Recyclable adhesive-free integrally formed sole and mold for manufacturing same

Abstract

The present application relates to a recyclable adhesive-free integrally formed sole and a mold for manufacturing same. The recyclable adhesive-free integrally formed sole comprises a wear-resistant outsole and an elastic midsole, wherein the elastic midsole is arranged on the wear-resistant outsole, and the wear resistance of the wear-resistant outsole is greater than that of the elastic midsole. A TPU sole sheet is cut into the wear-resistant outsole, the TPU sole sheet is placed in a mold having a formed pattern, and then the mold is filled with ETPU foam particles, so that the ETPU foam particles are laid on the upper surface of the wear-resistant outsole 2; and steam is introduced into the mold, so that the ETPU particles are formed into the elastic midsole.

Description

A recyclable glue-free one-piece molded shoe sole and the mold used for its manufacture Technical Field

[0001] This application relates to the field of shoe sole manufacturing technology, and in particular to a recyclable glue-free one-piece molded shoe sole and the mold used for manufacturing the same. Background Technology

[0002] ETPU foam material is a new type of polymer material composed of countless highly elastic and lightweight TPU foam balls. It has both the strength and dimensional stability of amorphous resins and the chemical resistance, fatigue resistance and wear resistance of crystalline resins.

[0003] ETPU material overcomes the shortcomings of TPU raw materials, such as heavy weight, high hardness, and poor shock absorption performance, and is suitable for products that need to withstand strong impacts and frequent use, such as the midsole of sports shoes.

[0004] Currently, to achieve wear resistance and slip resistance, ETPU shock-absorbing midsoles typically incorporate a wear-resistant rubber outsole at the bottom. Existing technology discloses a one-piece molding process for an ETPU shock-absorbing midsole and rubber outsole. This process involves cutting and cleaning rubber sheets to create the rubber outsole, which is then placed at the bottom of a steam mold. ETPU granules are added, and steam is used to heat the ETPU granules until their surface is molten. After pressing, the ETPU granules are bonded to the rubber outsole to form the final product.

[0005] However, due to the material differences between the rubber outsole and ETPU granules, their compatibility is poor, resulting in insufficient adhesion after one-piece molding. The rubber outsole is prone to peeling off from the ETPU foam granules. Furthermore, due to the differences in the melting point and molding process of the two materials, the texture structure on the rubber outsole needs to be pre-cured in a mold before being integrally molded with the ETPU granules, which is a cumbersome operation. In addition, the rubber outsole and ETPU granules are difficult to recycle together, which is not conducive to recycling. Summary of the Invention

[0006] To increase the bonding strength between the midsole and outsole, facilitate their recycling together, and eliminate the need for pre-formed patterns on the outsole, this application provides a recyclable glue-free one-piece molded shoe sole and a mold for its manufacture.

[0007] This application provides a recyclable, glue-free, one-piece molded shoe sole and a mold for its manufacture, employing the following technical solution:

[0008] A recyclable, glue-free, one-piece molded shoe sole includes an abrasion-resistant outsole and an elastic midsole. The elastic midsole is disposed on the abrasion-resistant outsole, and the abrasion resistance of the abrasion-resistant outsole is greater than that of the elastic midsole. A TPU sheet is cut into the desired shape to form the abrasion-resistant outsole. The abrasion-resistant outsole is laid in a mold containing a molding pattern, and then ETPU foam particles are filled into the mold, so that the ETPU foam particles are laid on the upper surface of the abrasion-resistant outsole 2. Steam is introduced into the mold to form the ETPU particles into the elastic midsole 1. The molding pressure is 0.1-0.3MPa, the molding temperature is 120-160℃, and the molding time is 150-190s. Then, the material is degassed, water-cooled, and demolded to obtain the recyclable, glue-free, one-piece molded shoe sole.

[0009] By adopting the above technical solutions, the abrasion-resistant outsole has high strength and hardness, capable of withstanding daily wear and impact, maintaining the shape and stability of the shoe. It also has high toughness, making it less prone to breakage or damage under external force. Furthermore, the abrasion-resistant outsole has excellent wear resistance and aging resistance, resisting long-term friction and wear, extending the shoe's lifespan. It maintains stable performance under different climates, is not prone to aging or deformation, and has good elasticity, adapting to the foot's movement needs. It achieves lightweight design, provides a comfortable wearing experience, and effectively relieves foot pressure, reducing foot fatigue.

[0010] The midsole uses ETPU granules, which, after molding, resemble popcorn and possess excellent resilience and deformation recovery, far surpassing the performance of traditional EVA materials. It also boasts superior abrasion resistance and low-temperature resistance, ultra-light density, excellent environmental friendliness, good flexural strength, resistance to yellowing, and good resilience. Furthermore, the mold incorporates a patterned cavity within the mold, allowing the abrasion-resistant outsole to be placed first. During molding, the ETPU granules and TPU outsole are simultaneously molded together, creating patterns on the outsole and simplifying the manufacturing process. Since both the ETPU granules in the elastic midsole and the TPU outsole are polyurethane-based materials, they are easier to melt and bond, resulting in a sole with strong interfacial adhesion. Additionally, the use of the same material for the sole makes it easier to recycle.

[0011] Optionally, the TPU substrate is manufactured as follows:

[0012] TPU particles are pressed into TPU films at 200-210℃;

[0013] Carbon nanotubes were dispersed in a polyvinyl alcohol solution and ultrasonically dispersed for 20-30 minutes. Ultra-high molecular weight polyethylene fibers were then added and ultrasonically dispersed for another 20-30 minutes. The mixture was then filtered and dried to obtain a fiber web. The mass ratio of ultra-high molecular weight polyethylene fibers to carbon nanotubes was 1:0.1-0.3.

[0014] At least one fiber mesh layer is placed on the top and bottom sides of the TPU film, with the same number of fiber mesh layers on both sides of the TPU film. Then, the film is hot-pressed at 130-140℃ and 0.034-0.04MPa for 6-7 minutes to obtain a TPU substrate.

[0015] By adopting the above technical solution, ultra-high molecular weight polyethylene (UHMWPE) fibers possess high modulus and high strength, as well as low density and high strength. They exhibit good energy absorption, an extremely low coefficient of friction, and excellent self-lubricating properties, resulting in superior wear resistance. UHMWPE fibers are ultrasonically dispersed in a polyvinyl alcohol solution containing carbon nanotubes. The UHMWPE fibers overlap, while the carbon nanotubes adhere to the surface of the UHMWPE fibers. The carbon nanotubes themselves possess excellent mechanical properties, enhancing the mechanical strength and wear resistance of the fibers. Furthermore, the adhesion of carbon nanotubes to the fiber surface increases the contact area between the UHMWPE fibers and the TPU film. This allows stress to be effectively transferred from carbon nanotubes and ultra-high molecular weight polyethylene fibers to the TPU film, ultimately improving the tensile strength, elongation at break, and other mechanical properties of the TPU sole. Furthermore, the increased roughness of the fibers due to carbon nanotube adhesion improves the friction between the fiber mesh and the ground, thus enhancing its anti-slip performance. During hot pressing, polyvinyl alcohol can permeate between the ultra-high molecular weight polyethylene fibers and carbon nanotubes, achieving full adhesion and increasing the bonding performance between the ultra-high molecular weight polyethylene fibers, carbon nanotubes, and the TPU film. It also improves the density of the fiber mesh, enhancing the overall mechanical strength of the TPU sole and thus strengthening the tensile and tear resistance of the shoe sole.

[0016] With a TPU film as the core layer, the TPU film itself possesses excellent elasticity and tensile strength. At least one fiber mesh layer is set on both sides of the film. After hot pressing, the TPU film and the fiber mesh layer adhere to each other. The fiber mesh layer formed by ultra-high molecular weight polyethylene fibers, carbon nanotubes, and polyvinyl alcohol further improves its tensile strength and tear resistance, as well as its abrasion resistance. As the number of fiber mesh layers increases, the mechanical strength gradually increases. This is because when subjected to external tensile force, the interface between the fiber mesh layer and the TPU film will debond, forming voids between the TPU film layers. As the tensile force gradually increases, the TPU segments will undergo fiberization. A large amount of energy is absorbed during the TPU fiberization and fiber mesh layer debonding process, thus giving the TPU substrate high tensile strength. Furthermore, the attachment of carbon nanotubes also increases the interfacial interaction between the ultra-high molecular weight polyethylene fibers and the TPU film, improving the mechanical strength of the TPU substrate. When the TPU sheet and ETPU particles come into contact and are integrally molded, the fiber mesh layer can be melt-bonded with the ETPU. One side of the fiber mesh layer is a TPU film, and the other side is ETPU particles. They are fused by steam heating to obtain a tightly bonded outsole and midsole.

[0017] Optionally, the carbon nanotubes undergo the following pretreatment:

[0018] Carbon nanotubes were dispersed in deionized water, cellulose nanofibers were added, and the mixture was ultrasonically dispersed for 20-30 minutes. After filtration and drying, a carbon nanotube dispersion was obtained.

[0019] Carbon nanotube dispersion was added to a mixed solution of isopropanol and deionized water, ammonia was added, and the mixture was sonicated for 10-20 min before adding tetraethyl orthosilicate. The mixture was reacted at 60-70℃ for 10-12 h, washed, dried, and ground to obtain silica-coated particles. The mass ratio of carbon nanotube dispersion to tetraethyl orthosilicate was 0.1:0.8-1.

[0020] Silica-coated particles were dispersed in anhydrous ethanol and ultrasonically dispersed for 20-30 minutes. Then, ultrapure water, acetic acid, and perfluorooctyltriethoxysilane were added. The mixture was reacted at 70-80℃ for 4-5 hours, filtered, and dried. The mass ratio of silica-coated particles to perfluorooctyltriethoxysilane was 1:2-3.

[0021] By adopting the above technical solution, cellulose nanofibers, due to their unique physical and chemical properties, can be used as dispersants. When cellulose nanofibers are mixed with carbon nanotubes, they can interact with the surface of carbon nanotubes through physical adsorption and chemical bonding, thereby reducing van der Waals interactions between carbon nanotubes, reducing agglomeration, and improving dispersibility. Furthermore, the carboxyl groups on the surface of nanocellulose can interact with the functional groups on the surface of carbon nanotubes, further enhancing the dispersion effect. The high strength and high modulus of cellulose nanofibers uniformly dispersed on carbon nanotubes also improve the overall strength of the material, helping to resist external forces during wear and thus extending the service life of carbon nanotubes. In addition, cellulose nanofibers also have a certain degree of lubricity, helping to reduce the coefficient of friction and wear during friction. The addition of cellulose nanofibers increases the surface roughness of carbon nanotubes, thereby increasing the friction between carbon nanotubes and ultra-high molecular weight polyethylene, and enhancing the load-bearing capacity between them. Then, hydroxyl-containing silica is grown in situ on the surface of the carbon nanotube dispersion using tetraethyl orthosilicate, which can composite with the cellulose nanofibers on the surface of the carbon nanotubes. Then, through a complete process... The hydrolysis of perfluorooctyltriethoxysilane generates a hydroxyl group at one end of the silane molecular chain. This hydroxyl group then undergoes a dehydration condensation reaction with the hydroxyl groups on the silica surface, grafting perfluorooctyltriethoxysilane onto the surface of the silica-coated particles via chemical covalent bonds. Because the R group in the perfluorooctyltriethoxysilane molecular chain is a perfluorinated alkyl group, the pretreated carbon nanotubes exhibit good hydrophobicity. Coating carbon nanotubes containing nanocellulose with silica further enhances their anti-slip properties due to silica's high hardness, high wear resistance, and thermal stability. The grafting of perfluorooctyltriethoxysilane makes the silica coated on the surface of carbon nanotubes hydrophobic, thereby reducing the adsorption of water molecules on the friction surface, weakening the lubricating effect of water, and further improving the anti-slip performance in wet environments. Moreover, the hydrophobic silica coating on the carbon nanotubes, which are loaded on ultra-high molecular weight polyethylene fibers, can increase the interfacial adhesion between the TPU hot melt components and the carbon nanotubes during the hot pressing fusion of the TPU film, improve the adhesion between the fiber web layer and the TPU film, and also improve the adhesion between the wear-resistant outsole and the elastic midsole.

[0022] Optionally, the ultra-high molecular weight polyethylene fibers undergo the following pretreatment:

[0023] Ultra-high molecular weight polyethylene fiber was plasma treated and then added to anhydrous ethanol. Nano-alumina and boron nitride were added, and the mixture was sonicated for 2-3 hours to form a dispersion.

[0024] Add KH550 silane coupling agent solution to the dispersion, stir at 80-90℃ for 4-5 hours, filter, wash, and dry.

[0025] By adopting the above technical solutions, nano-alumina has a large specific surface area and surface energy, and has high chemical activity and adsorption capacity. Boron nitride has excellent stability, friction resistance and lubricity, and can play a good role in reducing friction. It can also play a role in filling, reinforcing and reducing friction. Because ultra-high molecular weight polyethylene (UHMWPE) has a linear molecular chain structure with only hydrogen and carbon elements in the main chain, and lacks polar groups on the surface, its highly crystalline molecular structure is very dense, resulting in low surface energy and high chemical inertness. This makes it difficult to form a wear-resistant outsole with good adhesion to TPU film after hot pressing, thus easily causing the fiber mesh layer to wear away and detach from the sole. While using polyvinyl alcohol to load carbon nanotubes on the surface of UHMWPE fibers improves the hot melt adhesion to TPU film, surface modification is still performed beforehand using processes such as plasma treatment. Plasma treatment can significantly reduce its surface contact angle, increase surface energy, and introduce a large number of active functional groups such as -C=O, -OC=O, and -OH into its surface, thereby effectively improving the chemical properties of the fiber surface, enhancing its chemical reactivity, and strengthening its surface wettability. Then, utilizing the KH550 molecular chain... The siloxanes contained in the product hydrolyze in water to form silanols, which can form hydrogen bonds with the hydroxyl groups on the plasma-treated fibers. Upon heating, these bonds undergo dehydration condensation to form covalent bonds, allowing KH550 to be grafted onto the surface of the ultra-high molecular weight polyethylene (UHMWPE) fibers. Nano-alumina and boron nitride also contain hydroxyl groups, which can react with the other two hydroxyl groups on the silanols. Thus, using KH550 as a bridge, nano-alumina and boron nitride are chemically bonded to the UHMWPE fibers, achieving stable coating. Furthermore, the silanols within the KH550 molecules also react, causing the molecular chains to interconnect and form a network structure that covers the surface of the UHMWPE fibers, enhancing the interfacial force between the fibers and the TPU film. During wear, this strengthens the adhesion stability between the fiber network and the TPU film, thereby improving the abrasion resistance of the sole and enhancing the bonding strength between the abrasion-resistant outsole and the elastic midsole.

[0026] Optionally, the thickness of the TPU film is 0.1-0.2 mm.

[0027] Optionally, the thickness of the TPU substrate is 0.3-0.8 mm.

[0028] Optionally, the TPU film has three layers of fiber web on one side.

[0029] Optionally, the water cooling time is 80-100s, and the water cooling pressure is 40-50N / m2.

[0030] A mold for manufacturing a recyclable, glue-free, one-piece molded shoe sole includes an upper mold and a bottom mold that overlap each other. The upper mold and the bottom mold form a mold cavity. The upper mold has a first vent hole that communicates with the mold cavity. Along the direction from the bottom mold to the upper mold, the mold cavity is divided into a first mold cavity and a second mold cavity. The first mold cavity is used to accommodate a TPU sole sheet, and the second mold cavity is used to accommodate ETPU foam beads. The bottom sidewall of the mold cavity has a molding pattern, which is used to mold the bottom pattern of the TPU sole sheet. The TPU sole sheet is molded into a wear-resistant outsole. The ETPU foam beads are foamed into an elastic midsole. The wear resistance of the wear-resistant outsole is greater than that of the elastic midsole. Attached Figure Description

[0031] Figure 1 is a schematic diagram illustrating the structure of the recyclable glue-free one-piece molded sole in Example 1.

[0032] Figure 2 is a schematic diagram of the structure of the mold before it is closed in Example 1.

[0033] Figure 3 is an enlarged view of point A in Figure 2.

[0034] Figure 4 is a schematic diagram showing the structure of the mold after it is closed in Example 1.

[0035] Figure 5 is an enlarged view of point B in Figure 4.

[0036] Figure 6 is a structural schematic diagram illustrating the recyclable glue-free one-piece molded sole in Example 18.

[0037] Figure 7 is a schematic diagram showing the structure of the mold after mold closing in Example 18.

[0038] Explanation of reference numerals in the attached diagram: 1. Elastic midsole; 2. Wear-resistant outsole; 3. Upper mold; 31. Limiting protrusion; 32. Upper steam channel; 33. First air inlet; 34. First vent; 4. Bottom mold; 41. Receiving groove; 42. Molded pattern; 43. Positioning post; 44. Second vent; 45. Third vent; 46. Lower steam channel; 5. Mold cavity; 51. First mold cavity; 52. Second mold cavity; 6. Carbon fiber plate; 7. TPU base sheet; 71. Positioning hole; 8. ETPU foam beads. Detailed Implementation

[0039] The present application will be further described in detail below with reference to Figures 1-7.

[0040] Preparation of TPU film 7: Examples 1-16

[0041] In the preparation example, the TPU particles were selected from BASF, Germany, model 1185A; the ultra-high molecular weight polyethylene fiber was selected from Guangzhou Zhangdao Chemical, with a length of 12 mm and an equivalent diameter of 15-20 μm; the carbon nanotubes were selected from Sichuan Kenye, model KY-CNTs; the polyvinyl alcohol was PVA-1788, selected from Wuhan Runxingyuan Technology; the boron nitride was selected from Henan Yashun Chemical, product number 11-6; and the nano-alumina was selected from Jiangsu Tianxing New Materials, model TAP-A21, with a particle size of 40 nm.

[0042] Preparation Example 1: TPU particles were hot-pressed at 200℃ and 0.1MPa to form a TPU film with a thickness of 200μm, which was used as TPU substrate 7.

[0043] Preparation Example 2: (1) TPU particles were hot-pressed at 200°C and 0.1 MPa to form a TPU film with a thickness of 200 μm;

[0044] (2) Disperse 3g of carbon nanotubes into a 3wt% polyvinyl alcohol solution made of 3g of polyvinyl alcohol, ultrasonically disperse for 30min, add 10g of ultra-high molecular weight polyethylene fiber, ultrasonically disperse for 30min, filter, and dry at 80℃ to obtain a fiber web.

[0045] (3) Place three fiber mesh layers on the upper and lower sides of the TPU film respectively, and then press it at 140℃ and 0.04MPa for 6 minutes to make a TPU substrate 7 with a thickness of 0.8mm.

[0046] Preparation Example 3: (1) TPU particles were hot-pressed at 210°C and 0.06 MPa to form a TPU film with a thickness of 200 μm;

[0047] (2) 1g of carbon nanotubes were dispersed in a 3wt% polyvinyl alcohol solution made of 3g of polyvinyl alcohol. After ultrasonic dispersion for 20min, 10g of ultra-high molecular weight polyethylene fiber was added. After ultrasonic dispersion for 20min, the solution was filtered and dried at 80℃ to obtain a fiber web.

[0048] (3) Place one fiber mesh layer on the upper and lower sides of the TPU film respectively, and then press it at 130℃ and 0.04MPa for 7 minutes to make a TPU substrate 7 with a thickness of 0.4mm.

[0049] Preparation Example 4: The difference from Preparation Example 2 is that two fiber mesh layers were placed on the upper and lower sides of a TPU film with a thickness of 200 μm, and pressed at 140℃ and 0.04 MPa for 6 min to produce a TPU substrate 7 with a thickness of 0.6 mm.

[0050] Preparation Example 5: The difference from Preparation Example 2 is that TPU particles were hot-pressed at 200°C and 0.06MPa to form a 100μm TPU film. A fiber mesh layer was placed on the upper and lower sides of the TPU film, and the film was pressed at 130°C and 0.034MPa for 6 minutes to form a TPU substrate 7 with a thickness of 0.3mm.

[0051] Preparation Example 6: The difference from Preparation Example 2 is that only one layer of fiber mesh is placed on one side of the 200 μm thick TPU film, and it is pressed at 130°C and 0.034 MPa for 6 min to produce a TPU substrate 7 with a thickness of 0.3 mm.

[0052] Preparation Example 7: The difference from Preparation Example 2 is that the carbon nanotubes underwent the following pretreatment:

[0053] (1) Disperse 10g of carbon nanotubes into 90g of deionized water, add 5g of cellulose nanofibers, ultrasonically disperse for 20min, filter and dry to obtain carbon nanotube dispersion;

[0054] (2) 0.5g of carbon nanotube dispersion was added to a mixed solution of 6g isopropanol and 4g deionized water. After adding 2g of ammonia, the mixture was ultrasonically dispersed for 20min. Then, 5g of tetraethyl orthosilicate was added and reacted at 60℃ for 12h. The mixture was washed with deionized water and ethanol, dried at 70℃, and ground to obtain silica-coated particles.

[0055] (3) Disperse 0.5g of silica-coated particles into 100ml of anhydrous ethanol, sonicate for 20min, then add 2ml of ultrapure water, 2ml of acetic acid and 1g of perfluorooctyltriethoxysilane, react at 70℃ for 5h, filter and dry.

[0056] Preparation Example 8: The difference from Preparation Example 2 is that the carbon nanotubes underwent the following pretreatment:

[0057] (1) Disperse 10g of carbon nanotubes in 90g of deionized water, add 10g of cellulose nanofibers, ultrasonically disperse for 30min, filter and dry to obtain carbon nanotube dispersion;

[0058] (2) 0.5g of carbon nanotube dispersion was added to a mixed solution of 6g isopropanol and 4g deionized water. After adding 2g of ammonia, the mixture was ultrasonically dispersed for 20min. Then, 4g of tetraethyl orthosilicate was added and reacted at 70℃ for 10h. The mixture was washed with deionized water and ethanol, dried at 70℃, and ground to obtain silica-coated particles.

[0059] (3) Disperse 0.5g of silica-coated particles into 100ml of anhydrous ethanol, sonicate for 30min, then add 2ml of ultrapure water, 2ml of acetic acid and 1.5g of perfluorooctyltriethoxysilane, react at 80℃ for 4h, filter and dry.

[0060] Preparation Example 9: The difference from Preparation Example 7 is that silica coating was not used. 0.5g of carbon nanotube dispersion was added to 100ml of anhydrous ethanol, ultrasonically dispersed for 30min, and then 2ml of ultrapure water, 2ml of acetic acid and 1.5g of perfluorooctyltriethoxysilane were added. The mixture was reacted at 80℃ for 4h, filtered and dried.

[0061] Preparation Example 10: The difference from Preparation Example 7 is that 0.5g of carbon nanotubes were dispersed in 100ml of anhydrous ethanol, ultrasonically dispersed for 30min, and then 2ml of ultrapure water, 2ml of acetic acid and 1.5g of perfluorooctyltriethoxysilane were added. The mixture was reacted at 80℃ for 4h, filtered and dried.

[0062] Preparation Example 11: The difference from Preparation Example 7 is that perfluorooctyltriethoxysilane, pure water and acetic acid were not used to treat the silica-coated particles.

[0063] Preparation Example 12: The difference from Preparation Example 7 is that the ultra-high molecular weight polyethylene fiber was pretreated by the following method: 10g of ultra-high molecular weight polyethylene fiber was plasma treated and then added to 50g of anhydrous ethanol, 1g of nano alumina and 0.5g of boron nitride were added, and the mixture was sonicated for 3h to form a dispersion. The plasma treatment power was 30W and the treatment time was 3min.

[0064] Add KH550 silane coupling agent solution to the dispersion, stir at 80℃ for 5h, filter, wash 3 times with anhydrous ethanol, and dry at 110℃ for 8h. The KH550 silane coupling agent solution is prepared by mixing 0.3g KH550 and 12g deionized water, adjusting the solution to acidity with glacial acetic acid, and stirring for 10min.

[0065] Preparation Example 13: Ultra-high molecular weight polyethylene fiber was pretreated by the following method: 10g of ultra-high molecular weight polyethylene fiber was plasma treated and then added to 50g of anhydrous ethanol, along with 1g of nano-alumina and 0.1g of boron nitride. The mixture was sonicated for 2h to form a dispersion. The plasma treatment power was 30W and the treatment time was 3min.

[0066] Add KH550 silane coupling agent solution to the dispersion, stir at 90℃ for 4 hours, filter, wash 3 times with anhydrous ethanol, and dry at 110℃ for 8 hours. The KH550 silane coupling agent solution is prepared by mixing 0.11g KH550 and 6g deionized water, adjusting the solution to acidity with glacial acetic acid, and stirring for 10 minutes.

[0067] Preparation Example 14: The difference from Preparation Example 12 is that no nano-alumina and boron nitride were added.

[0068] Preparation Example 15: The difference from Preparation Example 12 is that an equal amount of nano-alumina is used instead of boron nitride.

[0069] Preparation Example 16: The difference from Preparation Example 12 is that KH550 silane coupling agent solution was not added, and the dispersion was dried at 110°C for 8 hours.

[0070] Example 1

[0071] Referring to Figure 1, this application discloses a recyclable, glue-free, one-piece molded shoe sole, including an elastic midsole 1 and an abrasion-resistant outsole 2. The elastic midsole 1 is fixed on the abrasion-resistant outsole 2, and both the elastic midsole 1 and the abrasion-resistant outsole 2 are formed of ETPU material. The abrasion resistance of the abrasion-resistant outsole 2 is greater than that of the elastic midsole 1, and the abrasion-resistant outsole 2 is in direct contact with the ground.

[0072] This application discloses a manufacturing process for a recyclable, glue-free, one-piece molded shoe sole, including the following steps:

[0073] S1. Making the wear-resistant outsole 2: Cut the TPU sheet 7 into the required shape to obtain the wear-resistant outsole 2. The TPU sheet 7 is made from Preparation Example 1.

[0074] S2. Main material: The wear-resistant outsole 2 is laid on the bottom of the mold containing the shaped pattern 42, and then ETPU foam particles are filled into the mold so that the ETPU foam particles are laid on the wear-resistant outsole 2. The ETPU particles are selected from Fujian Ruide Chemical Technology Co., Ltd., and the brand name is READCHEM.

[0075] S3. Steam Molding: Steam is introduced into the mold to form the ETPU particles into an elastic midsole 1. The molding pressure is 0.3 MPa, the molding temperature is 160℃, and the molding time is 150 s. Then, the air is degassed, water-cooled, and demolded to obtain a wear-resistant outsole 2 and an elastic midsole 1 bonded together, resulting in a recyclable, glue-free, one-piece molded sole. The water cooling time is 80 s, and the water cooling pressure is 40 N / m. 2 .

[0076] This embodiment also discloses a mold for manufacturing recyclable glue-free one-piece molded shoe soles, used to prepare recyclable glue-free one-piece molded shoe soles.

[0077] Referring to Figures 2 and 3, the mold for manufacturing a recyclable, glue-free, one-piece molded shoe sole includes an upper mold 3 and a bottom mold 4 that fit together. The bottom mold 4 has a receiving groove 41, and the upper mold 3 has a limiting protrusion 31 that covers the opening of the receiving groove 41. The limiting protrusion 31 and the side wall of the receiving groove 41 form a mold cavity 5. The bottom wall of the receiving groove 41 has a shoe sole forming pattern 42 to form the shoe sole pattern of the recyclable, glue-free, one-piece molded shoe sole.

[0078] Referring to Figures 4 and 5, along the direction from the bottom mold 4 to the upper mold 3, the mold cavity 5 is divided into a first mold cavity 51 and a second mold cavity 52. ​​The first mold cavity 51 is used to accommodate the TPU base sheet 7, and the second mold cavity 52 is used to accommodate the ETPU foam beads 8, which are the ETPU foam particles mentioned above. The bottom sidewall of the mold cavity 5 is provided with a molding pattern 42, which is used to form the bottom pattern of the TPU base sheet 7; to form several anti-slip ridges on the bottom of the wear-resistant outsole 2, thereby improving the anti-slip performance of the recyclable glue-free one-piece molded shoe sole. After the TPU base sheet 7 is molded, it forms the wear-resistant outsole 2, and the ETPU foam beads 8 are foamed to form the elastic midsole 1.

[0079] Referring to Figures 2 and 4, in this embodiment, the mold uses steam heating to heat the material in the mold cavity 5. In this embodiment, the upper mold 3 has an upper steam channel 32 for steam flow, and a limiting protrusion has a first air inlet 33 connected to the upper steam channel 32. Steam enters the mold cavity 5 through the upper steam channel 32 and the first air inlet 33. The bottom mold 4 has a lower steam channel 46 for steam flow. Both the upper steam channel 32 and the lower steam channel 46 are connected to a steam generating device. The high-temperature steam in the upper steam channel 32 and the lower steam channel 46 provides heat to the TPU base sheet 7 and ETPU foam beads 8 in the mold cavity 5 to improve the foaming quality of the recyclable glue-free one-piece molded shoe sole.

[0080] Referring to Figures 2 and 4, the upper mold 3 is provided with a first vent 34, which is connected to the mold cavity 5. The bottom mold 4 is provided with a second vent 44, which penetrates the bottom sidewall of the mold cavity 5 and is connected to the first mold cavity 51. The second vent 44 is used to release the gas between the TPU backing sheet 7 and the molded pattern 42, which is beneficial to the clear molding of the bottom pattern of the wear-resistant outsole 2.

[0081] Referring to Figures 4 and 5, the molded pattern 42 is provided with several positioning posts 43, and the TPU base sheet 7 has positioning holes 71 for the positioning posts 43 to pass through. The positioning posts 43 are used to limit the position of the TPU base sheet 7. Along the direction from the bottom mold 4 to the upper mold 3, the cross-sectional area of ​​the positioning posts 43 decreases. Through the coordinated cooperation of the positioning posts 43 and the positioning holes 71 on the TPU base sheet 7, the position of the TPU base sheet 7 in the mold is limited, thereby improving the quality of the foaming and molding of the recyclable glue-free one-piece molded shoe sole. At the same time, the positioning posts 43 have a trapezoidal cross-section to facilitate the demolding of the recyclable glue-free one-piece molded shoe sole.

[0082] Referring to Figures 4 and 5, in this embodiment, the end of the positioning post 43 extends into the second mold cavity 52; the bottom mold 4 also has a third vent 45, which penetrates the positioning post 43 and is connected to the second mold cavity 52. ​​By providing the third vent 45 on the bottom mold 4 and connecting it to the second mold cavity 52, the third vent 45 can discharge the gas in the second mold cavity 52. ​​This facilitates the flow of high-temperature gas to the ETPU foam beads 8 during the foaming process, improving the foaming effect of the ETPU foam beads 8 and increasing the uniformity of the foaming of the elastic insole 1.

[0083] The implementation principle of a recyclable glue-free one-piece molded shoe sole according to an embodiment of this application is as follows:

[0084] Referring to Figures 4 and 5, since the TPU base sheet 7 and ETPU foam beads 8 are polyurethane materials, and the melting point and molding conditions of the TPU base sheet 7 and ETPU foam beads 8 are the same, the TPU base sheet 7 and ETPU foam beads 8 can be integrally molded in the mold cavity 5 to form a recyclable glue-free one-piece molded sole. Moreover, the TPU base sheet 7 and ETPU foam beads 8 can be fully bonded, so that there is a large connection strength between the elastic midsole 1 and the wear-resistant outsole 2.

[0085] Furthermore, due to the performance differences between the TPU sole 7 and the ETPU foam beads 8, the TPU sole 7 softens and is molded to form the wear-resistant outsole 2, which has excellent wear resistance. Meanwhile, the ETPU foam beads 8 form the elastic midsole 1, which has excellent rebound performance; thus, the recyclable glue-free one-piece molded sole combines high rebound and wear resistance.

[0086] Example 2: A recyclable glue-free one-piece molded shoe sole, differing from Example 1 in that the recyclable glue-free one-piece molded shoe sole includes the following preparation steps:

[0087] S1. Making the wear-resistant outsole 2: Cut the TPU sheet 7 into the required shape to obtain the wear-resistant outsole 2. The TPU sheet 7 is made from Preparation Example 1.

[0088] S2. Main material: The wear-resistant outsole 2 is laid on the bottom of the mold containing the shaped pattern 42, and then ETPU foam particles are filled into the mold so that the ETPU foam particles are laid on the wear-resistant outsole 2.

[0089] S3. Steam Molding: Steam is introduced into the mold to form the ETPU particles into an elastic midsole 1. The molding pressure is 0.1 MPa, the molding temperature is 120℃, and the molding time is 190 s. Then, the material is degassed, water-cooled, and demolded to obtain a recyclable, glue-free, one-piece molded sole. The water-cooling time is 100 s, and the water-cooling pressure is 50 N / m.2 .

[0090] Examples 3-4: A recyclable glue-free one-piece molded shoe sole, which differs from Example 1 in that the TPU sole 7 is made from Preparation Examples 2-3 respectively.

[0091] Examples 5-9: A recyclable glue-free one-piece molded shoe sole, which differs from Example 3 in that the TPU sole 7 is made from Preparation Examples 4-8 respectively.

[0092] Examples 10-14: A recyclable glue-free one-piece molded shoe sole, which differs from Example 8 in that the TPU sole 7 is made from Preparation Examples 9-13 respectively.

[0093] Examples 15-17: A recyclable glue-free one-piece molded shoe sole, which differs from Example 13 in that the TPU sole 7 is made from Preparation Examples 14-16 respectively.

[0094] Comparative Example

[0095] Comparative Example 1: A shoe sole, which differs from Example 1 in that a nitrile rubber outsole is used instead of the wear-resistant outsole 2. The thickness of the nitrile rubber outsole is 0.2 mm. It is made by hot pressing nitrile rubber powder at 160°C and 2 MPa. The nitrile rubber powder is selected from Shenzhen Wansuyuan Rubber & Plastic, model MY60M, item number 002, and particle size 120 mesh.

[0096] Performance testing

[0097] The shoe soles were prepared according to the methods of the examples and comparative examples, and the various properties of the shoe soles were tested according to the following methods. The test results are recorded in Table 1.

[0098] 1. Peel strength: The interfacial adhesion between the abrasion-resistant outsole 2 and the elastic midsole 1 was tested by peel test using a tensile testing machine. The tensile speed was 100 mm / min and the test time was 150 s. Under the same conditions, at least 5 samples were recorded and the average value was taken.

[0099] 2. Slip resistance coefficient: Tested according to HG / T3780-2005 "Test Method for Static Slip Resistance Performance of Footwear".

[0100] 3. DIN wear: Tested according to GB / T9867-2008 "Determination of abrasion resistance of vulcanized rubber or thermoplastic rubber (rotary roller abrasion tester method)" with a test force of (10±0.2)N and a rotation speed of (40±1)r / min.

[0101] 4. Tear strength: Tested according to GB / T3903.12-2005 "Test Methods for Tear Strength of Footwear Outsoles", with a test speed of 500m / min.

[0102] 5. Tensile strength: Tested in accordance with GB / T6344-1996 "Determination of tensile strength and elongation at break of flexible foam polymer materials".

[0103] Table 1 Performance test results of recyclable glue-free one-piece molded shoe soles

[0104] Example 18

[0105] This embodiment 18 discloses a recyclable glue-free one-piece molded shoe sole. The difference between this embodiment 18 and embodiment 1 is that:

[0106] Referring to Figure 6, the recyclable glue-free one-piece molded sole also includes a carbon fiber plate 6, which is fixed between the elastic midsole 1 and the abrasion-resistant outsole 2 to improve the torsional resistance of the recyclable glue-free one-piece molded sole.

[0107] Referring to Figure 7, in the recyclable glue-free one-piece molded shoe sole mold, the second mold cavity 52 is also used to accommodate the carbon fiber plate 6. The carbon fiber plate 6 is disposed between the TPU base plate 7 and the ETPU foam beads 8. The positioning post 43 is used to abut against the carbon fiber plate 6 and to fix the position of the carbon fiber plate 6. The positioning post 43 can be disposed on the outer periphery of the carbon fiber plate 6, which also restricts the position of the carbon fiber plate 6, so as to place the carbon fiber plate 6 between the TPU base plate 7 and the ETPU foam beads 8; thus, after the recyclable glue-free one-piece molded shoe sole is foamed and molded, the carbon fiber plate 6 is fixed between the wear-resistant outsole 2 and the elastic midsole 1.

[0108] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A recyclable, glue-free, one-piece molded shoe sole, characterized in that: The system includes a wear-resistant outsole (2) and an elastic midsole (1). The elastic midsole (1) is placed on the wear-resistant outsole (2). The wear resistance of the wear-resistant outsole (2) is greater than that of the elastic midsole (1). The TPU sheet (7) is cut into the required shape to form the wear-resistant outsole (2). The wear-resistant outsole (2) is laid in a mold containing a molding pattern (42). Then, ETPU foam particles are filled into the mold so that the ETPU foam particles are laid on the upper surface of the wear-resistant outsole (2). Steam is introduced into the mold so that the ETPU particles are molded into the elastic midsole (1). The molding pressure is 0.1-0.3MPa, the molding temperature is 120-160℃, and the molding time is 150-190s. Then, the air is depressurized, water-cooled, and demolded to obtain a recyclable glue-free one-piece molded shoe sole.

2. The recyclable glue-free one-piece molded sole according to claim 1, characterized in that: The method for manufacturing the TPU substrate (7) is as follows: TPU particles are pressed into TPU films at 200-210℃; Carbon nanotubes were dispersed in a polyvinyl alcohol solution and ultrasonically dispersed for 20-30 minutes. Ultra-high molecular weight polyethylene fibers were then added and ultrasonically dispersed for another 20-30 minutes. The mixture was then filtered and dried to obtain a fiber web. The mass ratio of ultra-high molecular weight polyethylene fibers to carbon nanotubes was 1:0.1-0.

3. At least one fiber mesh layer is placed on the upper and lower sides of the TPU film, with the same number of fiber mesh layers on both sides of the TPU film. Then, the film is hot-pressed at 130-140℃ and 0.034-0.04MPa for 6-7 minutes to obtain a TPU substrate (7).

3. The recyclable glue-free one-piece molded sole according to claim 2, characterized in that: The carbon nanotubes undergo the following pretreatment: Carbon nanotubes were dispersed in deionized water, cellulose nanofibers were added, and the mixture was ultrasonically dispersed for 20-30 minutes. After filtration and drying, a carbon nanotube dispersion was obtained. Carbon nanotube dispersion was added to a mixed solution of isopropanol and deionized water, ammonia was added, and the mixture was sonicated for 10-20 min before adding tetraethyl orthosilicate. The mixture was reacted at 60-70℃ for 10-12 h, washed, dried, and ground to obtain silica-coated particles. The mass ratio of carbon nanotube dispersion to tetraethyl orthosilicate was 0.1:(0.8-1). Silica-coated particles were dispersed in anhydrous ethanol and ultrasonically dispersed for 20-30 min. Then, ultrapure water, acetic acid and perfluorooctyltriethoxysilane were added and reacted at 70-80℃ for 4-5 h. After filtration and drying, the mass ratio of silica-coated particles to perfluorooctyltriethoxysilane was 1:(2-3).

4. The recyclable glue-free one-piece molded sole according to claim 2, characterized in that: The ultra-high molecular weight polyethylene fiber is pretreated as follows: Ultra-high molecular weight polyethylene fiber was plasma treated and then added to anhydrous ethanol. Nano-alumina and boron nitride were added, and the mixture was sonicated for 2-3 hours to form a dispersion. Add KH550 silane coupling agent solution to the dispersion, stir at 80-90℃ for 4-5 hours, filter, wash, and dry.

5. The recyclable glue-free one-piece molded sole according to claim 4, characterized in that: The mass ratio of the ultra-high molecular weight polyethylene fiber to nano-alumina and boron nitride is 1:0.1:(0.01-0.05).

6. The recyclable glue-free one-piece molded sole according to claim 4, characterized in that: The amount of KH550 silane coupling agent used is 10-20 wt% of the total weight of nano-alumina and boron nitride.

7. A mold for manufacturing a recyclable, glue-free, one-piece molded shoe sole as described in any one of claims 1-6, characterized in that: The system includes an upper mold (3) and a bottom mold (4) that overlap each other. The upper mold (3) and the bottom mold (4) surround a mold cavity (5). The upper mold (3) has a first vent (34) that communicates with the mold cavity (5). Along the direction from the bottom mold (4) to the upper mold (3), the mold cavity (5) is divided into a first mold cavity (51) and a second mold cavity (52). The first mold cavity (51) is used to accommodate a TPU substrate. 7), the second mold cavity (52) is used to accommodate ETPU foam beads (8); the bottom side wall of the mold cavity (5) is provided with a molding pattern (42), the molding pattern (42) is used to form the bottom pattern of the TPU base sheet (7), the TPU base sheet (7) is molded into a wear-resistant outsole (2); the ETPU foam beads (8) are foamed into an elastic insole (1), the wear resistance of the wear-resistant outsole (2) is greater than that of the elastic insole (1).

8. The mold for manufacturing a recyclable, glue-free, one-piece molded shoe sole according to claim 7, characterized in that: The bottom mold (4) has a second vent (44) which penetrates the bottom sidewall of the mold cavity (5) and is connected to the first mold cavity (51). The second vent (44) is used to discharge the gas between the TPU substrate (7) and the molded pattern (42).

9. The mold for manufacturing a recyclable, glue-free, one-piece molded shoe sole according to claim 7, characterized in that: The molded pattern (42) is provided with a plurality of positioning posts (43), and the TPU substrate (7) is provided with positioning holes (71) for the positioning posts (43) to pass through. The positioning posts (43) are used to limit the position of the TPU substrate (7).

10. The mold for manufacturing a recyclable, glue-free, one-piece molded shoe sole according to claim 9, characterized in that: The bottom mold (4) is also provided with a third vent hole (45), which penetrates the positioning post (43) and is connected to the second mold cavity (52).

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