Electriccircuits are molded into plastic housings in a new technology introduced at K2010 by A. Schulman, a plastics compounder based in Akron, OH.

Schulmanshowed an electrically conductive plastic compound developed for Hella KGaA Hueck &Co., a Finnish lighting manufacturer.

Copper andtin are loaded at a very high level (60 and 25 percent respectively) inpolyamide 6. The tin acts like a solder connecting the copper fibers.

"Theconductivity of the compound is 1,000 times better than the next mostconductive plastic compound available (plastic loaded with steel fibers)," saysThilo Stier, innovation manager for A. Schulman.

The firstproduction part is a light that can be used for automotive or other end-marketapplications.

Theproduction process is novel.

First, theABS plate and the PMMA (acrylic) reflector are injection molded in athree-component process. The electrical resistor, diodes, LED and contact pinsfor the plug are inserted and connected with the new conductive compound, whichis called SchulatecTinCo 50. The ABS-coated reflector is then mounted to ensure watertightencapsulation.

Stier saysthe material can be used for housings and lighting applications. The newtechnology permits new design opportunities while also reducing costs throughintegration of structural and electrical functions into one part.

The specificelectrical conductivity of the compound is in the range of 5 x 10⁵S/m. The conductivity of copper alone is 5.69 x 10⁷ S/m.

Development ofthe technology began with Siemens in 1998 and was later supported by IKV Aachen, a German researchorganization.