

The 48-cavity Sintesi 32 PET preform production system from BM Biraghi allows dealing with all the variables of the process, from material physics or chemistry to wear conditions, without the need to reset the system or the risk of making bad parts. Biraghi will also be showing its new, patented preform cooling system. The preforms remain on the cores for three cycles to control possible changes in shape and when completely cooled are placed on an adjustable conveyor with automatic cycle signaling.

The all-new PET-Line 96 system is Netstal's response to the demands in the bottle preforms market to increase productivity. It is a fully integrated production cell built on the company's Synergy machine technology with robotics supplied by Netstal and Hekuma. The K'98 system includes a 96-cavity mold, built by O. Hofstetter of Switzerland, mounted on a 600-ton injection machine that is the company's largest clamp to date. Netstal's previous largest PET system supported 48 cavities. The new system can include an electrically driven screw motor drive to allow continuous plastification or fully separate plasticizing and injection units.

To compete with PET preform machines, high-speed preform molding with integrated bottle production will be featured by Sipa Packaging Systems. The ECS HS 12/32 will be producing .5-liter PET bottles at an output of 8,000 bottles/hour.

Machine Design
Machinery manufacturers have spent considerable effort in the last few years to manufacture more efficient machines that operate in less space. Improvements in clamp design, in platen and tiebar design, in all-electric or hybrid machines-all are designed to contribute to improvements in machine operation, energy efficiency, and initial capital outlay. For example, compared to previous Battenfeld designs, the number of parts in the TM clamp has been reduced by about 50 percent, from 23 to 11. Connecting toggle arms that appear to be three pieces joined by a bolt, and are just that in most other machines, are made as a single piece in the TM. Platens have been increased in size with longer guides and larger supports for optimum alignment and rigidity. L/D ratio is 22, there are three screw sizes available from 25 to 85 mm, and the injection stroke is 5D with 2000 bar of pressure.

HPM launches the Access line of tiebarless machines that features a c-frame construction. A 125-ton machine will be molding PP paintbox lids. HPM's Next Wave series will show off its Parabolic platen two-piece design. Stork also will launch a tiebarless machine, the SX-H, which uses hydraulic compensation for the deformation of the machine frame.

A 1600-ton example of Cincinnati Milacron's two-platen Maxima series introduced at last year's NPE in Chicago will mark the line's European debut. Engel's accessible tiebarless machines can accommodate much larger molds than machines of the same clamp-force class with tiebars. Engel has extended the clamp-force range from 4000 kN to 6000 kN and thereby entered the medium clamp-force range. At K, machines of type ES600HL will produce a TV housing. With tiebars, an 8000-kN machine would normally be needed because of the required mold size-not the required clamp force. The free platen area is of particular benefit here.

For the first time at K, NPM will show its seven-point toggle system: an 85-ton Unyka-CL will make spools and bobbins for textile processing applications. Compared to a standard five-point toggle, the CL has a three-point connecting rod attached between the clamp and an intermediate moving platen that provides the driving force.

The opening stroke is 30 to 45 percent longer than five-point toggles, but the clamp design maintains parallelism and prevents platen deflection associated with long-stroke machines.

Husky's 900-ton E Series two-platen machine is equipped with the just-announced mold carrier that accommodates either one standard stack mold or two normal two-plate molds. Taking advantage of the machine's long opening stroke, the carrier permits almost doubling the productivity of such relatively flat, high-volume parts as lids, shelves, boxes, and panels within the same footprint.

Electrics and Hybrids
Engel is presenting its first fully electric machine with 1000 kN clamp force. The main advantages lie in the rapid movements, absence of hydraulic fluid, low energy consumption, and easy accessibility of the mold area. The machine has five servoelectric drives. A highly dynamic servocrank drive with an injection rate of up to 200 mm/second is used at the stationary mold side and a high-speed servocrank drive at the moving mold half. At K, this machine will be producing closure caps in an eight-cavity mold with a cycle time of 8 seconds.

Demag Ergotech is raising the number of choices molders have in electric and hybrid, partially electric machines. A 200-ton model of the new Elexis hybrid series will be molding a PP flowerpot in 3.5-second cycles. The key design feature of the Elexis, which will be available from 50 to 300 tons, is a patented clamp design using a servoelectric motor and a hydrostatic gear. While offering high-speed opening and closing, the servo allows extremely high precision and small adjustment increments. A CANbus connection provides high-speed control of the ultrasound-based stroke measurement system. The machine's screw is driven by a frequency-controlled motor, injection movement is hydraulically powered by central memory, and such ancillaries as core pullers and ejectors are actuated by hydraulic valves.

All-electric Roboshot machines from Fanuc will produce an acetal beverage cap nearly 1 second faster than a hydraulic machine.

Ferromatik Milacron will show the increasing variety of its Elektra machines, launching a new 50-ton unit for DVD production. Growing the line at the top, a 300-ton unit will be followed soon by 200- and 400-ton machines, to be followed later by 500- and 660-ton models, which are currently on test in the U.S. The first two-color electric, a 100-ton model, will operate at K.

Gas Assist
For the first time, mono-sandwich molding will combine with Ferromatik Milacron's self-licensable Airpress III gas technology to produce a windshield wiper arm with a glass-filled

PA core and PP skin. A high-performance K-250 S will show fast cycle molding of a thin-wall cartridge and show how use of a barrier screw can improve concentricity and dimensionality through increased material homogeneity. Other displays will include a cleanroom enclosure and a two-component medical application involving the company's micro-molding technology.

Negri-Bossi's V680 machine with tiebar spacing of 950 x 820 mm will mold PP tabletops using gas assistance. Sandretto will demonstrate the Mega HCS 1300 with its Logigas gas injection system, producing the upper portion of a garden table, whose legs are being molded on a 400-ton Series Nine. Negri Bossi will have a machine, equipped with magnetic platens for easy mold changing, molding with a the gas connection that permits the use of any gas system. Cinpres will show attendees a live "inside" view of gas assist molding thanks to a glass-windowed mold and closed-circuit TV.