Patent US3504147A successfully refreshed from Google Patents.
EP0144157A2
Expired / Lapsed
EP
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Polymer extrusion die lips
Assignee: DuPont Canada Inc
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Filing: 1984-10-31
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Granted: —
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Expires: 2004-10-31
Abstract
Abstract Extrudate roughness of thermoplastic polymeric films, particularly films from linear polyethylene, is reduced by forming the die lips through which the polymer is extruded with a surface of one of the following materials, viz. (a) perfluoroalkoxy polymer; (b) a matrix of a metal or metal alloy impregnated with a fluorocarbon polymer; or (c) a matrix of a ceramic material impregnated with a fluorocarbon polymer.
Inventors
- 👤 Alistair Norman Mollison
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 15:49
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/30; B29C48/32; B29C48/03; B29C48/09; B29C48/10; B29C48/3001; B29C48/3003; B29C48/06; B29K; B29K2023/00
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
53 words
A polymer extrusion die comprising two spaced apart die lips, each die lip having a surface of a material selected from the group consisting of a)a perfluoroalkoxy polymer, b)a matrix of a metal or metal alloy impregnated with a fluorocarbon polymer, and c)a matrix of a ceramic material impregnated with a fluorocarbon polymer.
Claim 2
Dependent Claim
53 words
A polymer extrusion die comprising two spaced apart die lips, each die lip having a surface of a material selected from the group consisting of a)a perfluoroalkoxy polymer, b)a matrix of a metal or metal alloy impregnated with a fluorocarbon polymer, and c)a matrix of a ceramic material impregnated with a fluorocarbon polymer.
Claim 3
Dependent Claim
18 words
A polymer extrusion die according to Claim 1 wherein the die lips are coated with a perfluoroalkoxy polymer.
Claim 4
Dependent Claim
28 words
A polymer extrusion die according to Claim 1 wherein the die lips are coated with a matrix of a metal or metal alloy impregnated with a fluorocarbon polymer.
Claim 5
Dependent Claim
23 words
A polymer extrusion die according to Claim 1 wherein the die lips are coated with a ceramic material impregnated with a fluorocarbon polymer.
Claim 6
Dependent Claim
26 words
A polymer extrusion die according to any one of Claim 2, Claim 3 and Claim 4 wherein the die is an annular blown film extrusion die.
Claim 7
Dependent Claim
29 words
A polymer extrusion die according to Claim 1 wherein the die is an annular blown film extrusion die, the lips of which are coated with cured Teflon-P perfluoroalkoxy finish.
Claim 8
Dependent Claim
24 words
A polymer extrusion die according to Claim 3 or Claim 4 wherein the matrix is microporous and the fluorocarbon polymer is a tetrafluoroethylene polymer.
Claim 9
Dependent Claim
22 words
A polymer extrusion die according to Claim 3 wherein the matrix is microporous metal alloy and the fluorocarbon polymer is tetrafluoroethylene polymer.
Claim 10
Dependent Claim
71 words
A process for reducing extrudate roughness of polyethylene films comprising extruding a linear polyethylene through a film extrusion die having two die lips spaced apart less than about 1300 pm, each die lip having a surface of a material selected from the group consisting of a)a perfluoroalkoxy polymer, b)a matrix of a metal alloy impregnated with a fluorocarbon polymer, and c)a matrix of a ceramic material impregnated with a fluorocarbon polymer.
Claim 11
Dependent Claim
71 words
A process for reducing extrudate roughness of polyethylene films comprising extruding a linear polyethylene through a film extrusion die having two die lips spaced apart less than about 1300 pm, each die lip having a surface of a material selected from the group consisting of a)a perfluoroalkoxy polymer, b)a matrix of a metal alloy impregnated with a fluorocarbon polymer, and c)a matrix of a ceramic material impregnated with a fluorocarbon polymer.
Claim 12
Dependent Claim
20 words
A process according to Claim 9 wherein the linear polyethylene comprises a linear ethylene/C 4 - C IO a-olefin copolymer.
Claim 13
Dependent Claim
18 words
A process according to Claim 10 wherein the linear polyethylene is an ethylene/butene-1 copolymer or an ethylene/octene-1 copolymer.
Claim 14
Dependent Claim
37 words
A process according to Claim 10 or Claim 11 wherein the linear polyethylene is blended with up to about 30 parts by weight of a compatible polymer for every 100 parts by weight of the linear polyethylene.
Claim 15
Dependent Claim
41 words
A process according to Claim 10 or Claim 11 wherein the linear polyethylene is blended with up to about 30 parts by weight of a compatible polymer selected from the group consisting of conventional high pressure polyethylene and ethylene/vinyl acetate copolymer.
Claim 16
Dependent Claim
22 words
A process according to Claim 9 wherein the linear polyethylene has a density of from about 0.913 to 0.965 g/cm 3 .
Claim 17
Dependent Claim
24 words
A process according to Claim 10 or Claim 14 wherein the linear polyethylene has a density of from 0.915 to 0.940 g/cm 3 .
References Cited (Backward Citations)
No citation records indexed.
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