With the ever-increasing emissions standards and many companies pushing for sustainability solutions, Freudenberg-NOK Sealing Technologies developed an ethylene propylene diene monomer (EPDM) rubber compound from a polymer produced from sugarcane-based feedstock.
The bio-renewable rubber, which has been in development since 2012, is made from a polymer that is made with a process that begins with the sugarcane plant. A sugarcane-produced ethanol is converted into ethylene, which forms a substantial portion of the base polymer.
“We had been working with polymer suppliers for ways to reduce our carbon footprint, but the polymer offerings lacked the specific characteristics we needed for our advanced manufacturing processes,” said Joe Walker, global director, Advanced Materials Development. “So we initiated a project to research the area, and we were able to develop a material that can be used in our next generation injection molding process.”
The company has focused much of their next generation manufacturing technology on a single cavity, net shape injection molding process, which has resulted in reduced waste and energy demand and overall improved manufacturing control, yielding improved quality. This new concept is becoming a staple there. The advent of the new, more eco-friendly EPDM rubber is a natural fit for the machines.
Applications for the rubber include seals for coolants, steam, synthetic hydraulic fluids, brake fluids and aerospace hydraulic fluids (phosphate esters). The newly developed material is capable of withstanding temperatures up to 150° C, and the material has outstanding compressive stress force retention.
In addition to these properties, the sugarcane base allows the material to be 45% bio-renewable, which ultimately reduces the manufacturing carbon footprint.
Walker said that the new material has greater than 20% retained compressive sealing force after 1,000 hours at 150° C, and the durability/longevity is essentially the same as conventional, hydrocarbon based polymers. It is, as is true for any rubber article, a function of the environment and the design of the article.
“The material can be substituted for conventional EPDM applications. Initial indications are that the bio-renewable rubber may have an edge on upper temperature limits,” he said.