EP0392682A2
Expired / Lapsed
EP
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Paper machine pressing fabrics
Assignee: Albany International Corp
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Filing: 1990-03-21
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Granted: —
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Expires: 2010-03-21
Abstract
Abstract The present invention relates to a polymeric material from the family of polyamides characterised in that said polyamides have an amine end group concentration of at least 60 equivalents/10⁶g, and have been subjected to a phenol/aldehyde treatment process, to increase the intrinsic viscosity by at least 4% compared with standard materials.
Inventors
- 👤 Lionel Normandin
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 20:36
CPC Classifications
D; D06; D06M; D06M15/00; D06M15/19; D06M15/37; D06M15/39; D06M15/41; D01; D01F; D01F6/00; D01F6/58; D01F6/60
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
46 words
A polymeric material from the family of polyamides characterised in that said polyamides have an amine end group concentration of at least 60 equivalents/10⁶g, and have been subjected to a phenol/aldehyde treatment process, to increase the intrinsic viscosity by at least 4% compared with standard materials.
Claim 2
Dependent Claim
46 words
A polymeric material from the family of polyamides characterised in that said polyamides have an amine end group concentration of at least 60 equivalents/10⁶g, and have been subjected to a phenol/aldehyde treatment process, to increase the intrinsic viscosity by at least 4% compared with standard materials.
Claim 3
Dependent Claim
28 words
A polymeric material and process as described in claim 1 which is subsequently exposed to a heat treatment to further increase the intrinsic viscosity by at least 4%.
Claim 4
Dependent Claim
16 words
Fibers and yarns formed from the polymeric material as claimed in claim 1 and claim 2.
Claim 5
Dependent Claim
13 words
A pressing fabric composed of fibers and/or yarns as described in claim 3.
Claim 6
Dependent Claim
62 words
A paper making machine pressing fabric comprising a fiber layer formed of polyamide fibers characterised in that said polyamide fibers have an end group concentration such that the ratio of the amine end groups/carboxy end groups is greater than 1, and have been subjected to a phenol/aldehyde treatment to increase the intrinsic viscosity by at least 4% compared with the untreated material.
Claim 7
Dependent Claim
62 words
A paper making machine pressing fabric comprising a fiber layer formed of polyamide fibers characterised in that said polyamide fibers have an end group concentration such that the ratio of the amine end groups/carboxy end groups is greater than 1, and have been subjected to a phenol/aldehyde treatment to increase the intrinsic viscosity by at least 4% compared with the untreated material.
Claim 8
Dependent Claim
20 words
A pressing fabric as claimed in claim 5 wherein the excess amine end group concentration is at least 60 equivalents/10⁶g.
Claim 9
Dependent Claim
27 words
A pressing fabric as claimed in claim 5 wherein that the polyamide is polyamide 6,6 and the intrinsic viscosity after treatment is not less than 1.3 dl/g.
Claim 10
Dependent Claim
74 words
A pressing fabric as claimed in claim 5 wherein that the fiber is contacted with an aqueous solution of aldehyde at an elevated temperature and with an aqueous solution of phenol at an elevated temperature, the treatments being carried out at a temperature and for a time sufficient to impart an increase in intrinsic viscosity of the polyamide being at least 4% and thereafter forming a layer of said fiber on a base fabric.
Claim 11
Dependent Claim
31 words
A pressing fabric as claimed in claim 8 wherein the fiber is formed into a batt layer prior to attaching to the base fabric either before or after the aldehyde/phenol treatment.
Claim 12
Dependent Claim
32 words
A pressing fabric as claimed in claim 5 wherein the phenols used in the treatment of the fiber are selected from the group consisting of phenol, pyrocatechol, resorcinol, hydroquinone, pyrogallol and phloroglucinol.
Claim 13
Dependent Claim
36 words
A pressing fabric as claimed in claim 5 wherein the aldehydes used in the process are selected from the group consisting of formaldehyde, formaldehyde liberating compounds, oxaldehyde, malonaldehyde, succinaldehyde, glutaraldehyde, adipaldehyde, pimelaldehyde, suberaldehyde, azelaldehyde and sebacaldehyde.
Claim 14
Dependent Claim
23 words
A pressing fabric as claimed in claim 5 wherein the polyamide is selected from the group consisting of polyamide 6 and polyamide 6,6.
References Cited (Backward Citations)
No citation records indexed.
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