Encapsulated seals
27 May 2003
Precision Polymer Engineering (PPE) has developed a range of white encapsulated o-ring seals to tackle the risk of contamination arising from seal shredding during active pharmaceutical ingredient (API) manufacture.
Until now, API manufacturers have had a choice of either black or red encapsulated seals. However in the event of the seal failing, products are contaminated with black or red specks leading to the loss of entire production batches. PPE's encapsulated seals solve the problem without compromising sealing performance.
An encapsulated o-ring seal comprises two, FDA compliant, elements: an inflexible FEP (fluorinated ethylene propylene) or PFA (perfluoroalkoxy) jacket and a flexible internal core energiser elastomer designed to reduce the rigidity of the outer jacket and improve sealing. The white core materials available from PPE include FKM fluoroelastomer, silicone, Perlast perfluoroelastomer (FFKM) and, where appropriate, hollow core silicon. Astra seal is another alternative core material which uses a spring energiser made of high strength stainless steel and is ideal for low temperature applications down to -250 degrees C.
The choice of PPE white encapsulated seal will depend on factors such as static and dynamic sealing application, compression set and deformation recovery, all of which can have a significant effect in reducing the incidence of shredding.
