Patent US5141643A successfully refreshed from Google Patents.
US5141643A
Expired / Lapsed
US
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Filter material formed by fibride particles
Assignee: SEITZSCHENK FILTERSYSTEME GmbH
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Filing: 1991-03-07
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Granted: 1992-08-25
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Expires: 2011-03-07
Abstract
Abstract In a filter bed (11) for the solid/fluid separation of media which contain substances that attack or dissolve cellulose, for example cellulase-containing enzymes, a matrix comprising a fibrous material structure of polyolefin fibrid particles (12) which are matted and anchored in one another and which can additionally contain up to 20% by weight of narrower fibrid polyolefin fibres and/or polyolefin fibres that have a fibre length of up to 5 mm. and have just started to fibrillate, in order to strengthen the sheet formation of the matrix. The actual filter-active particles, in particular kieselguhr particles and/or perlite particles having grain sizes of 5 to 100 um., are embedded in the cellulose-free fiber matrix.
Inventors
- 👤 Peter P. Breitbach
- 👤 Gerd Ritter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:24
CPC Classifications
D; D21; D21H; D21H27/00; D21H27/08; B; B01; B01D; B01D39/00; B01D39/14; B01D39/16; B01D39/1607; B01D39/1623
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
109 words
Filter bed, suited for the solid-liquid separation of media containing ingredients which dissolve and/or react chemically with cellulose, said filter bed having a fiber material structure in which filter-active particles are embedded as auxiliary filtering agents, said filter bed (11) being built up in the form of a voluminous pulp and structured as a fleece, and having a fiber material skeleton formed entirely of polyolefin fibride particles (12) felted to one another and anchored in one another, said fibride particles (12) being present in a mixture of fiber particles of different degrees of fibrillation, from fiber particles (12a) in their incipient state of fibrillation to completely separated fibrils (12f).
Claim 2
Dependent Claim
109 words
Filter bed, suited for the solid-liquid separation of media containing ingredients which dissolve and/or react chemically with cellulose, said filter bed having a fiber material structure in which filter-active particles are embedded as auxiliary filtering agents, said filter bed (11) being built up in the form of a voluminous pulp and structured as a fleece, and having a fiber material skeleton formed entirely of polyolefin fibride particles (12) felted to one another and anchored in one another, said fibride particles (12) being present in a mixture of fiber particles of different degrees of fibrillation, from fiber particles (12a) in their incipient state of fibrillation to completely separated fibrils (12f).
Claim 3
Dependent Claim
31 words
Filter bed according to claim 1, wherein the fiber material skeleton is formed of polyethylene or polypropylene fibride particles (12), or of a mixture of polyethylene and polypropylene fibride particles (12).
Claim 4
Dependent Claim
28 words
Filter bed according to claim 1, wherein the weight percentage of polyolefin particles in relation to the total weight of the filter bed ranges between 40 and 60%.
Claim 5
Dependent Claim
24 words
Filter bed according to claim 1, wherein the polyolefin fibride particles have a fiber length from up to about 0.8 to about 1.2 mm.
Claim 6
Dependent Claim
42 words
Filter bed according to claim 1, wherein the fiber material skeleton contains, for up to 20% of its weight, longer-fibrous polyolefin fibers (15) and/or polyolefin fibers in their incipient state of fibrillation and having a fiber length of up to 5 mm.
Claim 7
Dependent Claim
30 words
Filter bed according to claim 1, wherein the auxiliary filtering agents embedded in the fiber material skeleton of polyolefin fibride particles (12) are kieselguhr particles (13) and/or perlite particles (14).
References Cited (Backward Citations)
DE2318831A1
Cited
US3888766A
Cited
US4859340A
Cited
DE2813356A1
Cited
GB2016943A
Cited
GB2059797A
Cited
US4460642A
Cited
DE3329385A1
Cited
EP0145849A1
Cited
US4678571A
Cited
EP0265762A1
Cited
DE8713306U1
Cited
GB2230278A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-25 | 1996-02-24 | 1996-08-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-25 | 2000-02-24 | 2000-08-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-25 | 2004-02-24 | 2004-08-25 | $7700.00 | Window Closed / Lapsed |