EP0042302B1
Expired / Lapsed
EP
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Method for producing ceramic honeycomb filters
Assignee: NGK Insulators Ltd
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Filing: 1981-06-16
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Granted: 1984-11-14
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Expires: 2001-06-16
Abstract
No abstract record available.
Inventors
- 👤 Noboru Higuchi
- 👤 Teruo Yano
- 👤 Masahiro Ohnishi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 05:31
CPC Classifications
B; B28; B28B; B28B11/00; B28B11/003; B28B11/006; B01; B01D; B01D29/00; B01D29/11; B01D29/111; B01D29/31; B01D29/50; B01D29/52; B01D46/00; B01D46/24; B01D46/2403; B01D46/2407; C; C04; C04B; C04B38/00; C04B38/0006; F; F01; F01N; F01N3/00; F01N3/08; F01N3/10; F01N3/24; F01N3/28; F01N3/2803; F01N3/2825; F01N3/2828; B01D2201/00; B01D2201/46; F01N2330/00; F01N2330/06
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
109 words
A method for producing a ceramic honeycomb filter from a porous ceramic honeycomb body (1) having a plurality of channels (2) extending therethrough from one end face to another end face thereof, characterized in that it comprises the steps of providing each end face of the honeycomb body with a perforated film the perforations in which correspond to given channels opening at the said end faces, and charging a sealing material (4) into the channels through the perforations in the film to seal the end portions of the given channels, and in that given channels, not sealed at one said end face, are sealed at the other end face.
Claim 2
Independent Claim
109 words
A method for producing a ceramic honeycomb filter from a porous ceramic honeycomb body (1) having a plurality of channels (2) extending therethrough from one end face to another end face thereof, characterized in that it comprises the steps of providing each end face of the honeycomb body with a perforated film the perforations in which correspond to given channels opening at the said end faces, and charging a sealing material (4) into the channels through the perforations in the film to seal the end portions of the given channels, and in that given channels, not sealed at one said end face, are sealed at the other end face.
Claim 3
Dependent Claim
48 words
A method as claimed in claim 1, characterized in that an unperforated film is first applied to the end face of the honeycomb body and perforations are formed in the film at the desired locations with the film in situ on the end face of the honeycomb body.
Claim 4
Dependent Claim
29 words
A method as claimed in claim 1, characterized in that a perforated film, having perforations at the desired locations, is applied to the end face of the honeycomb body.
Claim 5
Independent Claim
34 words
A method as claimed in any one of the preceding claims, characterized in that the film is formed of a paper, paper impregnated with a resin or a high molecular weight organic polymer film.
Claim 6
Independent Claim
21 words
A method as claimed in any one of the preceding claims, characterized in that the sealing material is a dilatant material.
Claim 7
Independent Claim
36 words
A method as claimed in any one of the preceding claims, characterized in that the sealing material is obtained by mixing a ceramic material with a binder and a plasticizer, or is an alumina cement mixture.
Claim 8
Dependent Claim
23 words
A method as claimed in claim 6, characterized in that the alumina cement contains not more than 27% by weight of calcium oxide.
Claim 9
Dependent Claim
27 words
A method as claimed in claim 6 or 7, characterized in that the sealing material is a mixture of an alumina cement and one or more aggregates.
Claim 10
Dependent Claim
23 words
A method as claimed in claim 6, characterized in that the binder is a cellulose derivative, a polyhydric alcohol or a mixture thereof.
Claim 11
Independent Claim
29 words
A method as claimed in any one of the preceding claims, characterized in that the sealing material is charged into the channels under pressure, by vibration and/or by dipping.
Claim 12
Independent Claim
61 words
A method as claimed in any one of claims 1-6, 9 and 10, characterized in that the sealing material is a ceramic material and the difference between the coefficient of the thermal expansion of the ceramic honeycomb body, from 40°C to 800°C, and that of the sealing material, from 40°C to 800°C, is not more than 3.5 x 10- 6 /°C.
Claim 13
Dependent Claim
20 words
A method as claimed in claim 11, characterized in that the said difference is not more than 2.5 x 10-s/oC.
Claim 14
Dependent Claim
39 words
A method as claimed in claim 11 or 12, characterized in that the ceramic honeycomb body is made of cordierite or mullite ceramic material, and the said sealing material comprises a cordierite ceramic material or a mullite ceramic material.
Claim 15
Dependent Claim
68 words
A modification of the method claimed in claim 1 in which the perforations in the films correspond to channels which it is not intended to seal, a heat fugitive material capable of being dissipated on firing or heat sealing of the honeycomb is charged into the channels, the films are removed, and the remaining channels, not charged with the heat fugitive material, are sealed with a sealing material.
References Cited (Backward Citations)
No citation records indexed.
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