Method of making a web from which elastic diaper closures can be stamped
Elastically stretchable diaper closure elements that each comprise an inelastic and reinforced attachment region for securing a closure component and an adjacent elastic stretch region can be punched from a textile web. A plurality of pairs of elastic film strips of an elastically stretchable polymer are inserted between two cover layers of nonwoven with the film strips parallel and spaced laterally from one another. Between each pair of elastic film strips a strip of a reinforcement film is inserted that has a support layer and an outer layer of polyethylene on at least one side between the cover layers with each reinforcement-film strip overlapping each of the respective elastic film strips at a respective overlap region. The reinforcement-film strips are bonded to the elastic film strips in the overlap regions, and the nonwoven cover layers are bonded to the reinforcement film strips by ultrasonic or thermal welding.
1. A method of making a textile web from which can be punched elastically stretchable diaper closure elements that each comprise an inelastic and reinforced attachment region for securing a closure component and an adjacent elastic stretch region, the method comprising:
inserting a plurality of pairs of elastic film strips of an elastically stretchable polymer between two cover layers of nonwoven with the film strips parallel and spaced laterally from one another;
inserting between each pair of elastic film strips a strip of a reinforcement film that has a support layer and an outer layer of polyethylene on at least one side between the cover layers with each reinforcement-film strip overlapping each of the respective elastic film strips at a respective overlap region;
bonding the reinforcement-film strips to the elastic film strips in the overlap regions; and
bonding the nonwoven cover layers to the reinforcement film strips by ultrasonic or thermal welding, the cover layer bonded to the outer polyethylene layer of the reinforcement film is itself composed of bicomponent fibers that have a fiber core of polypropylene and a fiber sheath of polyethylene, the support layer of the reinforcement film being composed of a polymer that has a higher melting point than the polyethylene of the outer layer.
2. The method defined in claim 1 , wherein the support layer is composed of a polypropylene.
3. The method defined in claim 2 wherein the polypropylene is polypropylene homopolymer, cycloolefin copolymer, styrene polymer, polyamide, polyactide, thermoplastic polyurethane, or blends thereof.
4. The method defined in claim 1 , wherein the support layer of the reinforcement film strip is composed of a polypropylene and the nonwoven has polypropylene fibers.
5. The method defined in claim 1 , wherein the reinforcement film strip is composed of a multilayer film that has the support layer as a core and an outer layer of polyethylene on both sides, the nonwoven cover layers being of bicomponent fibers that have a fiber core of polypropylene and a fiber sheath of polyethylene.
6. The method defined in claim 1 , wherein the elastic film strips bonded to the cover layers by gluing.
7. The method defined in claim 6 , wherein the reinforcement film is glued to the elastic film strips substantially only in the overlap regions.
8. The method defined in claim 1 , wherein the reinforcement film is first bonded to at least one cover layer by adhesive applied in stripes and thereafter is permanently bonded to both cover layers by ultrasonic or thermal welding
9. The method defined in claim 1 , wherein the ultrasonic welding is done by passing nonwoven cover layers and the reinforcement film between a sonotrode and a pixel roll whose surface has a structure of bumps and/or indentations.
10. The method defined in claim 8 , wherein the sonotrode is upright and has a smooth contact surface.
11. The method defined in claim 8 , wherein the sonotrode is cylindrical and rotatable.