STRETCH LAMINATE WITH CURVED ELASTIC

Abstract

Curved elastics are applied to both or either the front or rears of a pant type diaper extending near the leg and waist openings. An adhesive pattern is deposited onto a nonwoven sheet, and elastic strands are coupled to the nonwoven sheet. The elastic strands and nonwoven sheet are coupled to another web of ultrasonically bonded elastomeric material and nonwoven, and together the laminate is used as a front or rear portion of a diaper.

Claims

1. A method of forming a laminate comprising: forming independently a first laminate comprising a base layer coupled to an elastomeric layer; forming independently a second laminate comprising a top layer coupled to a series of elastic strands; coupling said first laminate to said second laminate.

2. A method according to claim 1, said top layer coupled to said series of elastic strands by adhesive.

3. A method according to claim 1, said elastic strands provided to said second laminate in a non-linear fashion.

4. A method according to claim 1, said base layer coupled to said elastomeric layer ultrasonically.

5. A method according to claim 1, said first laminate coupled to said second laminate ultrasonically.

6. A laminate according to claim 1, said laminate comprising an adhesive zone representing a location where said top layer is coupled to a series of curved elastic strands, and an ultrasonic zone representing where said first laminate is coupled to said second laminate.

7. A laminate according to claim 6, said ultrasonic zone containing no adhesives.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a side view of a prior art laminate in which a nonwoven layer covers elastic strands laid atop a second nonwoven layer, laid atop an elastomeric layer coupled to a bottom nonwoven layer;

[0020] FIG. 2 is a side schematic view of a laminate forming mechanism of the present invention in which a top nonwoven layer is applied with adhesive, and elastic strands are introduced to the top nonwoven layer prior to a combining point, at which a previously ultrasonically bonded elastomeric layer has been bonded with a bottom nonwoven layer;

[0021] FIG. 3 is a plan view of a diaper produced according to the methods of the present invention;

[0022] FIG. 4 is a cross sectional view of the diaper shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.

[0024] Referring now to FIG. 1, a side view of a prior art laminate in which a nonwoven layer 12 covers elastic strands 18 (which can be laid down in curved fashion according to known methods) laid atop a second nonwoven layer 14, laid atop an elastomeric layer 20 coupled to a bottom nonwoven layer 16 is shown. Adhesives are generally used to create the bonds in this laminate between layers.

[0025] Referring now to FIG. 2, a side schematic view of a laminate forming mechanism of the present invention is shown. A top nonwoven layer 14 is applied with adhesive by adhesive applicator 24. Elastic strands 18 are introduced to the top nonwoven layer prior to a combining point 26. Preferably, the curved elastic 18 is introduced to top nonwoven 14 just prior the combining point 26 for near instant capture of the curved elastic 18. An ultrasonic bonding unit 22 bonds elastomeric layer 20 with a bottom nonwoven layer 16, and this bi-laminate is fed to bonding unit or combining point 26 to receive the previously produced curved elastic 18 combination with top nonwoven 14. This laminate is fed downstream for further processing as desired.

[0026] The resulting laminate of this configuration can be used in a diaper product 50 as shown FIG. 3. As shown in FIG. 3, the diaper has a front panel (shown at left) comprised of a stretch laminate with a top nonwoven layer 14, bottom nonwoven layer 16, and both an elastomeric layer 20 and waist elastics 40 supplied. The bottom nonwoven 16 can be folded over at the left side in order to capture the waist elastics 40 and the top nonwoven 14.

[0027] A rear panel (shown at right) has two distinct bonding zones, an adhesive zone 34 and an ultrasonic zone 36. The adhesive zone is defined by the adhesive applicator 24 (FIG. 2) as where either zoned or continuous adhesive has been laid to top nonwoven layer 14. A portion of the adhesive 24a (seen in cross section, FIG. 4) laid down in adhesive pattern portions 30 presents a target area for elastic strands 18. A second adhesive pattern 32 presents a portion of adhesive zone 34 targeted to couple the elastomeric/nonwoven bilaminate 20/16 to the top laminate 14.

[0028] In ultrasonic zone 36, it is preferable that no adhesives are present, and elastomeric/nonwoven bilaminate 20/16 and top laminate 14 are coupled ultrasonically.

[0029] As with the front panel, bottom nonwoven 16 can be folded over at the right side in order to capture waist elastics 40 and the top nonwoven 14.

[0030] Still referring to FIG. 3, core components 42 are used to bridge the front and rear panels. Core components 42 can comprise acquisition layers, absorbent core material including superabsorbent polymer (SAP) and cellulosic fluff absorbent material, and nonwoven materials as preferred by the manufacturer. Core components are coupled to the front and rear panels, for instance adhesively or ultrasonically. The assembled components are shown in FIG. 4 in cross section.

[0031] The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.