Patent ID: 8679218

Claim:
A filter media comprising: a first layer comprising: a first phase including a first plurality of fibers and a second plurality of fibers different from the first plurality of fibers; and a second phase including a third plurality of fibers and a fourth plurality of fibers different from the third plurality of fibers, the third plurality of fibers being the same as or different from the first or second plurality of fibers and the fourth plurality of fibers being the same as or different from the first or second plurality of fibers, wherein the air permeability of the first plurality of fibers is greater than the air permeability of the second plurality of fibers, wherein the air permeability of the third plurality of fibers is greater than the air permeability of the fourth plurality of fibers, wherein the first or third pluralities of fibers are made from an organic polymeric material and have an average fiber length from about 1.5 mm to about 6 mm, wherein the first layer has a mean flow pore size of between about 30 microns and 400 microns; and a second layer attached to the first layer, wherein the second layer is a nanofiber layer.