US4522776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
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 14:54
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.
References Cited (Backward Citations)
US3125547A
Cited
US3382535A
Cited
US3920782A
Cited
US3879507A
Cited
US4080138A
Cited
US4243619A
Cited
JPS5521222A
Cited
US4282177A
Cited
US4348349A
Cited
US4329314A
Cited
US4360494A
Cited
US4342848A
Cited
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 |