Hexpol brings TPE with recycled material to auto interiors

MANCHESTER, England—For Hexpol, sustainability is "much more than a buzzword" as the international polymer compounder brings sustainable thermoplastic elastomers to the automotive sector.

Hexpol TPE Ltd., a subsidiary of Sweden's Hexpol A.B., says it is bringing the first TPE with recycled content to automotive interiors with the expansion of its Dryflex Circular TPE range.

"An important aspect of automotive interior parts is their emission behavior regarding odor and volatile substances," Hexpol said. "The exact specifications and requirements vary depending on application and OEM. But generally, the material odor must not be disturbing even at higher temperatures" like 80°C (176°F).

The company said that a 65 Shore A material—a representative of Dryflex—used for inlay mats with recycled content of 20 percent showed "very low" amounts of volatile organic compounds and semi-volatile "fogging" (FOG) compounds of 60 μg/g and 594 μg/g, respectively.

"The TPE was tested at an external accredited laboratory and shown to have almost no odor," Hexpol said in a statement, noting the material's mechanical properties fulfill automotive requirements.

First launched in 2019, Dryflex Circular TPEs' recycled polymers are from various sources—including post-consumer (PCR) and post-industrial (PIR)—and are incorporated into the material, Hexpol said, adding that they also can be recycled into closed-loop systems at the end of life.

"Dryflex Circular TPEs were developed to support the shift from finite fossil-based virgin materials," the company said in a statement.

Hexpol uses recycled materials diverted from waste streams during post-industrial manufacturing processes for its Dryflex Circular TPEs, the company said. For example, the company's molders/converters "can rework any scrap they produce in their own systems," a Hexpol spokeswoman told Rubber News in an email.

The recyclate originates "from injection molding sprues or edge trims in extrusions," Hexpol said. "The chosen recyclates were selected due to their high levels of consistency and purity. With consideration of transportation and energy impacts, the recyclates are sourced in Europe."

The sustainable TPEs are produced at Hexpol's European sites in Germany, the United Kingdom and Sweden, which use 100-percent renewable electricity.

According to Hexpol's 2020 environmental impact report, plants at its Lichenfels, Germany, location, for example, have run on 100-percent green electricity since Jan. 1, 2021.

"By implementing a new dry cooling system in 2020, we managed to cool our production facilities with outside air, as soon as outside temperature is below 15°C (59°F)," the company said in its report, adding the sites saved 282,327 kilowatts per hour.

The company also saved 90,913 kilowatts per hour by "optimizing the process parameters on our production lines," Hexpol said, by working to reduce the running times of materials produced and adjusting heating zones on extruder machines.

In January, Hexpol received the International Sustainability + Carbon Certification (ISCC Plus) rating for its Sweden operations. The international certification measures sustainability and carbon emission reduction benchmarks and allows the company to produce TPE materials with certified bio-positive or bio-circular content.

The Hexpol spokeswoman said the ISCC Plus designation further supports "a shift away from fossil feedstocks to use the concept of mass balance."

Hexpol said the amount of recyclate content in the Dryflex TPEs depends on several factors.

"The amount of recyclate content varies depending on the grade, the properties required and the application, but it is typically in the range of 10-60 percent," the spokeswoman said. "The grades for automotive interior applications are typically up to 40 percent recycled content, depending on requirements."

While containing recycled content, the materials maintain their colorability, Hexpol added.

The spokeswoman said Dryflex PCR grades are only available in dark colors, noting they're used in automotive exteriors like mudflaps, side-steps and wheel-arch liners.

"These grades can also be used for outdoor equipment such as lawnmower wheels or safety barriers," she said.

PIR grades, on the other hand, are available in light and dark colors, she added, "giving additional design possibilities. They are targeted to consumer goods, sports equipment, footwear, household and automotive applications."

Specific to automotive interior applications, the company said the new Dryflex Circular TPEs can be used in applications such as inlay mats, cup holders, sealing lips and HVAC parts.

"With the recent developments of Dryflex Circular TPE, it is now possible to realize high-performance interior applications," Thomas Koppl, Hexpol TPE group product manager, said in a statement. "Together with our Circular TPE grades for exterior applications and our bio-based TPEs, we are supporting automotive suppliers and OEMs to fulfill their targets to increase the use of recycled and renewable materials."

Hexpol A.B. is positioned in compounding, gaskets and wheels, and it serves customers in the global industries of automotive and engineering, construction, energy, oil and gas, medical equipment and OEM manufacturing. The company reported $1.65 billion in sales with an adjusted EBIT of $281.5 million, according to its 2021 year-end report. The group has approximately 4,800 employees in 14 countries.