Crystal clear liquid silicone from Momentive Performance Materials

High transparency Liquid Silicone Rubber (LSR) from Momentive Performance Materials for use in camera-based driver assistance systems from KOSTAL. KOSTAL, the technology specialist for automotive electronics and mechatronics, introduces a compact front view camera which attaches to the windscreen. Its special construction combines functional and technical design advantages. The material used to couple the camera directly to the windscreen was developed by LSR specialist Momentive Performance Materials.

Vehicle safety and comfort are central to modern automotive design
In view of the increasing volume of traffic on the roads, the combination of established security systems and innovative environmental sensors forms a forward-looking basis with which to safely deal with complex traffic situations.

Rain and light sensors are characteristic features of modern vehicles today. They increase comfort, reduce the workload of the driver and therefore make a significant contribution to improving active vehicle safety. Predictive driver assistance systems require a detailed analysis of the traffic situation using camera and video-based environment recognition. The corresponding optics must record the events in the environment of the vehicle reliably and true to life.

This requires robust, high-performance optical materials, which retain their characteristic transparent properties in the wavelength range of the light at the time, even in the event of extreme temperature fluctuations, differing levels of humidity and over a long lifespan.

The new driver assistance camera by KOSTAL with integrated rain and light sensors
KOSTAL GmbH & Co. KG and Momentive Performance Materials GmbH worked together to develop a new, highly-transparent liquid silicone rubber (LSR) for an innovative sensor module which integrates rain and light sensors as well as a camera and takes up minimal space.

The camera is attached directly to the windscreen to achieve maximum robustness against typical sources of interference such as dirt and light reflection. The highly transparent silicone cushion creates a blister-free transition between the optical sensors and the windscreen, adapts perfectly to different surfaces and thus also reduces scattered light and reproduction inaccuracies.

Highly transparent liquid silicone with the lowest hardness
Momentive Performance Materials meet this challenge with their completely new LSR material which will be launched as part of the new optically highly transparent LSR 7000 series as LSR 7005. The low hardness of the material (just 5 Shore A) allows a form-fitting, tolerance-compensating connection of the sensors to the windscreen, regardless of the windscreen radius, and low mounting forces. In addition, the new LSR does not adhere to the glass, even at high temperatures and after longer periods of time. This means the complete module can be used again when the windscreen is replaced. The excellent transmission values of 95% over a broad wavelength and temperature range and a refractive index comparable with glass ensure maximum light transmission and a clear, detailed visualization of the environment. Processing features are, the short cycle times for which LSR is renowned, a fully automated injection moulding process enabling the production of sophisticated geometries and complex multi-component parts.

Website: www.momentive.com.