Method of producing filter for air cleaner

摘要

A filter for an air cleaner is produced by impregnating a fiber web composed of one or more layers with a liquid binder in the form of solution, suspension, or emulsion. The impregnated fiber web is dried such that the solvent or dispersing medium on one side evaporates faster then that on the other side. As the result, more binder is deposited on one side than on the other side; in other words, a gradient of binder distribution is formed. The thus-produced filter has such a structure that the voids among fibers continuously change across the thickness, while fibers are bonded together by the binder. The filter thus produced can collect more dust than a conventional one.