US4540625A
Expired / Lapsed
US
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Flexible air permeable non-woven fabric filters
Assignee: HUCHES AIRCRAFT Co
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Filing: 1984-01-09
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Granted: 1985-09-10
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Expires: 2004-01-09
Abstract
Abstract A flexible, air permeable composite highly effective as a highly absorbent fiber filter, suitable for high throughput, low pressure drop applications. The composites and filters use a non-woven fabric substrate, in conjunction with organic polymer fibers, such as polypropylene fibers, formed in-situ from a solvent solution of the polymer, with solid particles such as carbon particles interstitially positioned within the mass, and forming a unique microstructure by the interaction of the flexible non-woven fibers and the polymer fibers. A method of entrapping small sorptive particles within such filters is also provided.
Inventors
- 👤 Charles H. Sherwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:24
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/28; B01J20/28014; B01J20/28033; B01D; B01D39/00; B01D39/08; B01D39/083; B01D39/086; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01J20/28002; B01J20/28004; B01J20/28028; B60; B60H; B60H1/00; B60H1/00357; B60H1/00414; B60H3/00; B60H3/06; B60H3/0658; D; D04; D04H; D04H13/00; B01D2239/00; B01D2239/04; B01D2239/0407; B01D2239/06; B01D2239/0604; B01D2239/064; B01D2239/12; B01D2239/1241; Y; Y10; Y10S; Y10S428/00; Y10S428/902; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249982; Y10T428/249985; Y10T428/249986; Y10T428/25; Y10T428/256; Y10T428/257; Y10T428/259; Y10T428/29; Y10T428/2913; Y10T428/2927; Y10T428/30; Y10T442/00; Y10T442/60; Y10T442/637; Y10T442/642; Y10T442/69; Y10T442/699
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
61 words
A tailorable air permeable flexible composite for use in the fabrication of filters, comprising a fiber mass formed of a randomly oriented mixture of flexible non-woven substrate fibers, and in-situ formed organic polymer fibers intertwined with said non-woven fibers and containing solid sorptive microscopic particles essentially captured against said non-woven fibers, to form a flexible, air permeable, highly absorbent fiber filter.
Claim 2
Dependent Claim
61 words
A tailorable air permeable flexible composite for use in the fabrication of filters, comprising a fiber mass formed of a randomly oriented mixture of flexible non-woven substrate fibers, and in-situ formed organic polymer fibers intertwined with said non-woven fibers and containing solid sorptive microscopic particles essentially captured against said non-woven fibers, to form a flexible, air permeable, highly absorbent fiber filter.
Claim 3
Dependent Claim
19 words
The composite of claim 1, wherein said solid particles comprise a major proportion of the weight of said composite.
Claim 4
Dependent Claim
21 words
The composite of claim 1, wherein said particles comprise about 60 to about 80% of the total weight of said composite.
Claim 5
Dependent Claim
28 words
The composite of claim 1, said flexible non-woven fibers interacting with said polymer fibers, and said polymer fibers functioning to attach said solid particles to said non-woven fibers.
Claim 6
Dependent Claim
13 words
The composite of claim 1, said organic polymer fibers being linear crystalline polyalkenes.
Claim 7
Dependent Claim
30 words
The composite of claim 1, wherein said solid particles are porous absorptive particles selected from the group consisting of carbon particles, silica gel, activated alumina, diatomaceous earth, and fuller's earth.
Claim 8
Dependent Claim
13 words
The composite of claim 1, wherein said solid sorptive particles are carbon particles.
Claim 9
Dependent Claim
13 words
The composite of claim 1, wherein said organic polymer fibers are polypropylene fibers.
Claim 10
Dependent Claim
21 words
The composite of claim 1, wherein said solid sorptive particles are carbon particles and said organic polymer fibers are polypropylene fibers.
Claim 11
Dependent Claim
14 words
The composite of claim 1, wherein said non-woven substrate fibers are aromatic polyamide fibers.
Claim 12
Dependent Claim
28 words
The composite of claim 1, wherein said solid sorptive particles are carbon particles, said non-woven fibers are aromatic polyamide fibers, and said organic polymer fibers are polypropylene fibers.
Claim 13
Dependent Claim
23 words
The flexible composite of claim 1 wherein said solid sorptive particles are of a size ranging from about 2 to about 5 micrometers.
Claim 14
Dependent Claim
41 words
The composite of claim 1, wherein said organic polymer fibers are selected from the group of polyethylene, polypropylene, polybutene, poly(4-methyl-1-pentene), polyvinylidene fluoride, polychlorotrifluoroethylene, nylon, polystyrene, polyethylene oxide, propyleneacrylic acid copolymers, polyacrylonitrile, acrylonitrile-butadiene-styrene terpolymers, and tetrafluoroethylene-hexafluoropropylene-vinylidene terpolymers, and mixtures of the above.
Claim 15
Dependent Claim
113 words
A tailorable air permeable, flexible composite for use in the fabrication of filters, comprising a fiber mass formed of a randomly oriented mixture of flexible non-woven substrate aromatic polyamide fibers and in-situ formed crystalline polypropylene fibers formed around said non-woven fibers, with a relatively small amount of said in-situ fibers extending between said non-woven fibers, and containing carbon particles of a size within the range of about 2 to 5 micrometers, said carbon particles comprising a major proportion of the weight of said composite, and said carbon particles essentially captured against said non-woven fibers and between said in-situ fibers and said non-woven fibers, to form a flexible, air permeable, highly absorbent fiber filter.
Claim 16
Dependent Claim
113 words
A tailorable air permeable, flexible composite for use in the fabrication of filters, comprising a fiber mass formed of a randomly oriented mixture of flexible non-woven substrate aromatic polyamide fibers and in-situ formed crystalline polypropylene fibers formed around said non-woven fibers, with a relatively small amount of said in-situ fibers extending between said non-woven fibers, and containing carbon particles of a size within the range of about 2 to 5 micrometers, said carbon particles comprising a major proportion of the weight of said composite, and said carbon particles essentially captured against said non-woven fibers and between said in-situ fibers and said non-woven fibers, to form a flexible, air permeable, highly absorbent fiber filter.
Claim 17
Dependent Claim
28 words
The composite of claim 14, said polyamide fibers interacting with said polypropylene fibers, and said polypropylene fibers functioning to attach said carbon particles to said non-woven polyamide fibers.
Claim 18
Independent Claim
85 words
A method of entrapping small sorptive particles within a fiber mass which comprises precipitating organic polymer fibers from an organic solvent solution of (1) a fiber-forming organic polymer and containing (2) suspended small sorptive solid particles and (3) flexible non-woven substrate fibers, and forming a fiber mass comprised of a mixture of flexible, non-woven substrate fibers and organic polymer fibers intertwined with each other and containing small solid sorptive particles interstitially positioned within said mass, to form a flexible, air permeable, highly absorbent fiber filter.
Claim 19
Independent Claim
85 words
A method of entrapping small sorptive particles within a fiber mass which comprises precipitating organic polymer fibers from an organic solvent solution of (1) a fiber-forming organic polymer and containing (2) suspended small sorptive solid particles and (3) flexible non-woven substrate fibers, and forming a fiber mass comprised of a mixture of flexible, non-woven substrate fibers and organic polymer fibers intertwined with each other and containing small solid sorptive particles interstitially positioned within said mass, to form a flexible, air permeable, highly absorbent fiber filter.
Claim 20
Dependent Claim
19 words
The method of claim 16, wherein said solid particles comprise a major proportion of the weight of said composite.
Claim 21
Dependent Claim
27 words
The method of claim 16, wherein said flexible non-woven fibers interact with the polymer fibers and the polymer fibers attach said solid particles to said non-woven fibers.
Claim 22
Independent Claim
117 words
A method of entrapping small sorptive particles and producing a tailorable air permeable flexible composite which comprises: (a) introducing into a hot organic solvent solution of a fiber-forming organic polymer containing suspended small sorptive solid particles, flexible non-woven substrate fibers; (b) subjecting said solution to agitation and cooling to a temperature which causes precipitation of fibers of said organic polymer from said solution, said organic fibers forming in-situ around the non-woven fibers of said substrate, and said solid particles captured against said non-woven fibers and between said in-situ formed fibers and said non-woven fibers; (c) removing the resulting fibrous mass from said solution; (d) washing said fibrous mass with fresh solvent; and (e) drying said fibrous mass.
Claim 23
Independent Claim
117 words
A method of entrapping small sorptive particles and producing a tailorable air permeable flexible composite which comprises: (a) introducing into a hot organic solvent solution of a fiber-forming organic polymer containing suspended small sorptive solid particles, flexible non-woven substrate fibers; (b) subjecting said solution to agitation and cooling to a temperature which causes precipitation of fibers of said organic polymer from said solution, said organic fibers forming in-situ around the non-woven fibers of said substrate, and said solid particles captured against said non-woven fibers and between said in-situ formed fibers and said non-woven fibers; (c) removing the resulting fibrous mass from said solution; (d) washing said fibrous mass with fresh solvent; and (e) drying said fibrous mass.
Claim 24
Dependent Claim
32 words
The method of claim 19, said organic solvent solution containing about 1 to 5% by weight of dissolved organic polymer and about 0.5 to about 3% by weight of sorptive solid particles.
Claim 25
Dependent Claim
41 words
The method of claim 20, said organic solvent being xylene and said organic polymer being polypropylene, and wherein said solution is cooled to a temperature between about 95° C. and about 105° C. to cause said precipitation of said polypropylene fibers.
Claim 26
Dependent Claim
36 words
The method of claim 21, including extracting said fibrous mass with fresh xylene, and said washing said fibrous mass taking place with a solvent selected from the group consisting of pentane, methanol, ethanol, acetone and toluene.
Claim 27
Dependent Claim
33 words
The method of claim 22, wherein said flexible non-woven substrate fibers are aromatic polyamide fibers and said sorptive solid particles are carbon particles of a size ranging from about 2 to 5 micrometers.
References Cited (Backward Citations)
US3971373A
Cited
US4127624A
Cited
US4296166A
Cited
US4411948A
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US4396663A
Cited
US4397907A
Cited
US4429001A
Cited
US4433024A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-09 | 1989-03-11 | 1989-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-09 | 1993-03-11 | 1993-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-09 | 1997-03-11 | 1997-09-10 | $7700.00 | Window Closed / Lapsed |