Patent US3343534A successfully refreshed from Google Patents.
Patent US4075303A successfully refreshed from Google Patents.
US4075303A
Expired / Lapsed
US
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Method of preparation of ceramic foam
Assignee: Consolidated Aluminum Corp
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Filing: 1977-02-22
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Granted: 1978-02-21
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Expires: 1997-02-22
Abstract
Abstract Ceramic foams possessing controlled permeability and uniformity are prepared by a combined rolling operation of impregnating an open-celled organic polymer foam material possessing a predetermined permeability and resilience with a fluid aqueous slurry of a thixotropic ceramic composition and immediate passage through at least two controlled roll gaps, wherein the rolls are preset to effect a temporary compression ranging from about 50 to 90% for the first pass and 70 to 90% for the second pass. The resulting material is thereby uniformly impregnated with the required amount of slurry, and is then dried and heated to remove the organic foam component. The foams prepared in accordance with the present invention are useful as filters for molten metals, especially aluminum and its alloys.
Inventors
- 👤 John C. Yarwood
- 👤 James E. Dore
- 👤 Robert K. Preuss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:58
CPC Classifications
C; C22; C22B; C22B9/00; C22B9/02; C22B9/023; B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2093; B22; B22D; B22D43/00; B22D43/001; B22D43/004; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B38/00; C04B38/06; C04B38/0615; C22B21/00; C22B21/06; C22B21/066; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
165 words
A method of preparing a ceramic foam possessing controlled permeability and structural uniformity which comprises: A. providing a hydrophobic, reticulated organic polymer foam possessing a predetermined permeability and resilience; B. preparing an aqueous slurry of a thixotropic ceramic composition having a viscosity within the range of 1 × 10 3 to 80 × 10 3 cps; C. providing at least three rolls mounted to furnish at least two gaps in close proximity between pairs of said rolls, the first gap being preset at a spacing of 50-90% of the thickness of said polymer foam and the second gap at 70-90% of said thickness; D. passing said polymer foam through said roll gaps while flowing said slurry over at least one roll and a surface of said polymer foam to establish a supply of said slurry at the entrance to said first gap, thereby uniformly impregnating said polymer foam with said slurry; and E. drying and heating said impregnated foam to remove the organic component therefrom.
Claim 2
Independent Claim
165 words
A method of preparing a ceramic foam possessing controlled permeability and structural uniformity which comprises: A. providing a hydrophobic, reticulated organic polymer foam possessing a predetermined permeability and resilience; B. preparing an aqueous slurry of a thixotropic ceramic composition having a viscosity within the range of 1 × 10 3 to 80 × 10 3 cps; C. providing at least three rolls mounted to furnish at least two gaps in close proximity between pairs of said rolls, the first gap being preset at a spacing of 50-90% of the thickness of said polymer foam and the second gap at 70-90% of said thickness; D. passing said polymer foam through said roll gaps while flowing said slurry over at least one roll and a surface of said polymer foam to establish a supply of said slurry at the entrance to said first gap, thereby uniformly impregnating said polymer foam with said slurry; and E. drying and heating said impregnated foam to remove the organic component therefrom.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein said roll gaps are provided by a triple-roll stand.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein said roll gaps are provided by a pair of two-roll stands.
Claim 5
Dependent Claim
28 words
The method of claim 1 wherein the said first roll gap is preset at a spacing equal to 50% to 90% of the thickness of said polymer foam.
Claim 6
Dependent Claim
27 words
The method of claim 1 wherein the said second gap is preset at a spacing equal to 70% to 90% of the thickness of said polymer foam.
Claim 7
Dependent Claim
19 words
The method of claim 1 wherein the said polymer foam has a thickness of 0.25 inch to 4 inches.
Claim 8
Dependent Claim
27 words
The method of claim 1 wherein the said polymer foam is selected from the group consisting of polyester polyurethanes, polyether polyurethanes, polyvinyl foam materials, and cellulosic derivatives.
Claim 9
Dependent Claim
53 words
The method of claim 1 wherein the said polymeric foam has a resilience measured by the ball rebound test of greater than 25%, a compression set not greater than 30% at 50% compression, a permeability of 4000 to 8000 × 10 -7 cm 2 and a pore size of 5 to 50 ppi.
Claim 10
Dependent Claim
33 words
The method of claim 1 wherein said aqueous slurry contains a ceramic composition comprising materials selected from the group consisting of alumina, chromia, zirconia, magnesia, titania, silica, mullite, calcined clay, and mixtures thereof.
Claim 11
Dependent Claim
26 words
The method of claim 9 wherein said composition further comprises 2.5 to 25% of an air setting agent and 0.1 to 12% of a rheological agent.
Claim 12
Dependent Claim
32 words
The method of claim 10 wherein said air setting agent is selected from the group consisting of colloidal aluminum orthophosphate, alkali metal silicates, ethyl silicate, aluminum hydroxychloride, magnesium orthoborate and mixtures thereof.
Claim 13
Dependent Claim
24 words
The method of claim 10 wherein said rheological agent is selected from the group consisting of organic cellulosic derivatives, bentonite, kaolin and mixtures thereof.
Claim 14
Dependent Claim
29 words
The method of claim 9 wherein said slurry comprises 40-80% alumina, up to 20% chromia, 2.5 to 25% aluminum orthophosphate, up to about 10% kaolin and about 0.1-10% bentonite.
Claim 15
Dependent Claim
21 words
The method of claim 13 wherein said slurry comprises 45-50% alumina, 10-15% chromia, 12.5-17.5% aluminum orthophosphate, 2-5% kaolin, and 0.5-2% bentonite.
Claim 16
Dependent Claim
22 words
The method of claim 1 wherein the viscosity of said slurry is 10 × 10 3 to 40 × 10 3 cps.
Claim 17
Dependent Claim
18 words
The method of claim 1 wherein said drying is conducted at a temperature ranging from about 400°-700° F.
Claim 18
Dependent Claim
19 words
The method of claim 16 wherein said foam material is further heated to sinter said ceramic composition entrained therein.
Claim 19
Dependent Claim
86 words
The method of claim 1 wherein the said polymer foam has a permeability of 4000 to 8000 × 10 -7 cm 2 , the said aqueous slurry has a viscosity of 25 to 35 cps, the said first roll gap being preset at a spacing of 50 to 80% of the thickness of the said polymer foam, and the said second gap being preset at a spacing at least the same as the first and up to 90% of the thickness of the said polymer foam.
Claim 20
Dependent Claim
142 words
In preparing a ceramic foam having controlled permeability and structural uniformity, the method comprising: A. providing a hydrophobic, reticulated organic polymer foam having a predetermined permeability and resilience; B. preparing an aqueous slurry of a thixotropic ceramic composition having a viscosity of 1 × 10 3 to 80 × 10 3 cps; C. providing at least three rolls mounted to furnish at least two gaps in close proximity between pairs of said rolls, the first gap being preset at a spacing of 50 to 90% of the thickness of said polymer foam and the second gap at 70 to 90% of the said thickness; and D. advancing said polymer foam through said roll gaps while flowing said slurry over at least one surface of said polymer foam and into said first roll gap, thereby uniformly impregnating said polymer foam with said slurry.
Claim 21
Dependent Claim
142 words
In preparing a ceramic foam having controlled permeability and structural uniformity, the method comprising: A. providing a hydrophobic, reticulated organic polymer foam having a predetermined permeability and resilience; B. preparing an aqueous slurry of a thixotropic ceramic composition having a viscosity of 1 × 10 3 to 80 × 10 3 cps; C. providing at least three rolls mounted to furnish at least two gaps in close proximity between pairs of said rolls, the first gap being preset at a spacing of 50 to 90% of the thickness of said polymer foam and the second gap at 70 to 90% of the said thickness; and D. advancing said polymer foam through said roll gaps while flowing said slurry over at least one surface of said polymer foam and into said first roll gap, thereby uniformly impregnating said polymer foam with said slurry.
Claim 22
Dependent Claim
20 words
The method of claim 19 wherein said polymer foam is advanced a plurality of times through the said roll gaps.
References Cited (Backward Citations)
US4024212A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |