Abstract:
A disposable diaper has a multi-layered diaper assembly. The disposable diaper has a first top surface exterior layer assembly comprising a non-woven material having a planar, soft, cloth-like surface layer. A second layer is provided and consists of non-chlorine bleached wood pulp. A third layer is provided having a top surface portion in contact with a bottom surface portion of the second layer. A fourth bottom surface interior layer is provided in contact with a bottom surface portion of the third layer and comprising a non-woven liquid permeable material having a planar, soft, cloth-like body contact surface portion.

Description:
RELATED APPLICATIONS  
       [0001]    The present application is related to U.S. Pat. No. 5,743,895 entitled “DISPOSABLE DIAPER AND METHOD THEREFOR”, issued on Apr. 28, 1998 in the name of the same inventors and incorporated by reference into the present application. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This invention relates to a disposable diaper and, more specifically, to a disposable diaper and method therefor that uses more natural materials in the manufacturing process.  
           [0004]    2. Description of the Prior Art  
           [0005]    Disposable diapers are well known and widely used. Over the years, disposable diapers have become the dominant diaper, largely replacing the old form of reusable diaper. Typical disposable diapers generally use an absorbent interior area for absorbing a wearer&#39;s urine, bounded by a thin plastic exterior layer. The interior portion of the typical disposable diaper presently on the market is generally comprised of a bottom layer of non-woven material that is in direct contact with the area of the child&#39;s skin covered by the diaper, a backing layer of tissue paper that contacts the bottom portion of the layer of non-woven material, a wadding batt layer of wood pulp that is located between the thin plastic exterior layer and the layer of tissue paper, and, in order to increase the diaper&#39;s fluid absorbency, diaper manufacturers add a superabsorbent polymer or other chemical additive to the wadding batt layer. Without the superabsorbent polymer, wood pulp generally absorbs in the range of 12 to 15 times its weight. With the superabsorbent polymer, the wadding batt layer is able to absorb in the range of 30 to 55 times its weight.  
           [0006]    One problem with current disposable diapers is that the wood pulp used is bleached with chlorine. This bleaching process produces low levels of dioxins or furons as by-products. While the government may allow certain low levels of dioxins, dioxins are toxic and carcinogenic.  
           [0007]    Another problem with current disposable diapers is that in order to increase fluid absorbency, a superabsorbent material is added to the wadding batt layer. In present disposable diapers, the superabsorbent material is an artificial superabsorbent polymer. Diapers with this polymer additive experience what is known in the industry as “rewet”—i.e., the transfer of wetness from the diaper back to the surface of the diaper and to the child&#39;s skin.  
           [0008]    Therefore, a need existed to provide an improved disposable diaper and method. The improved disposable diaper and method must use more natural materials. The improved disposable diaper and method must use materials that do not use a chlorine bleach during the manufacturing process. The improved disposable diaper and method may further use a more natural superabsorbent mixture.  
         SUMMARY OF THE INVENTION  
         [0009]    In accordance with one embodiment of the present invention, it is an object of the present invention to provide an improved disposable diaper and method.  
           [0010]    It is another object of the present invention to provide an improved disposable diaper and method that overcomes the above problems associated with prior art disposable diapers.  
           [0011]    It is still another object of the present invention to provide an improved disposable diaper and method that uses more natural materials.  
           [0012]    It is still another object of the present invention to provide an improved disposable diaper and method that use materials that do not use a chlorine bleach during the manufacturing process.  
           [0013]    It is yet another object of the present invention to provide an improved disposable diaper and method that may further use a more natural superabsorbent mixture.  
         BRIEF DESCRIPTION OF THE EMBODIMENTS  
         [0014]    In accordance with one embodiment of the present invention a disposable diaper is disclosed. The disposable diaper has a multi-layered diaper assembly. The disposable diaper has a first top surface exterior layer assembly comprising a non-woven material having a planar, soft, cloth-like surface layer. A second layer is provided and consists of non-chlorine bleached wood pulp. A third layer is provided having a top surface portion in contact with a bottom surface portion of the second layer. A fourth bottom surface interior layer is provided in contact with a bottom surface portion of the third layer and comprising a non-woven liquid permeable material having a planar, soft, cloth-like body contact surface portion.  
           [0015]    In accordance with another embodiment of the present invention, a method for providing a disposable diaper is disclosed. The method comprises the following steps: forming a first top surface exterior layer assembly comprising a non-woven material having a planar, soft, cloth-like surface layer; forming a second layer consisting solely of non-chlorine bleached wood pulp; providing a third layer comprising a thin planar layer of tissue paper having a top surface portion in contact with a bottom surface portion of the second layer; and providing a fourth bottom surface interior layer in contact with a bottom surface portion of the third layer and comprising a non-woven liquid permeable material having a planar, soft, cloth-like, body contact surface portion.  
           [0016]    The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawing. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself, as well as a preferred mode of use, and advantages thereof, will best be understood by reference to the following detailed description of illustrated embodiments when read in conjunction with the accompanying drawings.  
         [0018]    [0018]FIG. 1 is an elevated front side view of one embodiment of the disposable diaper of the present invention.  
         [0019]    [0019]FIG. 2 is an elevated rear side or backside view of one embodiment the disposable diaper of the present invention.  
         [0020]    [0020]FIG. 3 is a cross-sectional view of the disposable diaper of FIG. 1 taken along line  3 — 3  of FIG. 1. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0021]    Referring to the embodiment of FIGS.  1 - 3 , reference number  10  refers generally to the disposable diaper of this invention. It should be noted that the following description is one embodiment of the present invention.  
         [0022]    Referring to FIG. 1, a front or interior view of the disposable diaper  10  is shown, in the open position. The disposable diaper  10 , like other disposable diapers, comprises front flaps  12  and back flaps  14 . Reference numbers  12   a  and  14   a  refer to the side portions of the front flaps  12  and the back flaps  14 , respectively, that are visible in the front view of the disposable diaper  10  depicted in FIG. 1. Adhered to the back flaps  14   a , and oriented substantially parallel to an upper edge  16  of the diaper  10 , are preferably two tape assemblies  18 . Each tape assembly  18  comprises a base portion that is attached directly to the surface of the diaper  10 , and a partially separable adhesive portion that may be peeled from the base portion for adhesion attachment to the reverse side of front flaps  12  (see both FIGS. 1 and 2) when the diaper  10  is being placed on a baby or child. On both sides of the diaper  10 , oriented in a substantially perpendicular direction to the upper edge  16  and the lower edge  20 , are two elastic portions  22 . The elastic portions  22  snugly grip the legs of the child during the wearing of the diaper  10  to, among other things, minimize the leaking of fluid out of the diaper  10 .  
         [0023]    Referring to FIG. 2, a rear or backside exterior view of the disposable diaper  10  is shown, in the open position. Reference numbers  12   b  and  14   b  refer to the sides of the front flaps  12  and the back flaps  14 , respectively, that are visible in the rear or backside view of the disposable diaper  10 . Adhered to the back flaps  14   b , and oriented substantially parallel to the upper edge  16  of the diaper  10 , are portions of the two tape assemblies  18 . These are continuations of the portions of the tape assemblies  18  which are located on the back flaps  14   a , as shown in FIG. 1. Located between tabs  12   b  is a preferably rectangular plastic strip  22 A, which strip  22 A receives the adhesive portion of the tape assemblies  18  when the diaper is being placed on a baby or child.  
         [0024]    Referring to FIG. 3, a cross-sectional view of the disposable diaper  10  is shown, showing the layers of material comprising the diaper  10 . The interior portion of the disposable diaper  10  is comprised of a bottom layer  24   a  of non-woven material that is in direct contact with the area of the child&#39;s skin covered by the disposable diaper  10 . A backing layer  26  contacts the bottom portion of the layer of non-woven material. The backing layer  26  may be tissue paper or the like. It should be noted that the description of the different types of materials for the backing layer  26  should not be seen as to limit the scope of the present invention. In accordance with one embodiment of the present invention, an underlying thin plastic sheet  24   b  is provided, with the surface layer  24   a  and the plastic sheet  24   b  being in bonded contact with each other, preferably in the form of a laminate.  
         [0025]    In contact with a bottom or inner portion of the tissue layer  26  or, if desired, directly in contact with a bottom or inner surface portion of the plastic sheet  24   b , is a second layer  28 .  
         [0026]    The second layer  28  is a wadding batt layer consisting of a wood pulp mixture  30 . All present disposable diapers bleach their wood pulp with chlorine. This bleaching process low levels of dioxins. Even though low levels of dioxins are accepted by the government, many people would prefer to have a disposable diaper  10  made from non-chlorine bleached materials. Thus, in accordance with one embodiment of the present invention, a non-chlorine bleached wood pulp  30  is used. A bleached untreated softwood fluff pulp which is biodegradable and totally chlorine free may also be used. Additionally, wood pulp  30  used in the present invention may be bleached using other processes other than chlorine. In accordance with one embodiment of the present invention, the wood pulp  30  is bleached with a hydrogen peroxide mixture. The use of hydrogen peroxide should not be seen as to limit the scope of the present invention.  
         [0027]    The second layer  28  may be comprised solely of non-chlorine bleached wood pulp  30 . However, the non-chlorine bleached wood pulp  30  may be combined with other materials. For example, cotton  32  may be combined with the wood pulp  30 . The cotton  32  may be a regular (non-organic) cotton  32 , a certified organic cotton  32 , or combinations thereof. The wood pulp  30  and cotton  32  mixture creates a blend that is substantially more absorbent than a wadding batt layer comprised entirely of wood pulp  30 . In this regard, wood pulp  30  generally absorbs in the range of 12 to 15 times its weight. Cotton pulp  32 , in contrast, generally absorbs approximately 25 times its weight, depending on the quality of the particular cotton. By mixing cotton pulp  32  with wood pulp  30  in appropriate amounts, the absorbency of the resulting mixture is greater than that of pure wood pulp  30 . In the preferred embodiment of this invention, the second layer  28  is about five-eighths of an inch thick. However, it should be understood that changes can be made in the thicknesses of any of the layers comprising the diaper  10  without departing from the spirit or scope of this invention.  
         [0028]    The second layer  28  may further comprise a superabsorbent mixture  33 . The superabsorbent mixture will allow the wadding batt layer to absorb in the range of 30 to 55 times its weight. However, instead of a superabsorbent polymer such as polyacrylates, one that is more friendly to the skin would be used. The superabsorbent mixture may be a natural or an artificial superabsorbent mixture. In accordance with one embodiment of the present invention, a natural wheat based polysaccharide superabsorbent mixture is used. This type of superabsorbent mixture is biodegradable and is friendlier to the skin of the wearer and changer. It should be noted that the wheat based polysaccharide superabsorbent mixture is just an example and should not be seen as to limit the scope of the present invention. The superabsorbent mixture will still allow the wadding batt layer to absorb in the range of 30 to 55 times it weight, but will not have the side effects of irritating the wearer&#39;s skin during “rewet”.  
         [0029]    In contact with a bottom or upper portion of second layer  28  is a third layer  34 , comprising tissue paper. The tissue paper may be a regular type of tissue paper or a non-chlorine bleached tissue paper. The tissue paper would be bleached using a process similar to that described above. Finally, in contact with a bottom or upper portion of third layer  34  is a fourth layer  36 , comprising a non-woven bond material such as a polyester type of material. Accordingly, the fourth layer  36  is made of a soft cloth-like type material that is substantially porous, permitting a child&#39;s or baby&#39;s fluid waste to penetrate therethrough for fluid absorption by the second layer  28 , whereas the first layer  24  provides both a barrier layer to prevent fluid from penetrating outwardly therethrough from the second fluid absorbing layer  28  and a soft, cloth-like surface layer ( 24   a ) to provide a soft exterior layer that is non-abrasive to the skin of a baby or child or a person diapering the baby or child. Thus, both inner and outer soft layers are provided by this invention.  
         [0030]    While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.