Beaming from within – Bayer MaterialScience develops luminous licence plates

Leverkusen. The new self-luminous licence plate recently unveiled by diversified technology giant 3M was instantly featured on the pages of several automotive magazines.

While standard aluminium licence plates are unevenly lit by a small number of lights positioned around them, the entire of the new plastic plate is brightly beaming from within, making the whole unit highly visible.

The ability to discard exterior lighting elements does not just allow more freedom in customising rear-end designs though – safety is also improved. The fact that the licence plate is much more highly visible helps in avoiding rear-end collisions.

"We worked in very close cooperation with 3M throughout the development process for the entire assembly and produced a solution using several of our materials. For example, we custom-made a special transparent polycarbonate film from the Makrofol® / Bayfol® product range to support the reflective film from 3M, which distributes the light evenly over the surface of the licence plate," explains Dirk Pophusen, technical manager for polycarbonate films in the Business Development department of Bayer MaterialScience AG.

The licence plate housing is made of Bayblend® T 65 and incorporates the light source, which is made up of numerous light-emitting diodes (LEDs). The polycarbonate/ABS blend was chosen because it exhibits exceptional dimensional stability, is less prone to distortion, and remains impact-resistant in cold conditions. It also offers excellent heat resistance.

The translucent front of the casing, on which the actual licence details are positioned, is formed from a two-millimetre-thick sheet of the polycarbonate Makrolon®. A special technology is used to give the sheet a matt finish on one side, thus ensuring that the licence details are optically isolated from the light distribution system.

"The sheet also has a special surface layer that enables laser welding to create a long-lasting, tight seal between the sheet and the housing," explains Dr Peter Schwarz, technical product manager for polycarbonate sheets in the Business Development department of Bayer MaterialScience.

The construction is completed on the outside by the actual licence plate details - a laminate consisting of the special reflective and translucent film from 3M and the carrier film from Bayer MaterialScience. "Our polycarbonate film was chosen over other materials for a variety of reasons," comments Pophusen. "For example, it bonds securely with the outer film from 3M. It is highly light permeable, exhibits good mechanical strength over a broad range of temperatures, and is resistant to the kinds of chemicals usually found in vehicles. It is also important that our films can be formed with a minimal tendency to warp when using the simple, conventional cold-stamping machines found at the licence plate workshops attached to vehicle registration offices in Germany."

About BayerMaterialScience
With sales of EUR 10.7 billion in 2005, Bayer MaterialScience AG is one of the world’s largest polymer manufacturers. Its main fields of activity are the production of high-tech polymer materials and the development of innovative solutions for products used in many areas of everyday life. The main consumer sectors are the automotive, electrical/electronics, construction, sports and leisure industries.

Bayer MaterialScience has production facilities at 40 sites around the world and a workforce of approx. 18,800. Bayer MaterialScience is part of the Bayer Group.

More news and information about products, applications and services of Bayer MaterialScience can be found at http://www.bayerbms.com.
Further company facts and figures are outlined at http://www.facts.bayerbms.com.