US5137782A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Granular composite containing metal fibers and plastic articles made therefrom
Assignee: Bekaert NV SA
•
Filing: 1990-03-13
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Granted: 1992-08-11
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Expires: 2010-03-13
Abstract
Abstract The granular composite is obtained by chopping a composite strand containing metal fibers, said fibers being embedded as bundles in a plastic and is to be used for the shaping of plastic articles. The metal fibers comprise hardened material which has been derived from an austenitic ferric alloy in which the austenite has been converted into martensite for at least 75 vol. %.
Inventors
- 👤 Ludo Adriaensen
- 👤 Frans Verhaeghe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:25
CPC Classifications
C; C08; C08J; C08J5/00; C08J5/04; H; H05; H05K; H05K9/00; H05K9/0073; H05K9/0081; H05K9/009; B; B29; B29C; B29C70/00; B29C70/04; B29C70/06; B29C70/10; B29C70/16; B29C70/20; C08J3/00; C08J3/20; C08J3/22; C08J3/226; C08K; C08K7/00; C08K7/02; C08K7/04; C08K7/06; H01; H01B; H01B1/00; H01B1/20; H01B1/22; B29K; B29K2305/00; B29K2305/08; B29K2305/12; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12333; Y10T428/12389; Y10T428/12403; Y10T428/29; Y10T428/2913; Y10T428/2922; Y10T428/2924; Y10T428/2927; Y10T428/2982; Y10T428/2991; Y10T428/2998
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
120 words
A composite strand for improving the electromagnetic shielding efficiency of a plastics article having a main resin component, said strand comprising metal fibers embedded as bundles in a polymer, said strand containing said polymer in an amount between 20 to 80 volume percent, wherein (i) said metal fibers are formed of a metal derived from an austenitic stainless Fe/Cr/Ni-steel alloy, (ii) the austenite present in said alloy has been converted by plastic deformation into the martensite in an amount of at least 85 volume percent, and (iii) at least one of said bundles in said strand is a gear crimped bundle to facilitate even dispersion of said metal fibers throughout the plastics article thereby imparting improved electromagnetic shielding efficiency thereto.
Claim 2
Dependent Claim
120 words
A composite strand for improving the electromagnetic shielding efficiency of a plastics article having a main resin component, said strand comprising metal fibers embedded as bundles in a polymer, said strand containing said polymer in an amount between 20 to 80 volume percent, wherein (i) said metal fibers are formed of a metal derived from an austenitic stainless Fe/Cr/Ni-steel alloy, (ii) the austenite present in said alloy has been converted by plastic deformation into the martensite in an amount of at least 85 volume percent, and (iii) at least one of said bundles in said strand is a gear crimped bundle to facilitate even dispersion of said metal fibers throughout the plastics article thereby imparting improved electromagnetic shielding efficiency thereto.
Claim 3
Dependent Claim
19 words
A strand according to claim 1, in which at least 90% of the austenite has been converted into martensite.
Claim 4
Dependent Claim
18 words
A strand according to claim 1, in which the fibers have an almost constant and near-circular cross section.
Claim 5
Dependent Claim
26 words
A strand according to claim 1, in which the metal is almost free from non deformable inclusions with a grain size of more than 3 microns.
Claim 6
Dependent Claim
17 words
A strand according to claim 1, in which the fibers have a surface with a good conductivity.
Claim 7
Dependent Claim
20 words
A strand according to claim 1, in which fibers have an equivalent diameter D of not more than 15 microns.
Claim 8
Dependent Claim
17 words
A strand according to claim 1, in which the bundle contains between 500 and 35 000 fibers.
Claim 9
Dependent Claim
16 words
A strand according to claim 1, further comprising other fibers in addition to said metal fibers.
Claim 10
Dependent Claim
17 words
A strand according to claim 8, in which at least part of said other fibers are non-conductive.
Claim 11
Dependent Claim
28 words
A strand according to claim 8, in which at least part of said other fibers are conductive and have a conductivity lower than 0.5% of the copper standard.
Claim 12
Dependent Claim
16 words
A strand according to claim 1, in which the polymer has a relatively low melt viscosity.
Claim 13
Dependent Claim
32 words
A strand according to claim 1, wherein the polymer in which said metal fibers are embedded is the same or substantially the same as the main resin component of the plastic article.
Claim 14
Dependent Claim
17 words
A strand according to claim 1, in which the polymer contains very finely divided, electrically conductive materials.
Claim 15
Dependent Claim
16 words
A strand according to claim 1, in which the polymer contains at least one coupling agent.
Claim 16
Dependent Claim
26 words
A stand according to claim 1, wherein said strand contains a number of polymer impregnated fiber bundles, said strand being coated with an additional polymer layer.
Claim 17
Dependent Claim
27 words
A strand according to claim 15, wherein the addtional polymer layer has the same or substantially the same composition as the polymer used for impregnating the bundles.
Claim 18
Dependent Claim
28 words
A strand according to claim 15, wherein the additional polymer layer has the same or substantially the same composition as the main resin component of the plastic article.
Claim 19
Dependent Claim
18 words
A strand according to claim 1, in which the width of said strand is larger than its thickness.
Claim 20
Dependent Claim
30 words
A granular composite obtained by chopping granules from a strand according to claim 1, in which the fibers predominantly extend from one end of the granule to the opposite end.
Claim 21
Dependent Claim
25 words
A molding compound for use in forming shaped plastic articles, comprising a mixture of a granular composite according to claim 19, and another polymer granulate.
Claim 22
Dependent Claim
27 words
A plastic article obtained shaping the compound according to claim 20, in which the conductive fibers are evenly distributed at least throughout predetermined parts of the article.
Claim 23
Dependent Claim
18 words
A plastic article as a claim 21, wherein the conductive fibers are evenly distributed throughout the entire article.
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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) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |