초록 ▼

Enhanced performance fibrous media (60) is provided by orienting filter media fibers (62) dominantly parallel to the fluid flow direction (46). Filter media construction is provided by a sheet (80) having an internal pleated subsheet (88) with pleats (92, 94) engaging and packed against each other s

Enhanced performance fibrous media (60) is provided by orienting filter media fibers (62) dominantly parallel to the fluid flow direction (46). Filter media construction is provided by a sheet (80) having an internal pleated subsheet (88) with pleats (92, 94) engaging and packed against each other sufficiently tightly and bonded (104) such that fluid flows along the flow direction through the pleats in parallel therewith, rather than between the pleats and then transversely therethrough. An extended life two-stage fluid filter assembly includes first and second filter elements (80 and 112), wherein the pleats (114, 116) of a main downstream filter element (112) are spaced from each other along a spacing direction (122) transverse to the flow direction (46) and defining a transverse gap (124) therebetween through which fluid flows, and wherein the pleats (92, 94) of an upstream prefilter element (80) are packed against each other without such transverse gap and blocking fluid flow therebetween.

대표청구항 ▼

1. Filter media construction comprising a sheet of filter material having a thickness dimension between oppositely facing first and second sides for filtering particles in fluid flow therethrough along a flow direction perpendicular to said sheet and said first and second sides and parallel to said

1. Filter media construction comprising a sheet of filter material having a thickness dimension between oppositely facing first and second sides for filtering particles in fluid flow therethrough along a flow direction perpendicular to said sheet and said first and second sides and parallel to said thickness dimension, said sheet being formed by an internal pleated subsheet comprising a plurality of fibers and having a plurality of pleats extending between first and second sets of pleat tips, said pleats extending parallel to said flow direction, said first set, of pleat tips providing said first side of said sheet, said second set of pleat tips providing said second side of said sheet, said pleats engaging each other sufficiently tightly such that fluid flows along said flow direction through said pleats in parallel therewith, rather than between said pleats and then transversely therethrough, said subsheet having a prepleated planar condition with said fibers extending dominantly parallel thereto and dominantly unidirectionally parallel to each other, said subsheet having a pleated condition forming said sheet wherein said fibers extend along said pleats substantially parallel to said flow direction, and said fibers extend around said pleat tips substantially parallel to each respective side of said sheet and substantially perpendicular to said flow direction, and wherein said pleats are bonded to each other with bonding material to prevent flow of fluid therebetween along said flow direction parallel to said pleats, said bonding of said pleats to each other enhancing compression resistance of said sheet along said thickness dimension and eliminating needle holes associated with needling.