Title:
ELECTRET FILTR
Document Type and Number:
Japanese Patent JP3166866
Kind Code:
B2
Abstract:
PURPOSE: To provide filtering properties such as low pressure loss and high particle removing efficiency by making main fibers which compose a filter have superfine pores from the surface of the fibers to the inner parts and specifying the BET surface area.
CONSTITUTION: An electret filter is composed of electret fibers consisting of main fibers which compose the filter and have superfine pores from the surface of the fibers to the inner parts and at least 20m2/g BET surface area. The superfine pores are holes and cracks with about several nm to some thousands nm and which are within a range visible by an optical microscope or an electron microscope distributed from the fibrous surface to the inner parts. The holes and the side walls of the cracks are made to become electrets as same as the surfaces of the fibers. When the fibers having the supperfine pores are made to become electrets, not only the surface electrified density is hightened partly but also the total surface area of the fibers is increased remarkably as compared with conventional fibers having no superfine pore, so that particle removing efficiency is increased greatly.
Inventors:
Yahiro Tani
Satoshi Takase
Satoshi Takase
Application Number:
JP19095691A
Publication Date:
May 14, 2001
Filing Date:
July 04, 1991
Export Citation:
Assignee:
TOYO BOSEKI KABUSHIKI KAISHA
International Classes:
B01D39/14; B01D39/16; (IPC1-7): B01D39/14
Domestic Patent References:
| JP1194912A | ||||
| JP2241509A | ||||
| JP55134621A | ||||
| JP62277119A | ||||
| JP3249911A | ||||
| JP61174915A | ||||
| JP57711A | ||||
| JP188716U | ||||
| JP5647299B2 |