Large-part thermoformers headed to GE's labs.

GE Plastics, Pittsfield, Mass., has contracted Germany's Geiss AG (U.S. office in Elk Grove Village, Ill.) to build two advanced thermoforming machines to expand the use of GE's engineering thermoplastics in large parts. One of the two machines--an Aesthetics Composite Forming (ACF) unit--is destined for GE's Polymer Processing Development Center in Pittsfield. The other, a new twin-sheet former, will go to GE's European headquarters in Bergen op Zoom, Netherlands. Due to be shipped by the end of June, both machines can handle glass-filled or unfilled sheets up to 1700 x 1450 mm in a range of thicknesses.

The ACF machine is said to be unique because of its ability to laminate dissimilar materials. For instance, GE envisions structural composites such as GE's Azdel glassmat/thermoplastic composite formed with an aesthetic surface material such as Lexan SLX weatherable, glossy polycarbonate copolymer film. It will be used for shower tubs, boat components, aircraft and mass transit interiors, and auto parts.

The double-station ACF unit uses matched tools to press out heavy glass-filled materials. Another special feature is Geiss' "zero-gravity" forming, which uses air pressure under the sheet to prevent sagging.

The machine has Geiss' new Speedium halogen heaters for faster and more controlled heating. Developed with Philips, the heating system is reportedly effective with virtually all colored sheets. The 165-ton clamp is precisely controlled with four hydraulic pistons instead of the typical air bladder. The platens are run by servo motors and incorporate a shuttle mechanism on the lower platen.

The twin-sheet machine headed to GE's European development center is claimed to be one of the first to form twin sheets simultaneously instead of sequentially. Two sheets are heated together with a gap between them, and then opposing mold halves above and below the sheets press together as vacuum pulls each sheet into the corresponding mold. At the same time, blow pins are inserted between the sheets to provide internal air pressure to ensure good part detail. The system also has zero-gravity forming and Speedium halogen heaters. An articulating clamp frame moves to allow greater draw depths without wrinkling.

GE seeks to create twin-wall, hollow parts for cars, trucks, RVs, and building construction. Potential applications include bus panels and access doors as well as enclosures or panels that require thermal or acoustic insulation. The machine will be used with GE materials such as Azdel Rail-Lite composite (based on Ultem PEI) for large panels in train interiors. Other potential uses will be glazing of Lexan PC and paint-free auto parts using Xenoy PC/PBT, Lexan SLX, and Geloy XTW "extreme weathering" ASA grades. GE: [phone]/PT Direct: 132YT * Geiss: [phone]/PT Direct: 664MT

[ILLUSTRATION OMITTED]