The Aura of Polycarbonate Surrounds TVs

The new plasma FlatTV from Philips is enhanced by Ambilight, an innovative lighting concept built into the rear of the TV that improves the viewing environment by projecting background lighting onto the wall behind the set. To make this feature possible, the housing had to be redesigned to integrate a transparent intermediate frame between the back and front covers. Dubbed “Tech Cabinet 422”, the transparent frame is made of Makrolon 6555, a polycarbonate from Bayer MaterialScience.

“Using polycarbonate to build television housings is a new trend. Our material won out for this application because it boasts excellent flame-retardancy while simultaneously offering very high transparency and heat resistance,” explains Melanie-Isabel Stephan, key account manager at Bayer MaterialScience. The material satisfies UL 94 V-0.

The 120 by 60 cm Tech Cabinet frame also fulfils other tasks in addition to its function as a light transmitter. For example, anchoring points for the loudspeakers, various cables, the operating components and the screen mounts are all built into the frame. This high degree of integration and the variety of functions result in complex part geometry. Coupled with the size of the housing components, this posed quite a challenge in terms of part design, particularly because the polycarbonate has a relatively high melt viscosity.

Bayer MaterialScience and Philips worked together closely throughout the component development phase, which took only a few months. “Our services included extensive rheological calculations to position weld lines in areas hidden from view and to minimize stress in the molded part by means of optimum gating. Consequently, we were also very involved in the mold design work,” Stephan explains.

Bayer Inc. 800-668-2554