Future auto trends light the way for safety, style

Detroit — Both concept and production vehicles this year are once again showing how automotive lighting will continue to take on added roles not only for performance and aesthetics, but also for passenger and pedestrian safety.

Concept cars at the North American International Auto Show flaunted the many ways automotive designers are solving the challenge of how to seamlessly integrate cameras and sensors into vehicles without interrupting design or function. At the other end of the design spectrum, production vehicles are becoming more stylized as LED lighting becomes a mainstay in headlamps and taillights.

Paul Platte, senior marketing manager for automotive and transportation at Covestro LLC, one of the world's largest producers of polycarbonate, highlighted several of this year's trends during a Jan. 18 interview on the auto show floor and how specialty materials are in high demand in several applications.

If there is one trend auto show attendees have seen on concept cars this year, it is that seams are out and illumination is in. Take the all-electric Mercedes-Benz EQA concept, for example.

"The trend that we're really seeing is the seamless front end," Platte said. "The concept car is looking toward being an electric vehicle, so the front end can be closed off and, in doing so, what you're able to do is introduce a lot of new aesthetic and performance types of features."

A transparent material on the front end, most likely polycarbonate, shows an illuminated version of the Mercedes-Benz logo.

"There's also this lighting strip effect, which is something that is also being shown on the rear end of the vehicle. [That is] a very dynamic and a new type of lighting concept," he said, adding that the illuminated display on the rear of the vehicle could be used to transmit signals for pedestrian safety.

A "ribbon effect" for the lighting is also used in a white light for the headlamps. In the rear, the ribbon lighting is introduced in red, suggesting their role as brake lights, Platte said.

"In general, the styling overall is very seamless — not just physically on the front, but from a color standpoint, where you're able to see the black of the hood going across the whole end of the vehicle as well," Platte said.

Covestro's Lou Madrid, market development manager, pointed out the use of a material — most likely polycarbonate — in piano black, which achieves a high-gloss or wet look, on the EQA's roof.

"If you take a look at the roof there on the vehicle, you have a glazing and then you have a spoiler. … You can barely see the seam, but it's actually two different types of materials. They almost look exactly the same," Madrid said.

Achieving this level of seamlessness or uniformity is a challenge both automakers and suppliers face as they try to harmonize colors on varied materials.

"One of the things that we have found is black is not black. … Different OEMs have a different black," Platte said.

In addition, the use of black for hidden sensors and backlit areas requires two different color batches to achieve both translucence and opaqueness, he added.

"When everything is off, the stylist wants it to look the same color, but we have to work behind the scenes to actually have a different coloring package," Platte said. "When it's illuminated, you get the effects you want, and when it's not illuminated, it looks homogenous, so this whole idea of seamless goes [into] color seamless."

On vehicle interiors, Madrid shared how OEMs are using piano black in trim areas to avoid large areas of unsightly blemishes, such as fingerprints and scratches.

"The limitations with piano black are those kinds of defects, [such as fingerprints]," Madrid said. "We have a technology today where it will enable the OEM to have larger areas of piano black."

The technology, called DirectCoating, combines thermoplastic injection molding with reaction injection molding in a single mold and delivers a finished thermoplastic part with a customized polyurethane coating, the company said. The finished parts are ultraviolet stable and scratch- and chemical-resistant.

Platte said the DirectCoating technology is "approaching release" in the next year or so with an OEM. He could not comment on which automaker Covestro is working with on the launch, however.

"One thing that a designer has talked to me about is in order to have those lighting effects pop, you've got to have black," Platte said, referencing the high-gloss and low-gloss black materials used on the interior and exterior of the Volkswagen I.D. Crozz concept. "You've got to have it, so black is becoming more and more important as lighting is becoming more and more important. To me, it's another one of these dichotomies that is happening."

With the growing use of LEDs, headlamps are moving beyond safety and function and further into design. Designers for the 2019 Chevrolet Silverado pickup truck, for example, broke the headlamp assembly into multiple components for a three-part design — a trend Platte said he has been seeing a lot of despite the increased part count.

The use of LED technology requires the multiple parts because of the various sensors and lighting effects, Platte explained.

"Getting part count down does end up simplifying [production] and gives you the cost reductions … so it's kind of an odd trend that you've got where the styling is trying to reduce the components and then from a technology standpoint right now it's on an increase," he said.

Platte said it is also an opportunity for Covestro to find ways to consolidate different components and different types of functions together.

As the automotive industry sees greater use of LEDs in lighting applications, it will require the use of high-heat polycarbonate or other thermoconductive polymers to absorb some of the access heat as well.

"Today, the industry standard is using a polycarbonate outer lens, which is really protecting the whole lamp assembly," he added. "And it is sealed — it's not sealed completely, but there is a sealed lamp assembly — so heat can build up in that assembly as well. … When the heat builds up, that can adversely affect the LEDs, so the engineers are trying to find ways to reduce the heat and that's where thermoconductive grades start to come into play."