Multilayer nonwoven laminiferous structure
First Claim
1. A nonwoven laminiferous structure having at least two melt-extended nonwoven layers which comprises:
- (A) a first layer which comprises at least a portion of a first nonwoven web; and
(B) a second layer adjacent to said first layer which comprises at least a portion of a second nonwoven web;
in which,(1) the boundary between any two adjacent melt-extruded nonwoven layers is distinct in that fibers at or near the surfaces of such adjacent layers are not significantly intermingled;
(2) the fibers of at least one of said first and second layers are prepared by melt extrusion through a die at a shear rate of from about 50 to about 30,000 sec-1 and a throughput of no more than about 5.4 kg/cm/hour of a mixture of an additive and a thermoplastic polymer, which additive (a) is present at a level of from about 0.05 to about 15 percent by weight, based on the amount of thermoplastic polymer, and (b) imparts to the surfaces of said fibers, as a consequence of the preferential migration of said additive to the surfaces of said fibers as they are formed, at least one characteristic which is different from the surface characteristics of fibers prepared from said thermoplastic polymer alone, said preferential migration taking place spontaneously upon the formation of said fibers without the need for a post-formation treatment of any kind;
(3) the additive present in any melt-extruded nonwoven layer does not migrate to an adjacent layer to a significant degree in use, so that the surface characteristics of each layer remain substantially as originally prepared;
(4) said thermoplastic polymer is selected from the group consisting of polyolefins, polyesters, polyetheresters, and polyamides; and
(5) said laminiferous structure has been pattern bonded by the application of heat and pressure.
2 Assignments
0 Petitions
Accused Products
Abstract
A nonwoven laminiferous structure is provided which has at least two melt-extruded nonwoven layers:
(A) a first layer which includes at least a portion of a first nonwoven web; and
(B) a second layer adjacent to said first layer which includes at least a portion of a second nonwoven web; in which,
(1) the boundary between any two adjacent melt-extruded nonwoven layers is distinct in that fibers at or near the surfaces of such adjacent layer are not significantly intermingled;
(2) the fibers of at least one of such first and second layers are prepared by melt extrusion through a die at a shear rate of from about 50 to about 30,000 sec-1 and a throughput of no more than about 5.4 kg/cm/hour of a mixture of an additive and a thermoplastic polymer, which additive (a) is present at a level of from about 0.05 to about 15 percent by weight, based on the amount of thermoplastic polymer, and (b) imparts to the surfaces of the fibers, as a consequence of the preferential migration of the additive to the surfaces of the fibers as they are formed, at least one characteristic which is different from the surface characteristics of fibers prepared from the thermoplastic polymer alone, said preferential migration taking place spontaneously upon the formation of the fibers without the need for a post-formation treatment of any kind;
(3) the additive present in any melt-extruded nonwoven layer does not migrate to an adjacent layer to a significant degree in use, so that the surface characteristics of each layer remain substantially as originally prepared;
(4) the thermoplastic polymer is elected from the group consisting of polyolefins, polyesters, polyetheresters, and polyamides; and
(5) the laminiferous structure has been pattern bonded by the application of heat and pressure.
270 Citations
21 Claims
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1. A nonwoven laminiferous structure having at least two melt-extended nonwoven layers which comprises:
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(A) a first layer which comprises at least a portion of a first nonwoven web; and (B) a second layer adjacent to said first layer which comprises at least a portion of a second nonwoven web;
in which,(1) the boundary between any two adjacent melt-extruded nonwoven layers is distinct in that fibers at or near the surfaces of such adjacent layers are not significantly intermingled; (2) the fibers of at least one of said first and second layers are prepared by melt extrusion through a die at a shear rate of from about 50 to about 30,000 sec-1 and a throughput of no more than about 5.4 kg/cm/hour of a mixture of an additive and a thermoplastic polymer, which additive (a) is present at a level of from about 0.05 to about 15 percent by weight, based on the amount of thermoplastic polymer, and (b) imparts to the surfaces of said fibers, as a consequence of the preferential migration of said additive to the surfaces of said fibers as they are formed, at least one characteristic which is different from the surface characteristics of fibers prepared from said thermoplastic polymer alone, said preferential migration taking place spontaneously upon the formation of said fibers without the need for a post-formation treatment of any kind; (3) the additive present in any melt-extruded nonwoven layer does not migrate to an adjacent layer to a significant degree in use, so that the surface characteristics of each layer remain substantially as originally prepared; (4) said thermoplastic polymer is selected from the group consisting of polyolefins, polyesters, polyetheresters, and polyamides; and (5) said laminiferous structure has been pattern bonded by the application of heat and pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 19, 20, 21)
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12. A method of preparing a nonwoven laminiferous structure having at least two melt-extruded nonwoven layers adjacent to each other in which each melt-extruded nonwoven layer comprises at least a portion of a nonwoven web and the boundary between any two adjacent melt-extruded nonwoven layers is distinct in that fibers at or near the surfaces of such adjacent layers are not significantly intermingled, which method comprises the steps of:
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(A) separately preparing two or more nonwoven webs; (B) bringing all of the resulting separately prepared nonwoven webs together in a desired configuration; and (C) pattern bonding the resulting nonwoven laminiferous structure by the application of heat and pressure;
in which(1) the fibers of at least one melt-extruded nonwoven layer are prepared by melt extrusion through a die at a shear rate of from about 50 to about 30,000 sec-1 and a throughput of no more than about 5.4 kg/cm/hour of a mixture of an additive and a thermoplastic polymer, which additive (a) is present at a level of from about 0.05 to about 15 percent by weight, based on the amount of thermoplastic polymer, and (b) imparts to the surfaces of said fibers, as a consequence of the preferential migration of said additive to the surfaces of said fibers as they are formed, at least one characteristic which is different from the surface characteristics of fibers prepared from said thermoplastic polymer alone, said preferential migration taking place spontaneously upon the formation of said fibers without the need for a post-formation treatment of any kind; (2) said thermoplastic polymer is selected from the group consisting of polyolefins, polyesters, polyetheresters, and polyamides; and (3) the additive present in any melt-extruded nonwoven layer does not migrate to an adjacent layer to a significant degree in use, so that the surface characteristics of each layer remain substantially as originally prepared. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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Specification