Published On: Thu, Jan 30th, 2014

Bayer and Gerhardi collaboration achieves efficient production of polycarbonate automotive decorative strip

At the VDI conference Plastics in Automotive Engineering, Bayer MaterialScience will be showing numerous variants of a decorative strip based on Markrolon and Bayblend polycarbonate (PC).

polycarbonate automotive decorative strip

polycarbonate automotive decorative strip

The concept components were created in close collaboration with Gerhardi Kunststofftechnik in Lüdenscheid, Germany. The processing specialist developed a mold concept in which a diverse range of surfaces and design variants can be efficiently produced. Bayer said that its comprehensive performance spectrum of PC materials enables a single mold frame to be used for a wide range of decorating options.

“These include matte and high-gloss structures, attractive shades with deep luster and also coated, film-decorated and metallized surfaces,” says Dirk Kieslich, Head of Product and Process Development at Gerhardi. “This near-series mold can be used to replicate the most common surface design techniques and thus produce a wide array of variants without further processing steps.”

“One simple, but effective possibility is the production of three-dimensional laser-engraved graining with two different levels of gloss,” says Philipp Möller, Project Manager and Application Developer at Bayer MaterialScience’s Polycarbonates Business Unit.

In this application, the high flowability and processing temperature of the PC+ABS blend Bayblend HG allows for the precise reproduction of the graining. “The structure also pro-vides a natural form of scratch protection,” adds Mr Möller. The high quality, glossy surface can then be coated in a particular color using coatings formulated with polyurethane (PU) raw materials from Bayer, for instance.

The use of the metallizable product Bayblend T65 PG expands the spectrum of design possibilities. Attractive chrome surfaces can be produced on the component by means of galvanic plating. Furthermore, structures with matte or high-gloss designs can be produced using the StrukturChrom process, a decorating technology developed by Gerhardi. Components with integrated lighting provide a look at the plastic surface below. 3D laser engraving is also possible.

PC films such as Makrofol HF open up further prospects for the visual design of automotive interiors. These scratch-resistant, coated films are robust and thanks to new processing technologies can also be shaped 3D. The result is components with a customized appearance.

One interesting variant are surfaces with daytime/nighttime designs that are a good fit with the current infotainment trend. The optical display is only visible when switched on and is produced by means of LEDs behind the film. Otherwise the driver sees only an elegant, matte-black surface.