Method of making wall-flow monolith filter
US6840976B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2002 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | Jul 6, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/48
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A ceramic honeycomb wall-flow filter is prepared by plugging channels in a clay containing ceramic honeycomb by a method that has the following steps. First, a mixture of a dispersing liquid and ceramic powder is formed. Second, the mixture is inserted into at least one channel of a clay containing green ceramic honeycomb to form a plugged green ceramic honeycomb wherein the dispersing liquid essentially fails to swell the clay. Alternatively, the mixture is inserted into a calcined ceramic honeycomb to form a plugged calcined ceramic honeycomb. Finally, the plugged green or calcined ceramic honeycomb is heated to a temperature sufficient to sinter the plugged green ceramic honeycomb to form a porous sintered plugged ceramic honeycomb. The method is particularly useful for simultaneously making the plugs and discriminating layers in the channels. In particular the method is useful to make wall-flow filters having plugs on at least one end with same composition as the discriminating layer or plugs on each end having different compositions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.