US4726901A
Expired / Lapsed
US
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Cylindrical fibrous structures with graded pore size
Assignee: Pall Corp
•
Filing: 1986-03-17
•
Granted: 1988-02-23
•
Expires: 2006-03-17
Abstract
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.
Inventors
- 👤 David B. Pall
- 👤 Colin F. Harwood
- 👤 Arthur Bradley
- 👤 Timothy R. Brennan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:53
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/56; B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D39/163; D04H1/70; D04H1/76; B01D2239/00; B01D2239/04; B01D2239/06; B01D2239/065; B01D2239/0654; B01D2239/069; B01D2239/0695; B01D2239/10; B01D2239/12; B01D2239/1233
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
66 words
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.
Claim 2
Dependent Claim
66 words
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.
Claim 3
Dependent Claim
26 words
The cylindrical fibrous structure of claim 1 wherein said fibrous mass has a voids volume in the range of from about 60 to about 95 percent.
Claim 4
Dependent Claim
42 words
The cylindrical fibrous structure of claim 2 wherein said fibrous mass has a voids volume in the range of from about 64 to about 93 percent and said microfibers have diameters in the range of from about 1.5 to about 20 micrometers.
Claim 5
Dependent Claim
41 words
The cylindrical fibrous structure of claim 3 wherein said fibrous mass has a voids volume in the range of from about 75 to about 85 percent and said microfibers have diameters in the range from about 1.9 to about 12.6 micrometers.
Claim 6
Dependent Claim
28 words
The cylindrical fibrous structure of claim 1 wherein said nonwoven, synthetic, polymeric microfibers are comprised of a thermoplastic selected from the class consisting of polyolefins, polyamides and polyesters.
Claim 7
Dependent Claim
12 words
The cylindrical fibrous structure of claim 5 wherein said thermoplastic is polypropylene.
Claim 8
Dependent Claim
24 words
The cylindrical fibrous structure of claim 1 wherein said fibrous mass has a substantially constant voids volume throughout as measured in the radial direction.
Claim 9
Dependent Claim
24 words
The cylindrical fibrous structure of claim 1 wherein said fibrous mass has a continuously graded fiber diameter structure as measured in the radial direction.
Claim 10
Dependent Claim
28 words
The cylindrical fibrous structure of claim 1 wherein said fibrous mass has a graded fiber diameter structure over substantially its entire structure as measured in the radial direction.
Claim 11
Dependent Claim
52 words
The cylindrical fibrous structure of claim 1 wherein said fibrous mass has in a downstream portion thereof a substantially constant voids volume and in an upstream portion thereof the same substantially constant voids volume as in said downstream portion and a graded fiber diameter structure, all as measured in the radial direction.
Claim 12
Dependent Claim
21 words
The cylindrical fibrous structure of claim 1 wherein said fibrous structure has a removal rating of from 0.5 to 40 micrometers.
Claim 13
Dependent Claim
101 words
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.
Claim 14
Dependent Claim
101 words
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.
Claim 15
Dependent Claim
43 words
The cylindrical fibrous structure of claim 12 wherein said thermoplastic is polypropylene, said voids volume is in the range of from about 75 to about 85 percent, and said microfibers have diameters in the range of from about 1.9 to about 12.6 micrometers.
Claim 16
Dependent Claim
27 words
The cylindrical fibrous structure of claim 13 wherein said cylindrical fibrous structure has an efficiency for the removal of Pseudomonas diminuta of at least about 75 percent.
Claim 17
Dependent Claim
27 words
The cylindrical fibrous structure of claim 14 wherein said cylindrical fibrous structure has an efficiency for the removal of Pseudomonas diminuta of at least about 90 percent.
Claim 18
Dependent Claim
27 words
The cylindrical fibrous structure of claim 15 wherein said cylindrical fibrous structure has an efficiency for the removal of Pseudomonas diminuta of at least about 99.9 percent.
Claim 19
Dependent Claim
22 words
The cylindrical fibrous structure of claim 12 wherein said fibrous structure has a removal rating of from 0.5 to 40 micrometers. PG,82
Claim 20
Dependent Claim
80 words
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.
Claim 21
Dependent Claim
80 words
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.
Claim 22
Dependent Claim
26 words
The cylindrical fibrous structure of claim 18 wherein said fibrous mass has a voids volume in the range of from about 60 to about 95 percent.
Claim 23
Dependent Claim
42 words
The cylindrical fibrous structure of claim 19 wherein said fibrous mass has a voids volume in the range of from about 64 to about 93 percent and said microfibers have diameters in the range of from about 1.5 to about 20 micrometers.
Claim 24
Dependent Claim
41 words
The cylindrical fibrous structure of claim 20 wherein said fibrous mass has a voids volume in the range of from about 75 to about 85 percent and said microfibers have diameters in the range from about 1.9 to about 12.6 micrometers.
Claim 25
Dependent Claim
28 words
The cylindrical fibrous structure of claim 18 wherein said nonwoven, synthetic, polymeric microfibers are comprised of a thermoplastic selected from the class consisting of polyolefins, polyamides and polyesters.
Claim 26
Dependent Claim
12 words
The cylindrical fibrous structure of claim 22 wherein said thermoplastic is polypropylene.
Claim 27
Dependent Claim
24 words
The cylindrical fibrous structure of claim 18 wherein said fibrous mass has a substantially constant voids volume throughout as measured in the radial direction.
Claim 28
Dependent Claim
24 words
The cylindrical fibrous structure of claim 18 wherein said fibrous mass has a continuously graded fiber diameter structure as measured in the radial direction.
Claim 29
Dependent Claim
28 words
The cylindrical fibrous structure of claim 18 wherein said fibrous mass has a graded fiber diameter structure over substantially its entire structure as measured in the radial direction.
Claim 30
Dependent Claim
52 words
The cylindrical fibrous structure of claim 18 wherein said fibrous mass has in a downstream portion thereof a substantially constant voids volume and in an upstream portion thereof the same substantially constant voids volume as in said downstream portion and a graded fiber diameter structure, all as measured in the radial direction.
Claim 31
Dependent Claim
18 words
The cylindrical fibrous structure of claim 18 wherein said central support member comprises a core of self-bonded fibers.
Claim 32
Dependent Claim
21 words
The cylindrical fibrous structure of claim 19 wherein said fibrous structure has a removal rating of from 0.5 to 40 micrometers.
Claim 33
Dependent Claim
100 words
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.
Claim 34
Dependent Claim
100 words
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.
Claim 35
Dependent Claim
43 words
The cylindrical fibrous structure of claim 30 wherein said thermoplastic is polypropylene, said voids volume is in the range of from about 75 to about 85 percent, and said microfibers have diameters in the range of from about 1.9 to about 12.6 micrometers.
Claim 36
Dependent Claim
27 words
The cylindrical fibrous structure of claim 31 wherein said cylindrical fibrous structure has an efficiency for the removal of Pseudomonas diminuta of at least about 75 percent.
Claim 37
Dependent Claim
27 words
The cylindrical fibrous structure of claim 32 wherein said cylindrical fibrous structure has an efficiency for the removal of Pseudomonas diminuta of at least about 90 percent.
Claim 38
Dependent Claim
27 words
The cylindrical fibrous structure of claim 33 wherein said cylindrical fibrous structure has an efficiency for the removal of Pseudomonas diminuta of at least about 99.9 percent.
Claim 39
Dependent Claim
21 words
The cylindrical fibrous structure of claim 30 wherein said fibrous structure has a removal rating of from 0.5 to 40 micrometers.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-22 | 1991-08-24 | 1992-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-22 | 1995-08-24 | 1996-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-22 | 1999-08-24 | 2000-02-23 | $7700.00 | Window Closed / Lapsed |