Bus window seals go green with biobased EPDM

keltanWITH SUSTAINABILITY and carbon dioxide emissions being growing topical issues, Autotravi, a major South American automotive supplier based in Caxias do Sul, Brazil, has begun producing window seals from biobased ethylene-propylene-diene (EPDM) rubber, which is supplied by speciality chemicals firm Lanxess. The German materials firm also expects this trend to catch up in Asia, especially with the growth in the transportation sector and urbanisation.

Made of Keltan Eco 5470, the seals are supplied to prominent Brazilian bus manufacturer Marcopolo. The weather-resistant synthetic rubber constitutes 70% biobased ethylene obtained from sugarcane.

Cristiano Grillo, a spokesperson from Autotravi explains, “Sustainability of tomorrow needs immediate decisions, and Autotravi decides now to change tomorrow with Keltan Eco in our products!”

There are good reasons why Autotravi chose Keltan Eco 5470, says Marjan van Urk, Business Development Manager in the Lanxess Keltan Elastomers business unit in Geleen, the Netherlands: “Keltan Eco 5470 reduces our dependency on fossil resources and, because it is obtained from renewable sugarcane, has a significantly better CO2 footprint than petroleum-based polymers.”

Due to the combination of a highly crystalline structure and a narrow molecular weight distribution, Keltan Eco 5470, one of German firm Lanxess’s six biobased EPDM grades, is said to be a durable polymer.

The end product is said to display high strength in addition to the ozone, UV and heat resistance typical of EPDM rubber products. It differs only in terms of the origin of the ethylene used in manufacturing.

The switch from the conventional Keltan grade to its biobased counterpart imposes no requirements on users, says the manufacturer, adding that the products perform exactly like their conventional counterparts and can be exchanged without any approval. The biobased ethylene content, however, can be verified by the testing method ASTM D-6866.

Meanwhile, Hans Werhonig, Head of the Lanxess Keltan Elastomers business unit in Asia, welcomes the implementation and says that it shows that the fleet owner is aligned with a sustainable approach to serving the mobility megatrend. “The Keltan Eco range of products can also have a similar impact for fleet owners in Asia, especially considering the burgeoning transport systems and populations,” he adds.

Recognising the potential of the growing Asian markets, particularly in China, Lanxess is building a world-scale EPDM plant in Changzhou. With an investment of EUR235 million – the second largest in its history – the plant will have a capacity of 160,000 tonnes/year and create up to 200 new jobs when it comes on stream in 2015.

Besides Keltan Eco 5470, the rubber polymers also include other grades like Keltan Eco 6950 and Keltan Eco 9950. The latter two offer both a high molecular weight and a diene content of around 9%, making them ideal for fabricating foamed sections for automotive window seals. “All six grades are now available on the market,” says Marjan van Urk, “and interest in the industry is high, which undoubtedly is due to the increased demand from the market for sustainable products.”