INJECTION MOLDING: Sneak Peek at Fakuma News

What’s billed as the first demonstration of injection-compression molding on stack molds is one of several new developments slated to be on display this month at the Fakuma 2015 plastics show in Friedrichshafen, Germany. Others involve new machine models, “flexible” IML automation, micro-injection, dual-durometer LSR injection, integrated metal/plastic processing, new cleanroom technology, and new or modified machine models.

• Stack-mold injection-compression: Netstal of Switzerland (U.S. office in Florence, Ky.) will show off a “world first” by injection-compression molding margarine tubs (15 oz/425 g) in a 4 + 4 stack mold on a 280-metric-ton Netstal Elion hybrid machine. The cavities will be partly filled in only 100 millisec, and total cycle time—including IML—will be 5 sec.

Netstal says the low-pressure filling reduces stresses in the material and warpage, especially in lids. Weight reduction of up to 20% through thin-walling is also said to be possible with injection-compression.

• Improved energy efficiency: Netstal’s sister company, KraussMaffei (U.S. office in Florence, Ky.), will show off the upgraded version of its CX hydraulic two-platen machines, whose drive has been energy-optimized and now requires 10% less power.

• Micro-injection: Arburg (U.S. office in Rocky Hill, Conn.) will operate an all-electric, 35-m.t. Allrounder 270 A with a new micro-injection unit with two-stage injection. It has either a 15-mm or 18-mm screw for plastication (both of which can take standard pellets) and an 8-mm screw for injection. It will mold four 0.004 g PBT micro counter wheels in 12 sec.

• Dual-durometer LSR molding: Arburg will also run an electric, 100 m.t. Allrounder 470 A with two injectors in an L-arrangement, molding two-material liquid silicone buttons for car interiors in a 32 + 32 cavity rotary mold. The diaphragm of the part is a colored LSR with 50 A Shore Hardness, and the inner disc is a clear LSR with 80 A hardness.

• New machine and medical technology: Engel (U.S. office in York, Pa.) will debut the largest member yet in its all-electric, tiebarless e-motion TL series. The first 30-m.t. model appeared at K 2013, and a 50-m.t. unit followed at last year’s Fakuma show. This year brings an 80-m.t. addition, which will mold medical parts in 16 cavities using GMP-compliant cleanroom production. Two new elements of the cell (photos) are a stainless-steel pipe distributor for cavity separation and a special robot gripper housing with smooth, easily cleanable surfaces, which allows use of standard grippers in a GMP environment.

• Integrated metal/plastic processing: Engel will also present for the first time a highly integrated, fully automated process (photos) for manufacturing thermal switch housings from metal/plastic composite. These switches are used to monitor electric motors in cars and appliances. The sheet-metal and plastic operations are usually performed in separate locations. But here, a metal strip is unrolled from a coil and fed into a punch press and a thread is servo-electrically tapped in the same station. Next, the metal carrier plate is overmolded with glass-filled nylon in a vertical Engel machine. That is followed by camera-based inspection, high-voltage testing, laser marking, and subgate removal. Eight finished parts leave the cell every 20 sec.

• Highly flexible IML: Engel’s booth will also host the global debut of the newest Beck-Flex IML system from Beck Automation of Switzerland. Within the footprint of a standard system, this “all-around IML system” offers the flexibility to handle from one to four cavities, parts with inside or outside gating, both lids and containers, part diam. from 40 to around 200 mm, and a wide variety of labels—flat, 3- or 5-sided, with or without closed edges, and 360° labels. All of this is engineered for fast changeovers—e.g., from one lid to another in less than 30 min and from a lid to an inside-gated container in less than 60 min—and for fast cycles of around 4 sec.

• New servohydraulic models: Wittmann Battenfeld (U.S. office in Torrington, Conn.) is completing its new SmartPower series with larger models. These energy-efficient servohydraulic machines, which recover braking energy for barrel heating, were introduced at Fakuma 2014 as replacements for the hydraulic HM series in sizes from to 25 to 120 m.t. The line is now being topped off with models of 180, 240, and 350 m.t., the last of which is making its debut at this show. It has 800 x 720 mm tiebar spacing.