Cylindrical fibrous structures with graded pore size
AssigneePall Corporation
InventorsDavid B. Pall, Colin F. Harwood, Arthur Bradley, Timothy R. Brennan
Life of this patent
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Abstract
Cylindrical fibrous structures comprising a fibrous mass of nonwoven, synthetic, polymeric microfibers wherein the microfibers are substantially free of fiber-to-fiber bonding and secured to each other by mechanical entanglement or intertwining, the fiber structure having a substantially constant voids volume over at least a substantial portion of the structure and, preferably, a graded fiber diameter structure, both as measured in the radial direction. The structures are particularly useful as depth filters.
Claims35
A cylindrical fibrous structure comprising a fibrous mass of nonwoven, synthetic, polymeric microfibers, said microfibers substantially free of fiber-to-fiber bonding and secured to each other by mechanical entanglement or intertwining, and said fibrous mass having a substantially constant voids volume and varying fiber diameter over at least a substantial portion thereof as measured in the radial direction to achieve a graded pore size over said portion.
A cylindrical fibrous structure comprising a fibrous mass of nonwoven, synthetic, polymeric thermoplastic microfibers having a voids volume in the range of from about 64 to about 93 percent, said microfibers having diameters in the range of from about 1.5 to about 20 micrometers and said microfibers being substantially free of fiber-to-fiber bonding and secured to each other by mechanical entanglement or intertwining, said fibrous mass having a substantially constant voids volume and a graded fiber diameter structure over at least an upstream portion thereof, both as measured in the radial direction to achieve a graded pore size over said portion.
A cylindrical fibrous structure comprising an open, relatively rigid, central support member and a fibrous mass of nonwoven, synthetic, polymeric microfibers on the exterior of said support, said microfibers substantially free of fiber-to-fiber bonding and secured to each other by mechanical entanglement or intertwining and said fibrous mass having a substantially constant voids volume and varying fiber diameter over at least a substantial portion thereof as measured in the radial direction to achieve a graded pore size over said portion.
A cylindrical fibrous structure comprising an open relatively rigid, central support member and a fibrous mass of nonwoven, synthetic, polymeric, thermoplastic microfibers having a voids volume in the range of from about 64 to about 93 percent, said microfibers having diameters in the range of from about 1.5 to about 20 micrometers and said microfibers being substantially free of fiber-to-fiber bonding and secured to each other by mechanical entanglement or intertwining, said fibrous mass having a substantially constant voids volume and a graded fiber diameter structure over at least an upstream portion thereof, both as measured in the radial direction.
Dependencies are inferred from the claim text.