New surface finishing process for seals

Stockholm - Seal and equipment manufacturers face unique challenges in high vacuum environments, or in those with explosive and toxic gases. For these demanding situations, Flexfinish offers a new surface finishing process that virtually eradicates leak paths.

Leak paths can be a challenge in any sealing environment, reducing performance and sometimes leading to failure, replacement or redesign. But what about in applications where failure can have serious consequences?

Many existing surface finishing processes, though offering excellent leak-free operation in many applications, do not offer the levels of surface quality that vacuum and toxic gas operations require, and can often be unsuccessful on large diameter seals. The height of flash is absolutely critical to tight sealing functionality and de-flashing procedures must not create scratches or holes on the seal surface.

“We noticed that certain applications, particularly those involving high vacuum processes and large diameter O- Rings, were not performing up to our expectations,” says Simone Frick, product manager O-rings and surfacefinishing at Trelleborg Sealing Solutions. “The performance was usually acceptable, but we knew that a better solution could be found.”

Traditionally, tumbling and grinding methods are used to remove flash, frequently leaving minute scratches on the surfaces of the seals which can act as leak paths. “We began research to determine a better way of providing a higher level of quality for large diameter seals, one that would be unmatched in the industry,” continues Simone.

Trelleborg Sealing Solutions research and development teams along with application engineers worked together globally to create a new surface finishing solution that outperformed existing methods.

“The result was Flexfinish, a special de-flashing method which results in the lowest possible flash height and an outstandingly even surface finish, especially when compared to the methods used on large diameter seals,” explains Simone. “We can offer flash heights down to ISO 3601-3, grade S or N, depending on the customer's requirements and the material chosen, while providing very high surface qualities depending on the material and production method.”

“When combined with large diameter O-Rings produced by Trelleborg’s unique FlexiMold process, Flexfinish can result in cost-effective sealing solutions that can give outstanding leak-tightness when sealing in a vacuum or with gas,” concludes Simone.