Product and method of forming succesive layers of face-to-face adjacent media with calculated pore size

摘要

A filter media product and method of making the same wherein at least two independent filter media thicknesses of differing coarse and fine pore sizes are held in face-to-face relationship with the pore sizes being so calculated that the overall average pore size of successive thicknesses is smaller than the pore size of the finest fiber thickness.