Auto materials: Recyclable materials for cars with additive specialties from Evonik; Toray develops recycled PA66 from silicone-coated airbags

A consortium of 19 leading industrial companies and research institutes, including the BMW Group, Evonik, Thyssenkrupp, the Fraunhofer Institute, and the Technical University of Munich, has set itself the goal of developing new processes for using sustainable materials for circular automotive production. Evonik is contributing its expertise in plastics and additives for recycling to the project. The project, which is funded for three years by the German Federal Ministry of Economics and Climate Protection (BMWK), was launched at the end of last year.

The core of the "Future Sustainable Car Materials (FSCM)" initiative launched by BMW is to develop innovative process routes and material concepts for large parts of the value chain, thus enabling a circular economy in vehicle production.

"We are pleased to contribute our specialty chemicals expertise to this pioneering consortium of industry leaders and internationally renowned research institutions to develop circular plastics solutions for the automobiles of tomorrow," said Lauren Kjeldsen, member of the Executive Board of Evonik Operations GmbH and head of the Smart Materials Division.

According to the principle of the circular economy, materials must be kept in the value chain after they have reached the end of their useful life so that new objects, such as automotive parts, can be produced without the use of fossil resources. It is particularly challenging to keep these materials in the cycle while maintaining the same quality and safety properties.

"Our mechanical recycling experts work closely with recyclers to prepare methods for cleaning up plastic parts, such as separating paint at the end of useful life,” said Patrick Glöckner, Head of the Global Circular Plastics Program at Evonik. “We also work with compounders to develop solutions for using the highest possible proportion of recycled plastics in new automotive parts."

This form of integrated collaboration enables the consortium to quickly identify challenges and jointly develop solutions. Due to the high complexity of automotive manufacturing, the participants in the FSCM project are optimistic that the knowledge gained can also be applied to other industrial products in the future, such as commercial vehicles, electrical and household appliances, and will thus be a decisive impetus for future circular economy systems in the German economy.

In related news, Japan’s Toray Industries says that it has developed recycled nylon 66 recovered from silicone-coated airbag fabric scrap cuttings. This material achieves the same flowability and mechanical properties as injection moulding grades from virgin nylon 66, it claims.

The company created this product by combining particular additives with resin that Refinverse Group recycled by stripping silicone from airbag fabric scrap cuttings. and thereafter washed. The new offering will debut as Ecouse Amilan.

Toray says it looks for that offering to accelerate the expansion of Ecouse (pronounced Eco-Use), a proprietary integrated brand for eco-friendly recycled materials and products that it rolled out worldwide in 2015.

The nylon 66 fabric of airbags can be silicone-coated or non-coated. Manufacturers normally recycle the scrap cuttings of non-coated fabrics. Recycling coated airbag fabric scrap cuttings requires removing the silicone. It adds that Refinverse was the first in Japan to achieve commercial-scale silicone-coated fabric recycling.

Recycling through stripping and washing has typically left silicone traces, however, degrading the resin and contaminating moulds during injection moulding. Another issue has been that the high viscosity of airbag yarn limits applications in thin-wall and other injection moulding processes in which high fluidity is vital.

Toray accordingly combined particular additives so residual silicone resin would not migrate to the surface of moulded products. It also greatly reduced mould adhesion. That is why the flowability and mechanical properties of recycled nylon 66 with Toray’s technique are on par with those of virgin nylon 66.

Toray plans to start full-fledged sample work in April 2023 or later. It ultimately looks to procure recycled raw materials at its overseas sites to establish a global supply system. It will also explore commercialising recycled nylon 66 products made from airbags recovered from end-of-life vehicles.

The company has cultivated recycled plastic products derived primarily from post industrial scrap materials from in-house production processes, undertaking such efforts as recycling used air conditioner parts into new ones. It aims to extend recycling to used automotive parts and industrial equipment.

Toray intends to launch Ecouse Toraycon as a chemically-recycled polybutylene terephthalate resin product that has properties equivalent to virgin materials.

It will keep assessing material recycling and chemical recycling for its own polymers in driving to expand the Ecouse lineup by bringing out such products as Ecouse Toyolac acrylonitrile butadiene styrene, Ecouse Torelina polyphenylene sulphide.

Subscribe to Get the Latest Updates from IMA  Please click here