US4430157A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Calcined serpentine as inorganic charge in sheet materials
Assignee: NATIONAL DE L'AMIANTE Ste
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Filing: 1983-03-11
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Granted: 1984-02-07
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Expires: 2003-03-11
Abstract
Abstract There is provided an improved non-woven fibrous felt material made up of fibers, partially fibrous agglomerates of forsterite, enstatite and silica as filler and an organic binder. The improved felt material possesses increased hot tensile strength over felt material made from non-calcined asbestos tailings or inert inorganic fillers.
Inventors
- 👤 Jean M. Lalancette
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:46
CPC Classifications
D; D21; D21H; D21H13/00; D21H13/36; D21H13/38
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
121 words
An improved non-woven fibrous base felt which comprises a solid homogeneous sheet of a mixture of from about 2% to about 40% by weight of fibrous material, from about 10% to about 80% of the partially fibrous agglomerates devoid of asbestos fibers, free of magnesium oxide not bonded to silica and containing crystalline forsterite as the main constituent, the remainder being amorphous silica or a mixture of crystalline enstatite and amorphous silica obtained by calcination of asbestos tailings, at least 85% of which having a granulometry of between -60 to about +400 mesh and from about 2% to about 25% by weight of an organic binder, said felt being characterized by the total absence of asbestos fibers coming from the agglomerate.
Claim 2
Dependent Claim
121 words
An improved non-woven fibrous base felt which comprises a solid homogeneous sheet of a mixture of from about 2% to about 40% by weight of fibrous material, from about 10% to about 80% of the partially fibrous agglomerates devoid of asbestos fibers, free of magnesium oxide not bonded to silica and containing crystalline forsterite as the main constituent, the remainder being amorphous silica or a mixture of crystalline enstatite and amorphous silica obtained by calcination of asbestos tailings, at least 85% of which having a granulometry of between -60 to about +400 mesh and from about 2% to about 25% by weight of an organic binder, said felt being characterized by the total absence of asbestos fibers coming from the agglomerate.
Claim 3
Dependent Claim
41 words
A base felt as in claim 1, where the heat treatment applied to asbestos tailings was sufficient to insure the complete disappearance of chrysotile as shown by transmission electron microscopy at a magnification sufficient to detect fibers 1.0 nm in length.
Claim 4
Dependent Claim
119 words
An improved non-woven fibrous base felt which comprises a solid homogeneous sheet of a mixture of about 10 to 25% by weight of fibers with a majority of organic fibers, about 60 to 70% by weight of partially fibrous agglomerates devoid of asbestos fibers, free of magnesium oxide not bonded to silica and containing crystalline forsterite as the main constituent, the remainder being amorphous silica or a mixture of crystalline enstatite and amorphous silica obtained by calcination of asbestos tailings, at least 85% of which having a granulometry of between -60 to about +400 mesh and about 5 to 10% by weight of latex, said felt being characterized by the total absence of asbestos fibers coming from the agglomerate.
Claim 5
Dependent Claim
119 words
An improved non-woven fibrous base felt which comprises a solid homogeneous sheet of a mixture of about 10 to 25% by weight of fibers with a majority of organic fibers, about 60 to 70% by weight of partially fibrous agglomerates devoid of asbestos fibers, free of magnesium oxide not bonded to silica and containing crystalline forsterite as the main constituent, the remainder being amorphous silica or a mixture of crystalline enstatite and amorphous silica obtained by calcination of asbestos tailings, at least 85% of which having a granulometry of between -60 to about +400 mesh and about 5 to 10% by weight of latex, said felt being characterized by the total absence of asbestos fibers coming from the agglomerate.
Claim 6
Independent Claim
102 words
A method of making an improved non-woven fibrous base felt which comprises mixing an aqueous slurry of fibers having a consistency of from 0.10 to 5.0% with an aqueous slurry of asbestos tailings having been calcined at a temperature of from 800° to 1300° C., to form partially fibrous agglomerates devoid of asbestos fibers, free of magnesium oxide not bonded to silica and containing crystalline forsterite as the main constituent, the remainder being amorphous silica or a mixture of crystalline enstatite and amorphous silica, adding to said mixture an organic binder, forming a felt from said slurry mixture and drying said felt.
Claim 7
Independent Claim
102 words
A method of making an improved non-woven fibrous base felt which comprises mixing an aqueous slurry of fibers having a consistency of from 0.10 to 5.0% with an aqueous slurry of asbestos tailings having been calcined at a temperature of from 800° to 1300° C., to form partially fibrous agglomerates devoid of asbestos fibers, free of magnesium oxide not bonded to silica and containing crystalline forsterite as the main constituent, the remainder being amorphous silica or a mixture of crystalline enstatite and amorphous silica, adding to said mixture an organic binder, forming a felt from said slurry mixture and drying said felt.
Claim 8
Dependent Claim
17 words
A method as in claim 4 wherein the calcining temperature range is from 800° to 900° C.
Claim 9
Dependent Claim
17 words
A method as in claim 4 wherein the calcining temperature range is from 900° to 1200° C.
Claim 10
Dependent Claim
31 words
A method as in claim 4 where the heat treatment has been such as to reincorporate at least part of the liberated silica at the formation of forsterite to generate enstatite.
Claim 11
Independent Claim
106 words
A method of making an improved non-woven fibrous base felt which is free of asbestos fibers which comprises mixing in the presence of water from 2 to 40% by weight of a fibrous material with from 10 to 80% by weight of asbestos tailings, at least 85% of which having a granulometry of between -60 to about +400 mesh, said asbestos tailings having been calcined at a temperature of from 800° to 1300° C., to form partially fibrous agglomerates adding to said mixture from 2 to 25% by weight of an organic binder, forming a felt from the thus obtained slurry mixture and drying said felt.
Claim 12
Independent Claim
106 words
A method of making an improved non-woven fibrous base felt which is free of asbestos fibers which comprises mixing in the presence of water from 2 to 40% by weight of a fibrous material with from 10 to 80% by weight of asbestos tailings, at least 85% of which having a granulometry of between -60 to about +400 mesh, said asbestos tailings having been calcined at a temperature of from 800° to 1300° C., to form partially fibrous agglomerates adding to said mixture from 2 to 25% by weight of an organic binder, forming a felt from the thus obtained slurry mixture and drying said felt.
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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) | 1987-02-06 | 1987-08-08 | 1988-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-02-06 | 1991-08-08 | 1992-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-02-06 | 1995-08-08 | 1996-02-07 | $7700.00 | Window Closed / Lapsed |