US4610832A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a ceramic foam
Assignee: SWISS ALUMINIUM Ltd A SWITZERLAND CORP
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Filing: 1984-09-26
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Granted: 1986-09-09
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Expires: 2004-09-26
Abstract
Abstract A ceramic foam material and process for making same having superior strength and durability properties wherein the impregnated foam impregnated with an alumina hydrate binder is fired at an elevated temperature so as to produce a ceramic body characterized by a solid state, sintered ceramic bond.
Inventors
- 👤 Jerry W. Brockmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:02
CPC Classifications
C; C22; C22B; C22B9/00; C22B9/02; C22B9/023; B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2093; C04; C04B; C04B38/00; C04B38/06; C04B38/0615; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
85 words
A process for preparing a ceramic foam filter for filtering molten metal which comprises: providing a reticulated, organic polymer foam; impregnating said foam with an aqueous slurry of a thixotropic ceramic composition including a gelled alumina hydrate binder in an amount of from 3 to 15%; drying and heating said impregnated polymer foam to remove the organic component therefrom; and firing at an elevated temperature to produce a solid state, sintered ceramic bond characterized by being substantially binder free and substantially free of glassy phases.
Claim 2
Dependent Claim
85 words
A process for preparing a ceramic foam filter for filtering molten metal which comprises: providing a reticulated, organic polymer foam; impregnating said foam with an aqueous slurry of a thixotropic ceramic composition including a gelled alumina hydrate binder in an amount of from 3 to 15%; drying and heating said impregnated polymer foam to remove the organic component therefrom; and firing at an elevated temperature to produce a solid state, sintered ceramic bond characterized by being substantially binder free and substantially free of glassy phases.
Claim 3
Dependent Claim
14 words
A process according to claim 1 wherein the polymer foam is a polyurethane foam.
Claim 4
Dependent Claim
12 words
A process according to claim 1 wherein boehmite is the alumina hydrate.
Claim 5
Dependent Claim
34 words
A process according to claim 1 wherein a colloidal dispersion of the hydrate is made with an acid that will volatilize under firing temperature and a thixotropic slurry is made with the ceramic material.
Claim 6
Dependent Claim
12 words
A process according to claim 4 wherein said acid is nitric acid.
Claim 7
Dependent Claim
21 words
A process according to claim 4 wherein the hydrate to acid ratio is from 2:1 to 5:1 based on 70% acid.
Claim 8
Dependent Claim
15 words
A process according to claim 6 wherein the hydrate to acid ratio is about 3:1.
Claim 9
Dependent Claim
30 words
A process according to claim 6 wherein the hydrate is first gelled with the acid followed by admixing the gelled material with the ceramic and water to form the slurry.
Claim 10
Dependent Claim
12 words
A process according to claim 8 wherein all components are admixed together.
Claim 11
Dependent Claim
23 words
A process according to claim 1 wherein the firing is at a temperature of at least 2000° F. for at least 15 minutes.
Claim 12
Dependent Claim
16 words
A process according to claim 10 wherein the firing is from 15 minutes to 10 hours.
Claim 13
Dependent Claim
18 words
A process according to claim 10 wherein the firing is at a temperature of at least 2500° F.
Claim 14
Dependent Claim
14 words
A process according to claim 10 wherein the firing temperature is approximately 3000° F.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-08 | 1990-03-10 | 1990-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-08 | 1994-03-10 | 1994-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-08 | 1998-03-10 | 1998-09-09 | $7700.00 | Window Closed / Lapsed |