Patent ID: 6974490

Claim:
A filter element arrangement comprising: (a) a media pack including a corrugated substrate secured to a non-corrugated substrate; each substrate being selected from media comprising natural fibers and media comprising a mixture at natural and synthetic fibers; each substrate having a filter efficiency measured under ATSM 1215-89 with 0.78μ monodispersed polystyrene spherical particles, at 20 fpm, and a basis weight of less than about 200 grams-m −2 , said substrates forming a plurality of flutes in said media pack; wherein: (i) selected ones of said flutes are open at a first end portion and closed at a second end portion; and selected ones of said flutes being closed at a first end portion and open at a second end portion; and (ii) said substrates each comprising at least one surface that is at least partially covered by a layer comprising a line fiber layer having a basis of weight of about 0.01 to 240 micrograms-cm −2 , the fine fiber comprising a polymer selected from the group consisting or: (A) nylon 66, the fine fiber having a fiber size of about 0.01 to 0.5 micron; (B) a blend of a hydrophobic additive and a polymer comprising a blend of at least two different nylon polymers, the fine fiber having a fiber size of about 0.01 to 0.5 micron; (C) a blend of a hydrophobic additive and a nylon polymer comprising a nylon other than a copolymer formed from a cyclic lactam and a C 6-10 diamine monomer or a C 6-10 diacid monomer, the fine fiber having a fiber size of about 0.01 to 0.5 micron; or (D) mixtures thereof; (c) a seal system secured to an outside of the media pack, for sealing the filter arrangement in place, during use.