CHICAGO - GE Plastics is gearing up to help manufacturers face the challenges of designing a new age of thin-walled plastic products. The Pittsfield, Mass., company has modified standard finite-element analysis software, which measures force, deflection, stress and strain, to do impact analysis of injection molded thin-walled housings for smaller, portable electronic applications, such as notebook computers and cellular phones.
Plastic in such applications has been going to thinner and thinner walls in the past four to six years, according to Dan Sowle, technical program leader for GE Plastics. Sowle spoke on designing new products with thin-wall technology at a session held during the National Design Engineering Show, March 18-22, in Chicago.
A few equipment manufacturers have been behind the push to drive wall thicknesses down, he said in a post-show interview. Most designers and molders are comfortable working with conventional wall thicknesses of .080-0.100 inch, he said. But the leaders in thin-wall technology are making cellular phones and battery packs - which typically are injection molded at 0.040-0.050 inch - with walls in the 0.020-inch range, he said.
``Only a handful of molders and designers tried to develop that expertise,'' Sowle said.
The GE software allows the mechanical designer to simulate impact on different corners and sides of parts made of various materials, such as GE's Cycoloy polycarbonate/ABS blends, and Lexan SP polycarbonates, including glass-filled varieties, according to Sowle.
The test will not tell you if impact has damaged the electronic insides of the product, but it can tell you if and how it has damaged the housing, he said. One critical breakthrough, according to Sowle, is that the software can identify whether a performance failure is a brittle failure or a ductal failure.
The GE program allows designers to apply some science in trying to engineer their products, reduce risk and get to market sooner, without going through the long, drawn-out process of working with prototypes, according to Sowle.
Omar Hasan, with GE's corporate research and development, came up with the method about a year ago, and since then he has been experimenting on different applications, making the analyses more accurate, Sowle said.
Although the program is not yet commercially available, GE currently is using it to help customers develop individual applications.