Microporous laminate with pin-hole free areas
AssigneeClopay Plastic Products Company, Inc.
InventorThomas G. Mushaben
Life of this patent
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Abstract
The method and apparatus of the present invention prevents the formation of pin-holes during stretching of strip laminates in the cross machine direction. Pin-holes are prevented by creating slack areas along the length of the web where the edges of the non-woven strips meet with the polymer film, pressing the slack areas into the interdigital stretching rollers without stretching the slack areas, and stretching the remainder of the web in a typical manner. The slack regions are formed prior to interdigitation by, for example, formation of a furrow, a fold or a corrugation.
Claims16
A laminate of non-woven fibrous web and microporous polymer film comprising:
- a microporous polymer film;
- and
- at least one strip of a non-woven fibrous web having opposite edges, the strip laminated to the film to form a laminated area along the length of the film and unlaminated film areas along the opposite edges, each of said opposite strip edges defining a boundary area between the laminated area and the unlaminated areas;
- wherein each boundary area is substantially unstretched and the laminated area and the unlaminated areas are interdigitally stretched such that each boundary area is substantially pinhole free.
A microporous laminate sheet of a polymer film layer and a non-woven fibrous web comprising:
- a microporous polymer film layer;
- and
- at least one non-woven fibrous web having opposite edges laminated to the microporous polymer film layer forming a laminated area and an unlaminated area of the polymer film layer and having boundary areas at the edges of the laminated non-woven fibrous web;
- wherein the laminated area and the unlaminated polymer film area are interdigitally stretched and the boundary areas are substantially unstretched such that the boundary areas are substantially pinhole free.
Dependencies are inferred from the claim text.