Abstract: A method and system for manufacturing a mask for plugging cells in a honeycomb substrate includes capturing an image of the substrate's end through an end-adhered transparent or translucent film using a camera, forming openings using a laser, wherein a working distance, WDC, of the camera while capturing the image is substantially the same as a working distance, WDL, of the laser while forming the openings. Also disclosed is an apparatus for manufacturing a mask on a honeycomb substrate, having a laser to form openings in a film applied to the substrate's end; and an optical system, wherein either the optical system or the substrate is moveable between first and second operating positions. In a first embodiment, the camera moves whereas in the second, the substrate moves. In each embodiment, the image is obtained without obstructing the path of the laser.

Abstract: A mask for plugging cells in a monolith body includes a planar sheet having a cell mask region bordered by a skin mask region. The cell mask region includes a plurality of openings through which a filler material can be injected into selected cells in the monolith body. The planar sheet has a size such that when it is mounted on an end face of the monolith body, the cell mask region overlaps the cells in the end face of the monolith body and the skin mask region extends laterally past a periphery of the monolith body.