US3985846A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ceramic firing process
Assignee: WR Grace and Co
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Filing: 1975-04-16
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Granted: 1976-10-12
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Expires: 1995-04-16
Abstract
Abstract This invention relates to an improvement in the process of preparing porous ceramic articles which are formed by blending a composition containing a polyolefin, a ceramic filler and a plasticizer; shaping the blend; extracting the plasticizer and firing the article to remove the polyolefin. The improvement comprises soaking the extracted article in a water solution of a surfactant prior to firing which results in a substantial reduction in the number of cracked pieces when firing many pieces simultaneously.
Inventors
- 👤 Christian Bent Lundsager
- 👤 Robert Matthews Murch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:08
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01J; B01J37/00; B01J37/0009; B01J37/0018; C; C04; C04B; C04B26/00; C04B26/02; C04B26/04; C04B26/045; C04B38/00; C04B38/06; C04B38/0615
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
91 words
In a process for preparing porous ceramic structures with good resistance to cracking during firing wherein a composition consisting essentially of a polyolefin, a ceramic filler and a plasticizer is homogeneously blended, said composition is shaped to form a plastic structure, whereupon said plasticizer is extracted with an appropriate solvent and said polyolefin is subsequently removed by heating to form a porous ceramic structure, the improvement which consists of soaking said extracted ceramic structure in an aqueous solution of 1/2% synthetic surfactant for 8 to 16 hours prior to said heating.
Claim 2
Dependent Claim
91 words
In a process for preparing porous ceramic structures with good resistance to cracking during firing wherein a composition consisting essentially of a polyolefin, a ceramic filler and a plasticizer is homogeneously blended, said composition is shaped to form a plastic structure, whereupon said plasticizer is extracted with an appropriate solvent and said polyolefin is subsequently removed by heating to form a porous ceramic structure, the improvement which consists of soaking said extracted ceramic structure in an aqueous solution of 1/2% synthetic surfactant for 8 to 16 hours prior to said heating.
Claim 3
Dependent Claim
25 words
The process of claim 1 further characterized in that said firing of the ceramic structures takes place in a kiln operated at reducing atmosphere conditions.
References Cited (Backward Citations)
US3261894A
Cited
US3755204A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-10-12 | 1980-04-12 | 1980-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-12 | 1984-04-12 | 1984-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-12 | 1988-04-12 | 1988-10-12 | $7700.00 | Window Closed / Lapsed |