GORE RASTEX Fibers Sewing Thread, made from 100 percent expanded PTFE and engineered specifically for the demands of filtration applications, withstands exposure to chemicals, high temperatures, abrasives, and moist environments.

Filter bags, cartridges, and other sewn filter media are exposed to extreme temperatures chemicals, abrasives, and, occasionally, moist environments, for extended periods. These conditions degrade the filter media and thread, and the thread often gives out first. In some cases the thread is not appropriate for the application, or it simply wears out from chemical, temperature, or abrasive attack before the filter media.

PTFE Filtration Sewing Threads are almost always used in situations where aggressive chemicals or gases at very high temperatures of 200°C – 260°C act on the filter media and their seams. In this temperature range, high-quality GORE RASTEX Fibers Sewing Threads made from expanded PTFE are superior to other PTFE products on the market, in some cases considerably so, with their long-lasting, high endurance strength. This is vitally important to the lifetime of the filter, significantly reducing the number of changeover cycles and achieving superior reliability throughout the entire usage period.

In practice PTFE Filtration Sewing Threads are exposed to temperatures of 230°C – 260°C. This heat results in “hot air shrinkage” of the threads and therefore the filter seams. In GORE RASTEX Fibers Sewing Threads made from expanded PTFE, the shrinkage is significantly less than 3%, making it a very high-quality product compared with other products on the market. High shrinkage inevitably results in shortened, non-dimensionally stable seams that may impair the function and performance of the filter.