Flexsil®, the industry-leading refractory cloth filter material, is recognized as the premier filter cloth solution. Ideal for most ferrous alloy filtering and de-gating applications, Flexsil filter material is tailor-formed to meet the needs of both the standard sand foundry and investment casting foundry.

Flexsil fabric is woven from high-strength silica fibers, and is then coated with a unique, proprietary resin. Flexsil fabric is available in two different stages, “B” or “C”. The “B” stage cloth is semi-soft, slightly tacky, and is the base material for thermally cured end products such as investment casting filter cups and pre-stiffened cut pieces. The “C” stage cloth is cured to a strong, rigid state ideal for de-gating and riser knock-off applications.

Upon contact with molten ferrous alloys, special coatings on the fabric create a Fayalite-based surface that enhances filtration efficiency, capturing inclusion particles small enough to pass through the open mesh holes. This sticky surface is unique to Flexsil, as no similar reaction occurs with standard ceramic foam or cellular filters.

Key Features
  • Chemically active surface traps more impurities
  • Available as rigid filter cups that increase pour rates