Of Eucalyptus and Bone Ash

Riches from renewables

Sustainable sealing materials contain ingredients derived from renewable resources. These include plant or animal sources and recycled materials. While fossil fuels are also formed from plants and animals, these reserves are ancient and cannot be readily replenished.

Base polymers exhibit many properties that make them excellent for sealing applications – temperature and chemical resistance, high flexibility, excellent elastic behaviors. But these polymers can also lack stiffness and strength. Mineral fillers are typically added to increase these properties, and it is these ingredients that the company’s Advanced Materials team is working to replace.

In the company’s R&D laboratories in Plymouth, Mich., the material experts have assembled an inventory of sustainable ingredients and their sources. There is calcium phosphate derived from bone ash. Bottles with an antioxidant extracted from Eucalyptus plants, and Rapeseed Oil from Rapeseed flowers, are on display. A container of beef tallow – a sustainable source for processing aids – sits next to material fillers made from lignins that are extracted from forestry processes. And there are others – sugarcane, grain chaff, recycled rubber – can all be processed into useful and sustainable polymer ingredients. Such renewable resources hold promise, but only if they can replace fossil fuel ingredients, one for one, while maintaining the quality and performance of the original polymer.

“Freudenberg Sealing Technologies specializes in developing and mixing elastomers that are a combination of polymers and reinforcements,” said Materials Fellow Dr. Paul Hochgesang. “There are plenty of sustainable ingredients out there, including materials that can be recycled. But we are researching sustainable ingredients that will result in an optimized product performance.” Finding that perfect match involves extensive evaluation and testing.

“In the beginning, we will not exclude any sustainable ingredients from consideration,” said Traber. “We look at the ingredients our suppliers offer and evaluate their properties. We benchmark them against fossil fuel- derived ingredients. If the performance and quality of a material is not changed, then we can make a recommendation to the company’s Divisions about using sustainable ingredients in our materials.”