#windows

As automakers face slowly diminishing returns in their attempts to make internal combustion engines more efficient (while facing huge challenges in electric, hydrogen and other alt-fuel drivetrains), they are looking ever more closely at alternative materials to improve efficiency (and, to a lesser extent, driving pleasure) through weight-savings. Perhaps the biggest emerging trend in this area, especially at the higher end of the market, is in the use of carbon fiber, which is being actively pursued by automakers like BMW, Toyota, Lamborghini and Daimler. But, as WardsAuto points out, there’s another material that’s trying to earn a place in the lightweight cars of tomorrow: polycarbonate plastics.

Polycarbonate windows weigh half as much as glass, and because they are made with injection molding they can come in shapes that can’t be imagined with glass.

However, the material is more expensive. To get auto makers to convert, Sabic and its main material competitor, Bayer MaterialScience, have to sell the idea of integrating other parts into the plastic mold that makes the window.

For example, says Umamaheswara, “on a liftgate, a lot of features can be integrated, and if the manufacturer is short of room in the factory, it can be delivered as a module.”

A modular liftgate could include the window, cladding for the D-pillar, a roof spoiler, the high-mounted rear brake light, a rear wiper foot, handles and logos. When all those processing costs are included, he says, polycarbonate is competitive with glass and metal.