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US 6,319,452 B1Granted
Method of making electret fibers that have low level of extractable hydrocarbon material
Assignee3M Innovative Properties Company
InventorsAlan D. Rousseau, Joel W. Miller
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Abstract
A method of making electret fibers, which method comprises the steps of: blending a polymeric material with a fluorochemical additive compound; extruding the blend at a temperature maintained below 290° C. to form extruded fibers; and annealing and charging the extruded fibers; wherein the polymeric material and extrusion conditions are selected such that the resulting fibers have a level of extractable hydrocarbon material that is less than about 3.0 weight percent based on the weight of the fibers.
Claims12
A method of making electret fibers, which method comprises the steps of:
- blending a polymeric material with a fluorochemical additive compound;
- extruding the blend at a temperature maintained below 290° C. to form extruded fibers;
- and
- annealing and charging the extruded fibers;
- wherein the polymeric material and extrusion conditions are selected such that the resulting fibers have a level of extractable hydrocarbon material that is less than about 3.0 weight percent based on the weight of the fibers.
2 more elements
Dependencies are inferred from the claim text.