US3864124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing sintered articles from flexible preforms containing polytetrafluoroethylene and at least about 85 volume percent of sinterable particulate material
Assignee: Composite Sciences Inc
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Filing: 1972-02-28
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Granted: 1975-02-04
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Expires: 1992-02-28
Abstract
Abstract A process for preparing sintered articles by heating a preform having good green strength and low modulii of elasticity, and comprising a matrix of fibrillated polytetrafluoroethylene interconnecting and entrapping a high volume, at least about 85%, of a particulate and preferably a sinterable material selected from the group consisting of metals, intermetallic, compounds, ceramics, salts, plastics, and combinations thereof. Said preforms are formed by mechanically working a substantially dry mixture of a fibrillable polytetrafluoroethylene polymer and a high volume, at least about 85%, of the particulate material. Metal, ceramic and plastic articles prepared by heat treating, such as sintering, the preforms are also disclosed. The heat treated products are useful, inter alia, as structural elements and electronic components.
Inventors
- 👤 Ernest J Breton
- 👤 Jack D Wolf
- 👤 Dexter Worden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:52
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/16; B01; B01J; B01J37/00; B01J37/0009; B22; B22F; B22F1/00; B22F1/10; B23; B23K; B23K35/00; B23K35/02; B23K35/0222; B23K35/0244; B29; B29C; B29C67/00; B29C67/02; B29C67/04; B32B15/00; B32B15/04; B32B27/00; B32B27/06; B32B27/14; C; C22; C22C; C22C32/00; C22C32/0094; G; G21; G21F; G21F1/00; G21F1/02; G21F1/06; G21F1/10; G21F1/103; B29K; B29K2227/00; B29K2227/12; B29K2227/18; B32B2264/00; B32B2264/10; B32B2264/105; B32B2307/00; B32B2307/50; B32B2307/554
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
130 words
A PROCESS FOR PREPARING A SINTERED ARTICLE COMPRISING: A. CONFORMING A SELF-SUSTAINING, CLOTH-LIKE, FLEXIBLE, NONWOVEN PREFORM TO A DESIRED CONFIGURATION, SAID PREFORM COMPRISING FROM ABOUT 85 TO ABOUT 99% BY VOLUME OF A SOLID SINTERABLE PARTICULATE MATERIAL SELECTED FROM THE GROUP CONSISTING OF CERAMICS, METALS, INTERMETALLIC COMPOUNDS, SYNTHETIC ORGANIC POLYMERS AND MIXTURES THEREOF AND FROM ABOUT 1 TO ABOUT 15% BY VOLUME OF POLYTETRAFLUOROETHYLENE RESIN, SAID PARTICULATE MATERIAL BEING INTERCONNECTED AND ENTRAPPED BY FIBRILS OF SAID POLYTETRAFLUOROETHYLENE TO IMPART A SELF-SUSTAINING CONDITION AND FLEXIBILITY TO THE PREFORM, B. HEATING THE PREFORM TO A TEMPERATURE SUFFICIENT TO DECOMPOSE AND REMOVE THE POLYTETRAFLUOROETHYLENE RESIN AND TO SINTER THE PARTICULATE MATERIAL THEREBY BONDING THE PARTICULATE MATERIAL INTO A UNITARY STRUCTURE, AND C. COOLING THE PRODUCT OF STEP B) TO OBTAIN THE SINTERED ARTICLE.
Claim 2
Dependent Claim
130 words
A PROCESS FOR PREPARING A SINTERED ARTICLE COMPRISING: A. CONFORMING A SELF-SUSTAINING, CLOTH-LIKE, FLEXIBLE, NONWOVEN PREFORM TO A DESIRED CONFIGURATION, SAID PREFORM COMPRISING FROM ABOUT 85 TO ABOUT 99% BY VOLUME OF A SOLID SINTERABLE PARTICULATE MATERIAL SELECTED FROM THE GROUP CONSISTING OF CERAMICS, METALS, INTERMETALLIC COMPOUNDS, SYNTHETIC ORGANIC POLYMERS AND MIXTURES THEREOF AND FROM ABOUT 1 TO ABOUT 15% BY VOLUME OF POLYTETRAFLUOROETHYLENE RESIN, SAID PARTICULATE MATERIAL BEING INTERCONNECTED AND ENTRAPPED BY FIBRILS OF SAID POLYTETRAFLUOROETHYLENE TO IMPART A SELF-SUSTAINING CONDITION AND FLEXIBILITY TO THE PREFORM, B. HEATING THE PREFORM TO A TEMPERATURE SUFFICIENT TO DECOMPOSE AND REMOVE THE POLYTETRAFLUOROETHYLENE RESIN AND TO SINTER THE PARTICULATE MATERIAL THEREBY BONDING THE PARTICULATE MATERIAL INTO A UNITARY STRUCTURE, AND C. COOLING THE PRODUCT OF STEP B) TO OBTAIN THE SINTERED ARTICLE.
Claim 3
Dependent Claim
13 words
The process according to claim 1 wherein the particulate material comprises a metal.
Claim 4
Dependent Claim
113 words
The process according to claim 2 wherein the preform is composed of a first sheet and a second sheet, at least one of the particle size of the particulate material, the percent by volume of the particulate material and the property of the particulate material in the first sheet being different from at least one of the particle size of the particulate material, the percent by volume of the particulate material and the property of the particulate material of the second sheet whereby upon heating the preform, at least a portion of the resulting sintered article is porous and contains two areas of different pore structure corresponding to the first and second sheets.
Claim 5
Dependent Claim
57 words
The process according to claim 1 wherein the preform is produced by mechanically working a mixture of said particulate material and particulate polytetrafluoroethylene resin in the substantial absence of liquid lubricants until fibrillation of the polytetrafluoroethylene occurs and the resulting fibrils interconnect and entrap the particulate material to impart a self-sustaining condition and flexibility to the preform.
Claim 6
Dependent Claim
32 words
The process according to claim 1 wherein the preform is contacted with a substrate material during step b) and the preform is sintered and bonded to the substrate material during said heating.
Claim 7
Dependent Claim
20 words
The process according to claim 1 wherein the preform is conformed to the desired configuration by shaping with a die.
References Cited (Backward Citations)
US3315020A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |