Method for manufacturing a filter of electrically charged electret fiber material and electret filters obtained according to said method
AssigneeMinnesota Mining and Manufacturing Company
InventorsJan van Turnhout, Johannes C. Rieke
Life of this patent
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Abstract
A method for forming a filter of electrically charged electret fiber material, consisting of a high molecular weight, nonpolar polymeric substance, comprising drawing, charging, and fibrillating a foil of said high molecular weight substance. The fibrillated foil is wound and then crimping is effected.
Claims10
A method for manufacturing a filter of electrically charged electret fiber material, consisting of a high-molecular weight, non-polar polymeric substance, comprising the steps of:
- continuously supplying a foil of said substance, drawing, charging and fibrillating of the foil and the processing of the thus obtained filter material into a filter, selecting the foil and/or the type of drawing to manufacture spontaneously crimpable fiber material, winding said material in uncrimped condition to a fibrous package and subsequently effecting crimping to interlock the fibers of said fibrous package.
An electret fibrous web comprising fibers fibrillated from a film of a high-molecular-weight nonpolar substance and which contain electric charges embedded therein so as to enhance filtration properties of the web, said fibers being crimped after fibrillation and intermeshed with one another, said fibrous web being capable of being loaded with high amounts of dust while still maintaining high filtration efficiency.
Dependencies are inferred from the claim text.