Covestro has developed a wide range of films for car interiors. The focus is on displays and operating panels that are protected by scratch-resistant, glare-free films. Using them enables new lighting effects and the integration of functions into the instrument panel. They are part of a new concept for vehicle interiors that also takes account of trends such as increasing networking and customization, electric mobility and autonomous driving.
Many of the film solutions were created in close collaboration with partners from various sections of the process chain – film processing by printing, shaping and back-injecting, surface galvanization, mold construction and integrating electronics.
The films can be matte or high gloss, with defined optical properties, including anti-glare effect. The current top issue is the process of seamlessly integrating displays into the large, three-dimensional surfaces of instrument panels and central consoles. “This meets consumers’ desire for a quality, comfortable atmosphere in the interior,” says Dirk Pophusen, a film specialist at Covestro.
Seeing and feeling electronic displays
He explains the various aspects of film development in a video clip (https://www.youtube.com/watch?v=6gwGnETu1EY) using a display and surface demonstrator constructed by Covestro. It will be showcased at the VDI conference “Plastics in Automotive Engineering” on March 29 and 30 in Mannheim (https://www.vdi-wissensforum.de/en/plastics-in-automotive-engineering/).
The Makrofol HF polycarbonate products are available in various matte grades, are formable in three dimensions, and have a scratch-resistant coating. Thanks to a special layer of coating that is only pre-cured, the films can be formed and back-injected using film insert molding (FIM) after printing. Between shaping and back-injecting, the coating is fully cured using UV lamps.
Another application for polycarbonate films integrated into the demonstrator is switches with “flying symbols.” These center on an innovative combination of printed films and cutting-edge injection molding techniques. This creates switches with a kind of optical 3D effect.
During production, several layers of Makrofol DE films are printed with various symbols. Their bottom layer has a patterned reverse side. The top layer consists of a particularly scratch-resistant film. When a switch is printed with this film structure, various three-dimensional images appear, or the pattern on the reverse side, depending on whether the LED lighting comes from the side or from below.