Polypropylene (PP)

The information provided on this website is intended as a guide for filter bag applications. SLY, LLC. makes no guarantee about the performance or results you can expect from the application of this information unless provided in writing from our staff.

Polypropylene Felt: Normal maximum continuous operating temperature is 170°F. Polypropylene felt is used for general applications where chemical and moisture attacks other fibers. Polypropylenes offer high strength, excellent resistance to most acids and alkalis. Smoothness of fibers allows good cake release and resistance to blinding. Moisture absorption is virtually non-existent. This media has very good resistance to both mineral and organic acids and generally good resistance to alkalis with the exception of sodium and potassium hydroxide above 200°F. Good resistance to most reducing agents. Polypropylene also has fair resistance to most organic solvents with the exception of ketones, esters, and chlorinated hydrocarbons.

Fiber Filter Properties (PDF)
Fiber Filter Chemical Compatibility Chart (PDF)

  • Available Finishes for Polypropylene Felt:
    Plain (PL); Singed (SI); Glazed (GL); ST-01 (Oleophobic); ST-04 (Code 9); PTFE membrane (XP); ST-09 ; ST-10; ST-11; Fire Retardant (FR); SlyCharge (EX); ST-12 (SS fibers); Epitropic (EP); SlyHE (High efficiency). See detail information on finishes here.
  • Available Weights for Polypropylene Felt: 16 oz./yd2

Polypropylene Felt Common Finishes:

Singed (SIPP) – The felt is singed on the dust cake side for improved cake release. The process involves exposing the surface fibers to an open flame that melts back the loose fiber ends to which dust particles could adhere.

Glazed (GLPP) – This process involves running the felt through two heated rollers to melt back the loose fiber ends improving the cake release. The process can also compress the felt to smooth the surface, further improving the cake release.

SlyTech-01 (ST-01) – Oleophobic -water and oil repellent finish. SlyTech-01 is a complete PTFE bath which provides an excellent cake release finish to each fiber. This finish is cheaper and more durable than a membrane that can be easily scratched. Click here for more information on ST-01.