NOK develops new bio-PU for hydraulic sealing

Tokyo – NOK Corp has developed a new biomass-based material for polyurethane (PU) elastomer packings, achieving a plant-derived content of 48% – and reducing CO2 emissions during raw material production by a similar level.

The biomaterial is said to fully retain the rubber elasticity and resin toughness of conventional PU elastomer products, delivering on both environmental and performance fronts.

PU elastomer packings are “suited for hydraulic equipment using biodegradable hydraulic fluid, where their superior sealing properties prevent oil leaks and help reduce environmental impact,” explained NOK.

According to the company, the new material achieves ‘carbon neutrality’ through high biomass content, and supports a ‘circular economy’ through compatibility with biodegradable hydraulic fluid.

Increasing the proportion of plant-derived polymers in polyurethane makes it more difficult to achieve stable moulding and curing, and to maintain performance characteristics.

Biodegradable hydraulic fluid also presented a challenge, as it tends to cause excessive swelling in packings, accelerating wear and compromising durability the company added.

Resolving these challenges, said NOK, involved leveraging its ‘integrated technology platform,’ which covers the entire process from material development through to evaluation and analysis.

Target applications for the packing material include construction machinery and other equipment operating in forests, waterways and other areas where oil leaks pose a direct risk of environmental damage.

NOK’s statement did not include further details about the composition of the bio-based polyurethane.