Freudenberg Sealing develops PTFE-alternative polyurethane seal

Weinheim, Germany – Freudenberg Sealing Technologies has developed a polyurethane-based alternative to traditional polytetrafluoroethylene (PTFE) seals materials.

The ‘98 AU 30500’ material is “a hydrolysis-resistant high-performance polyurethane that offers considerably better properties for mobile hydraulic sealing systems than conventional PTFE variants,” said FST 4 Oct.

The product has already “impressed” the first customers, who are within the construction machinery sector, said the FST statement.

PTFE materials offer high media resistance and a broad temperature range for hydraulic applications, while being low-friction and reliable, according to FST’s Dr Juergen Hieber.

“But our 98 AU 30500 material can actually top that, as it is extremely wear-resistant and also highly media-resistant,” added the material development manager.

Helped by the “optimised alignment of material and geometry”, the seals made of 98 AU 30500 are claimed to have low friction and “very low gap extrusion”, which extends service life.

In addition to “excellent friction and sealing performance”, the seals can operate in a temperature range of -25 degrees to +120 degrees, Hieber added.

The material is also claimed to enable “previously unfeasible low-friction and hydrodynamically optimised sealing geometries” in the future.

In terms of cost-effectiveness, FST claims that the longer service and lower need for maintenance will lower operational costs for the users of the seals.

For its initial application in the construction equipment industry, the material has been used in the ‘OMK-PU 30500’ piston seal in 17 dimensions.

The two-part piston seal is made of hydrolysis-resistant high-performance polyurethane combined with an O-ring contact element, using injection moulding process.

The seal is claimed to be interchangeable with seals for standard PTFE ISO installation spaces and requires no recalibration after the installation.

Primarily developed for mobile hydraulic applications in the construction equipment sector in regions with high humidity, the seal can also be used in industries such as food and packaging.

Most importantly, FST sees strong growth potential for the material as it offers an alternative to fluoropolymers, which are now the target of a blanket ban in Europe.