Patent US4784820A successfully refreshed from Google Patents.
US4784820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of solution of high molecular weight polymers
Assignee: Honeywell International Inc
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Filing: 1986-08-11
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Granted: 1988-11-15
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Expires: 2006-08-11
Abstract
Abstract Solutions of high molecular weight polymers, such as ultrahigh molecular weight polyolefins are prepared, by forming a slurry of particles of the polymer in a solvent for the polymer, then transferring the slurry to a pumping device, then pumping the slurry under pressure to insure positive displacement to a screw extruder, and maintaining the slurry in the screw extruder for sufficient residence time at sufficient temperature so that a homogeneous solution is formed, then conveying the solution with the screw extruder to metering device which can feed a spinnerette, or a film-forming or tape-forming slit extruder.
Inventors
- 👤 Sheldon Kavesh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:27
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/395; B29C48/022; B29C48/03; B29C48/365; B29K; B29K2995/00; B29K2995/0037; B29K2995/0088
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
A method to prepare homogeneous solutions for extrusion of high molecular weight polymer comprising forming a slurry of particles of the high molecular weight polymer in a solvent for the polymer, then transferring said slurry to a positive displacement pump, then pumping said slurry with said positive displacement pump under sufficient pressure to insure positive conveyance to a screw extruder, then maintaining said slurry in said screw extruder for sufficient residence time and at a sufficient temperature so that a homogeneous solution of the polymer is formed, then conveying said solution with a metering pump to an extruding device.
Claim 2
Independent Claim
99 words
A method to prepare homogeneous solutions for extrusion of high molecular weight polymer comprising forming a slurry of particles of the high molecular weight polymer in a solvent for the polymer, then transferring said slurry to a positive displacement pump, then pumping said slurry with said positive displacement pump under sufficient pressure to insure positive conveyance to a screw extruder, then maintaining said slurry in said screw extruder for sufficient residence time and at a sufficient temperature so that a homogeneous solution of the polymer is formed, then conveying said solution with a metering pump to an extruding device.
Claim 3
Dependent Claim
14 words
The method of claim 1 wherein said polymer is an ultrahigh molecular weight polyolefin.
Claim 4
Dependent Claim
22 words
The method of claim 2 where said olefin is polyethylene having a molecular weight of from between about 300,000 to about 7,000,000.
Claim 5
Dependent Claim
21 words
The method of claim 1 wherein the polymer is selected from the group consisting of polyolefins, polyvinyl alcohol, polyacrylonitrile and nylon-6.
Claim 6
Dependent Claim
20 words
The method of claim 1 wherein the temperature in said screw extruder is between about 150° C. and 300° C.
Claim 7
Dependent Claim
22 words
The method of claim 1 wherein the residence time in said screw extruder is between about 3 minutes and about 1 hour.
Claim 8
Dependent Claim
14 words
The method of claim 1 wherein said positive displacement pump is a piston pump.
Claim 9
Dependent Claim
28 words
The method of claim 7 wherein the pressure at the discharge of said positive displacement pump is between about 50 and 1500 psig (0.34 to 10.3 mega pascals).
Claim 10
Dependent Claim
27 words
The method of claim 1 wherein the pressure at the discharge of said metering pump is between about 100 and 2000 psig (0.7 to 13.8 mega pascals).
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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) | 1991-11-15 | 1992-05-16 | 1992-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-15 | 1996-05-16 | 1996-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-15 | 2000-05-16 | 2000-11-15 | $7700.00 | Window Closed / Lapsed |