Written on 01.04.2011 - Technology
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Simrit develops PU materials to meet sealing challenges

Developed specifically to meet the sealing challenges of cylinder makers, Simrit's NOK U641 and NOK UH05 materials are proven to help engineers extend seal life in numerous applications. When incorporated properly, these materials provide 8,000 to more than 10,000 hours of running time in the field without failure, says the company.

For customers currently using the Disogrin 9250 material, the NOK U641 urethane is an alternative solution that is hydrolysis/glycol resistant and increases the long term operating temperature of the system to 110 °C with standard and biodegradable hydraulic oils. It can be run in the same tooling as Disogrin 9250 and has been a proven solution for more than a half decade. For those looking to significantly increase the life target of a system, substituting a NOK A505 NBR rod seal (with proper back-up) and a U641 buffer can double the life of this system.

NOK UH05 urethane is a hydrolysis/glycol resistant solution for 120 °C systems with standard and biodegradable hydraulic oils. In particular, NOK UH05 (40 – 120 °C temperature range) seals have been successful in hydraulic cylinders exposed to harsh conditions.

According to Simrit, it is rare for a material to not only have this high of a temperature range in the industry (allowing for use in a Columbian coal mine), but also one of the lowest temperature capabilities (allowing for use in Antarctic applications). Traditionally, a manufacturer would require two different sealing packages for each application. Using a NOK UH05 (buffer) in combination with NOK G928 HNBR rod seal (with proper back-up) can double the life of a system at 120 °C, while providing exceptional low temperature capabilities, says the company.

Simrit is part of the Freudenberg and NOK Group Companies, which have total annual sales of more than USD 7 billion.