Abstract: The present invention provides for a process for reducing the content of one or more residuals in aramid fibers or filaments, comprising, in this order, the steps of introducing the aramid fiber or filaments into a extraction solution adjusted to a pH ranging from of 2 to 7, adjusting the extraction solution and the aramid fibers or filaments to a temperature of to from 80° C. to 140° C., removing the aramid fibers or filaments from the extraction solution, introducing the aramid fiber or filaments into a first rinsing solution adjusted to a pH ranging from of 2 to 7, optionally comprising a detergent, adjusting the first rinsing solution and the aramid fibers and filaments to a temperature of from 70° C. to 100° C., removing the aramid fibers or filaments from the first rinsing solution.

Abstract: This invention relates to a method for providing a dyed meta-aramid material, wherein said method comprises at least a step of pretreatment of the material and a subsequent step of dyeing the material, characterized in that the step of pretreatment is carried out under closed conditions, in the presence of an aqueous medium, and at a target temperature of 80 to 130° C. This invention also relates to fibers, yarns, and fabrics obtained from this method.

Abstract: The present invention provides for a process for reducing the content of one or more residuals in aramid fibers or filaments, comprising, in this order, the steps of introducing the aramid fiber or filaments into a extraction solution adjusted to a pH ranging from of 2 to 7, adjusting the extraction solution and the aramid fibers or filaments to a temperature of to from 80° C. to 140° C., removing the aramid fibers or filaments from the extraction solution, introducing the aramid fiber or filaments into a first rinsing solution adjusted to a pH ranging from of 2 to 7, optionally comprising a detergent, adjusting the first rinsing solution and the aramid fibers and filaments to a temperature of from 70° C. to 100° C., removing the aramid fibers or filaments from the first rinsing solution.

Abstract: A filter fabric having improved filtering properties for hot gas filtration containing a nonwoven aramid mat The mat has a basis weight of at least 9.7 ounces per square yard (330 grams per square meter) and is characterized by a pore size distribution in which the number of pores in a given range as measured by ASTM F316-03 test method is plotted against pore size. In a preferred embodiment, the percentage of pores having a size in between 10 and 26 microns is greater than 50% while the percentage of pores having a size of greater than 50 microns is less than 0.5%.

Abstract: A bag filter having a support structure clothed in a filter bag. The cloth of the filter bag is a composite of at least one substrate layer and at least one nanoweb bonded thereto in a face-to-face relationship. The nanoweb is positioned at the surface of the filter bag first exposed to the hot particle laden gas stream and can have a basis weight of greater than about 0.1 gsm.

Abstract: A bag filter having a support structure clothed in a filter bag. The cloth of the filter bag is a composite of at least one substrate layer and at least one nanoweb bonded thereto in a face-to-face relationship. The nanoweb is positioned at the surface of the filter bag first exposed to the hot particle laden gas stream and can have a basis weight of greater than about 2 gsm.

Abstract: A filter fabric having improved filtering properties for hot gas filtration containing a nonwoven aramid mat The mat has a basis weight of at least 9.7 ounces per square yard (330 grams per square meter) and is characterized by a pore size distribution in which the number of pores in a given range as measured by ASTM F316-03 test method is plotted against pore size. In a preferred embodiment, the percentage of pores having a size in between 10 and 26 microns is greater than 50% while the percentage of pores having a size of greater than 50 microns is less than 0.5%.

Abstract: Structures containing a fiber mat inserted into a high modulus scrim of minimum basis weight 35 gsm. The structures have reduced tensile elongation at 50 N per 5 cm fabric strip in MD under ISO 9073-3 standard norm. The structure has a basis weight of at least 9 ounces per square yard (305 grams per square meter). The structure also has heat resistance of at least 150° to 190° C., preferably over 200 up to 260° C. to for service under typical hot flue gas filtration conditions. Filter bags made from these structures provide a controlled dimensional stability over their entire filter life time. In addition such stable structures are suitable for lamination with fragile membranes especially e-PTFE membranes where minimum amount of mechanical damage to the membrane occurs.

Abstract: This invention relates to a bag filter having a tubular section, a closed end, and an open end; the tubular section comprising a scrimless filter felt consisting essentially of a needle-punched batt of an intimate blend of fibers consisting of 50 to 79 percent by weight meta-aramid staple fiber, and 21 to 50 percent by weight para-aramid staple fiber; said needle-punched batt having a basis weight of from 10 to 17 ounces per square yard (340 to 580 grams per square meter).

Abstract: This invention relates to a bag filter having a tubular section, a closed end, and an open end; the tubular section comprising a scrimless filter felt consisting essentially of a needle-punched batt of an intimate blend of fibers consisting of 50 to 79 percent by weight meta-aramid staple fiber, and 21 to 50 percent by weight para-aramid staple fiber; said needle-punched batt having a basis weight of from 10 to 17 ounces per square yard (340 to 580 grams per square meter).

Abstract: This invention relates to a bag filter having a tubular section, a closed end, and an open end; the tubular section comprising a filter felt consisting essentially of a batt of an intimate blend of fibers needle-punched to a woven scrim, the blend of fibers consisting of 50 to 70 percent by weight meta-aramid staple fiber, and 30 to 50 percent by weight para-aramid staple fiber; said filter felt having a total basis weight of from 10 to 19 ounces per square yard (340 to 580 grams per square meter).

Abstract: This invention relates to a filter felt and bag filters comprising an intimate staple fiber blend of 20 to 75 parts by weight polymeric staple fiber containing a polymer or copolymer derived from a monomer selected from the group consisting of 4,4?diaminodiphenyl sulfone, 3,3?diaminodiphenyl sulfone, and mixtures thereof; and 25 to 80 parts by weight of a heat resistant staple fiber selected from the group consisting on meta-aramid fiber, acrylic fiber, polyphenylene sulfide fiber, and para-aramid fiber; based on 100 parts by weight of the polymeric fibers and heat resistant fibers in the felt.

Abstract: Fabrics resistant to molten metal are provided, comprising non-melting base fabric treated with a composition comprising polymerisable polyurethane monomers, and ceramic particles.

Abstract: A bag filter having a support structure clothed in a filter bag. The cloth of the filter bag is a composite of at least one substrate layer and at least one nanoweb bonded thereto in a face-to-face relationship. The nanoweb is positioned at the surface of the filter bag first exposed to the hot particle laden gas stream and can have a basis weight of greater than about 0.1 gsm.

Abstract: This invention relates to a filter felt and bag filters comprising an intimate staple fiber blend of 20 to 75 parts by weight polymeric staple fiber containing a polymer or copolymer derived from a monomer selected from the group consisting of 4,4?diaminodiphenyl sulfone, 3,3?diaminodiphenyl sulfone, and mixtures thereof; and 25 to 80 parts by weight of a heat resistant staple fiber selected from the group consisting on meta-aramid fiber, acrylic fiber, polyphenylene sulfide fiber, and para-aramid fiber; based on 100 parts by weight of the polymeric fibers and heat resistant fibers in the felt.

Abstract: 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.

Abstract: 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.

Abstract: A bag filter having a support structure clothed in a filter bag. The cloth of the filter bag is a composite of at least one substrate layer and at least one nanoweb bonded thereto in a face-to-face relationship. The nanoweb is positioned at the surface of the filter bag first exposed to the hot particle laden gas stream and can have a basis weight of greater than about 2 gsm.

Abstract: 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.

Abstract: 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.