Patent ID: 7819936

Claim:
A bag filter containing a filter felt the bag filter having a tubular section, one closed end and one open end, wherein the filter felt is a nonwoven felt and forms at least the tubular section of the bag filter, wherein the filter felt comprises an intimate staple fiber blend of a) 20 to 75 parts by weight polymeric staple fiber of a polymer or copolymer consisting of sulfone amine monomer reacted with at least one acid monomer, the sulfone amine monomer selected from the group consisting of 4,4′ diaminodiphenyl sulfone, 3,3′ diaminodiphenyl sulfone, and mixtures thereof; and b) 25 to 80 parts by weight of a heat resistant staple fiber selected from the group consisting of meta-aramid fiber, acrylic fiber, polyphenylene sulfide fiber, and para-aramid fiber; based on the 100 parts by weight of the polymeric fibers and heat resistant fibers in the felt.