| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a filter material which improves reduction of dust holding characteristics of a pleat filter in a bonded filter material with a melt-blow unwoven fabric without sacrificing pressure loss and collection efficiency, and exhibits high productivity.SOLUTION: An electret filter material has a filter material having a layer structure in which at least a melt-blow unwoven fabric of polypropylene and a support layer are bonded, and the melt-blow unwoven fabric includes 150-500 small pores per square inch with a hole diameter of 1.0 mm or less. The electret filter material is used as a pleat filter to improve dust holding characteristics of the pleat filter without sacrificing pressure loss and collection efficiency.</p> |
