| 摘要 |
PURPOSE:To reduce pressure drop without lowering a filter function by making individual cell of a cell structure constituting a foam filter long, and also making the ratio of an average long diameter and an average short diameter of the cell to be a specific value. CONSTITUTION:For instance, the opposing ends of bulks of a polyurethane foam wherein a foam film is removed to provide communicating foams are stretched, fixed to and stretched by a jig, and then put in a warm air dryer while being maintained in a stretched state. After the whole is heated up uniformly, the same is restored to normal temperature, an organic foam filter is obtained, which is a multifaced, almost elliptic body of a cell structure with a skeleton 22 of three-dimensional network having an inner communicated space 24 and with a long single cell 20, and having the ratio b/a of at least 1.5 between the average long diameter (b) and the average short diameter (a) of the cell. |
