| 摘要 |
PURPOSE:To obtain an electret nonwoven fabric having a large amount of static electrification and excellent stability by controlling an absolute water content in the atmosphere around a corona generator >= a specific value in forming nonwoven fabric of electret. CONSTITUTION:In forming nonwoven fabric of electret from nonwoven fabric comprising an olefinic polymer such as preferably polypropylene or alpha-polyolefin by using an electrically positive corona ion, an absolute water content around a corona generator is controlled >=0.006 (steam kg/dry gas), generation of positive corona ion is greatly increased and treatment of electret formation is carried out to give nonwoven fabric of electret having a large amount of static electrification which has not been obtained by conventional electret formation technology, extremely excellent stability of electret and is capable of splendidly removing fine particles in air. |
