Method of making a nonwoven absorbent fabric
View Patent ↗The present invention is directed to a low-linting laminated nonwoven fabric comprised of a reticulated film layer and an associated absorbent layer, which is suitable for medical, hygiene, and industrial applications, wherein said nonwoven fabric performs to absorb liquids, such as human exudates, while significantly reducing the amount of particulates released. The reticulated film of the invention is comprised of a series or network of small, geometrically profiled, depressed areas, wherein the depressed areas of the film are able to collect liquids such as blood, and channel such liquids through openings in the film layer into the associated absorbent layer.
1. A method of making a low-lint laminated nonwoven fabric comprising the steps of:
a. providing an olefin polymer;
b. providing an absorbent layer, comprising a nonwoven fabric;
c. providing a heated first roll having a smooth surface;
d. providing an embossing second roll having an embossed surface comprising a series of raised nubs;
e. extruding said olefin polymer into a continuous thin molten film directly onto said absorbent layer to form a laminate being advanced on said heated first roll wherein said heated first roll is rotating at a first peripheral speed;
f. advancing said laminate with said thin molten film remaining molten and formable when said laminate reaches a nip between said heated first roll and said embossing second roll wherein said embossing second roll is rotating at a second peripheral speed that is from 1 to 20 percent different than said first peripheral speed of said heated first roll for embossing said film side of said laminate wherein said film side comes in contact with said embossing second roll, which is wiped with said raised nubs so as to reticulate said film side of said laminate to form a series or network of geometrically profiled depressed areas, wherein the difference in peripheral speeds of said heated first roll and said embossing second roll creates openings in the film layer in said depressed areas, and wherein the depressed areas of the film are able to collect liquids and channel said liquids through said openings in the film layer into the absorbent layer, to form a laminated fabric.
2. A method of making a laminated fabric as in claim 1 , wherein said embossing second roll is rotating at said second peripheral speed that is from 1 to 20 percent greater than said first peripheral speed of said heated first roll.
3. A method of making a laminated fabric as in claim 1 , wherein said heated first roll has a surface temperature of about 175° F. to about 350° F.
4. A method of making a laminated fabric as in claim 1 , wherein said embossing second roll is cooled.
5. A method of making a laminated fabric as in claim 1 , wherein said embossing second roll comprises a resilient engraved surface in the form of continuous recessed areas surrounding discontinuous raised areas.
6. A method of making a laminated fabric as in claim 1 , further comprising providing said olefin polymer in a mixture with thermoplastic rubber.
7. A method of making a low-lint laminated nonwoven fabric comprising the steps of:
a. providing an olefin polymer;
b. providing an absorbent layer comprising a nonwoven fabric;
c. providing a liquid impermeable backsheet;
d. providing a heated first roll having a smooth surface;
e. providing a an embossing second roll having an embossed surface comprising a series of raised nubs;
f. extruding said olefin polymer into a continuous thin molten film directly onto said absorbent layer;
g. positioning said liquid impermeable backsheet so that said absorbent layer is medial to said thin molten film and said backsheet to form a laminate being advanced on said heated first roll wherein said heated first roll is rotating at a first peripheral speed;
h. advancing said laminate with said thin molten film remaining molten and formable when said laminate reaches a nip between said heated first roll and said embossing second roll wherein said embossing second roll is rotating at a second peripheral speed that is from 1 to 20 percent different than said first peripheral speed of said heated first for embossing said film side of said laminate wherein said film side comes in contact with said embossing second roll, which is wiped with said raised nubs so as to reticulate said film side of said laminate to form a series or network of geometrically profiled depressed areas, wherein the difference in peripheral speeds of said heated first roll and said embossing second roll creates openings in the film layer in said depressed areas, and wherein the depressed areas of the film are able to collect liquids and channel said liquids through said openings in the film layer into the absorbent layer, to form a laminated fabric.
8. A method of making a laminated fabric as in claim 7 , wherein said olefin polymer is selected from the group consisting of isotactic polypropylene, polyethylene, linear low density polyethylene, low density polyethylene, high density polyethylene, amorphous polypropylene, polybutylene, ethylene/vinyl acetate copolymer, ethylene/ethyl acrylate copolymer, ethylene/methyl acrylate copolymer, polystyrene, and the combination thereof.
9. A method of making a laminated fabric as in claim 7 , wherein said laminated fabric is a surgical drape.
10. A method of making a laminated fabric as in claim 7 , wherein said laminated fabric is a feminine hygiene product component.
11. A method of making a laminated fabric as in claim 7 , wherein said embossing second roll is rotating at said second peripheral speed that is from 1 to 20 percent greater than said first peripheral speed of said heated first roll.
12. A method of making a laminated fabric as in claim 7 , wherein said heated first roll has a surface temperature of about 175° F. to about 350° F.
13. A method of making a laminated fabric as in claim 7 , wherein said embossing second roll is cooled.
14. A method of making a laminated fabric as in claim 7 , wherein said embossing second roll comprises a resilient engraved surface in the form of continuous recessed areas surrounding discontinuous raised areas.
15. A method of making a laminated fabric as in claim 7 , further comprising providing said olefin polymer in a mixture with thermoplastic rubber.