As thermoplastic composite materials and processes continue to evolve, their use is expanding into new industries and applications.
For years, reinforced thermoplastics have been used in the automotive market, mostly for non-structural, interior components. But thermoplastic composites are advancing into new applications – and markets – as manufacturers strive for lighter, tougher parts that can be rapidly produced, post-formed and recycled.
“Thermosets widely out sell thermoplastics in the total market, but more structural thermoplastics are marking in roads in automotive for vehicle lightweighting,” says Marianne Morgan in new business development with BASF. In addition, as aerospace has adopted more thermoplastic composites in the last five years, their overall role within the industry has begun to change.
“[The use of thermoplastics in aerospace] proves the technology to other industries,” explains Dwight Baker, vice president of advanced composites at Composites One. “At the same time, it increases the education of the engineers, so they are able to engineer them into other products.” Today, reinforced thermoplastics have expanded into structural automotive parts, as well as oil and gas, electronics, infrastructure and marine applications.
Making a Case for Thermoplastics
Thermoplastic composites are used for applications that require high levels of rigidity (stiffness) and impact strength, as well as temperature, humidity and chemical resistance. “In many cases, thermoplastics are the best solution for applications requiring higher output production, lightweighting or fracture toughness,” says Baker.
In contrast to thermoset composites, thermoplastics have a one-step cure process that doesn’t require a catalyst, oven or autoclave. This fast-cure cycle is why thermoplastic composites are used in mass production methods, such as injection molding. Thermoplastic polymers aren’t chemically cross-linked after curing, which allows them to be remelted and reformed. This provides unique post-forming capabilities and solves the end-of-life cycle challenges associated with thermoset composites. In fact, many see their recyclability as key to future growth.
Polystrand, which was acquired by PolyOne in 2016, began working with thermoplastic composites in 2001 because of their recyclability. “At the time, there was a lot of attention on recycling – and there still is,” says Mike Gordon, formerly with Polystrand and now president of Gordon Development. “Thermoset composites are very, very difficult to recycle. We saw the future as being able to make products with thermoplastic composites and use the manufacturing byproducts to make other products.”
Dana Swan, business development manager of the Elium® product line at Arkema agrees. She points to automobile standards in the European Union (EU) and Asia that require nearly fully recyclable vehicles. “Right now, it’s the EU. But I believe [similar standards] are coming to the U.S.,” she says. “There’s been great strides with thermosets’ recyclability, but in order to truly get a recyclable model, you have to go to thermoplastics.”