Patent US3297831A successfully refreshed from Google Patents.
EP0531473B1
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EP
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Polymeric materials
Assignee: BTG International Ltd
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Filing: 1992-03-06
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Granted: 1995-07-05
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Expires: 2012-03-06
Abstract
Abstract Polymeric monoliths having high stiffness and strength can be produced by heating an assembly of polymer fibres under a contact pressure to a temperature at which a proportion of the fibre is selectively melted and then compressing the assembly. Preferably at least 5% of the polymer is melted so that on compression the molten materials fills the voids within the assembly. The use of polyolefin fibres especially melt spun polyethylene fibres is preferred. The products are useful e.g. as orthodontic brackets, bone prostheses and in body armour.
Inventors
- 👤 Ian Macmillan Ward
- 👤 Peter John Hine
- 👤 Keith Norris
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 10:41
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/22; B32B5/24; B32B5/26; A; A61; A61L; A61L27/00; A61L27/14; A61L27/16; A61L27/50; B29; B29C; B29C43/00; B29C43/006; B29C43/02; B29C43/14; B32B5/02; B32B5/024; C; C08; C08L; C08L27/00; C08L59/00; C08L67/00; C08L71/00; C08L71/08; C08L71/10; C08L71/12; C08L79/00; D; D04; D04H; D04H1/00; D04H1/40; D04H1/54; D04H1/542; D04H1/544; F; F41; F41H; F41H5/00; F41H5/02; F41H5/04; F41H5/0471; F41H5/0485; A61C; A61C7/00; A61C7/12; A61C7/14; A61F; A61F2/00; A61F2/02; A61F2/28; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0658; B29K2023/0683; B29K2105/00; B29K2105/06; B29K2105/25; B29K2223/00; B29K2223/04; B29K2223/06; B29L; B29L2031/00; B29L2031/753; B29L2031/7532; B32B2250/00; B32B2250/20; B32B2250/40; B32B2262/00; B32B2262/02; B32B2262/0253; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24826; Y10T428/249921; Y10T428/249924; Y10T428/24994; Y10T428/249942; Y10T428/249947; Y10T442/00; Y10T442/60; Y10T442/69
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
39 words
A process for the production of a homogeneous polymeric monolith characterised in that an assembly of oriented polymer fibres is maintained in intimate contact at an elevated temperature sufficient to melt a proportion of the polymer and subsequently compressed.
Claim 2
Dependent Claim
43 words
A process according to Claim 1 characterised in that the assembly is maintained at a temperature at least that at which an extrapolation of the leading edge of the endotherm of the oriented fibres measured by differential scanning calorimetry intersects the temperature axis.
Claim 3
Dependent Claim
39 words
A process according to either of Claims 1 to 2 characterised in that the temperature at which the assembly is maintained is less than the peak temperature of melting of the polymer fibres as measured by differential scanning calorimetry.
Claim 4
Dependent Claim
32 words
A process according to any of Claims 1 to 3 characterised in that the assembly is maintained at a temperature such that at least 5% by weight of the polymer is melted.
Claim 5
Dependent Claim
32 words
A process according to any of the preceding claims characterised in that the assembly is maintained at a temperature such that no more than 20% by weight of the polymer is melted.
Claim 6
Dependent Claim
33 words
A process according to either of Claims 4 or 5 characterised in that the assembly is maintained at a temperature such that from 5 to 10% by weight of the polymer is melted.
Claim 7
Dependent Claim
19 words
A process according to any of the preceding claims characterised in that the assembly is maintained under contact pressure.
Claim 8
Dependent Claim
27 words
A process according to any of the preceding claims characterised in that the heated assembly is compressed under a compaction pressure of from 0.5 to 2.0 MPa.
Claim 9
Dependent Claim
22 words
A process according to Claim 8 characterised in that the compaction pressure is maintained for a period of at least 5 seconds.
Claim 10
Dependent Claim
27 words
A process according to any of the preceding claims characterised in that the hot compressed material is allowed to cool to ambient temperature by standing in air.
Claim 11
Dependent Claim
22 words
A process according to any of the preceding claims characterised in that the polymer fibres are homo or copolymers of a polyolefin.
Claim 12
Dependent Claim
15 words
A process according to Claim 11 characterised in that the polymer fibres are polyethylene fibres.
Claim 13
Dependent Claim
26 words
A process according to either of Claim 11 or 12 characterised in that the polymer has a weight average molecular weight of from 50,000 to 3,000,000.
Claim 14
Dependent Claim
25 words
A process according to any Claims 11 to 13 characterised in that the polymer has a weight average molecular weight of from 500,000 to 3,000,000.
Claim 15
Dependent Claim
26 words
A process according to any of Claims 11 to 13 characterised in that the polymer has a weight average molecular weight of from 50,000 to 300,000.
Claim 16
Dependent Claim
20 words
A process according to any of Claims 11 to 15 characterised in that the fibre is a melt spun fibre.
Claim 17
Dependent Claim
36 words
A process according to any of Claims 11 to 16 characterised in that the assembly is maintained at a temperature which is no more than 5°C below the peak temperature of melting of the polymer fibre.
Claim 18
Dependent Claim
35 words
A process according to any of Claims 11 to 17 characterised in that the assembly is maintained at a temperature which is no more than 2°C below the peak temperature of melting of the polymer.
Claim 19
Dependent Claim
28 words
A process according to any of the preceding claims characterised in that the compressed product has a density which is at least 90% of the original fibre density.
References Cited (Backward Citations)
EP0354285A1
Cited
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