TPO Plastic Aims to End Cheap-Looking Interiors

TROY, MI – If a potential car buyer sits in a vehicle and complains the interior has “too much plastic,” it can be the kiss of death for a new-car sale, even though the impression is misplaced.

With the exception of high-end luxury cars where interior surfaces are swathed in leather, metal or wood, all vehicle interiors are mostly plastic.

The 3-day TPO Automotive Engineered Polyolefins conference, held Oct. 1-3, celebrates a family of plastics known as thermoplastic polyolefins (TPOs) touted as being the solution to cheap-looking interiors.

The difference between a high-quality interior and a “plasticky” one boils down to how well engineers and designers disguise the true identity of the materials, plastics experts say. Low-gloss finishes and natural leather-like grains win approval. Being pleasantly pliable and soft also is key.

Shiny hard surfaces look shoddy and leave consumers thinking just one word. And that word is not polyolefins.

Billed as the world’s leading automotive forum on these types of polymers, the annual TPO conference is expected to attract more than 600 attendees this year from 20 countries, significantly more than last year, says Bill Windscheif, conference co-chair.

Demand for polyolefins and related plastics is growing in the auto industry, but supply will not be a problem, says Veronica Perez, global strategic market manager for elastomers at Dow Chemical.

“We are the largest producer and have plants in Europe, the U.S. and Thailand,” she says. 

TPOs are used in a variety of vehicle applications, from body panels to bumpers, but they touch the consumer most in interiors, where TPOs are used on instrument panels and other surfaces.

Patrick Stewart, vice president and executive director of interior supplier Inteva Products, touts TPOs as a means of giving even economy cars more luxurious interiors. 

“We’re taking what used to be called a cheap plastic and refining it to the point where anybody who touches it, feels it, looks at it – the execution says it’s not a cheap plastic, it’s luxury,” he says.

Auto makers started adopting TPOs about 20 years ago when European and U.S. governments began requiring auto makers to phase out polyvinyl chloride (vinyl) for environmental reasons.

Outright vinyl bans subsequently were relaxed, but some interior suppliers continued to develop TPO applications because they found the material offered numerous benefits.

For one, it can be recycled easily, unlike vinyl. That makes TPO attractive to auto makers facing end-of-life recycling rules in Europe. It also saves money on the factory floor because scrap can be ground up and immediately reused.

TPO instrument-panel covers also are far more resistant to drying and cracking from sunlight exposure than vinyl. And airbag covers made of TPO will not fragment like shrapnel if deployed in extreme cold. Both features are big selling points to auto makers, Stewart says.

Inteva, which was a unit of Delphi before being spun off in 2008, has been a long-time proponent of TPO. Its investments in research and processing technology now are paying off, Stewart says.

In the early days, the plastic was more expensive than vinyl and very stiff and prone to warping. It also used to be difficult to coat TPOs. Now, Inteva can offer TPO parts at a lower system cost than vinyl, and the material is soft and pliable enough to be sewn like leather, Stewart says.

It even could replace leather in certain situations, he says.

To make his point, Stewart dons a leather-like vest made from TPO.

“If you talked about putting on a TPO vest 10 years ago, it would have been stiff as a board. It’s incredible what we’ve done with the chemistry of the material and the surface coatings,” he says.

“And you could wear this on the beach for 10 years without any problems,” he says with a grin, referring to the material’s resistance to the sun’s ultraviolet rays.

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