Polycarbonate film furnishes functionality and finish in auto interiors

To win over consumers, automotive interior designs must feature improved component functionality without sacrificing an elegant, luxurious appearance. Two recent innovations illustrate how materials and process technologies developed by Bayer MaterialScience LLC (Troy, MI) are helping automotive OEMs satisfy this trend.

Bayer recently created a concept center stack—the console between the driver and passenger seats where many instrument panel controls, such as audio and temperature, are located—incorporating advanced materials and processes. By using the high pressure forming (HPF) process to form Makrofol polycarbonate film, Bayer developed an all-in-one center console, which integrates a back-lit LCD module, printed hidden symbols and printed electronic capacitive switches to provide drivers high functionality in one contained part.

Recognizing the potential behind this concept, automakers are taking this idea from concept to practice. One example is using Makrofol DE 9-2 polycarbonate film and Makrolon 2207 polycarbonate resin to form an interior overhead console capacitive touch switch assembly. The switch provides solid state capacitive touch activation, which embodies the automotive industry trend of integrating exciting and valuable technology to improve overall driving experience.

Makrofol DE 9-2 film provides a unique texture with a uniform, low-gloss appearance that meets designers' requirements for appearance and function, as well as a very fine matte finish upon which layers of ink are printed, matching the car's interior colors. The low-gloss appearance is maintained through the decorating, forming and molding process, reducing fingerprints when the film is touched to activate the capacitive switches. Additional layers of conductive ink are printed on the film in an engineered pattern, creating the electrical circuits for the switch that controls several vehicle functions, including interior lights, a garage door opener and the moon roof.

After printing, the film is formed into the shape of the interior overhead console using HPF, which maintains the functionality of the electrical circuits. To complete the console assembly, Makrolon polycarbonate resin is injection molded behind the film's second surface using a film insert molding process.

Overall, the switch offers an extremely thin profile, reducing the component's thickness from 2.75 inches to 0.25 inches, and reducing weight by 70% when compared with traditional overhead consoles. This integration represents not only space and weight savings, but advances the technology of printed electronics on Makrofol film for automotive interiors. —[email protected]