E.i. Dupont De Nemours and Company

Herman H Forsten

Kurt Hans Wyss

Anil Kohli

Wo K Kwok

Laurence Nelson Bascom

Anthony Anton

Michael S Frankosky

Jagdish N Shah

Peter E Frankenburg

Sami Khan

Gordon R Cotman, Jr

This invention relates to a bag filter having a tubular section, one closed end and one open end, the tubular section having a nonwoven felt comprising an intimate fiber blend of 50 to 80 parts by weight polyphenylene sulfide fiber and 20 to 50 parts by weight acrylic fiber, based on the total weight of polyphenylene sulfide and acrylic fibers in the felt, wherein the acrylic fiber has an equal or lower denier per filament than the polyphenylene sulfide fiber.

Bag filter comprising polyphenylene sulfide and acrylic fiber

This invention relates to a bag filter having a tubular section, one closed end and one open end, the tubular section having a nonwoven felt comprising an intimate fiber blend of 50 to 80 parts by weight meta-aramid fiber and 20 to 50 parts by weight acrylic fiber, based on the total weight of meta-aramid and acrylic fibers in the felt, wherein the acrylic fiber has an equal or lower denier per filament than the meta-aramid fiber.

Bag filter comprising meta-aramid and acrylic fiber

This invention relates to a thin reinforced nonwoven fabric having ridges and grooves for fire blocking an article and articles containing such fabrics. When exposed to heat or flame, the fabric is capable of increasing to a thickness that is at least 1.5 times its original thickness. The fabric comprises an open mesh scrim having a having crimped, heat-resistant organic fibers compressed thereon and held in a compressed state by a thermoplastic binder, on which is imparted a ridge and groove structure. When subjected to high heat or flame, the binder in the structure softens, releasing the restrained crimped fibers and any ridges and grooves and allowing the thickness of the fabric to increase.

Reinforced nonwoven fire blocking fabric having ridges and grooves and articles fire blocked therewith

A sheet composition with certain proportions of meta-aramids and mica used as a flame barrier composition.

Flame barrier compositions and their use

The present invention relates to a stiffened fabric for use in cartridge filters comprising flat fabric formed from entangled heat resistant staple fibers having a weight of from 4 to 8 oz/yd.sup.2 wherein the stiffened fabric is characterized by a flex modulus of at least 10 KSI measured at 200.degree. C.

High performance fabrics for cartridge filters

A fire-resistant material used in items such as sleeping bags, comforters, wearing apparel, upholstered furniture and mattress tops comprises a fiberfill batt and a layer of a fire-resistant aramid fiber contacting at least one side of the aramid fiber layer. The fiberfill batt may comprise synthetic fiber, which may be either polyester fiber or polyolefin fiber. Alternatively, the fiberfill batt may comprise natural fiber. The aramid fiber layer may comprise poly(m-phenylene isophthalamide) fiber, poly(p-phenylene terephthalamide) fiber or a blend of poly(m-phenylene isophthalamide) and poly(p-phenylene terephthalamide) fiber. The aramid fiber layer may be needle-punched, hydroentangled, or laminated to the fiberfill batt.

Fire-resistant material comprising a fiberfill batt and at least one

Spunlaced fabrics from poly(p-phenylene terephthalamide) or mixtures thereof with poly(m-phenylene isophthalamide) fibers having a specified flocked nylon surface can be dyed or printed and the flock does not significantly reduce the fire resistance of the base fabric.

Fire resistant fabrics with a flocked nylon surface

As a cloth for filter bags, a laminate comprising thin layer of nonwoven poly(p-phenylene terephthalamide) needled to a felt of poly(m-phenylene isophthalamide), polyester or polyphenylenesulfide fiber felt increases the resistance to burn through by hot sparks.

Filter bag for hot gases

Nonwoven fabrics of poly(m-phenylene isophthalamide) having a cross-machine modulus greater than 40, and good resistance to abrasion that is useful as a gas filtration substrate, and the process of producing such a fabric by heating an entangled web while stretching the fabric transversely 5 to 15% for a time sufficient to increase the crystallinity index at least about 0.05 units.

Light weight filter felt

65-99 percent by weight poly(tetrafluoroethylene) fibers and 1-35 percent by weight glass fibers are combined in an intimate blend suitable for the preparation of filter felts having reduced leakage while maintaining high permeability to gas flow.

Filter of poly(tetrafluoroethylene) and glass fibers

A scrimless poly(m-phenylene isophthalamide) fiber felt suitable for high temperature gas filtration and a process for preparing the felt.

Process for heat treating a needled batt

A scrimless, dimensionally stable filter felt suitable for high temperature gas filtration is comprised of at least 80% by weight poly(m-phenylene isophthalamide) staple fibers having at least a low degree of crystallinity and a staple length of 4 to 16 cm., and has a felt density of 0.15 to 0.4 g./cm..sup.3 and an air permeability of 3 to 30 m..sup.3 /min./m..sup.2 (0.degree. C. basis pressure differential = 1.27 g./cm..sup.3.

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Hockessin, DE, United States of America

Herman H Forsten