Abstract:
The present invention provides a fastening strap for disposable absorbing articles comprising a fabric backing and a hook strap on which a plurality of hooks are formed for releasably engaging loops on a loop strap of the disposable absorbing articles, wherein the hook strap is secured directly to the fabric backing by means of fusion bonding to form patterns on the fastening strap to thereby producing a fastening strap for disposable absorbing articles in a more simple process without using any adhesive. A method for manufacturing this fastening strap and a disposable absorbing article including this fastening strap are also provided.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a fastening strap for a disposable absorbing article, and more specifically to a fastening strap for a disposable absorbing article with great softness that is produced by a simplified process without using any adhesive, a manufacturing method for making the fastening strap and a disposable absorbing article including the fastening strap. 
     BACKGROUND OF THE INVENTION 
     A hook-and-loop type fastener is a well know mechanical fastener and wildly used in disposable absorbing articles, such as diapers for babies and adults, to fasten the diaper around the waist of a wear&#39;s body. As illustrated in  FIG. 1 , a hook-and-loop type fastener utilized as a fastening device of a diaper  1  usually consists of two fastening straps  10  each secured to a lateral side of a first end of the diaper  1  respectively and a loop strap  20  provided on an outer face of a second end of the diaper  1 . Each of the fastening strap  10  has a plurality of hooks  12  formed thereon for releasably engaging with the loops  22  formed on the loop strap  20  to fasten the diaper  1  on the wear&#39;s body. Traditional fastening strap  10 , as illustrated in  FIG. 2 , usually includes a backing layer  14 , a hook strap layer  16 , and an adhesive layer  18  disposed between the backing layer  14  and the hook strap layer  16  to bond the backing layer  14  and the hook strap layer  16  together to form the fastening strap  10 . The hook strap layer  16  is a plastic layer that includes a plastic substrate and a plurality of hooks  12  that is integrally formed on the substrate by means of a plastic injection process. 
     Because the traditional fastening strap  10  consists of three layers and the hook strap layer  16  is a plastic layer, it is too stiff for applications that suppleness of a fastening strap is a critical factor. For instance, when utilized in a diaper the fastening strap is used to keep the diaper in place about the wearer and thus has an intimate contact with the skin of the wear. Therefore, if the fastening strap does not have sufficient suppleness, the wearer of the diaper may feel uncomfortable and even may leave marks on the skin of the wearer. 
     Additionally, because the traditional fastening strap  10  uses an adhesive layer to bind the hook strap  16  and the backing layer  14  together, the manufacturing process is thus complicated. Moreover, because an adhesive layer  18  is used to bind the hook strap  16  and the backing layer  14  the manufacturing cost is inevitably increased and so is the sale price, and thus making the fastening strap  10  less competitive in the market. 
     In view of the shortcomings of traditional fastening strap described above, there exists a need for a fastening strap for a disposable absorbing article that possess a sufficient fastening strength and a sufficient suppleness. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a fastening strap for a disposable absorbing article that possess a sufficient fastening strength and a sufficient suppleness. 
     Another object of the present invention is to provide a fastening strap for a disposable absorbing article that is produced in a more environmental friendly and more simply way that has a higher yield, a lower manufacturing cost, and does not use any adhesive in the process and thus is suitable for mass production. 
     The above objects may be achieved by a fastening strap for a disposable absorbing article. According to one aspect of the present invention, the fastening strap for a disposable absorbing article comprises: 
     a fabric backing; 
     a plastic hook strap disposed on at least a portion of the fabric backing and having a plurality of hooks formed on a face facing away from the backing, wherein the plastic hook strap is directly bind to the fabric backing by means of a fusion bonding process, and binding patterns are formed on the fastening strap during the fusion bonding process to lower the overall stiffness of the fastening strap to provide a sufficient softness to the fastening strap. 
     Preferably, the fastening strap for a disposable absorbing article includes sealing portions at both lateral sides of the hook strap and the sealing portions are formed by performing a fusion bonding process along both lateral sides of the plastic hook strap to bind the lateral sides of the hook strap to the fabric backing so as to prevent the lateral sides of the hook strap from warping upwardly. Additionally, the fabric backing may be a non-woven fabric, and the fusion bonding process may be an ultrasonic welding process or a thermal welding process. The binding patterns may be a plurality of linear grooves that are parallel with each other and evenly spaced apart from each other. The binding patterns may be a matrix of circular or polygonal dimples. 
     A method of manufacturing a fastening strap for a disposable absorbing article is also provided and the method includes the steps of: 
     providing a web of fabric backing; 
     placing a plastic hook strap on at least a portion of the fabric backing, the plastic hook strap having a plurality of hooks integrally formed on a face thereof facing away from the fabric backing; and 
     performing a fusion bonding process to the stacked plastic hook strap and fabric backing to allow the plastic melted from the plastic hook strap to penetrate into the fabric backing so as to directly fix the plastic hook strap to the backing, in the mean time, a number of binding patterns are formed on the fastening strap such that the overall stiffness of the fastening strap is lowered so as to provide a sufficient softness to the fastening strap. 
     Preferably, the method further comprises the step of performing a fusion bonding process along both lateral sides of the plastic hook strap to bind the lateral sides of the hook strap to the fabric backing so as to prevent the lateral sides of the hook strap from warping upwardly. 
     Preferably, the method further comprises a cutting step to cut the fastening strap into desired size and shape. 
     According to another embodiment, the fastening strap for a disposable absorbing article comprises: 
     a plastic hook strap including a plurality of hooks integrally formed on a face thereof; and 
     two fabric side wings, which are disposed at two lateral sides of the plastic hook strap respectively and directly bonded thereto by performing a fusion bonding process on the stacked portions of lateral sides of the plastic hook strap and the two fabric side wings. 
     Preferably, the two fabric side wings may be non-woven fabric, and the fusion bonding process may be an supersonic welding process or a thermal welding process. 
     According to yet another embodiment, the fastening strap for a disposable absorbing article comprises: 
     a plastic hook strap including a plurality of hooks integrally formed on a face thereof; 
     two fabric side wings, which are overlaid at two lateral sides of the plastic hook strap respectively and directly bonded thereto by performing a fusion bonding process on the overlaid portions of lateral sides of the plastic hook strap and the two fabric side wings; and 
     a connecting member having an adhesive film provided at a top face thereof and disposed on one of the fabric side wings such that a distal edge of the fabric side wing located at a substantially middle portion of the connecting member, and the connecting member is directly fixed to the fabric side wing at the substantially middle portion such that two end sides of the connecting member may be folded toward each other. 
     Preferably, the two fabric side wings and the connecting member may be non-woven fabric, and the fusion bonding process may be a supersonic welding process or a thermal welding process. 
     Another aspect of the present invention provides a disposable absorbing article comprising a front waist portion; a rear waist portion; a crotch portion extending between the front and the rear waist portions; a loop strap provided on an outer face of the front waist portion and having a plurality of loops formed thereon; and two fastening straps according to the embodiments described above, each of the fastening straps being attached to a lateral side of the rear waist portion for releasably engaging with the loops of the loop strap so as to fastening the disposable absorbing article on to a wear&#39;s body. 
     Features and objects of the present invention other than the above will become clear by reading the description of the present specification with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a schematic perspective view of a diaper having traditional fastening straps attached thereon; 
         FIG. 2  is a schematic cross-sectional view of a traditional fastening strap; 
         FIG. 3  is a schematic perspective view of a fastening strap for a disposable absorbing article according to an embodiment of a first aspect of the present invention; 
         FIG. 4  is a schematic cross-sectional view of the fastening strap for a disposable absorbing article shown in  FIG. 3 ; 
         FIG. 5  is a schematic perspective view of a fastening strap for a disposable absorbing article according to another embodiment of a first aspect of the present invention; 
         FIGS. 6   a  and  6   b  are schematic plane view and schematic cross-sectional view respectively which illustrate a fastening strap for a disposable absorbing article according to a second embodiment of the present invention; 
         FIGS. 7   a  and  7   b  are schematic plane view and schematic cross-sectional view respectively illustrating a fastening strap for a disposable absorbing article according to a third embodiment of the present invention; and 
         FIG. 8  is a schematic perspective view illustrating a diaper according to a second aspect of the present invention which has fastening straps of  FIG. 3  attached thereon. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to  FIGS. 3-8 , embodiments of the present invention are illustrated for describing a fastening strap for a disposable absorbing article and a diaper having the fastening strap attached thereon. It will be appreciated that although following discussions are provided with reference to a diaper, the scope of the present invention is not limited thereto, instead, the fastening strap of the present invention is equally applicable to other types of disposable absorbing articles. 
     Referring now to  FIGS. 3 and 4 ,  FIG. 3  a schematic perspective view of a fastening strap  100  for a disposable absorbing article (e.g. a diaper) according to an embodiment of a first aspect of the present invention; and  FIG. 4  is a schematic cross-sectional view of the fastening strap  100  for a disposable absorbing article shown in  FIG. 3 . 
     As illustrated in  FIGS. 3 and 4 , the fastening strap  100  for a disposable absorbing article of the present invention mainly includes a fabric backing  110  and a plastic hook strap  120 . Preferably, the fabric backing  110  is a non-woven fabric backing Alternatively, the fabric backing  110  may be made of other suitable fabric material. The plastic hook strap  120  is overlay on top of at least a portion of the fabric backing  110  and has a plurality of hook  122  integrally formed on a face facing away from the fabric backing  110 . The plastic hook strap  120  is directly secured to the fabric backing  110  by means of a fusion bonding process, such as a supersonic welding process, a thermal welding process. During the fusion bonding process, binding patterns  124  are formed on the fastening strap  100  and in the embodiment illustrated in  FIGS. 3 and 4 , the binding patterns  124  are parallel linear grooves  124  that are evenly spaced from each other. According to another embodiment, the binding patterns  124  may be an array of circular dimples  124 ′, as illustrated in  FIG. 5 , or polygonal dimples (not shown). Additionally, in order to prevent two later sides of the plastic hook strap  120  that are not welded to the fabric backing  110  from warping upwardly, sealing portions  126  are formed along the lateral sides of the plastic hook strap  120  by performing a welding process so as to fix the lateral sides of the plastic hook strap  120  to the fabric backing  110 . 
       FIGS. 6   a  and  6   b  are schematic plane view and schematic cross-sectional view respectively, which illustrate a fastening strap  100 ′ for a disposable absorbing article according to a second embodiment of the present invention. As illustrated in the drawings, the fastening strap  100 ′ mainly includes a plastic hook strap  120  having a plurality of hooks  122  integrally formed on a face thereof, and two fabric side wings  130  with one fabric side wings  130  being overlaid on one side of the plastic hook strap  120  respectively and directly secured thereto by performing a fusion bonding process (e.g., a supersonic welding process or a thermal welding process) on overlaid portions  132  between the side wings  130  and the hook strap  120  so as to bind the side wings  130  directly to the sides of the plastic hook strap  120  to form the fastening strap  100 ′. 
       FIGS. 7   a  and  7   b  are schematic plane view and schematic cross-sectional view respectively, which illustrate a fastening strap  100 ″ for a disposable absorbing article according to a third embodiment of the present invention. As illustrated in the drawings, the fastening strap  100 ″ mainly includes a plastic hook strap  120  having a plurality of hooks  122  integrally formed on a face thereof, two fabric side wings  130  with one of which being overlaid on one side of the plastic hook strap  120  respectively and directly secured thereto by means of a fusion bonding press, and a connecting member  140  having an adhesive film  142  provided at a top face thereof and disposed on one of the fabric side wings  130  such that a distal free edge of the fabric side wing  130  located at a substantially middle portion of the connecting member  140 . The connecting member  140  is directly secured to the fabric side wing  130  on which it is disposed at the substantially middle portion by means of a welding process such that two end sides  141 ,  143  of the connecting member  140  may be folded toward each other. The end sides  141 ,  143  of the connecting member  140  may be welded to a disposable absorbing article (e.g., a diaper) so as to attach the fastening strap  100 ″ to the disposable absorbing article (e.g., a diaper). 
     Next, a process for making a fastening strap  100  for a disposable absorbing article according to the first embodiment of the present invention will be described. First, a web of fabric backing  110 , such as a web of non-woven fabric or other suitable fabric material, is provided. Then, overlaying a hook strap  120  on top of at least one portion of the fabric backing  110 , wherein the plastic hook strap  120  has a plurality of hook  122  integrally formed on a face thereof facing away from the fabric backing  110 . Next, performing a fusion bonding process, such as a supersonic welding process, a thermal welding process and the like, to the overlaid plastic hook strap  120  and fabric backing  110  to allow the plastic melted from the plastic hook strap to penetrate into the fabric backing  110  so as to directly secure the plastic hook strap  120  to the backing  110 , and in the mean time a number of binding patterns  124  are formed on the fastening strap  100  such that the overall stiffness of the fastening strap  100  is lowered so as to provide a sufficient softness to the fastening strap  100 . Then, a fusion bonding process along both lateral sides of the plastic hook strap  100  is performed so as to bind the lateral sides of the hook strap  120  to the fabric backing  110  so as to prevent the lateral sides of the hook strap  120  from warping upwardly. Finally, cutting thus formed fastening strap  100  into desired sizes and shapes. 
     Referring now to  FIG. 8 , a diaper (i.e., a disposable absorbing article)  200  according to a second aspect of the present invention which has fastening straps  100  of  FIG. 3  attached thereon will be described below. As illustrated in  FIG. 8 , the diaper  200  mainly includes a front waist portion  202 , a rear waist portion  204 , a crotch portion  206  extending between the front and the rear waist portions, a loop strap  208  provided on an outer face of the front waist portion  202  and having a plurality of loops  209  formed thereon, and two fastening straps  100  according to the embodiment illustrated in  FIG. 3  and described above. Each of the two fastening straps  100  is attached to a lateral side of the rear waist portion  204  for releasably engaging with the loops  209  of the loop strap  208  so as to fastening the disposable absorbing article  200  on to a wear&#39;s body. Because the fastening strap  100  of the present invention has a number of binding patterns  124  formed thereon, the overall stiffness of the fastening strap  100  is thus lowered and the softness of fastening strap  100  is thus improved, and this in turn improve the comfortableness of a diaper incorporate the fastening strap  100  of the present invention. 
     The present invention utilizes a technique that is completely different from the traditional technique for forming fastening strap for a disposable absorbing article. Specifically, in the traditional technique, the fastening strap is formed by using an adhesive layer to bond a hook strap to a backing substrate. The present invention on the other hand forms the fastening strap by securing a hook strap directly to the fabric backing substrate using a fusion bonding process, such as a supersonic welding process or a thermal welding process. Most importantly, because the fastening strap made by the present invention does not include a layer of adhesive across the entire surface of the fastening strap, the fastening strap provided by the present invention has great suppleness. 
     Although the present invention has been described above according to preferred embodiments of the fastening strap and method illustrated in the accompanying drawings, this does not mean that the scope of the present invention is limited to specific configurations of the fastening strap and the steps or sequences of the method described above. In fact, there exist various modifications and variations under the principle and spirit disclosed above. For instance, although it is illustrated in  FIGS. 3-7  that the hooks  122  are dual hook arms type of hooks, other types of hooks, such as mono hook arm hooks, mushroom-headed hooks, are also applicable to the present invention. 
     It will be apparent to people skilled in this art that many modifications can be made to the disclosed structures without departing from the true scope of the invention defined by the appended claims. Therefore, it is the intent of the appended claims to cover all such variations and modifications as come within the sprit and scope of this invention.