Method and apparatus for providing powder into fibrous web structures

摘要

A method and apparatus for incorporating a powder into a continuous fibrous web containing multiple corrugations. In the method, a fibrous web provided with multiple parallel corrugations is continuously passed over a curved surface having an arc with a radius to web thickness ratio of 0.5-3 and the corrugations are opened at their upper side, while any bonded fibers connecting adjacent corrugations together are broken apart. A powder having 50-1000 micron particle size is deposited by gravity into the opened spaces between adjacent corrugations of the web. The deposited powder is then compacted into the fibrous corrugated web by rubbing with a pad moved in an oscillating motion generally perpendicular to the corrugations. The powder filled web is bent in the opposite direction around a roller to break the fibers between the corrugations on the opposite side of the web. The second roller can be made vertically movable so as to convert the web continuous forward motion to an intermittent forward motion.