Patent Publication Number: US-2011072686-A1

Title: Non-peelabel  insole and manufacturing method

Description:
BACKGROUND OF THE PRESENT INVENTION 
     1. Field of Invention 
     The present invention relates to an insole of a shoe, and more particularly to a non-peelable insole, wherein the non-peelable insole has a first layer integrally and continuously formed with a second layer, such that the first and second layer are firmly attached with each other to form the non-peelable insole. 
     2. Description of Related Arts 
     Most of the shoes have an insole, which normally has an upper layer and a lower layer attached to the upper layer by glue, and the lower layer may be provided as a cushion layer for enhancing the comfortableness when the user is wearing the shoe, while the upper layer may provide a smoothie surface for being directly contacted with the user&#39;s feet, so as to provide different designed graphics thereon within the shoe cavity for replacing on the bottom shoe sole. The China Patent application, which has an application number of 200410026765, has published a process of making the shoe insole. This invention disclosed the upper layer of the shoe insole is made by forming a center piece of the upper layer and disposing the center piece in a center portion of a cavity of the mold. Then, the injection material, which is PU material, is injected into the cavity of the mold such that the injection material is outwardly extended from the center piece and is formed at the outer peripheral portion of the upper layer. Accordingly, the center piece of the upper layer is made of EVA material treated with foaming process and precut into a predetermined shape. Alternatively, the center piece can be flattened and precut into the predetermined shape. 
     Traditionally, the insoles are made by a process comprises the steps of providing a sheet of the first layer, such as PU layer (polyurethane), and a sheet of the second layer, such as PVC layer (polyvinyl chloride), cutting the sheet of the first and second layers to a desired shape in accordance to each other, alignedly gluing the first and second layers of the cut sheets, and pressing the corresponding first and second layers of the cut sheets to firmly glue with each other and drying the first and second layers of the cut sheets, so that the insole is formed. However, the insole commonly made by the above mentioned process has the plurality of drawbacks. 
     Firstly, the process of separately forming, tailoring, and gluing the two layers, such as the PU layer and PVC layer, requires a great amount of work by human, so that it is time consuming and inefficient. 
     Secondly, some traditional process of making insole glues the two layer of the insole before tailoring the two layers thereof, so that the efficiency of the process is slightly increased. However, the pre-glued two layers of insole require a large amount of glue, which is material waste and rising another the environmental issue of the pollutant of glue. Further more, the large gluing surface between the two layers is hard to control the amount of the glue, so as to reduce the quality of the insole. 
     Third, the sheets of first and second layers are trimmed or cut to a predetermined shape for fittedly accommodated within the bottom sole of the shoe, so that only the cut parts of the cut sheets are used for making the insole. The other non-cut parts of the cut sheets are wasted. 
     Fourth, in order to align the cut sheets of the first and second layers for being bonding therewith via glue, a predetermined accuracy of the aligning step for attaching the cut sheets of first layer to the second layer is required for the perfect looking of the insole. The amount of glue is hard to evenly apply thereon, so that partial of the first and second layers are insecurely attached with each other, so as to reduce the quality of insole. 
     Fifth, the manually glued first and second layers are easily detached apart from each other during the washing or cleaning process of the insole, so as to decrease the life time of the insole. 
     Sixth, the glue used in the process usually has the property of volatile, so that the toxicity of the glue may be easily evaporated in the air, so as to harm the health and pollute the environment. 
     On the other hand, the present invention is preferably making the insole with the TPR material, which is made of thermoplastic material, has both characteristics of rubber and thermoplastic material, such that this type of material has the processability of thermoplastic and the physical properties of vulcanized rubber. The second layer is also made of cushioning material for providing a cushion effect of the non-peelable insole pad. Moreover, the TPR material is able to be processed by the traditional plastic material processing equipments without vulcanizing, so as to provide a relatively more environmental friendly product. 
     SUMMARY OF THE PRESENT INVENTION 
     An object of the present invention is to provide an insole and its manufacturing method of integrally forming the first and second layers by mold injection in order to improve the above mentioned shortages of existing art. 
     Accordingly, in order to accomplish the above objects, the present invention provides an insole, which comprises a first layer, embodied as PU layer, and a second layer, embodied as TPR layer, integrally and continuously formed with the first layer preferably by thermoplastic process. In particular, the present invention provides an insole, which is non-peelable for enhancing the durability of the insole. Accordingly, the bonding between the first and second layer of the insole is relatively strong, so that after bending, heating, or soaking the insole in water, the first and second layers are not separated from each other. In addition, no complicated alignment is involved for bonding the first and second layers of the insole, so as to simplify the manufacturing process of the insole. 
     Another object of the present invention is to provide an insole, wherein no glue is required for bonding the first and second layer of the insole, so as to provide a relatively more eco friendly product. 
     Another object of the present invention is to provide an insole, wherein the injected second layer of the insole minimizes the waste of raw material. 
     Another object of the present invention is to provide a method of making the insole, wherein the method significantly increases the productivity and efficiency of manufacturing process of insole, so as to minimize the manufacturing cost. 
     Another object of the present invention is to provide a method of making the insole, which does not require to alter the original structural design of the insole, so as to minimize the manufacturing cost of the insole with the integrated structure. 
     Another object of the present invention is to provide a method of making the insole, wherein no expensive or complicated structure is required to employ in the present invention in order to achieve the above mentioned objects. Therefore, the present invention successfully provides an economic and efficient solution for providing an integrated configuration for the insole. 
     The present invention also provides a method for making the insole, wherein the method comprises the following steps. 
     (a) Cut a first sheet to form a plurality of first layers of an insole. 
     (b) Dispose the first layers into a sealing cavity of the insole mold, and enclose the first layer within the sealing cavity. 
     (c) Inject an injection material of the second layer at a fluid state, which is embodied as TPR material, wherein the injection material is injected into the sealing cavity of the insole mold to evenly dispense on the first layer. It is worth mentioning that a thickness of the second layer is selectively adjusted by a volume of the fluid material of the second layer. After the injection material is cooled down, the TPR as the injection material is formed a predetermined shape of the insole in accordance with the first layer and to bond with the first layer, which is embodied as PU layer. In other words, the first layer is bonded with the second layer through the thermoplastic formation. 
     (d) Open the sealing cavity of the insole mold to remove the final product of the non-peelable insole. 
     In the step of injecting the fluid injection material of the method of making the insole, the injecting temperature is between 150° C. and 300° C. 
     In the method of making the insole, the insole mold comprises a first molding body having a first molding cavity and a second molding body having a second molding cavity, wherein the first layer is disposed within the first molding cavity, wherein said injection material in injected into the second molding cavity through an injection channel thereat. 
     Therefore, the present invention eliminates the trimming process of the second material, which embodied as TPR material, and the process of manually gluing the first layer embodied as PU layer and the second layer, so as to enhance the efficiency of producing the insole. The first layer of the PU material and the second layer of the second layer of the TPR material are bonded under high temperature, so that the first and second layers are able to be firmly and securely attached to each other, so as to prolong the life time of the insole. Furthermore, the present invention is able to efficiently utilize the TPR or other injection source of the second material, so as to minimize the original material cost to minimize the unnecessary waste of material. The TPR material is also recyclable, so as to meet the environmental friendly requirement. 
     Accordingly, the second layer is integrally bonded with the first layer to form the non-peelable insole with the following advantages. 
     Perfect bounding: By injecting the fluid material of the second layer to bond with the first layer via a relatively strong bonding in comparison with the glue, the first and second layers will not be separate after wearing, bending, heating, washing, or soaking the insole. 
     Environmental friendly: The first and second layers are bonded together without the use of glue. As it is mentioned above, the glue is a chemical compound having the property of volatile, so that the toxicity of the glue may be easily evaporated in the air, so as to harm the health and pollute the environment. 
     Better appearance: Since the second layer is injected on the first layer, the second layer will perfectly align with the first layer. As the conventional glue method, the second layer is cut and is required to align with the first layer in order to glue the second layer on the first layer. Therefore, the conventional insole must be trimmed its edge to keep the clean edge. 
     Clean appearance: No glue seam between the first and second layers is formed. Accordingly, with the conventional glue method, the glue seam between the first and second layers is virtually impossible to eliminate. 
     Product expansion ability: With the injection method of the present invention, the material of the first layer will not be limited as PU only. In other words, other materials can be used for the first layer to integrally bond with the second layer. However, the conventional glue method can only apply to the PU and TPR glue-bonding. 
     Mass production: The process of the present invention will significantly increase the productivity and efficiency of manufacturing process of the non-peelable insole. The present invention eliminates the conventional steps of cutting the second layer to match with the first layer, aligning the second layer with the first layer, applying the glue between the first and second layers, and trimming the edge of the insole after the second layer is glued on the first layer. In other words, the present invention simplifies the entire process by only cutting the first layer and injecting the second layer on the first layer. Therefore, the present invention can save the production time and increase the productivity. 
     Minimize manpower: The present invention can further minimize the labor cost of the non-peelable insole by simply using the injection machine. 
     Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
     These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a non-peelable insole according to a preferred embodiment of the present invention. 
         FIG. 2  is a perspective view of making the first layer of the non-peelable insole according to the preferred embodiment of the present invention. 
         FIG. 3  is a top view of an insole mold of the method thereof according to the preferred embodiment of the present invention. 
         FIG. 4  is a sectional view of the insole mold according to the preferred embodiment of the present invention. 
         FIG. 5  is a sectional view of the insole mold according to the preferred embodiment of the present invention, illustrating the injection material is being injected into a sealing cavity of the insole mold. 
         FIG. 6  is a sectional view of a non-peelable insole according to the preferred embodiment of the present invention, illustrating a first layer and second layer integrally attached therewith to form the insole. 
         FIG. 7  is a flow diagram of a process of making a non-peelable insole according to a preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
     Referring to  FIGS. 1 and 6  of the drawings, a non-peelable insole according to a preferred embodiment of the present invention is illustrated, wherein the insole comprises a first layer  1  and a second layer  2  integrally and continuously formed with the first layer  1  in a glue-less manner, wherein the first layers  1  are preferably trimmed and cut from a first sheet, such as leather, rubber or the like, and embodied as PU material (polyurethane). The second layer  2  is preferably formed via mold injecting process, so as to integrally and automatically bond with the first layer  10 , embodied as PU layer, via heat or melting to form the bonding therebetween. Accordingly, the non-peelable insole pad can be a removable insole received in the shoe. Accordingly, the first layer  1  has a top surface for being contacted with a foot of a wearer and a lower surface being integrally bonded with the second layer  2 . Preferably, the first layer  1  is made of non-leather material such as PU material. The second layer  2  has a shape in accordance with the first layer  1  and is heat-bonded on the lower surface of the first layer  1 . Preferably, the second layer  2  is injected to the first layer  10  to form the non-peelable insole pad, such that no glue is required to bond between the first and second layers  1 ,  2 . Accordingly, the second layer  2  is made of cushioning material for providing a cushion effect of the non-peelable insole pad. In particularly, the second layer  2  is made of TPR material. The second layer  2  is preferably formed by molding injection method, so as to integrally bonding with the first layer  1  to form the non-peelable insole pad. Therefore, the second layer  2  is preferably formed by a fluid material as an injection material, wherein the injection material is injected directly on the lower surface of the first layer  1 , such that a secure bonding is formed between the lower surface of the first layer  1  and an upper surface of the second layer  2 . Accordingly the second layer  2  also has a bottom surface provided for contacting with a bottom sole of the shoe, so as to be supported and accommodated therewithin. It is worth mentioning that the upper and bottom surfaces of the second layer  2  are formed after the fluid material of the second layer  2  is solidified. 
     More specifically, in order to manufacture the non-peelable insole, the present invention provides a process for making the non-peelable insole which comprises the following steps. First, cut a first sheet  3  to form a plurality of the first layers  1 . Second, heat-bond the second layer  2  on the first layer  1  to formed the non-peelable insole pad in a glue-less manner. 
     As shown in  FIGS. 2 and 7 , the step of cutting the first sheet  3 , which is preferably PU material, to form a plurality of the first layers  1  of the insole is provided. Accordingly, the first sheet  3  is cut to form the first layers  1  having a predetermined shape for being able to be accommodated within a bottom sole of a shoe. The first sheet  3  is preferably made by a material of polyurethane (PU) and being cut to form the first layer  1 , wherein a graphic print, such as a predetermined pattern, color, and/or texture, may be provided on the top surface of the first layer  1 , such that the predetermined pattern, such as a designed graphic, and texture may enhance the aesthetic appearance of the insole and create a smoothie and comfy texture for being contacted with the foot of the wearer. It is worth mentioning the after the first layer  1  is cut from the first sheet  3 , the graphic print will form on the top surface of the first layer  1 . 
     As shown in  FIGS. 3 and 4  of the drawings, an insole mold  4  for making the non-peelable insole is illustrated, wherein the insole mold  4  comprises a second molding body  41  as an upper mold body and a first molding body  42  as a bottom mold body to pivotally enclose with the second molding body  41  to form a sealing cavity therewithin of the insole mold, which has a shape in accordance with a shape of the insole, wherein an injecting channel  410  is preferably formed at the second molding body  41  for communicating with the sealing cavity. 
     Accordingly, as shown in  FIG. 4 , following the step of cutting the first sheet  3 , the method further comprises a step of disposing the cut first layer  1  in the respective first molding body  42  of the insole mold  4 , enclosing the second molding body  41  with the first molding body  42  to seal the sealing cavity of the insole mold, and placing an injection material, embodied as TPR material into an injecting device  5 , as shown in  FIG. 5 . When the injection material within the injecting device  5  is fluidized, a step of injecting the injection material is started, wherein an injecting temperature during the injecting process is preferably set between 150° C. and 300° C., so that the injected injection material will not damage the material structure of the first layer  1  while being able to securely attach with the first layer  1 . In other words, the fluid material of the second layer  2  is injected evenly onto the first layer  1 . Then, a shape of the fluid material is retained to match with the first layer  1  until the fluid material of the second layer  2  becomes solid, so as to integrally form the second layer  2  on the first layer  1 . More specifically, the injection material is previously being heated to a predetermined temperature and liquefied for injecting into an insole mold  4 , such that a covalent bonding may occurred between the lower surface of the first layer  1  and the upper surface of the second layer  2 . Thus, the first and second layers  1 ,  2  are integrally and continuously formed the non-peelable insole without any glue involved. The first layer  1  is directly bonded to the second layer  2  via the covalent bonding therebetween, which is a more secure and stronger bonding than traditional Van der Waals force between the first and second layers  1 ,  2  via glue. 
     After finishing the process of injecting the injection material into the insole mold  4 , the finished insole formed by the first layer  1  and the second layer  2  of the injection material is able to be removed from the insole mold when the temperature of the injection material is cooled to a predetermined temperature. The injection material for making the second layer  2  is preferably made by a material having the physical properties of both plastic and rubber, so that the second layer  2  is able to provide a predetermined hardness for supporting the first layer  1  thereon, while having a predetermined flexibility for being bended for enhancing the comfortableness of the shoe with the insole. In the preferred embodiment, the second layer  2  is embodied as a material of thermoplastic rubber (TPR) for bonding with the first layer  1 , so as to form the covalent bonding between the lower surface of the first layer  1  and the upper surface of the second layer  2 . 
     A step of trimming a peripheral edge of the finished insole may be provided if the insole formed by the above mentioned injecting process has imperfectly remaining injection material protruded at the peripheral edge thereof, so as to obtain a finalized product of non-peelable insole. 
     Accordingly, the present invention is able to effectively enhance the production rate and to securely and evenly form the first layer  1  embodied as PU layer with the second layer  2  embodied as the TPR layer. Therefore, the life time of the insole is significantly increased. The preferred TPR material used for the injecting process also meet the environmental standard. As will be readily appreciated that the TPR material has the physical properties of both plastic and rubber, so that it is TPR is preferably adapted as the injection material to form the second layer  2  in the mold injection manner. The TPR material is also well known as a material for easily processing via mold injection. It is appreciated by one skilled in the art that the TPR has widely adhesive properties for being easily adhesive with variety of materials, and great resistance of deformation while having a desired flexibility. Therefore, the second layer  2  made by the TPR material having the desired flexibility also provides a cushioning properties of the insole to enhance the comfortableness thereof. The resistance of deformation of the TPR increases the durability of the insole and provides a support for the first layer  10 , so as to remain its position and shape thereof. 
     One of the advantages of the present invention is that the thickness of the second layer  2  is selectively adjusted by a volume of the fluid material of the second layer  2 . In comparison with the conventional insole, the thickness of the second layer  2  is fixed. As it is mentioned above, the second layer  2  of the present invention provides the cushioning effect of the non-peelable insole pad. When the thickness of the second layer  2  is increased, the second layer  2  will provide better cushioning effect of the non-peelable insole pad. Therefore, the thickness of the second layer  2  of the present invention can be selectively controlled by the volume of the fluid material of the second layer  2  injected on the first layer  1 . 
     One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
     It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.