A so-called solid radial shaft seal is machined from tube or solid stock and formed to the nominal shaft diameter so that it can also be optimized for low friction. The sealing lips can be designed to face either the same or opposite directions, allowing two media to be separated (e.g., food products from gear grease). The use of a suitable PTFE compound with modern fillers, some of which are FDA-compliant (PEEK, PI, Ekonol®, PPSO₂), has also allowed operation against soft mating surfaces (stainless steel), as are often required in filling equipment and the pharmaceutical industry. Traditional fillers such as glass fiber, carbon, graphite, bronze, and molybdenum disulfide (MoS₂) have been used for cost-sensitive applications.
With our PFAS-free polyethylene materials (e.g., Enduflon P16), these requirements can now also be met without fillers and without significant compromises. Another advantage of UHMW-PE is its resistance to X-ray radiation.
Installation in the housing, and thus secure retention, can be achieved in various ways. Usually, a simple interference fit is sufficient. At somewhat higher temperatures, the outside diameter is additionally secured with an O-ring or quad ring (X-ring) or reinforced with an internal steel ring.
Teflon® is a registered trademark of The Chemours Company.
