US3953566A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing porous products
Assignee: W.L. Gore and Associates Inc
•
Filing: 1973-07-03
•
Granted: 1976-04-27
•
Expires: 1993-07-03
Abstract
Abstract This invention provides a tetrafluoroethylene polymer in a porous form which has an amorphous content exceeding about 5% and which has a micro-structure characterized by nodes interconnected by fibrils. The material has high porosity and high strength. It can be used to produce all kinds of shaped articles such as films, tubes, rods, and continuous filaments. Laminations can be employed and impregnation and bonding can readily be used to produce a large variety of articles. Compressed articles of very high strength can also be produced from these porous forms.
Inventors
- 👤 Robert W. Gore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 15:52
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/22; B32B5/32; B01; B01D; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/36; B29; B29C; B29C55/00; B29C55/005; B29C55/02; B29C55/10; B29C55/12; B29C55/18; B32B5/18; C; C08; C08J; C08J5/00; C08J5/12; C08J5/124; C08J5/18; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/44; H01B3/443; H01B3/445; B29K; B29K2027/00; B29K2027/12; B29K2027/18; B29K2105/00; B29K2105/04; B32B38/00; B32B2038/0052; B32B2038/0088; B32B2266/00; B32B2266/02; B32B2266/0214; B32B2266/025; B32B2305/00; B32B2305/02; B32B2305/026; B32B2307/00; B32B2307/50; B32B2307/54; B32B2307/70; B32B2307/702; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; Y; Y10; Y10S; Y10S264/00; Y10S264/70; Y10S384/00; Y10S384/90; Y10S384/902; Y10S55/00; Y10S55/05; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/139; Y10T428/1397; Y10T428/249921; Y10T428/249953; Y10T428/249978; Y10T428/249994; Y10T428/25; Y10T428/251; Y10T428/252; Y10T428/254; Y10T428/259; Y10T428/29; Y10T428/2913; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
76 words
A process for the production of a porous article of manufacture of a polymer of tetrafluoroethylene which process comprises expanding a shaped article consisting essentially of highly crystalline poly(tetrafluoroethylene) made by a paste-forming extrusion technique, after removal of lubricant, by stretching said unsintered shaped article at a rate exceeding about 10% per second and maintaining said shaped article at a temperature between about 35°C. and the crystalline melt point of said tetrafluoroethylene polymer during said stretching.
Claim 2
Dependent Claim
76 words
A process for the production of a porous article of manufacture of a polymer of tetrafluoroethylene which process comprises expanding a shaped article consisting essentially of highly crystalline poly(tetrafluoroethylene) made by a paste-forming extrusion technique, after removal of lubricant, by stretching said unsintered shaped article at a rate exceeding about 10% per second and maintaining said shaped article at a temperature between about 35°C. and the crystalline melt point of said tetrafluoroethylene polymer during said stretching.
Claim 3
Dependent Claim
16 words
The process of claim 1 in which the rate of stretch is about 30% per second.
Claim 4
Dependent Claim
16 words
The process of claim 1 in which the rate of stretch is about 100% per second.
Claim 5
Dependent Claim
16 words
The process of claim 1 in which the rate of stretch is about 500% per second.
Claim 6
Dependent Claim
16 words
The process of claim 1 in which the rate of stretch is about 1000% per second.
Claim 7
Dependent Claim
16 words
The process of claim 1 in which the rate of stretch is about 5000% per second.
Claim 8
Dependent Claim
16 words
The process of claim 1 in which the rate of stretch is about 10,000% per second.
Claim 9
Dependent Claim
16 words
The process of claim 1 in which the rate of stretch is about 40,000% per second.
Claim 10
Dependent Claim
20 words
A process in accordance with claim 1 in which said shaped article has an amorphous content not exceeding about 3.5%.
Claim 11
Dependent Claim
35 words
A process in accordance with claim 1 in which said expanding is effected by clamping said shaped article and rapidly forming a vacuum on one side of said article to rapidly stretch said shaped article.
Claim 12
Dependent Claim
17 words
A process in accordance with claim 1 in which said expanding is effected in only one direction.
Claim 13
Dependent Claim
14 words
A process in accordance with claim 1 in which said expanding is effected biaxially.
Claim 14
Dependent Claim
26 words
A process in accordance with claim 1 in which said expanding produces a porosity of about 40% to about 97% in said resultant, porous stretched article.
Claim 15
Dependent Claim
15 words
A process according to claim 1 including the step of compressing the resultant porous article.
Claim 16
Dependent Claim
29 words
The process of claim 1 in which said shaped article is expanded by rapidly creating a pressure differential across said shaped article to cause said shaped article to stretch.
Claim 17
Dependent Claim
18 words
The process of claim 1 in which the expanding step is effected at a temperature above about 93°C.
Claim 18
Dependent Claim
30 words
The process of claim 1 in which the shaped article is expanded such that its final length in the direction of expansion is greater than about twice the original length.
Claim 19
Dependent Claim
19 words
The process of claim 17 in which said final length is greater than about three times the original length.
Claim 20
Dependent Claim
19 words
The process of claim 17 in which said final length is greater than about five times the original length.
Claim 21
Dependent Claim
19 words
The process of claim 17 in which said final length is greater than about seven times the original length.
Claim 22
Dependent Claim
17 words
The process of claim 17 in which said final length is about fifteen times the original length.
Claim 23
Dependent Claim
19 words
The process of claim 17 in which said final length is greater than about 24 times the original length.
Claim 24
Dependent Claim
28 words
A process in accordance with claim 1 which includes the subsequent step of heating the stretched-shaped article to a temperature above the crystalline melting temperature of said polymer.
Claim 25
Dependent Claim
22 words
The process of claim 23 in which said heating produces in said stretched-shaped article an increase in amorphous content exceeding about 1%.
References Cited (Backward Citations)
US2953428A
Cited
US2915786A
Cited
US3054761A
Cited
JPS4213560Y1
Cited
US3544671A
Cited
US3634564A
Cited
US3637906A
Cited
JPS4430807Y1
Cited
US3664915A
Cited
US3813461A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |