Patent US4522776A successfully refreshed from Google Patents.
US4522776A
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Process for substantially eliminating surface melt fracture when extruding ethylene polymers
Assignee: Union Carbide Corp
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Filing: 1983-06-28
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Granted: 1985-06-11
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Expires: 2003-06-28
Abstract
Abstract A process for substantially eliminating surface melt fracture during extrusion of an ethylene polymer wherein the die land has a surface fabricated from a material which increases adhesion between the die land surface and the polymer.
Inventors
- 👤 Arakalgud V. Ramamurthy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 15:59
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/30; B29C48/32; B08; B08B; B08B9/00; B08B9/02; B08B9/027; B29C48/022; B29C48/03; B29C48/09; B29C48/10; B29C48/27; B29C48/272; B29C48/3001; B29C48/3003; B29C48/001; B29C48/0018; B29C48/0019; B29C48/07; B29C48/08; B29K; B29K2023/00; B29K2995/00; B29K2995/0037; B29K2995/0072; B29L; B29L2023/00; B29L2023/003
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
A process for substantially eliminating surface melt fracture during extrusion of an ethylene polymer under adhesion conditions between the material constituting a conventional die land surface and the polymer, which would otherwise produce higher levels of melt fracture which comprises extruding said polymer through a die having a die land surface fabricated from a material other than a conventional die land material which increases adhesion between the die land surface and the polymer to an extent sufficient to substantially eliminate surface melt fracture.
Claim 2
Dependent Claim
83 words
A process for substantially eliminating surface melt fracture during extrusion of an ethylene polymer under adhesion conditions between the material constituting a conventional die land surface and the polymer, which would otherwise produce higher levels of melt fracture which comprises extruding said polymer through a die having a die land surface fabricated from a material other than a conventional die land material which increases adhesion between the die land surface and the polymer to an extent sufficient to substantially eliminate surface melt fracture.
Claim 3
Dependent Claim
16 words
A process according to claim 1 wherein said material is a metal, or a metal alloy.
Claim 4
Dependent Claim
23 words
A process according to claim 2 herein said metal material is contained in inserts secured to the pin and collar of said die.
Claim 5
Dependent Claim
26 words
A process according to claim 2 wherein said metal material constitutes the material of construction of the die pin of the die collar of said die.
Claim 6
Dependent Claim
43 words
A process according to claim 1 wherein said copolymer is a copolymer of greater than or equal to 80 mol percent of ethylene and less than or equal to 20 mol percent of at least one C 3 to C 8 alpha olefin.
Claim 7
Dependent Claim
28 words
A process according to claim 5 in which said copolymer has a melt index of greater than or equal to 0.1 to less than or equal to 5.0.
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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) | 1988-06-10 | 1988-12-10 | 1989-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-10 | 1992-12-10 | 1993-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-10 | 1996-12-10 | 1997-06-11 | $7700.00 | Window Closed / Lapsed |