| 摘要 |
<p>PURPOSE:To prevent the damage to a filter material while extending the clogging life thereof by holding an electret low density nonwoven fabric between the pleated filtering surfaces formed by folding back the filter material of an air filter to use the same as a shape retaining member also used as an auxiliary filter material. CONSTITUTION:This air filter 1 is constituted by holding a low density nonwoven fabric 2 between the respective filtering surfaces 12 of a filter material 11 composed of filter paper as a shape retaining material. Since the shape retaining material is fibrous, no abrasion or damage is applied to the filter material 11. The nonwoven fabric 2 catches coarse dust because of low density and low resistance increase. Since the nonwoven fabric 2 is made to be an electret, it also catches fine dust. Thus, the air filter is enhanced in durability and extended in clogging life.</p> |
