Method of making cylindrical fibrous filter structures
US4594202A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1984 |
| Grant date | Jun 10, 1986 |
| Priority date | — |
| Expiry date | Jan 6, 2004 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2239/1233
- WIPO fieldChemical engineering
- WIPO sectorChemistry
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 of 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. The process for preparing such fibrous structures comprises the steps of: PA0 (a) extruding synthetic, polymeric material from a fiberizing die and attenuating the extruded polymeric material to form microfibers by the application of one or more gas streams directed toward a rotating mandrel and a forming roll in operative relationship with the mandrel; PA0 (b) cooling the synthetic, polymeric microfibers prior to their collection on the mandrel to a temperature below that at which they bond or fuse together, thereby substantially eliminating fiber-to-fiber bonding; and PA0 (c) collecting the cooled microfibers on the mandrel as a nonwoven, synthetic fibrous mass while applyin…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.