Abstract: Shown is a filter in which powder aggregation (bridge) is hard to occur, and a time until a rise of differential pressure is caused is long, more specifically, a filtration life is long. The filter has a base material layer, a filtration layer and a skin layer, in which the base material layer is a layer formed by a nonwoven fabric being wound in a multiple manner, and subjected to the thermocompression bonding, the filtration layer is a layer formed by a laminate prepared by laminating at least a through-air nonwoven fabric and a net, being wound in a multiple manner, and subjected to no thermocompression bonding, the skin layer is a layer including a nonwoven fabric, and a mean pore diameter of the nonwoven fabric composing the base material layer and the skin layer is larger than a mean pore diameter of the through-air nonwoven fabric composing the filtration layer.

Abstract: Shown is a filter in which powder aggregation (bridge) is hard to occur, and a time until a rise of differential pressure is caused is long, more specifically, a filtration life is long. The filter has a base material layer, a filtration layer and a skin layer, in which the base material layer is a layer formed by a nonwoven fabric being wound in a multiple manner, and subjected to the thermocompression bonding, the filtration layer is a layer formed by a laminate prepared by laminating at least a through-air nonwoven fabric and a net, being wound in a multiple manner, and subjected to no thermocompression bonding, the skin layer is a layer including a nonwoven fabric, and a mean pore diameter of the nonwoven fabric composing the base material layer and the skin layer is larger than a mean pore diameter of the through-air nonwoven fabric composing the filtration layer.

Abstract: The present invention provides a single-layer shape retaining material which is a fibrous, band-like, or sheet-like stretched formed material comprising 100 parts by weight of a high-density polyethylene resin having a weight-average molecular weight of 100,000 to 500,000 and a density of 0.945 to 0.960 g/cm3 and 3 to 50 parts by weight of an ethylene-?-olefin copolymer obtained by copolymerizing ethylene with an ?-olefin having 4 to 10 carbon atoms, the copolymer having a density of 0.935 to 0.960 g/cm3, the difference in density between the copolymer and the high-density polyethylene resin being ±0.020 g/cm3 or less and a method for producing same.

Abstract: The present invention provides a single-layer shape retaining material which is a fibrous, band-like, or sheet-like stretched formed material comprising 100 parts by weight of a high-density polyethylene resin having a weight-average molecular weight of 100,000 to 500,000 and a density of 0.945 to 0.960 g/cm3 and 3 to 50 parts by weight of an ethylene-?-olefin copolymer obtained by copolymerizing ethylene with an ?-olefin having 4 to 10 carbon atoms, the copolymer having a density of 0.935 to 0.960 g/cm3, the difference in density between the copolymer and the high-density polyethylene resin being ±0.020 g/cm3 or less and a method for producing same.

Abstract: The cartridge filter of the present invention is a filter comprising a wound and laminated composite non-woven fabric containing heat fusible fibers, wherein the delamination strength between layers of the laminated composite non-woven fabric of said filter increases continuously or discontinuously from the outer layer toward the inner layer, the delamination strength of the inner layer-exceeds 1000 gf/5 cm, and the delamination strength of the outer layer is 5 to 1000 gf/5 cm. This cartridge excels in filtering life, filtering accuracy, and pressure resistance.

Abstract: A cylindrical filter is disclosed which comprises a wound up layer of a fibrous aggregate comprising melt-adhesive composite fibers bonded each other through the melt of a melt-adhesive component in the composite fibers and a layer of non-woven fabric of glass fibers, the layer of non-woven fabric is arranged on the outer surface of the wound up layer of the fibrous aggregate, and glass fibers have a smaller diameter than that of the melt-adhesive composite fibers. The cylindrical filter has an excellent filter rating and filter life.