摘要 |
The air filter unit has a pleated filter medium with a zigzag shape in which a fibrous filter medium has been folded multiple times. The coefficients of linear expansion of the separators (space-supporting members) provided in each of the multiple folded spaces of the pleated filter medium are equal to or greater than the coefficient of linear expansion of the metal filter frame of the filter unit. Moreover, among said separators, the coefficient of linear expansion of each of separators that are provided at the side regions, which comprise the two side sections located at the outermost ends of the pleated filter medium in a second direction that is orthogonal to the direction of folding of the pleated filter medium (the first direction), is smaller than the coefficient of linear expansion of a separators provided in the central region that is flanked by the side regions. |