| 摘要 |
PROBLEM TO BE SOLVED: To provide a mask filter unit which can realize both suppression of pressure loss and improvement of filtering efficiency, at low costs.SOLUTION: A filter unit 100 comprises a charged filter having an inflow surface into which air flows, an outflow surface from which air flows out, and a lateral surface which extends from the inflow surface to the outflow surface. The charged filter comprises a first layer and a second layer. The first layer is provided with a base 11 and a plurality of solid protrusions 20 which extends from a surface of the base and is adjacent to the second layer, the protrusions having a stem portion including a root-side lateral surface and a tip-side lateral surface. A first angle which is one of the angle formed between the root-side lateral surface of the stem portion and the base of the first layer and the angle formed between the tip-side lateral surface of the stem portion and the base of the second layer, is 90° or more and less than 180°, and a second angle which is the other of the angles is 45° or more and less than 180°.SELECTED DRAWING: Figure 15 |
