US5374473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dense polytetrafluoroethylene articles
Assignee: W.L. Gore and Associates Inc
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Filing: 1992-08-19
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Granted: 1994-12-20
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Expires: 2012-08-19
Abstract
Abstract This invention provides a densified previously expanded PTFE article having remnants of a fibril and node structure and a process for producing the article. A PTFE shape is compressed through the application of heat and pressure while the shape itself is under a vacuum, thus forming the densified ePTFE article. The densified PTFE article exhibits increased flexural strength. A diaphragm containing the densified ePTFE article as one layer is also disclosed.
Inventors
- 👤 John B. Knox
- 👤 William E. Delaney, III
- 👤 John M. Connelly, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 03:28
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/02; B29C43/18; B29C43/003; B29C43/006; B29C43/20; B29C70/00; B29C70/04; B29C70/06; B29C70/28; B29C70/30; B29C70/34; B29C70/342; B29D; B29D99/00; B29D99/0053; B32; B32B; B32B37/00; B32B37/10; B32B37/1018; F; F16; F16J; F16J3/00; F16J3/02; B29C2791/00; B29C2791/004; B29C2791/006; B29K; B29K2027/00; B29K2027/12; B29K2027/18; B29K2105/00; B29K2105/06; B29K2105/08; B29K2105/0809; B29L; B29L2031/00; B29L2031/26; B29L2031/755; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/131; Y10T428/1314; Y10T428/1317; Y10T428/1352; Y10T428/1355; Y10T428/1359; Y10T428/1376; Y10T428/23; Y10T428/233; Y10T428/24; Y10T428/24942; Y10T428/24992
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
60 words
A material consisting essentially of a sintered, densified expanded polytetrafluoroethylene having remnants of a fibril and node structure as characterized by peaks at about 327° C. and about 380° C. in a thermogram of differential scanning calorimetry in the course of temperature rise of 10° C./min, having a density of 2.10 gm/cc or greater and being substantially free of pores.
Claim 2
Dependent Claim
60 words
A material consisting essentially of a sintered, densified expanded polytetrafluoroethylene having remnants of a fibril and node structure as characterized by peaks at about 327° C. and about 380° C. in a thermogram of differential scanning calorimetry in the course of temperature rise of 10° C./min, having a density of 2.10 gm/cc or greater and being substantially free of pores.
Claim 3
Dependent Claim
16 words
The material of claim 1 wherein the material has a density of 2.14 cm/cc or greater.
Claim 4
Dependent Claim
16 words
The material of claim 1 wherein the material has a density of 2.175 g/cc or greater.
Claim 5
Dependent Claim
20 words
The material of claim 1 in which the material is in the form of a plurality of layers of sheets.
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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) | 1997-12-19 | 1998-06-20 | 1998-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-12-19 | 2002-06-20 | 2002-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-12-19 | 2006-06-20 | 2006-12-20 | $7700.00 | Window Closed / Lapsed |