Method of making post-bonded grooved elastic materials
An elastic nonwoven laminate that contains an elastic film laminated to one or more nonwoven facings is provided. The nonwoven facing contains a conventional polyolefin and can also contain a polyolefin-based plastomer. The laminate is activated by grooving to decouple the nonwoven facing from the elastic film. To reduce fiber-pull out that can result due to activation by grooving, the laminate can be post-bonded at room or elevated temperatures and a specific range of pressures to compact the fibers of the facing and minimize fiber pull-out/fuzziness while not sacrificing the softness, elasticity, and feel of the laminate.
1. A method of forming an elastic nonwoven laminate having a machine direction and a cross machine direction, the method comprising:
joining an elastic film with a first nonwoven facing to form a laminate, wherein the first nonwoven facing comprises a first polyolefin, further wherein the first nonwoven facing is meltblown or spunbond, further wherein the elastic film is in an unstretched state;
feeding the laminate through a first nip formed by a first roll and a second roll, wherein at least one of the rolls defines grooves, and wherein the laminate is fed in between the two rolls with sufficient nip pressure to groove the first nonwoven facing, wherein the grooving decouples the first nonwoven facing from the elastic film in the machine direction or the cross-machine direction; and
feeding the laminate through a second nip formed by bond rolls at a bonding station to bond least an outer surface of the first nonwoven facing, wherein the bonding occurs at a temperature ranging from about 65° F. to about 300° F. and at a pressure ranging from about 5 psi to about 100 psi.
2. The method of claim 1 , wherein the first polyolefin comprises polyethylene, polypropylene, or a combination thereof.
3. The method of claim 1 , wherein the first nonwoven facing further comprises a second polyolefin, wherein the second polyolefin comprises an elastomeric semi-crystalline polyolefin.
4. The method of claim 3 , wherein the elastomeric semi-crystalline polyolefin is an ethylene/α-olefin copolymer, propylene/α-olefin copolymer, or a combination thereof.
5. The method of claim 1 , wherein the at least one of the bond rolls is patterned.
6. The method of claim 5 , wherein the pattern covers from 10% to about 60% of the total surface area of the first nonwoven facing.
7. The method of claim 1 , wherein the elastic film is disposed between the first nonwoven facing and a second nonwoven facing.
8. The method of claim 1 , wherein the elastic nonwoven laminate is grooved in the machine direction to provide cross-machine direction stretch to the elastic nonwoven laminate.
9. The method of claim 1 , wherein a tab attached to the first nonwoven facing can be elongated from about 50% to about 200% before becoming disengaged from the first nonwoven facing.
10. The method of claim 1 , wherein the elastic nonwoven laminate has a percent elongation of at least about 200% in the cross machine direction.
11. The method of claim 1 , wherein the elastic film comprises a core layer disposed between two skin layers, wherein the core layer is an elastic layer comprising a styrenic block copolymer, an ethylene/α-olefin copolymer, a propylene/α-olefin copolymer, or a combination thereof.
12. The method of claim 1 , wherein the elastic film is disposed between the first nonwoven facing and a second nonwoven facing, wherein the first nonwoven facing and the second nonwoven facing are meltblown, wherein the elastic film comprises a core layer disposed between two skin layers, wherein the core layer is a strength layer and the two skin layers are elastic layers.