CHICAGO — An integrated Hull/ Finmac Inc. system for preheating, compression molding and deflashing is making thin-wall computer laptop housings with Fiberite Inc. sheet molding compound in demonstrations at 11 a.m., 1 p.m. and 3 p.m. daily at NPE Booth E11020. At Fiberite's request, Hull/Finmac combined the three separate operations into one work cell. A processor ``can go from raw material to a finished part in a short cycle,'' said Dave Roedersheimer, Enduron market manager.
The integration uses existing technology.
``We build a lot of machines for powder compression for molding, and they asked for one to use with SMCs,'' said Mark Bahmueller, sales manager for Hull/Finmac in Warminster, Pa.
Bahmueller estimated the integrated system costs $150,000-$400,000.
Preforms consisting of 15 SMC sheets are preheated to 165§ F. The 150-ton compression press molds the 0.03-inch-thick laptop computer cover, and a pick-and-place unit feeds the 10-inch-by-12-inch part automatically to a deflashing unit, Bahmueller said. Total cycle time: 60-70 seconds, rather than 120-140 seconds with conventional systems, according to Roedersheimer.
Enduron consists of thermosetting phenolic resin and high-performance carbon fibers.
``We can go very thin using this technology and, by using the compression process, get improved carbon fiber distribution throughout the part,'' Roedersheimer said.
The part can provide the electronics with protection from electromagnetic and radio-frequency interference.
Fiberite plans to install the demonstration unit or a similar system at its Winona, Minn., plant as part of its materials laboratory.
``We can provide an applications development capability now,'' Roedersheimer said.
The Hull/Finmac system was integrated to decrease Enduron SMC total cycle time, reduce scrap and offer built-in EMI/RFI shielding.
``We can produce thin-wall enclosures while maintaining impact resistance, rigidity and flammability requirements'' needed by original equipment manufacturers, Roedersheimer said.
A definitive agreement for Hexcel Corp. of Stamford, Conn., to acquire most Fiberite Inc. assets, including the Minnesota facility, was announced April 21. The transaction is expected to close in 1997's third quarter.