US4904520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas-permeable, liquid-impermeable nonwoven material
Assignee: Hercules LLC
•
Filing: 1988-10-17
•
Granted: 1990-02-27
•
Expires: 2008-10-17
Abstract
Abstract Disclosed is a liquid-impermeable, gas-permeable nonwoven material comprising a thermally consolidated blend of (1) 5% to 30% of a first polyolefin pulp, (2) 15% to 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (3) 5% to 55% of a staple fiber. Also disclosed is a wet forming method for making such a nonwoven material without the use of surfactants.
Inventors
- 👤 David H. Dumas
- 👤 Elliott Echt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:49
CPC Classifications
A; A41; A41D; A41D31/00; A61; A61B; A61B46/00; A61B46/40; A61F; A61F13/00; D; D04; D04H; D04H1/00; D04H1/40; D04H1/42; D04H1/4282; D04H1/4291; D04H1/54; D04H1/542; D04H1/544; D04H1/58; D04H1/64; D04H1/70; D21; D21H; D21H13/00; D21H13/10; D21H13/12; D21H13/14; A61F2013/00089; A61F2013/00246; A61F2013/00268; A61F2013/00361; A61F2013/00727; A61F2013/00731; A61F2013/00744; A61F2013/00855; A61F2013/00885; A61F13/15; A61F2013/15008; A61F2013/15073; A61F13/15577; A61F2013/15821; A61F2013/15861; A61F2013/15878; A61F2013/15934; A61F2013/15951; A61F13/51; A61F2013/51002; A61F2013/51004; A61F2013/51023; A61F2013/51026; A61F13/514; A61F13/51401; A61F2013/51441; A61F2013/51443; Y; Y10; Y10S; Y10S206/00; Y10S206/811; Y10S220/00; Y10S220/11; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/24998; Y10T442/00; Y10T442/60; Y10T442/659; Y10T442/668
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
80 words
A nonwoven material comprising a thermally consolidated , wet laid blend comprising (1) from about 5% to about 30% of a first polyolefin pulp, (2) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (3) from about 5% to about 55% of a staple fiber, based on the total weight of the blend, said material being impermeable to liquids and permeable to gases.
Claim 2
Dependent Claim
80 words
A nonwoven material comprising a thermally consolidated , wet laid blend comprising (1) from about 5% to about 30% of a first polyolefin pulp, (2) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (3) from about 5% to about 55% of a staple fiber, based on the total weight of the blend, said material being impermeable to liquids and permeable to gases.
Claim 3
Dependent Claim
17 words
The material of claim 1 which additionally comprises from about 0.5% to about 20% of wood pulp.
Claim 4
Dependent Claim
21 words
The material of claim 1 wherein the first polyolefin pulp is polyethylene pulp and the second polyolefin pulp is polypropylene pulp.
Claim 5
Dependent Claim
13 words
The material of claim 1 wherein the staple fiber is polypropylene staple fiber.
Claim 6
Dependent Claim
13 words
The material of claim 3 wherein the staple fiber is polypropylene staple fiber.
Claim 7
Dependent Claim
131 words
A wet forming process for the preparation of a nonwoven material comprising (1) dispersing in water a mixture comprising (a) from about 5% to about 30% of a first polyolefin pulp, (b) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (c) from about 5% to about 55% of a staple fiber, based on the total weight of the material, in the presence of at least one water-soluble polymer and in the absence of a surface active agent, (2) forming a sheet from the aqueous dispersion, (3) drying, and (4) heating the sheet to a temperature sufficient to melt the first polyolefin pulp, said nonwoven material being impermeable to liquids and permeable to gases.
Claim 8
Dependent Claim
131 words
A wet forming process for the preparation of a nonwoven material comprising (1) dispersing in water a mixture comprising (a) from about 5% to about 30% of a first polyolefin pulp, (b) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (c) from about 5% to about 55% of a staple fiber, based on the total weight of the material, in the presence of at least one water-soluble polymer and in the absence of a surface active agent, (2) forming a sheet from the aqueous dispersion, (3) drying, and (4) heating the sheet to a temperature sufficient to melt the first polyolefin pulp, said nonwoven material being impermeable to liquids and permeable to gases.
Claim 9
Dependent Claim
21 words
The process of claim 6 wherein the mixture of step (1) additionally comprises from about 0.5% to about 20% wood pulp.
Claim 10
Dependent Claim
21 words
The process of claim 6 wherein the first polyolefin pulp is polyethylene pulp and the second polyolefin pulp is polypropylene pulp.
Claim 11
Dependent Claim
13 words
The process of claim 6 wherein the staple fiber is polypropylene staple fiber.
Claim 12
Dependent Claim
13 words
The process of claim 8 wherein the staple fiber is polypropylene staple fiber.
Claim 13
Dependent Claim
19 words
The process of claim 6 wherein the water-soluble polymer is a combination of an anionic acrylamide copolymer and hydroxypropylguar.
Claim 14
Dependent Claim
9 words
The product made by the process of claim 6.
Claim 15
Dependent Claim
9 words
The product made by the process of claim 7.
Claim 16
Dependent Claim
91 words
A process for preventing the passage of liquids to an object while allowing the passage of gases comprising covering the object with a nonwoven material comprising a thermally consolidated, wet laid blend comprising: (1) from about 5% to about 30% of a first polyolefin pulp, (2) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (3) from about 5% to about 55% of a staple fiber, based on the total weight of the blend.
Claim 17
Dependent Claim
91 words
A process for preventing the passage of liquids to an object while allowing the passage of gases comprising covering the object with a nonwoven material comprising a thermally consolidated, wet laid blend comprising: (1) from about 5% to about 30% of a first polyolefin pulp, (2) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (3) from about 5% to about 55% of a staple fiber, based on the total weight of the blend.
Claim 18
Dependent Claim
20 words
The process of claim 14 wherein the thermally consolidated blend additionally comprises from about 0.5% to about 20% wood pulp.
Claim 19
Dependent Claim
21 words
The process of claim 14 wherein the first polyolefin pulp is polyethylene pulp and the second polyolefin pulp is polypropylene pulp.
Claim 20
Dependent Claim
13 words
The process of claim 14 wherein the staple fiber is polypropylene staple fiber.
Claim 21
Dependent Claim
13 words
The process of claim 16 wherein the staple fiber is polypropylene staple fiber.
Claim 22
Dependent Claim
89 words
A laminate comprising a first layer and a second layer, said second layer comprising a thermally consolidated, wet laid blend comprising (1) for about 5% to about 30% of a first polyolefin pulp, (2) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (3) from about 5% to about 55% of a staple fiber, based on the total weight of the blend, said laminate being impermeable to liquids and permeable to gases.
Claim 23
Dependent Claim
89 words
A laminate comprising a first layer and a second layer, said second layer comprising a thermally consolidated, wet laid blend comprising (1) for about 5% to about 30% of a first polyolefin pulp, (2) from about 15% to about 90% of a second polyolefin pulp having a melting point at least 20° C. higher than the first polyolefin pulp, and (3) from about 5% to about 55% of a staple fiber, based on the total weight of the blend, said laminate being impermeable to liquids and permeable to gases.
Claim 24
Dependent Claim
20 words
The laminate of claim 19 wherein the thermally consolidated blend additionally comprises form about 0.5% to about 20% wood pulp.
Claim 25
Dependent Claim
22 words
The laminate of claim 19 wherein said second layer comprises a consolidated blend of polyethylene pulp, polypropylene pulp and polypropylene staple fiber.
Claim 26
Dependent Claim
16 words
The laminate of claim 19 which additionally comprises a third layer adjacent to the second layer.
Claim 27
Dependent Claim
16 words
The laminate of claim 22 wherein the first and third layers comprise carded polypropylene staple fiber.
Claim 28
Dependent Claim
16 words
The laminate of claim 20 which additionally comprises a third layer adjacent to the second layer.
References Cited (Backward Citations)
US3158532A
Cited
US3808094A
Cited
US4210487A
Cited
US4084949A
Cited
US4154883A
Cited
US4196245A
Cited
US4264691A
Cited
US4330602A
Cited
US4645565A
Cited
GB2095616A
Cited
US4341216A
Cited
US4818340A
Cited
US4508113A
Cited
US4728394A
Cited
US4657804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |