Abstract: Methods and apparatus for plugging cells of honeycomb structures are disclosed. A first method covers the honeycomb structure's end face with a mask having a body and plurality of sized openings positioned to oppose certain cell channels, wherein the outer edge of the body extends radially outwardly from the end face. A film also extends outwardly of the end face, and a plug of material is provided upon the film. The mask and film material are sealed to one another, and a force is applied to the film forcing the material through the mask and into the cells. Also disclosed is adhering a mask to a first end face of the honeycomb structure such that the mask has an outer portion that extends radially beyond an outer edge of the honeycomb; providing a volume of plugging material; clamping the outer portion between a first clamping portion and a second clamping portion; and transferring the plugging material into the honeycomb.

Abstract: A method of making a plugged honeycomb structure includes providing a honeycomb structure having a first end face and a second end face and an array of cells extending between the first end face and the second end face. The method includes bringing a first mask into contact with the first end face and injecting a plugging medium through the first flexible mask into at least some of the cells at the first end face. The method further includes removing the mask from the first end face, followed by contacting the first end face with a heated first solid body, wherein the plugging medium in the first end face is heated.