Patent Abstract:
A pants type disposable undergarment is provided which is equipped with a pre-fastened pull-on pant with a side lap seam formed by the methods of the present invention, and methods for producing such disposable undergarments.

Full Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of co-pending U.S. Provisional Patent Application Ser. No. 61/397,093, filed 7 Jun. 2010. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention related to disposable undergarments and more particularly, a pants type undergarment which is equipped with refastenable side seams. 
         [0003]    Disposable undergarments of the children&#39;s training pant type, or of the adult incontinence type, are generally made up of two nonwoven layers of material with elastic strands of material placed between the two nonwoven layers of material thus creating an elastic web laminate. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention discloses methods of forming a pants type diaper with refastenable side seams. A pants type disposable undergarment is provided which is equipped with a pre-fastened pull-on pant with a side lap seam formed by the methods of the present invention. Top and bottom portions of a side panel assembly are folded over a stretch portion of the side panel, and both the top and bottom portions are bonded to the stretch portion of the side panel, at first temporary bond points and at second ultrasonic or mechanical bond portions. The second ultrasonic or mechanical bond portions are overlain with a hook-type fastener for later bonding with the first temporary bond points, to form a lap seam at the left and right sides of the waist of a wearer. A folded product is produced that is pre-fastened in this manner, but the bond between the hook-type fastener and the first temporary bonded portion can be released and re-fastened if desired. 
         [0005]    A product and method to produce a resealable pant such that the front and rear waist side panel regions can be easily engaged with one another. 
         [0006]    A method to produce a resealable pant in such a manner so that the front and rear waist side panels are a single piece during manufacturing is disclosed. A hinged panel with a resealable fastener to align with the mating side panel when folded to form a lap seam is also disclosed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of an undergarment produced according to the present invention. 
           [0008]      FIG. 2  is a top planar view of a composite of material used to form a side panel. 
           [0009]      FIG. 3  is a top planar view of a side panel assembly of embodiment shown in  FIG. 2 , with the top and bottom non-stretch materials folded over. 
           [0010]      FIG. 4  is a top planar view of assembly of embodiment shown in  FIG. 3 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions. 
           [0011]      FIG. 5  is a top planar view of assembly of embodiment shown in  FIG. 4 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions, and a hook material applied to the back side panel proximate to the bond area. 
           [0012]      FIG. 6  is a top planar view of assembly of embodiment shown in  FIG. 5 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions, and a hook material applied to the back side panel proximate to the bond area, with portions of the assembly removed by die cut to facilitate shaping of the side panel. 
           [0013]      FIG. 7  is a top planar view of assembly of embodiment shown in  FIG. 6 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions, and a hook material applied to the back side panel proximate to the bond area, with portions of the assembly removed by die cut to facilitate shaping of the side panel, and the side panel slit and spread apart. 
           [0014]      FIG. 8  is a top planar view of assembly of embodiment shown in  FIG. 7 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions, and a hook material applied to the back side panel proximate to the bond area, with portions of the assembly removed by die cut to facilitate shaping of the side panel, and the side panel slit and spread apart, bonded to a top sheet material. 
           [0015]      FIG. 9  is a top planar view of assembly of embodiment shown in  FIG. 8 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions, and a hook material applied to the back side panel proximate to the bond area, with portions of the assembly removed by die cut to facilitate shaping of the side panel, and the side panel slit and spread apart, bonded to a top sheet material, and this combination combined with a core and back sheet material. 
           [0016]      FIG. 10  is a top planar view of assembly of embodiment shown in  FIG. 9 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions, and a hook material applied to the back side panel proximate to the bond area, with portions of the assembly removed by die cut to facilitate shaping of the side panel, and the side panel slit and spread apart, bonded to a top sheet material, and this combination combined with a core and back sheet material, showing the finished product prior to folding. 
           [0017]      FIG. 11  is a finished product after folding, and prior to packaging. 
           [0018]      FIG. 12  is an exploded cross sectional view of the pre-fastened pull-on pant with a side lap seam formed by the methods of the present invention. 
           [0019]      FIG. 13  is schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with a continuous hook formation, with the hooks away from the body. 
           [0020]      FIG. 14  is a schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with a discrete hook formation, with the hooks away from the body. 
           [0021]      FIG. 15  is a schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with a discrete hook formation extending into a die cut region, with the hooks away from the body. 
           [0022]      FIG. 16  is a schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with a discrete hook overlapping cut formation, with the hooks away from the body. 
           [0023]      FIG. 17  is a schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with a multiple discrete hook overlapping cut formation, with the hooks away from the body. 
           [0024]      FIG. 18  is a schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with hooks on the front side panel, with the hooks away from the body. 
           [0025]      FIG. 19  is a schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with hooks on the front side panel, and nonwoven tabs on the back panel, with hooks toward the body. 
           [0026]      FIG. 20  is a schematic representation of formation of an alternate embodiment of the present invention, disclosed is a nonwoven tab process with hooks on the rear or back side panel, and nonwoven tabs on the front panel, with hooks toward the body. 
           [0027]      FIG. 21  is a plan view of a product produced according to the present invention. 
           [0028]      FIGS. 22-24  are cross sectional views of a product produced according to the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0029]    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. 
         [0030]    Referring to the Figures generally, two adjacent products are shown constructed next to one another because the products  10  are preferably constructed on a continuous processing system for later separation to form individual diaper products (see, e.g.,  FIG. 9  prior to separation to form individual products in  FIG. 10 ). 
         [0031]      FIG. 1  is a perspective view of an undergarment  10  produced according to the present invention. 
         [0032]    Referring now to  FIG. 2  a top planar view of a composite of material used to form a side panel is shown. First and second segments of material  22  are provided at the top and bottom of the composite, along with first and second segments of preferably stretchy material  20 . The first and second segments of material  22  can be formed of the same piece of stretch material  20 , or formed separately of stretch or non-stretch material and then bonded to the stretch material  20 . A segment of non-stretch material  24  is provided between the first and second segments  20  as shown. 
         [0033]    Referring now to  FIG. 3 , the first and second segments of material  22  are folded either over or under the adjoining first and second segments of stretch material  22 . This can be done with a folding machine known in the art. 
         [0034]    As shown in  FIG. 4  a top planar view of assembly of embodiment shown in  FIG. 3  is shown, with the top and bottom segments of material  22  folded over. The top and bottom segments of material  22  are then conceptually divided into segments  22   a  and  22   b , both at the top and the bottom of the composite, alternating continuously in what will eventually become physically divided portions which will be the front left (top  22   a L), front right (bottom  22   a R) and the back left (top  22   b L) and back right (bottom  22   b R) side panel portions. 
         [0035]    In areas  22   a R and  22   a L (front left and right side panel portions), the folded segments of material  22  are temporarily bonded to the underlying (or overlying) layer(s) of stretch material  20 . The temporary bonding can be done for instance at spaced apart tack bond sites. The purpose of the temporary bond is to provide control of the material throughout the high-speed manufacturing process, but to allow the bond to become detached when the lap seam is eventually formed, and worn about the waist of a user. 
         [0036]    In areas  22   b R and  22   b L (rear left and right side panel portions), the folded segments of material  22  are ultrasonically or mechanically bonded to the underlying (or overlying) layer(s) of stretch material  20  in zones  26 . The bonding can be done in other ways, such as adhesively. 
         [0037]    Following this step, and referring now to  FIG. 5 , after the top and bottom materials  22  have been folded over and bonded in portions to the stretch portions  20  as previously described, a material  28  is applied to the back side panel in areas  22   b L and  22   b R proximate to and preferably overlying at least in part the bond areas  26  suitable for later attachment to the tack-bonded portions  22 . Preferably, the material  28  is a hook type material suitable for attachment to loose loop type material if used for portions  22 . 
         [0038]    Referring now to  FIG. 6 , the next step in the process is to die cut areas  30  from side panel assembly which can be discarded or preferably recycled. Preferably, portions  30  of the side panel assembly are removed by die cut or other means to facilitate shaping of the side panel to conform with the waist or leg openings of the diaper configuration, shaped to conform to the body of the wearer. 
         [0039]    Next, as shown in  FIG. 7 , the side panel assemblies are slit, preferably in the middle of the non-stretch panel  24 , and spread apart to increase the distance between the left side panels ( 22   a L and  22   b L) and the right side panels ( 22   a R and  22   a L) panels to form left and right intermediate assemblies. Next, the front panel ( 22   a L and  22   a R) assemblies are separated from the  22   b L rear panel assemblies ( 22   b L and  22   b R) panels, for instance by slitting and slip cutting methods (not shown) for deployment onto a continuous top sheet web  30  in the positions as shown in  FIG. 8 . 
         [0040]    As shown on  FIG. 8 , the non-stretch panel  24  portions of the side panel assemblies are introduced to the top sheet assembly  12  in overlapping fashion, and bonded thereto in the portions of an overlap between the non-stretch panel  24  and top sheet assembly area identified as overlap area  32 . 
         [0041]    Referring to  FIGS. 9 and 12  (showing the product cross-section after folding), after slitting the side panel assembly to form independent left ( 22   a L and  22   b L) and right ( 22   a R and  22   b R) panels, the left panels are further subdivided to form the left front ( 22   a L) and left rear ( 22   b L) panels, and to form the right front ( 22   a R) and right rear ( 22   b R) panels, and introduced to the back sheet material  30 . At this point, as shown in  FIG. 9 , additional components of the diaper panel can be introduced either independently or in pre-constructed fashion. Included are the cuff non-woven  46  containing cuff elastics  44 , leg elastics  34 , the inner non-woven  38 , the absorbent core  36  captured by tissue, the acquisition layer  47 , poly layer  40 , inner non-woven  38 , and waist band  48 . 
         [0042]    Referring now to  FIG. 10 , two adjacent products can be separated from one another, for instance, by die cutting, to form independent products  10 . is a top planar view of assembly of embodiment shown in  FIG. 9 , with the top and bottom non-stretch materials folded over and bonded in portions to the stretch portions, and a hook material applied to the back side panel proximate to the bond area, with portions of the assembly removed by die cut to facilitate shaping of the side panel, and the side panel slit and spread apart, bonded to a top sheet material, and this combination combined with a core and back sheet material, showing the finished product prior to folding. 
         [0043]    Referring now to  FIG. 11 , the diaper product is folded generally at its midsection to form a folded product, with the material  28  being urged against the material  22 , to form the refastenable pre-fastened product. In this fashion, the hook material  28  contained on side panel portion  22   b L is joined with the side panel portion  22   a L, and the hook material  28  contained on side panel portion  22   b R is joined with the side panel portion  22   a R. This joinder is done by pressure during the folding process, such that the finished product after folding will have pre-sealed sides. If the user desires, the hook material  28  can then be separated from the side panel portions  22   a L and  22   a R for taking the garment off the user if the product is insulted, or can be opened and re-sealed if the product is still clean. 
         [0044]    Referring now to  FIG. 13 , a schematic representation of formation of an alternate embodiment of the present invention is shown, disclosed is a nonwoven tab process with a continuous hook  28  formation, with the hooks  28  away from the body. The formation of this product is much the same as previously described. Working from left to right on  FIG. 13 , in sequential fashion, non-woven tab material  22  is folded over at the top and the bottom and tack bonded. Next, hook material  28  is coupled to the tack bonded material  22 , slit and spread. Next, this composite is introduced to side panel material  20 . Die cut areas  30  are removed from the side panel assembly. At this point in the procedure, the construction process resumes at the point previously described with reference to  FIGS. 6-11 . To recap, the left and right and front and back panels are slit and separated, as shown in  FIG. 7 , bonded to the incoming chassis web ( FIGS. 8 ,  9 ), severed into individual diapers ( FIG. 10 ) and folded ( FIG. 11 ) prior to packaging. 
         [0045]    Referring now to  FIG. 14 , a schematic representation of formation of an alternate embodiment of the present invention is shown. In this embodiment, the hook material  28  is applied to tack bonded material  22  discretely (as opposed to continuously, as shown on  FIG. 13 ). Discrete application of the hook material  28  can be performed, for instanced by slip/cut techniques. In this embodiment, the discrete hook material  28  is not severed, instead the combination tab  20 /hook  28  material is severed in between hook  28  portions. 
         [0046]    Referring now to  FIG. 15 , an alternate embodiment of the present invention is shown, in which a nonwoven tab created of material  20  (longer than the hook material  28  segments) extend into the die cut region  30  such that in use the material  20  would extend nearly the length of the back side panel  20 . 
         [0047]    Referring now to  FIG. 16 , an alternate embodiment is shown, with a discrete hook  28  overlapping the die-cut formation, with the hooks away from the body. In this embodiment, the hook material is introduced such that the hook material  28  overlaps the space where the material is cut prior to introduction onto the side panel. The result is that the hook material  28  resides on the back side panel in two discrete pieces. The same result is achieved if, as shown in  FIG. 17 , multiple discrete hook portions  28  are applied to the nonwoven tab  20  material, slit and separated prior to introduction onto the side panels  22 . 
         [0048]    Referring now to  FIG. 18 , an alternate embodiment of the present invention is shown with nonwoven tab process with hooks  28  on the front side panel, with the hooks  28  facing away from the body. 
         [0049]    Referring now to  FIG. 19  an alternate embodiment of the present invention is shown, with hooks  28  on the front side panel, and the folded over nonwoven  22  on the back panel, with hooks  28  toward the body.  FIG. 20  is similar, except that the folded over nonwoven  22  is on the front panel, and the hooks  28  are on the back panel. 
         [0050]    Referring now to  FIG. 21  is a plan view of a product produced according to the present invention, is shown, with a back side panel cross section shown in  FIG. 22 , a front side panel construction shown in  FIG. 23 , and a lap-seam full product cross section shown in  FIG. 24 . Referring to  FIG. 22  showing the back panel cross section, undergarment  10  is formed with top sheet  12 , back sheet  14 , bonded where desired with adhesive  16  or ultrasonic bonds  18 , or tack bonds  19 . A poly layer  40  is provided, as are leg elastics  34 , panels  20 , absorbent core  35  carried by core wrap  37  (preferably non-woven), top tissue  50 , acquisition layer  47 , and cuff elastics  44  carried by cuff non-woven  46 . 
         [0051]    Referring to  FIG. 23  showing the front panel cross section, the top sheet  12  is coupled to the cuff  46 , and the acquisition layer  47 , the top tissue  50 , and next the ftong panels about the core  36  carried by the core wrap  37 . Leg elastics  34  are provided, and completing the cross section is poly  40  coupled to the back sheet  14 . 
         [0052]      FIG. 24  shows the lap seam (overlap) provided by the hook material  38 , releasably coupled about the waist of a user with material  22 . 
         [0053]    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 embodiments have been described, the details may be changed without departing from the invention, which is defined by the claims.

Technology Classification (CPC): 8