CD extensible nonwoven composite
A nonwoven composite that has a dimension in a machine direction and a cross-machine direction is provided. The composite comprises a nonwoven facing positioned adjacent to an elastic film. The nonwoven facing contains a spunbond web that is formed by necking a base spunbond web. The base spunbond web includes a plurality of fibers generally oriented in the machine direction and exhibiting a machine direction tensile strength and cross-machine direction tensile strength. The ratio of the machine direction tensile strength to the cross-machine direction tensile strength is about 4:1 or more.
1. A method for forming a nonwoven facing having a dimension in a machine direction and cross-machine direction, the method comprising necking a base spunbond web so that a dimension of the web is reduced in the cross-machine direction, wherein the base spunbond web has a machine direction tensile strength and cross-machine direction tensile strength, the ratio of the machine direction tensile strength to the cross-machine direction tensile strength being 4:1 or more.
2. The method of claim 1 , wherein the base spunbond web contains a plurality of fibers that are generally oriented in the machine direction.
3. The method of claim 1 , wherein the base spunbond web has a machine direction tensile strength of 400 grams-force per inch (157.48 grams-force per centimeter) or more.
4. The method of claim 1 , wherein the base spunbond web has a percent necking of 50% or more.
5. A method for forming a composite that has a dimension in a machine direction and cross-machine direction, the method comprising:
necking a base spunbond web so that a dimension of the web is reduced in the cross-machine direction, wherein the base spunbond web has a machine direction tensile strength and cross-machine direction tensile strength, the ratio of the machine direction tensile strength to the cross-machine direction tensile strength being 4:1 or more; and
laminating an elastic film to the necked spunbond web.
6. The method of claim 1 , wherein the base spunbond web exhibits a load loss of 60% of less in the cross-machine direction.
7. The method of claim 2 , wherein the plurality of fibers comprise a polymer composition that includes a ductile polymer having a modulus of elasticity of 800 MPa or less as determined in accordance with ASTM D638-10, and optionally a fatty acid derivative.
8. The method of claim 7 , wherein the plurality of fibers are bicomponent fibers containing a low modulus component that includes the ductile polymer.
9. The method of claim 7 , wherein the plurality of fibers comprise monocomponent fibers.
10. The method of claim 7 , wherein the ductile polymer is an ethylene polymer.
11. The method of claim 7 , wherein the ductile polymer is a copolymer of propylene and an α-olefin.
12. The method of claim 7 , wherein the polymer composition further contains a propylene homopolymer having a modulus of elasticity of from 800 MPa to 4,000 MPa as determined in accordance with ASTM D638-10.
13. The method of claim 2 , comprising bonding the fibers together at multiple bond regions, wherein at least a portion of the bond regions are generally oriented in the machine direction.
14. The method of claim 13 , wherein at least a portion of the bond regions have an aspect ratio of from 2 to 100.
15. The method of claim 5 , wherein the base spunbond web contains a plurality of fibers that are generally oriented in the machine direction.
16. The method of claim 5 , wherein the base spunbond web has a machine direction tensile strength of 400 grams-force per inch (157.48 grams-force per centimeter) or more.
17. The method of claim 5 , wherein the base spunbond web has a percent necking of 50% or more.
18. The method of claim 5 , wherein the elastic film is bonded to the base spunbond web at multiple bond regions, wherein at least a portion of the bond regions are generally oriented in the machine direction.
19. The method of claim 18 , wherein at least a portion of the bond regions have an aspect ratio of from 2 to 100.
20. The method of claim 15 , wherein the plurality of fibers comprise a polymer composition that includes a ductile polymer having a modulus of elasticity of 800 MPa or less as determined in accordance with ASTM D638-10, and optionally a fatty acid derivative.