LOW-RESISTANCE FILTER MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a low-resistance filter material whose ventilation resistance is low, initial cleaning efficiency is high, dust holding amount is large, filtering performance is good, and which is especially favorable for an engine filter for a vehicle. SOLUTION: The filter material has a three-layer structure of a rough layer 1, a middle layer 2 and a tight layer 3 comprising a polyester staple fiber and having a density gradient. The three layer structure body is needle processed in which the average fineness of each layer is 4.5 to 8.0 decitex (dtex) for the rough layer 1, 1.6 to 3.0 dtex for the middle layer, and 1.36 to 1.41 dtex for the tight layer; and it comprises a laminate body integrally bonded by binder processing. The rough layer part of the laminate body at least includes a hollow fiber in the constituent fiber, and the binder resin content for binder-imparting tight layer part gross weight is 10 to 20 wt.% in the tight layer part. The filter material has the characteristics in which the initial ventilation resistance is≤45 Pa and the initial cleaning efficiency is≥98% where the layer basis weight of the laminate body is 180 to 240 g/m2, and the thickness is 3.0 to 4.5 mm. COPYRIGHT: (C)2010,JPO&INPIT