METHOD FOR COATING A WALL FLOW FILTER WITH A COATING COMPOSITION

摘要

Wall flow filters can be provided with a catalytically active coating in a reproducible manner by depositing a defined quantity of a coating composition and sucking said coating composition through the openings of the inlet channels into the filter body. The aspiration of the coating composition is carried out by applying a depression to the openings of the outlet channels of the wall flow filters. According to the type of coating composition (slurry of fine-particle solids, colloidal solution or solution of soluble precursors of catalytically active constituents), a different ratio between the coating quantities on the inner surfaces (pore surfaces) and outer surfaces (geometrical surfaces of the channel walls) is obtained.