| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a formation method of an air filter medium folded zigzag, dispensing with insertion of a reinforcement member or a resin such as a separator between folding crests of the filter medium.SOLUTION: Concerning an air filter medium 3, when the planar air filter medium 3 is folded zigzag, a folding crest of the filter medium is formed in a web shape, and the folded air filter medium 3 is formed, or a V-shape is formed so that a center line of the air filter medium 3 is projected.</p> |
