Methods of saturating nonwoven fabrics with liquid and the making of electret thereof
AssigneeUniversity of Tennessee Research Foundation
InventorPeter Ping-Yi Tsai
Life of this patent
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Abstract
A method of preparing an electret by saturating a nonwoven fabric with a liquid, such as water, and removing the liquid via suction to generate charges by friction between the fabric fibers and the liquid is described. The saturating can be carried out, for example, by impinging the bottom side of the fabric with a jet or jets of water while the fabric is being pulled under a solid roller. Excess water can also be applied during a water quenching step of a meltblowing or spunbonding process. An apparatus for preparing an electret according to the presently disclosed methods is also described.
Claims10
A method of making an electret, the method comprising:
- (a) providing a sheet comprising a nonwoven web of thermoplastic fibers;
- (b) passing the sheet under a solid roller wherein the top surface of the sheet is in contact with the solid roller while simultaneously impinging the bottom surface of the sheet with one or more jets of water, thereby saturating the sheet with water to provide a saturated sheet;
- and
- (c) transporting the saturated sheet away from the solid roller and the one or more jets of water to a position over an opening of a vacuum chamber and removing the water from the saturated sheet via suction to provide a charge, thereby providing an electret.
Dependencies are inferred from the claim text.