PLASTIC COMPOSITES, WHILE light and inexpensive, have always been harder to produce than metal parts. That's changing. Researchers at Stevens Institute of Technology have designed a plastic-composite nose cone for a shoulder-fired missile for the U.S. Marines that should cost $40 apiece to manufacture vs. $400 for the aluminum one in use now. Next, for the U.S. Army, they plan to design plastic-composite parts that could lower the weight of an M-113 tank to 38 tons, vs. 70 tons now. The key to the Stevens designs is a software package developed at the Hoboken (N.J.) school with more than $20 million in Defense Dept. funding.
The software, Designer's Apprentice, brings together in one Unix workstation all the data and more than 1,000 rules of thumb needed to design plastic parts and choose production methods. The first version was for injection molding. The next is for the trickier process of resin transfer molding, which creates strong, reinforced parts. Stevens may create a private company to commercialize Designer's Apprentice.