A no-seam sole and a method of making the same

Abstract

The application discloses a kind of no edge seam sole and its manufacturing method.The method mainly includes: first, high-density polyurethane mixed solution with catalyst is injected into special mould, and is extruded into thin wear-resistant layer containing non-woven fabric pattern layer and having reserved air hole on surface by bottom die with needle foot and upper cover with buckle foot;Then, the wear-resistant layer is placed in foaming mould, TPU film paper is covered and tightly attached by vacuumizing;Finally, low-density polyurethane stock solution is injected, and TPU film paper, wear-resistant layer and foaming layer are fused into one by high temperature and high pressure generated in foaming process, so as to realize seamless connection.The sole made by the application has the advantages of no edge seam, light weight, good skid resistance, various appearance patterns and smooth side without air hole, effectively solving the problems of joint cracking, heavy weight and rough surface in traditional process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of foamed shoe sole manufacturing, in particular to a no-seam sole and a manufacturing method thereof. BACKGROUND

[0002] Traditional soles are usually combined by multiple layers (such as wear-resistant layer and foamed layer) through gluing or physical splicing, which is prone to uneven seams, cracking, and heavy weight. The bubbles generated during foaming process will cause rough surface, affecting the appearance and functionality. In addition, the wear-resistant layer is usually thick and has a single pattern, which is difficult to balance the lightweight and personalized needs. In the prior art, the control of the shrinkage ratio of polyurethane material is not accurate, resulting in size deviation of the finished product, and insufficient exhaust limits the further reduction of the wear-resistant layer thickness. SUMMARY

[0003] The present application aims to provide a no-seam sole and a manufacturing method thereof, which overcomes the defects of the prior art and solves the problems of thick wear-resistant layer and single pattern of the existing soles, and the bubbles generated during the foaming process will cause rough surface, affecting the appearance and functionality.

[0004] To this end, the present application provides a manufacturing method of a no-seam sole, comprising the following steps:

[0005] S1: manufacturing a wear-resistant layer with air holes: pouring a high-density polyurethane mixed solution mixed with a catalyst into the bottom mold of the wear-resistant layer mold, covering the upper cover, and extruding to obtain a wear-resistant layer with a non-woven fabric layer embedded inside and air holes; and spraying glue on the upper surface of the wear-resistant layer and air drying;

[0006] S2: providing a forming mold, which includes a wear-resistant layer bottom mold for accommodating the wear-resistant layer and a mold cavity for forming a foamed layer, the wear-resistant layer bottom mold is provided with a vacuum air hole corresponding to the wear-resistant layer air hole and a connected vacuum air nozzle;

[0007] S3: laying the wear-resistant layer made in S1 on the wear-resistant layer bottom mold of the forming mold, so that the air holes of the wear-resistant layer are aligned with the vacuum air holes;

[0008] S4: covering the TPU film paper layer on the mold cavity, and fixing the periphery of the TPU film paper layer by the pressing plate;

[0010] S5: drawing vacuum through the vacuum air nozzle to make the TPU film paper layer tightly adhere to the surface of the wear-resistant layer and the side wall of the mold cavity;

[0011] S6: injecting low-density polyurethane foaming solution into the cavity formed by the TPU film paper layer;

[0012] S7: covering the upper mold and heating to make the low-density polyurethane solution foam, and the high temperature and high pressure generated by foaming makes the TPU film paper layer fuse with the wear-resistant layer and the foamed layer.

[0012] S8: trimming the excess TPU film paper on the edge of the sole to form an integrated no-seam sole.

[0013] Preferably, in step S1, the catalyst comprises a foaming agent and a hardening agent.

[0014] Preferably, in step S1, before the upper cover is closed, the non-woven fabric printed with the pattern is fixed to the clamping feet on the inner side of the upper cover of the wear-resistant layer mold, and after the mold is closed, the non-woven fabric is embedded in the wear-resistant layer after the mold is closed.

[0015] Preferably, the depth of the front end of the bottom mold of the wear-resistant layer mold is greater than the depth of the rear end, and the gas in the mixed solution is pushed out from front to back when the upper cover is closed.

[0016] Preferably, in step S1, the bottom mold of the wear-resistant layer mold is provided with a needle foot for forming air holes on the wear-resistant layer.

[0017] Preferably, in step S1, the upper cover of the wear-resistant layer mold is provided with clamping feet for fixing the non-woven fabric layer at the edge of the upper cover.

[0018] Preferably, in step S2, the air nozzle is provided with a switch valve.

[0019] Preferably, in step S1, the upper cover is provided with a protrusion matching the shape of the bottom mold, and the side of the protrusion is also provided with a raised edge, so that the non-woven fabric layer is embedded in the high-density polyurethane solution.

[0020] Preferably, in step S7, the pressure generated by foaming is not less than 10 atmospheres.

[0021] The application also provides a no-seam sole, which comprises a wear-resistant layer, the wear-resistant layer is embedded with a non-woven fabric layer, the non-woven fabric layer can be printed with a desired pattern, and a TPU film paper layer is further provided between the wear-resistant layer and the foaming layer, and the three are integrated and connected by high-temperature fusion.

[0022] Preferably, the TPU film paper layer completely wraps the outer edge of the foaming layer.

[0023] The present application provides a no-seam sole and a manufacturing method thereof, which has the following advantages: 1) no-seam design: the wear-resistant layer and the foaming layer are fused by TPU film paper layer under high temperature and high pressure, realizing seamless connection and improving the integrity and aesthetic appearance; 2) light weight and thin type: the polyurethane formula and the exhaust process are optimized, so that the wear-resistant layer can be made thinner, reducing the weight of the sole; 3) enhanced stability: the non-woven fabric is embedded in the wear-resistant layer, reducing shrinkage and deformation, and providing a variety of pattern selection; 4) smooth surface without bubbles: the vacuum film suction process ensures that the TPU film tightly wraps the foaming layer, avoiding air holes and smooth side edges; 5) high process compatibility: by adjusting the catalyst ratio and mold design, the molding requirements of different density polyurethane can be met.

[0024] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be described in detail below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings accompanying the specification of the present application serve to provide further understanding of the present application, the illustrative embodiments thereof, and the explanation thereof, and do not constitute an improper limitation on the present application. In the drawings:

[0026] Figure 1 A structure diagram of a wear-resistant layer mold in the manufacturing method of the no-seam sole of the present application;

[0027] Figure 2 A structure diagram of a forming mold in the manufacturing method of the no-seam sole of the present application;

[0028] Figure 3 A structure diagram of the no-seam sole of the present application;

[0029] Figure 4 A structure diagram of the no-seam sole of the present application;

[0030] Explanation of reference numerals: 10, wear-resistant layer mold; 20, forming mold; 30, sole; 11, bottom mold; 12, upper cover; 21, wear-resistant layer bottom mold; 22, mold cavity; 23, pressing plate; 24, upper mold; 111, pin; 121, buckle; 211, vacuum hole; 212, air nozzle; 31, wear-resistant layer; 32, non-woven fabric layer; 33, TPU film paper layer; 34, foaming layer. DETAILED DESCRIPTION

[0031] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0032] As Figure 3 , Figure 4As shown, this invention discloses a seamless shoe sole. The shoe sole 30 includes an abrasion-resistant layer 31, in which a non-woven fabric layer 32 is embedded. The non-woven fabric layer 32 can be printed with desired patterns. The abrasion-resistant layer 31 is made of transparent material. A TPU film layer 33 is also provided between the abrasion-resistant layer 31 and the foam layer 34. The TPU film layer 33 completely wraps the outer edge of the foam layer. The abrasion-resistant layer 31, the foam layer 34, and the TPU film layer 33 are fused together at high temperature.

[0033] Material selection for wear-resistant layer 31: High-density polyurethane raw material is mixed with catalysts (foaming agent and hardener) to adjust the viscosity, hardness, and cooling cycle of the high-density polyurethane raw material, so that the wear-resistant layer 31 can be formed better. Since polyurethane material itself has a certain shrinkage ratio, high-density polyurethane generally has a shrinkage ratio of about 0.3%, and low-density polyurethane has a shrinkage ratio of about 0.7%. Therefore, in mold making, the size of the mold is slightly adjusted according to its shrinkage ratio so that the size of the formed wear-resistant layer 31 is closer to the required standard size.

[0034] like Figure 1 As shown, the bottom mold 11 of the wear-resistant layer mold 10 has anti-slip textures, and the anti-slip textures also have needles 111, which facilitates the pre-reservation of air holes in the wear-resistant layer 31. The front end of the mold is slightly deeper and the rear end is slightly shallower. When the mold is closed, the upper cover 12 pushes the mold from front to back (due to the adjustment of the cooling cycle of the polyurethane solution, there is enough time to push the mold closed), so as to better expel the gas in the polyurethane solution (similar to the film application process). Because the gas in the polyurethane solution is fully expelled, this method can make the wear-resistant layer 31 thinner, thus making the entire sole lighter. The upper cover 12 of the wear-resistant layer mold 10 has protrusions that match the shape of the bottom mold 11. The protrusions have textures that are concave and convex mirrors the anti-slip textures on the bottom mold 11.

[0035] Further, in order to strengthen the stability of the wear-resistant layer 31, increase the edge height of the side edge of the wear-resistant layer 31, reduce its shrinkage ratio, and make the wear-resistant layer 31 have a variety of pattern selection, the wear-resistant layer 31 is selected to be transparent material, a non-woven fabric layer 32 is arranged on the upper cover 12, the non-woven fabric can print various patterns, the non-woven fabric is fixed on the upper cover 12, the transparent high-density polyurethane solution is poured into the bottom mold 11, after the upper cover 12 is covered, the non-woven fabric layer 32 is immersed in the high-density polyurethane solution, and then the non-woven fabric layer 32 is further completely immersed in the wear-resistant layer 31 through the protrusions on the upper cover 12 and the patterns on the protrusions. The side edge of the protrusion of the upper cover 12 is also provided with a raised edge. When the upper cover 12 is located at the edge part, the non-woven fabric layer 32 is extruded by the raised edge to make the non-woven fabric layer 32 embedded in the high-density polyurethane solution; it is ensured that the non-woven fabric layer 32 is uniformly immersed in the formed wear-resistant layer, and the embedded non-woven fabric layer 32 not only has the effect of reinforcing rib, strengthens the stability of the wear-resistant layer 31, but also ensures that the glue is on the high-density polyurethane material when the glue is sprayed, which is convenient for subsequent fusion with the TPU film paper 33; at the same time, the wear-resistant layer 31 is integrally formed, the side edge end face of the formed polyurethane material is flat, and only the excess non-woven fabric layer 32 needs to be trimmed, which ensures the flatness of the side edge end face of the wear-resistant layer 31, and further ensures the flatness of the joint surface after the wear-resistant layer 31 is fused and connected with the foaming layer 34.

[0036] As shown in Figure 2 The shoe sole forming mold 20 includes a wear-resistant layer bottom mold 21 matched with the wear-resistant layer 31, a foaming layer mold cavity 22 matched with the foaming layer 34, a pressing plate 23, and an upper mold 24. The wear-resistant layer bottom mold 21 is provided with a plurality of vacuum holes 211 corresponding to the wear-resistant layer air holes and connected with a vacuum nozzle 212; the vacuum nozzle 212 is selectively connected with an external vacuum device, and a switch valve is installed on the vacuum nozzle 212. The wear-resistant layer bottom mold 21, the foaming layer mold cavity 22, and the pressing plate 23 are sequentially sealed and buckled.

[0037] The upper surface of the dried wear-resistant layer 31 is laid on the wear-resistant layer bottom die 21, the wear-resistant layer bottom die 21 is tightly attached to the wear-resistant layer 31, a layer of TPU film paper 33 is covered on the mold, the TPU film paper 33 is fixed on the upper surface of the mold by the pressing plate 23, the air nozzle is connected to the air suction machine, the TPU film paper 33 is tightly attached to the wear-resistant layer 31 and the foam layer cavity 22 by vacuumizing the bottom of the mold, the valve is closed, the low-density polyurethane solution is poured, the upper die 24 is covered, the high temperature and high pressure generated by the foaming of the low-density polyurethane solution make the TPU film paper 33, the wear-resistant layer 31, the glue and the foam layer 34 high-temperature fusion, the fusion of the wear-resistant layer 31 and the foam layer is realized, and the side of the foam layer is coated by the TPU film paper 33, the TPU film paper itself is smooth and flat, so that the outer edge surface of the foam layer 34 is smooth and flat, the aesthetic degree of the shoe sole is effectively improved, and the product yield is improved, and the foam layer 34 does not need to be repaired due to the bubbles generated on the outer edge during foaming, time and labor are saved.

[0038] Generally, a large amount of heat is generated during the foaming process of the foaming material, and high pressure is also generated in the closed cavity of the mold, which can generally reach 10 atmospheres. The TPU film paper is fused by high temperature and high pressure, which is flat, smooth and tightly fused.

[0039] In summary, the application provides a manufacturing method of a no-edge-seam shoe sole, which comprises the following steps:

[0040] S1: manufacturing a wear-resistant layer with air holes; pouring a high-density polyurethane mixed solution mixed with a catalyst into a bottom die of a wear-resistant layer mold, covering an upper cover, and obtaining a wear-resistant layer with a non-woven fabric layer embedded inside and air holes on the surface by extrusion molding; and spraying glue on the upper surface of the wear-resistant layer and drying;

[0041] S2: providing a forming mold, which comprises a wear-resistant layer bottom die for accommodating the wear-resistant layer and a cavity for forming a foam layer, and the wear-resistant layer bottom die is provided with a vacuum air hole corresponding to the air hole of the wear-resistant layer and a connected vacuum air nozzle;

[0042] S3: laying the wear-resistant layer manufactured in S1 on the wear-resistant layer bottom die of the forming mold, so that the air hole of the wear-resistant layer is aligned with the vacuum air hole;

[0043] S4: covering a TPU film paper layer on the cavity, and sealing and fixing the periphery of the TPU film paper layer by a pressing plate;

[0044] S5: vacuumizing through the vacuum air nozzle, so that the TPU film paper layer is tightly attached to the surface of the wear-resistant layer and the side wall of the cavity;

[0045] S6: injecting a low-density polyurethane foaming solution into a cavity formed by the TPU film paper layer;

[0046] S7: Covering the upper mold, heating, making the low-density polyurethane solution foaming, the high temperature and high pressure generated by the foaming makes the TPU film paper layer and wear-resistant layer and foaming layer fusion.

[0047] S8: Trimming the excess TPU film paper on the edge of the sole to form an integrally formed edgeless sole.

[0048] As a preferred technical solution of the present application, the upper cover 12 of the wear-resistant layer mold 10 is provided with a buckle foot 121 for fixing the non-woven fabric. The non-woven fabric is fixed on the buckle foot 121. After the high-density polyurethane mixed solution is injected into the bottom mold, the upper cover 12 is closed, and the non-woven fabric layer 32 invades the high-density polyurethane mixed solution. The non-woven fabric on the side wall is embedded in the high-density polyurethane solution due to the protruding edge on the side of the protruding block of the upper cover 21. The non-woven fabric layer is embedded in the high-density polyurethane solution by extrusion through the edge. It is ensured that the non-woven fabric layer is immersed in the formed wear-resistant layer. The bottom mold upper surface is designed with a hole corresponding to the buckle foot 121.

[0049] As a preferred technical solution of the present application, the front end of the bottom mold is slightly deep, and the rear end is slightly shallow. When the mold is closed, the upper cover 12 is pushed from front to back to extrude the mold (since the cooling period of the polyurethane solution is adjusted, there is enough time to extrude the mold), so as to better exhaust the gas in the polyurethane solution (similar to the film pasting process).

[0050] The working process and principle of the edgeless sole are briefly described below.

[0051] Wear-resistant layer production

[0052] Material configuration: mixing high-density polyurethane solution with catalyst (foaming agent, hardening agent) to adjust viscosity, hardness and cooling time.

[0053] Preferably, the high-density polyurethane solution and catalyst (foaming agent, hardening agent) mixture is a transparent material.

[0054] Mold design: the bottom mold is provided with a needle (for forming air holes), a retaining edge and an anti-skid pattern. The upper cover is provided with a buckle foot for fixing the non-woven fabric and a protruding block. The protruding block is provided with a pattern that is a mirror image of the anti-skid pattern. The front end of the mold is deep, and the rear end is shallow. When the mold is closed, it is pushed from front to back to fully exhaust the gas. Shrinkage ratio compensation: the mold size is adjusted according to the polyurethane shrinkage ratio (high-density one thousandth, low-density seven thousandth).

[0055] Non-woven fabric integration: the non-woven fabric is fixed on the upper cover after printing the pattern. When the mold is closed, it invades the polyurethane solution. After forming, it is located inside the wear-resistant layer. Only the inner edge of the non-woven fabric layer needs to be trimmed, which ensures the flatness of the end surface of the wear-resistant layer side wall.

[0056] The above descriptions are only the preferred embodiments of the present application, and are not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for manufacturing a seamless shoe sole, characterized in that, Includes the following steps: S1: Making a wear-resistant layer with pores (31): Pour a high-density polyurethane mixture containing a catalyst into the bottom mold (11) of the wear-resistant layer mold (10). The bottom mold (11) has anti-slip textures and stitches (111) on the anti-slip textures. The top cover (12) of the wear-resistant layer mold (10) has protrusions that match the shape of the bottom mold (11). The protrusions have textures that are mirror images of the anti-slip textures on the bottom mold (11). The top cover (12) is put on and extruded to obtain a wear-resistant layer (31) with a non-woven fabric layer (32) embedded inside and pores. Glue is sprayed onto the surface of the wear-resistant layer (31) and then air-dried. S2: Provide a molding die (20), which includes a wear-resistant layer bottom mold (21) for accommodating the wear-resistant layer (31) and a mold cavity (22) for molding the foam layer. The wear-resistant layer bottom mold (21) is provided with vacuum holes (211) corresponding to the air holes of the wear-resistant layer (31) and connected vacuum nozzles (212). S3: The wear-resistant layer (31) made in S1 is laid on the wear-resistant layer bottom mold (21) of the molding mold (20), so that the air holes of the wear-resistant layer (31) are aligned with the vacuum air holes (211); S4: Cover the mold cavity (22) with a TPU film paper layer (33) and fix the periphery of the TPU film paper layer (33) by a pressure plate (23); S5: Vacuum is drawn through the vacuum nozzle (212) to make the TPU film paper layer (33) adhere tightly to the surface of the wear-resistant layer (31) and the side wall of the mold cavity (22); S6: Inject low-density polyurethane foam into the cavity formed by the TPU film layer (33); S7: Cover with the upper mold (24), heat it, and make the low-density polyurethane liquid foam. The high temperature and pressure generated by foaming cause the TPU film paper layer (33) to fuse with the wear-resistant layer (31) and the foam layer (34). S8: Trim off the excess TPU film paper from the edge of the sole to form a seamless, one-piece sole.

2. The method for manufacturing a seamless shoe sole according to claim 1, characterized in that, In step S1, the catalyst includes a foaming agent and a hardening agent.

3. The method for manufacturing a seamless shoe sole according to claim 1, characterized in that, In step S1, before closing the top cover (12), the non-woven fabric with the printed pattern is fixed to the buckle (121) on the inside of the top cover (12) of the wear-resistant layer mold (10). After the mold is closed, the non-woven fabric is embedded in the interior and inner wall of the formed wear-resistant layer (31).

4. The method for manufacturing a seamless shoe sole according to claim 1 or 3, characterized in that, The front end of the bottom mold (11) of the wear-resistant layer mold (10) is deeper than the rear end. When the top cover (12) is closed, it is pushed from front to back to expel the gas in the mixture.

5. The method for manufacturing a seamless shoe sole according to claim 1, characterized in that, In step S1, the upper cover (12) of the wear-resistant layer mold (10) is provided with buckles (121) for fixing the non-woven fabric layer (32) at the edge.

6. The method for manufacturing a seamless shoe sole according to claim 1, characterized in that, In step S2, the air nozzle (212) is equipped with a switching valve.

7. The method for manufacturing a seamless shoe sole according to claim 1, characterized in that, In step S1, the upper cover (12) is provided with a protrusion that matches the shape of the bottom mold (11), and the side of the protrusion is also provided with a raised grinding edge, so that the non-woven fabric layer (32) is embedded in the high-density polyurethane solution.

8. A seamless shoe sole, manufactured according to any one of claims 1-7, characterized in that, It includes a wear-resistant layer (31), a non-woven fabric layer (32) is embedded in the wear-resistant layer (31), the required pattern is printed on the non-woven fabric layer (32), and a TPU film paper layer (33) is provided between the wear-resistant layer (31) and the foam layer (34). The three are connected by high temperature fusion.

9. The seamless sole according to claim 8, characterized in that, The TPU film layer (33) completely wraps the outer edge of the foam layer (34).

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