Diaper closure and method of making same
A laminated web from which diaper closure elements may be punched is made by first applying at least two pairs longitudinally extending and transversely spaced bend-resistant strips to a first longitudinally extending nonwoven tape. Then a respective longitudinally extending strip of an elastically stretchable polymer is applied to the first nonwoven tape between each of the pairs of the bend-resistant strips with the polymer strip partially overlapping both of the bend-resistant strips of the respective pair. A second longitudinally extending nonwoven tape that covers and extends transversely to both sides of the polymer strip is applied over the bend-resistant strips and the polymer strips to form a laminate with the polymer strip between the first and second nonwoven tapes.
1. A method of making diaper closure elements from a laminated web, the method comprising the steps of sequentially:
applying to a first longitudinally extending nonwoven tape at least two pairs of longitudinally extending and transversely spaced strips of an elastically stretchable polymer;
applying to the first nonwoven tape only between each of the pairs of the stretchable polymer strips a respective longitudinally extending bend-resistant strip with the bend-resistant strip partially overlapping both of the polymer strips of the respective pair;
applying over the bend-resistant strips and the stretchable polymer strips a second longitudinally extending nonwoven tape to form a laminate with the stretchable polymer strip between the first and second nonwoven tapes; and
punching the closure elements from the web with one end of each element lying between the bend-resistant strips of a respective one of the pairs of elastically stretchable polymer strips and an end of each element opposite the respective one end lying between the respective one pair of polymer strips and an adjacent pair of elastically stretchable polymer strips.
2. The method defined in claim 1 , further comprising the step of
hot bonding the stiff strips to the first nonwoven tape.
3. The method defined in claim 1 wherein a hot-melt adhesive is used to secure the stiff strips to the first nonwoven tape.
4. The method defined in claim 1 wherein the stiff strips are hot bonded to the first nonwoven tape by hot embossing rollers.
5. The method defined in claim 1 wherein the stiff strips are adhesively bonded to the first nonwoven tape.
6. The method defined in claim 1 wherein the bend-resistant strips are of polyolefins, polyolefin copolymers, styrene polymers, cycloolefin copolymers, polyamides, a polyactide, polyester, thermoplastic polyurethanes or mixtures of these polymers.
7. The method defined in claim 1 , further comprising the step of
stretching the laminate substantially only at the polymer strips transversely thereof so as to overstretch the first and second nonwoven tapes thereat.
8. The method defined in claim 1 , further comprising the step of:
leaving longitudinally extending spaces between adjacent pairs of the stretchable polymer strips free such that the first and second nonwoven tapes directly engage each other between adjacent pairs of the stretchable polymer strips.
9. A method of making diaper closure elements from a laminated web, the method comprising the steps of sequentially:
applying to a first longitudinally extending nonwoven tape at least two pairs of longitudinally extending and transversely spaced strips of an elastically stretchable polymer;
applying to the first nonwoven tape between each of the pairs of the stretchable polymer strips a respective longitudinally extending stiff polymer or nonwoven bend-resistant strip with the bend-resistant strips partially overlapping both of the polymer strips of the respective pair;
applying over the bend-resistant strips and the stretchable polymer strips a second longitudinally extending nonwoven tape to form a laminate with the stretchable polymer strip between the first and second nonwoven tapes; and
punching the closure elements from the web with one end of each element lying between the bend-resistant strips of a respective one of the pairs of elastically stretchable polymer strips and an end of each element opposite the respective one end lying between the respective one pair of polymer strips and an adjacent pair of elastically stretchable polymer strips.
10. The method defined in claim 9 wherein the first nonwoven tape is secured by a relatively strong bond to the stiff strips and to the polymer strips and the second nonwoven tape is secured by a less strong bond to the stiff strips and polymer strips.
11. The method defined in claim 9 wherein the stiff strips are pretreated on both faces to improve bonding.
12. The method defined in claim 9 wherein the stiff strips are each pretreated on only one face for differential bonding to the first and second nonwoven tapes.
13. A method of making a laminated web from which diaper closure elements may be punched, the method comprising the steps of sequentially:
securing a first longitudinally extending nonwoven tape with a relatively strong bond to at least two pairs of longitudinally extending and transversely spaced strips of an elastically stretchable polymer;
securing to the first nonwoven tape between each of the pairs of the polymer strips by another relatively strong bond a respective longitudinally extending stiff polymer or nonwoven bend-resistant strip with the bend-resistant strips partially overlapping both of the polymer strips of the respective pair; and
securing over the bend-resistant strips and the polymer strips by a less strong bond a second longitudinally extending nonwoven tape to form a laminate with the polymer strip between the first and second nonwoven tapes.
14. The method defined in claim 13 wherein the relatively strong bond is a full-coverage bond and the less strong bond is a partial-coverage bond.
15. The method defined in claim 14 wherein the partial-coverage bond is made by a swirl nozzle.