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Patent US4392876A successfully refreshed from Google Patents.
US4392876A
Expired / Lapsed
US
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Filter packing
Assignee: Carl Freudenberg KG
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Filing: 1981-09-15
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Granted: 1983-07-12
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Expires: 2001-09-15
Abstract
Abstract A filter packing of electrostatically spray formed microfibers, the structure of which is a foamed coating layer containing open cell pores completely surrounding a nonporous fiber core. The pores extend perpendicularly through the foamed coating and have a substantially uniform distribution in cross section. The foamed coating and the fiber core are made of the same polymer composition.
Inventors
- 👤 Klaus Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:35
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/70; D04H1/72; D04H1/728; B; B01; B01D; B01D39/00; B01D39/02; B01D39/04; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623; B01D39/1669; B01D39/1676; D01; D01D; D01D5/00; D01D5/24; D01D5/247; D04H1/40; D04H1/54; D04H1/56; Y; Y10; Y10S; Y10S428/00; Y10S428/903; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2938
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
78 words
A filter packing comprising a composite of electrostatically spray formed microfibers alone or in combination with one or more porous carrier layers, wherein the microfibers comprise a nonporous fiber core surrounded by a foamed coating layer containing open cell pores which extend through the foam coating in a substantially perpendicular direction to the surface, the cross section distribution of pores being substantially uniform and the foamed coating and the fiber core being made of the same polymer composition.
Claim 2
Dependent Claim
78 words
A filter packing comprising a composite of electrostatically spray formed microfibers alone or in combination with one or more porous carrier layers, wherein the microfibers comprise a nonporous fiber core surrounded by a foamed coating layer containing open cell pores which extend through the foam coating in a substantially perpendicular direction to the surface, the cross section distribution of pores being substantially uniform and the foamed coating and the fiber core being made of the same polymer composition.
Claim 3
Dependent Claim
32 words
A filter packing according to claim 1, wherein the microfibers are deposited with random distribution, and with thir long axes perpendicular to the direction of air flow and are optionally pressed together.
Claim 4
Dependent Claim
23 words
A filter packing according to claim 1 or 2, wherein the microfibers are mixed in a substantially uniform manner with wrinkled staple fibers.
Claim 5
Dependent Claim
24 words
A filter packing according to claim 3, wherein the staple fibers comprise the same or a similar polymer composition as that comprising the microfibers.
Claim 6
Dependent Claim
29 words
A filter packing according to claim 4, wherein that ratio of the mean diameter of the staple fibers to the maximum diameter of the microfibers is 3:1 to 10:1.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-11 | 1987-01-10 | 1987-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-11 | 1991-01-10 | 1991-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-11 | 1995-01-10 | 1995-07-12 | $7700.00 | Window Closed / Lapsed |