Virgin grade PTFE gaskets are made from 100% pure material which is used in most general applications. It is extremely soft and formable and is often used for chemical resistant seals and gaskets. It possesses the highest physical and electrical insulation properties and has increased resistance to creep (compression) under load. Virgin grade PTFE can be recognized by its whiter color compared to mechanical grade PTFE.
Filled PTFE gaskets are made from PTFE which integrates additives and fillers in order to improve the performance of the gasket. This improves the gaskets ability to wear and enhances its unique combination of chemical, physical and electrical properties. Filled PTFE is the most common type of PTFE gasket for industrial use as it exhibits improved mechanical strength compared to Virgin PTFE. Glass, carbon and fiber particles are typical fillers that are used to enhance the mechanical strength of the gasket depending on the application.
Expanded PTFE gasket material is produced by expanding Virgin PTFE using a process that creates a uniform and highly fibrillated microstructure with equal tensile strength in all directions. This means that expanded PTFE possesses no structural weakness or a “grain”. Since no additives are required, expanded PTFE also possesses the unique chemical resistance of Virgin. Expanded PTFE is much softer and more flexible than regular PTFE gaskets and thus conforms easily to irregular and rough surfaces. The material is easier to compress and minimizes creep and cold flow.