The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 24, 1991
Filed:
Jul. 19, 1990
Ryoichi Togashi, Shiga, JP;
Katsutoshi Ando, Otsu, JP;
Toray Industries, Inc., Tokyo, JP;
Abstract
A process apparatus for producing a non-woven, especially a non-woven electret, fiber sheet provides for directing the non-woven fibers at a collecting surface and into an electric field between at least one electrode and the collecting surface. This process, in which the fibers are collected in the electric field, enables the economical production of a non-woven electret fiber sheet of single layer structure having large amount of polarized charges (giving a total electric charge per unit area of at least 7.times.10.sup.-11 Coulomb/cm.sup.2), and a weight of at least 60 g/m.sup.2, preferably greater than 80 g/cm.sup.2. The non-woven electret sheet may have the large amount of electret charge throughout its thickness and/or a uniform weight distribution and thus have excellent dust collecting properties.