Molding method for multilayer composite material insole

Abstract

According to the forming method for the multilayer composite insole, adsorption forming is matched with high-frequency fusion forming, and the manual glue brushing procedure is reduced. The device comprises a high-frequency fusion welding jig, a plurality of first nozzles arranged on the high-frequency fusion welding jig in a surrounding mode and second nozzles correspondingly arranged on the peripheries of the first nozzles, and an upper insole shell and a lower insole shell are subjected to plastic uptake forming; the insole lower shell is put into a high-frequency positioning mold, and an edge step of the insole lower shell and the high-frequency fusion mold are positioned; the insole lower shell is filled with a dynamic response layer; the insole upper shell is placed into the inner layer step of the insole lower shell to be positioned; the high-frequency fusion welding jig is close to the upper shell; a plurality of first nozzles spray normal-temperature shielding gas on the periphery of the high-frequency jig in advance 0.2-0.7 second, high-frequency fusion is started, and the first nozzles are closed; the plurality of second nozzles spray low-temperature cooling gas to cool the high-frequency fusion joint of the upper shell and the lower shell; fusion is completed, and the insole is taken out. The forming method is applied to the technical field of multi-layer composite insole forming methods.

Description

Technical Field

[0001] The present invention relates to the technical field of forming methods for multi-layer composite material insoles, and particularly relates to a forming method for multi-layer composite material insoles. Background Art

[0002] The shoe body structure mainly includes an insole and a vamp. The insole is further divided into a midsole and an outsole. The midsole generally refers to the layer structure in contact with the sole of the foot, and the outsole generally refers to the layer structure provided under the midsole and in contact with the road surface as the bottom layer of the shoe body. Among them, since the outsole is located at the bottom of the shoe body, it needs to have good anti-slip, wear-resistant, corrosion-resistant and other functions. Rubber has material properties such as softness, elasticity, bend resistance, anti-slip and wear resistance. Therefore, the technology of using rubber as the main material for functional insoles has a history of nearly a hundred years. From early natural rubber to synthetic rubber including: SBR, NBR, EPDM, BR, IIR, CR, FKM, etc. have been widely used in insole materials and their manufacturing processes.

[0003] Most multi-layer insoles on the market rely on glue bonding, which has the risk of delamination, and the layer-to-layer bonding accuracy is low, easily leading to uneven foot pressure distribution and affecting comfort. In the prior art, the design of the midsole buffer layer is single, and it is difficult to meet the differentiated support requirements of different foot regions. In addition, the insole production process is complex and the positioning accuracy is insufficient, resulting in low efficiency. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a forming method for multi-layer composite material insoles that reduces the manual gluing process through adsorption molding and high-frequency fusion molding.

[0005] The technical solution adopted by the present invention is as follows: The present invention 1. includes a high-frequency fusion fixture, a plurality of first nozzles arranged around the high-frequency fusion fixture, and second nozzles correspondingly arranged around the respective first nozzles. The forming method includes the following steps:

[0006] S1. The upper insole shell and the lower insole shell are respectively vacuum-formed.

[0007] S2. The lower insole shell is placed in a high-frequency positioning mold, and the edge step of the lower insole shell is positioned with the high-frequency fusion mold.

[0008] S3. A dynamic response layer is filled in the lower insole shell.

[0009] S4. The upper insole shell is placed in the inner step of the lower insole shell for positioning.

[0010] S5. The high-frequency fusion fixture approaches the upper shell.

[0011] S6. Several first nozzles spray room-temperature protective gas around the high-frequency fixture 0.2 - 0.7 seconds in advance, start high-frequency welding, and several first nozzles are closed;

[0012] S7. Several second nozzles spray low-temperature cooling gas at -10°C to 10°C to cool the high-frequency welded part of the insole upper shell and the insole lower shell;

[0013] S8. Complete the welding and take out the insole.

[0014] Furthermore, in step S1, the insole upper shell is integrally formed by an elastic layer, a non-woven fabric, and a hot-melt adhesive film through a co-extrusion lamination method or a hot-melt adhesive lamination method.

[0015] Furthermore, in step S1, the step of thermoforming the lower shell:

[0016] S1.1 Place the midfoot piece in the middle of the insole lower shell mold, and place the heel piece at the rear of the insole lower shell mold;

[0017] S1.2 Place the insole lower shell mold on the support layer. After the support layer is heated, it is thermoformed with the midfoot piece and the heel piece.

[0018] Furthermore, the midfoot piece adopts an asymmetric involute surface, and the midfoot piece is provided with a plurality of through holes that adsorb and fit with the insole lower shell.

[0019] Furthermore, the material of the heel piece can be ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane elastomer, hydrogenated styrene-butadiene block copolymer styrenic block copolymer, or natural rubber or latex or aromatic polyamide organic fiber material.

[0020] Furthermore, the insole lower shell is provided with a forefoot area, a midfoot area, a heel area, and a heel center area for filling foamed particles or blocks.

[0021] Furthermore, the forefoot area is provided with a plurality of breathable lines for gas interaction with the insole upper shell.

[0022] Furthermore, the first nozzle blows out room-temperature nitrogen or room-temperature argon, the second nozzle sprays low-temperature nitrogen or low-temperature argon, and the gas flow rate of the first nozzle and the second nozzle is 5 - 10 L / min.

[0023] Furthermore, in step S3, the dynamic response layer is composed of alternately combined foamed particles or blocks with different Shore hardnesses, and the foamed particles or blocks are ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane elastomer, hydrogenated styrene-butadiene block copolymer, styrenic block copolymer, natural rubber, latex, or aromatic polyamide organic fiber.

[0024] Further, the elastic layer is a TPU, EVA or PU film.

[0025] The beneficial effects of the present invention are as follows: Since the upper insole shell and the lower insole shell of the present invention are formed by vacuum thermoforming, utilizing the high elastic state characteristics of the film, vacuum adsorption makes the material closely fit the mold, ensuring the curvature accuracy and improving the comfort. At the same time, a multi-layer composite structure is adopted. The upper insole shell is pre-composite with non-woven fabric to improve wear resistance; the middle waist piece and the heel piece of the lower insole shell adopt a porous structure for positioning and enhance the bonding strength with the lower insole shell through vacuum adsorption pressure; a sandwich structure of the upper insole shell, the dynamic response layer and the lower insole shell is adopted, and precise conformal of multiple layers of materials is achieved through vacuum adsorption. Utilizing the high elastic state characteristics of the film above the glass transition temperature (Tg), the plantar curvature replication with an accuracy of 0.1 - 0.5 mm is achieved through the mold air pressure difference (△P≥0.8 MPa), which is applicable to the fields of sports, medical correction, functional foot support and daily insoles;

[0026] The internal design of the multi-block structure of the lower insole shell has steps for positioning functions, allowing the plantar physiological curve of the upper insole shell to be snapped in, making it more convenient and efficient to place and position the upper insole shell. Moreover, the outside of the steps is oriented and positioned with the high-frequency welding mold, improving the positioning efficiency of placing the lower insole shell and simplifying the positioning process flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic structural diagram of the present invention;

[0028] Figure 2 is an exploded view of the present invention;

[0029] Figure 3 is an exploded view of the upper insole shell and the lower insole shell of the present invention;

[0030] Figure 4 is a schematic structural diagram of the cooperation of the lower insole shell, the middle waist piece and the heel piece of the present invention.

[0031] In the figure: 1, high-frequency positioning mold; 2, first nozzle; 3, second nozzle; 4, upper insole shell; 5, lower insole shell; 51, forefoot area; 52, middle waist area; 53, heel area; 54, heel center area; 55, breathable line; 6, high-frequency welding jig; 7, middle waist piece; 8, heel piece. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] As Figures 1 to 4 shown, in this embodiment, the present invention includes a high-frequency welding jig 6, a plurality of first nozzles 2 arranged around the high-frequency welding jig 6, and second nozzles 3 correspondingly arranged around the respective first nozzles 2. The forming method includes the following steps:

[0033] S1. The upper insole shell 4 and the lower insole shell 5 are respectively formed by thermoforming;

[0034] S2. Place the insole lower shell 5 into the high-frequency positioning mold 1, and position the edge step of the insole lower shell 5 with the high-frequency welding mold;

[0035] S3. Fill the dynamic response layer in the insole lower shell 5;

[0036] S4. Place the insole upper shell 4 into the inner step of the insole lower shell 5 for positioning;

[0037] S5. Move the high-frequency welding fixture 6 close to the upper shell;

[0038] S6. A number of first nozzles 2 spray normal-temperature protective gas around the high-frequency fixture 0.2 - 0.7 seconds in advance, start high-frequency welding, and then a number of first nozzles 2 are closed;

[0039] S7. A number of second nozzles 3 spray low-temperature cooling gas to cool the high-frequency welding area of the upper shell and the lower shell;

[0040] S8. Complete the welding and take out the insole.

[0041] In steps S2 and S4, the insole lower shell 5 or the insole upper shell 4 is placed manually or by a manipulator;

[0042] In step S3, the dynamic response layer is filled by a robotic arm. The robotic arm precisely places the foaming particles to ensure that the density and elasticity of each area meet the design requirements;

[0043] The insole upper shell 4 and the insole lower shell 5 are formed by vacuum thermoforming. Utilizing the high elastic state characteristics of the film, vacuum adsorption makes the material closely fit the mold, ensuring the curvature accuracy and improving the comfort. At the same time, a multi-layer composite structure is adopted. The insole upper shell 4 is pre-compounded with non-woven fabric to improve wear resistance; the middle waist piece 7 and the heel piece 8 of the insole lower shell 5 adopt a porous structure for positioning and enhance the bonding strength with the insole lower shell through vacuum adsorption pressure; a sandwich structure of the insole upper shell 4, the dynamic response layer, and the insole lower shell 5 is adopted, and precise conformal of multiple layers of materials is achieved through vacuum adsorption. Utilizing the high elastic state characteristics of the film above the glass transition temperature (Tg), the plantar curvature replication with an accuracy of 0.1 - 0.5 mm is achieved through the mold air pressure difference (△P≥0.8 MPa), which is applicable to the fields of sports, medical correction, functional foot support, and daily insoles; the internal design of the stepped structure in the multi-block insole lower shell 5 plays a positioning role, allowing the insole upper shell to be inserted into the foot physiological curve more conveniently and efficiently. Moreover, the outside of the step is oriented and positioned with the high-frequency welding mold, improving the positioning efficiency of the insole lower shell 5 and simplifying the positioning process flow.

[0044] In this embodiment, in step S1, the insole upper shell 4 is integrally formed by a co-extrusion lamination method or a hot melt adhesive lamination method using an elastic layer, a non-woven fabric, and a hot melt adhesive film. The elastic layer is a TPU, EVA, or PU film. The elastic layer is combined with the non-woven fabric and the hot melt adhesive film to form a multi-layer film by co-extrusion lamination or hot melt adhesive lamination, and then heat-formed by thermoforming after heating. The film is heated above the glass transition temperature (Tg) and formed by vacuum thermoforming (ΔP≥0.8MPa) to replicate the plantar curvature with an accuracy of 0.1 - 0.5mm, forming a surface layer that conforms to the physiological curve of the sole of the foot, or hot melt adhesive lamination (pre-lamination) to form a multi-layer film and then heat-formed by thermoforming to form a surface layer that conforms to the physiological curve of the sole of the foot.

[0045] In this embodiment, in step S1, the step of thermoforming the lower shell is as follows:

[0046] S1.1 Place the midfoot piece 7 in the middle of the insole lower shell 5 mold, and place the heel piece 8 at the rear of the insole lower shell 5 mold;

[0047] S1.2 Place the insole lower shell 5 mold on the support layer. After the support layer is heated, it is thermoformed with the midfoot piece 7 and the heel piece 8 by enhanced vacuum adsorption pressure. The midfoot piece 7 is used for arch support, and the midfoot piece 7 can be made of carbon fiber, PP, or PA.

[0048] In this embodiment, the midfoot piece 7 adopts an asymmetric involute surface. The midfoot piece 7 is provided with a number of through holes that adsorb and fit with the insole lower shell 5, which are applicable to different outer shapes, hole shapes, sizes, and positions. The hole diameter is 0.5 - 8mm, the hole pitch is 1 - 8mm, and the thickness is 0.5 - 4mm. The asymmetric involute surface of the midfoot piece 7 has a curvature radius R = 50 - 80mm. The through hole design facilitates the tight fitting of the midfoot piece 7 during the adsorption molding process of the insole lower shell, improving the adsorption fitting degree.

[0049] In this embodiment, the material of the heel piece 8 can be ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane elastomer, hydrogenated styrene-butadiene block copolymer styrene block copolymer, natural rubber, latex, or aromatic polyamide organic fiber material. The heel piece 8 has a porous structure with a pore diameter of 0.5 - 8mm and a porosity of 30 - 50%, which has shock absorption and shock mitigation properties; the heel piece is provided with a number of through holes that adsorb and fit with the insole lower shell, which are applicable to different outer shapes, hole shapes, sizes, and positions. The hole diameter is 0.5 - 8mm, the hole pitch is 1 - 8mm, and the thickness is 0.5 - 8mm.

[0050] In this embodiment, the insole lower shell 5 is provided with a forefoot area 51, a midfoot area 52, a heel area 53, and a heel center area 54 for filling foamed particles or blocks. The four areas are filled with foamed particles or blocks of ethylene-vinyl acetate copolymer (EVA), polyurethane (PU), thermoplastic polyurethane elastomer (TPU), hydrogenated styrene-butadiene block copolymer (SEBS), styrenic block copolymer (such as SBS, SIS, etc.), natural rubber (RB), latex, or aromatic polyamide organic fiber with different Shore hardnesses in an alternating combination to serve as the function of the pressure distribution of the human foot, forming a good buffering effect and improving the user's comfort; the texture of the forefoot area 51 enhances ventilation, the midfoot arc structure corrects the arch of the foot, and dynamically responds to the foot pressure distribution.

[0051] In this embodiment, the forefoot area 51 is provided with a number of breathable lines 55 for gas interaction with the insole upper shell 4. The breathable lines 55 have a width of 0.5 - 2 mm and a depth of 0.5 - 2 mm, forming a breathable structure to facilitate gas interaction and circulation between the forefoot area 51 and the in-shoe space.

[0052] In this embodiment, the first nozzle 2 blows out normal-temperature nitrogen or normal-temperature argon, the second nozzle 3 sprays out low-temperature nitrogen or low-temperature argon, the gas flow rates of the first nozzle 2 and the second nozzle 3 are 5 - 10 L / min, and the temperature of the low-temperature cooling gas is -10°C to 10°C. The gas outlets of the first nozzle 2 and the second nozzle 3 are aligned with the high-frequency welding positions of the insole upper shell 4 for introducing nitrogen or argon (flow rate 5 - 10 L / min) to inhibit oxidation and thermal decomposition during the high-frequency process in an environment with an O2 concentration < 50 ppm and prevent high-temperature carbonization. The temperature of the low-temperature cooling gas blown out by the second nozzle is -10°C to 10°C.

[0053] In this embodiment, in step S3, the dynamic response layer is composed of an alternating combination of foamed particles or blocks with different Shore hardnesses, and the foamed particles or blocks are ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane elastomer, hydrogenated styrene-butadiene block copolymer, styrenic block copolymer, natural rubber, latex, or aromatic polyamide organic fiber.

[0054] In this embodiment, the elastic layer is a TPU, EVA, or PU film.

[0055] Although the embodiments of the present invention are described with actual solutions, they do not constitute a limitation to the meaning of the present invention. For those skilled in the art, modifications to its implementation solutions according to this specification and combinations with other solutions are obvious.

Claims

1. A method for forming a multi-layer composite insole, characterized in that: The invention comprises a high-frequency positioning mold (1), a plurality of first nozzles (2) arranged around the high-frequency positioning mold (1), and second nozzles (3) arranged correspondingly around the first nozzles (2). The molding method comprises the following steps: S1, the upper shell of the insole (4) and the lower shell of the insole (5) are respectively formed by vacuum forming; S2, the lower shell of the insole (5) is placed into the high-frequency positioning mold (1), and the edge step of the lower shell of the insole (5) is positioned with the high-frequency fusion mold; S3, filling a dynamic response layer in the lower shell (5) of the insole; S4, placing the upper insole shell (4) into the inner step of the lower insole shell (5) for positioning; S5, a high frequency welding jig (6) is placed close to the upper shell; S6, a plurality of first nozzles (2) spray room temperature protective gas around the high-frequency fixture 0.2-0.7 seconds in advance, start high-frequency welding, and a plurality of first nozzles (2) are closed; S7, a plurality of second nozzles (3) spray low-temperature cooling gas at a temperature of -10°C to 10°C to cool the high-frequency fusion joint between the upper shell (4) of the insole and the lower shell (5) of the insole; S8. After the fusion is completed, the insole is removed.

2. A method for forming a multi-layer composite insole according to claim 1, characterized in that: In step S1, the insole upper shell (4) is integrally formed from an elastic layer, a non-woven fabric and a hot-melt adhesive film by a co-extrusion composite method or a hot-melt adhesive composite method.

3. The method for forming a multi-layer composite insole according to claim 1, characterized in that: In step S1, the lower shell is blister-formed: S1.1 Place the middle waist piece (7) in the middle of the mold of the lower shell of the insole (5), and place the heel piece (8) in the rear of the mold of the lower shell of the insole (5); S1.2 The mold of the lower shell of the insole (5) is placed in the support layer, and after the support layer is heated, it is formed by vacuum forming with the middle waist piece (7) and the heel piece (8).

4. The method for forming a multi-layer composite insole according to claim 3, characterized in that: The middle waist piece (7) adopts an asymmetric involute curved surface, and the middle waist piece (7) is provided with a plurality of through holes which are adsorbed and fitted with the lower shell of the insole (5).

5. The method for forming a multi-layer composite insole according to claim 3, characterized in that: The material of the heel piece (8) can be ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane elastomer, hydrogenated styrene-butadiene block copolymer, styrene block copolymer or natural rubber or latex or aromatic polyamide organic fiber material.

6. The method for forming a multi-layer composite insole according to claim 1, characterized in that: The insole lower shell (5) is provided with a forefoot area (51) for filling with foamed particles or blocks, a mid-waist area (52), a heel area (53) and a heel center area (54).

7. A method for forming a multi-layer composite insole according to claim 6, characterized in that: The forefoot area (51) is provided with a plurality of ventilation lines (55) for gas exchange with the insole upper shell (4).

8. The method for forming a multi-layer composite insole according to claim 1, characterized in that: The first nozzle (2) blows out nitrogen or argon at room temperature, and the second nozzle (3) sprays out low-temperature nitrogen or argon. The gas flow rates of the first nozzle (2) and the second nozzle (3) are 5-10 L / min.

9. The method for forming a multi-layer composite insole according to claim 1, characterized in that: In step S3, the dynamic response layer is composed of an alternating combination of foamed particles or blocks with different Shore hardnesses, and the foamed particles or blocks are ethylene-vinyl acetate copolymer, polyurethane, thermoplastic polyurethane elastomer, hydrogenated styrene-butadiene block copolymer, styrene block copolymer, natural rubber, latex or aromatic polyamide organic fiber.

10. The method for forming a multi-layer composite insole according to claim 1, characterized in that: The elastic layer is TPU, EVA or PU film.

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