A composite processing method for soles

Abstract

The present invention relates to the field of sole processing technology, and specifically to a sole composite processing method, comprising: configuring a high-density slurry with a silicon nitride ceramic powder accounting for 30-40% according to the rigidity requirements of the arch support area, forming an #imgabs0# crystal phase by microwave-assisted sintering, and controlling the porosity at 10-20%; adding graphene oxide / carboxymethyl cellulose aerogel powder to the slurry to meet the energy rebound requirements of the forefoot buffer zone to 25%, and combining a honeycomb porous network design to increase the porosity to 40-60%; introducing a nano-silica reinforcing agent to 15% in the heel wear-resistant zone, and forming a diamond-like carbon coating by plasma surface treatment, with a porosity limit of 5-15%. The present invention uses polyurea microcapsules to encapsulate silane, which is released only when the material is damaged, achieving dynamic self-repair, giving the sole dynamic repair ability, and extending its service life.

Description

Technical Field

[0001] The invention relates to the technical field of sole processing, and in particular to a sole composite processing method. Background Art

[0002] In modern shoemaking technology, soles, as a key component of shoes, not only need to have good wear resistance, anti-slip, elasticity and support, but also need to meet the diverse needs of comfort, aesthetics and adaptability to different usage scenarios. With the continuous advancement of science and technology and the increasing quality requirements of consumers for footwear products, traditional sole processing methods have gradually exposed some limitations, prompting the industry to continuously explore and develop more advanced sole composite processing technologies. Early soles were mostly made of a single material, such as rubber, leather, polyurethane, etc. Although rubber soles have excellent wear resistance and anti-slip properties, they are hard in texture and not comfortable to wear. It is difficult for a single traditional sole material to simultaneously possess multiple excellent properties such as high wear resistance and lightweight cushioning. In addition, it is difficult for traditional chemical foaming methods to accurately control the pore morphology, which may lead to problems such as uneven bubble size and irregular shape, affecting the performance and quality of the sole. There are certain limitations in compressive strength, and it may not be able to withstand large pressure or may easily deform or collapse after long-term use, affecting the service life and comfort of the sole. Summary of the Invention

[0003] The present invention aims to solve the technical problems existing in the prior art and provides a sole composite processing method.

[0004] The present invention solves the above-mentioned technical problems with the following technical solution: obtaining foot biomechanical data, dividing the sole of the foot into an arch support area, a forefoot buffer area, and a heel wear-resistant area based on a three-dimensional pressure distribution model, calculating the required porosity range of each area through finite element analysis, performing a gradient injection molding process of a porous ceramic-polymer composite slurry, and using supercritical carbon dioxide directional foaming technology to generate a gradient pore structure with biomimetic characteristics, specifically comprising the following sub-steps:

[0005] S101, according to the rigidity requirements of the arch support area, a high-density slurry with 30-40% silicon nitride ceramic powder is prepared and formed by microwave-assisted sintering. Crystalline phase, porosity controlled at 10-20%;

[0006] S102: To meet the energy rebound requirements of the forefoot buffer zone, at least 25% of graphene oxide / carboxymethyl cellulose aerogel powder is added to the slurry. Combined with a honeycomb porous network design, the porosity is increased to 40-60%.

[0007] S103, introduce nano-silica reinforcement of at least 15% in the heel wear-resistant area, and form a diamond-like carbon coating through plasma surface treatment with a porosity of 5-15%;

[0008] Based on the above-mentioned zoning design, a stepped temperature rising sintering process is adopted, heating the material to 1700-1750°C at a rate of 15-20°C / min in a nitrogen atmosphere and keeping it warm for 0.5-2h to form a composite sole with wear resistance, flexible cushioning and breathable functions.

[0009] Preferably, the gradient pore structure with biomimetic characteristics of the three-dimensional pressure distribution model sequentially performs the following steps:

[0010] S1. Dynamic plantar pressure data is collected using a flexible piezoelectric film sensor array. Simultaneously, 3D laser scanning is used to obtain arch curvature radius and sagittal plane angle morphological parameters. A spatiotemporal association database is constructed and motion pattern parameters are annotated.

[0011] S2. Divide the sole of the foot into: an arch support area with high curvature and low transient pressure, a forefoot buffer area subject to high-frequency impact loads, and a heel wear-resistant area subject to a combination of static pressure and shear force;

[0012] S3. A three-dimensional plantar model is established based on non-uniform rational B-spline surfaces. Dynamic pressure data is fused with the parameters of arch ligament stiffness and fascia elastic modulus through Gaussian kernel interpolation to generate a biomechanically corrected continuous pressure field.

[0013] S4: Define the arch support area elastic modulus 15±2MPa and energy absorption rate ≥75%, and the forefoot buffer damping coefficient 0.35±0.05 , the target performance of the heel area shear strength ≥ 8MPa, and the mapping relationship between porosity and elastic modulus is established;

[0014] S5. Generate a pore gradient distribution. The arch support area forms a 5%-15% increasing pore along the curvature path. The forefoot area sets a three-layer gradient structure from the surface layer to the core layer with a porosity of 20%-40%-25%. The heel area adopts a honeycomb fiber composite structure with a porosity of 10%±2%. Output a design parameter set including porosity, pore size, and orientation angle.

[0015] A further improvement of the technical solution of the present invention is that the sole is divided into an arch support area, a forefoot buffer area and a heel wear-resistant area through a three-dimensional pressure distribution model.

[0016] Preferably, the porous ceramic-polymer composite slurry includes the following mass ratio components and preparation rules:

[0017] (a) Matrix material: 30-50% thermoplastic polyurethane with a melt index of 20-30 g / 10 min and a glass transition temperature of ≤-30°C;

[0018] (b) Ceramic phase: 20-40% silicon nitride ceramic powder, particle size range 0.5-5 , The phase ratio is ≥90%, the particle size distribution is verified by laser particle size analyzer, and the crystal phase purity is analyzed by XRD;

[0019] (c) Aerogel reinforcement: 10-25% graphene oxide aerogel powder, specific surface area ≥ 600 , the pore size distribution is 10-500 nm, and the aerogel is freeze-dried and crushed to 200-400 mesh;

[0020] (d) Functional additives: nano-silica reinforcing agent 5-15%, microencapsulated silane coupling agent 2-5%, foaming agent 1-3%;

[0021] The slurry preparation process includes: melting thermoplastic polyurethane particles at 180-200 ° C, adding silicon nitride powder, aerogel and additives in sequence, and mixing them evenly in a twin-screw extruder at a speed of 300-400 rpm. The solid content of the slurry is controlled to be 45-60%, and the viscosity range is 5000-8000 mPa. After mixing, seal and let stand for 12 hours to eliminate bubbles.

[0022] A further improvement of the technical solution of the present invention is that graphene oxide / carboxymethyl cellulose aerogel is introduced as a reinforcing agent to form a ceramic-aerogel-polymer ternary composite system with silicon carbide and thermoplastic polyurethane matrix.

[0023] Preferably, the directional foaming process is carried out by injecting the composite slurry into a mold cavity preheated to 90-110°C, pre-setting a micron-scale groove structure on the inner wall of the mold to guide the foaming direction, injecting supercritical carbon dioxide fluid into the mold, using the supercritical carbon dioxide fluid as a foaming agent, controlling the critical temperature to 31.1°C, and the pressure to 8-12MPa, maintaining for 15 minutes to allow the aerogel powder to fully expand, and achieving directional pore growth by controlling the mold temperature gradient, controlling the mold temperature at 80-120°C in the arch support area, limiting the foaming rate to form a dense structure, and reducing the mold temperature of the forefoot buffer area to 80°C to promote rapid expansion of the aerogel to form open pores. After foaming is completed, the pressure is quickly released to normal pressure, and the elastic memory effect of the aerogel skeleton is used to fix the pore morphology, and finally obtaining a gradient pore structure.

[0024] Preferably, the distribution rules of the gradient pores include:

[0025] Wear-resistant base layer: porosity 10-20%, pore size ≤ By limiting the amount of foaming agent added to 1-2% and increasing the sintering temperature to 1700-1750°C, densification is achieved. The silicon nitride content of this layer is increased to 35-40%, and the surface is plasma treated to generate a diamond-like carbon coating;

[0026] Buffer layer: porosity 40-60%, pore size 100-300 , using 25% graphene oxide aerogel powder and 45% thermoplastic polyurethane matrix to form a three-dimensional honeycomb structure through supercritical carbon dioxide foaming;

[0027] Breathable surface: porosity 70-85%, pore size 500-800 , the sacrificial template method is used to decompose during the sintering process to form through channels, and the surface is sprayed with fluorosilane-modified graphene oxide hydrophobic coating.

[0028] Preferably, the implementation of the functional partitioning includes:

[0029] (a) Data of the arch support area: Based on the finite element analysis to determine the rigidity requirements, the silicon nitride content in the slurry was adjusted to 35-40%, and nano-silicon dioxide was added as a grain boundary strengthener. The sintering was carried out under microwave assisted sintering at 2.45 GHz and a power density of 8 Downward promotion Towards Phase transformation, β phase accounts for ≥95%, forming an interwoven rod-like grain structure, and the porosity is controlled at 15-20%;

[0030] (b) Forefoot buffer zone data: According to the impact absorption rate requirement, the impact absorption rate is ≥70%. Graphene oxide aerogel powder is added to the slurry to 25%. Combined with the step-by-step foaming process, a gradient pore size distribution is generated to form a honeycomb porous network. The wall thickness of the honeycomb pores is 20-50 ;

[0031] (c) Heel wear-resistant area: 15% nano-silicon dioxide and 5% silicon carbide whiskers are introduced and a dual-phase reinforced structure is formed by hot pressing and sintering.

[0032] Preferably, a sole composite processing method further includes surface functionalization treatment:

[0033] (a) Preparation of hydrophobic coating: Fluorosilane and graphene oxide were dispersed in ethanol solution, ultrasonically treated for 30 min, and then blended with thermoplastic polyurethane particles. Electrostatic spraying was used to form a 10-30 coating;

[0034] (b) Antibacterial functionalization: Nano-zinc oxide is added to the hydrophobic coating and loaded on the graphene oxide surface via the melt-gel method;

[0035] (c) Wear-resistant strengthening: magnetron sputtering technology is used to deposit 2-5 Thick hard film.

[0036] Preferably, microwave assisted sintering is introduced into the sintering process, and 2.45 GHz microwave assisted heating is adopted under nitrogen atmosphere, and the microwave power density is 5-10 , accelerating ceramic phase transformation and reducing energy consumption.

[0037] Preferably, the preparation of the graphene oxide aerogel powder includes:

[0038] S1. Dispersion preparation: Graphene oxide was dispersed in deionized water at a concentration of 2 mg / mL. After ultrasonic treatment for 24 h, the graphene oxide dispersion was blended with carboxymethyl cellulose and stirred for 24 h to form a homogeneous mixture.

[0039] S2, freeze drying process: the mixed solution was injected into a polytetrafluoroethylene mold, pre-frozen to -80 ° C, then transferred to a freeze dryer with a vacuum degree of ≤ 0.1 mbar, heated to -20 ° C and maintained for 12 h, then heated to 25 ° C and maintained for 24 h to obtain block aerogel;

[0040] S3, crushing and screening: use air flow mill to crush the aerogel into 200-400 mesh, and then sieve to obtain particle size of 10-50 The powder has a specific surface area of 600-800 , the pore size distribution peak is located at 50nm;

[0041] S4. Surface modification: The aerogel powder was immersed in an ethanol solution of a silane coupling agent, refluxed at 60° C. for 2 h, and centrifugally dried to obtain a hydrophobically modified aerogel.

[0042] Preferably, a sole composite processing method also includes a dynamic pore repair mechanism, using interfacial polymerization to prepare microcapsules with polyurea as shell material and silane coupling agent as core material, with a shell wall thickness of 0.5-1 , particle size distribution 20-50 , the core material loading rate is ≥85%. When the sole is subjected to local pressure ≥5MPa, the microcapsules rupture to release the coupling agent, which reacts with the hydroxyl groups in the thermoplastic polyurethane matrix to form -Si-OC- bonds, and at the same time penetrates into the pores and combines with the hydroxyl groups on the surface of the ceramic phase to form a three-dimensional cross-linked network, automatically filling the pores and repairing the structure.

[0043] Preferably, the performance indicators of the composite sole include: compressive strength ≥ 15MPa, density 0.8 , air permeability ≥ 2000mL, abrasion resistance ≤ 50mg / 1000 turns.

[0044] The beneficial effects of the present invention are: the present invention drives the pore distribution through foot biomechanical data to achieve zoning function optimization, combines the high wear resistance of silicon carbide with the lightweight cushioning properties of aerogel, breaks through the performance bottleneck of traditional sole materials, and uses the supercritical state of carbon dioxide to accurately control the pore morphology, avoiding residual pollution of traditional chemical foaming agents. Through the synergistic effect of supercritical foaming of gradient pore structure and microwave sintering, the pore morphology is accurately matched with functional requirements, and the compressive strength is improved. Polyurea microcapsules are used to encapsulate silane, which is only released when the material is damaged to achieve dynamic self-repair, giving the sole dynamic repair ability and extending the service life. The fixed pore morphology is restored by aerogel elasticity to avoid the collapse problem of traditional foaming materials after pressure relief, ensuring the stability of the gradient structure. The buffer layer adopts a honeycomb porous network to improve the energy absorption rate of the sole. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Flowchart of the present invention. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0047] Example 1

[0048] like Figure 1 This embodiment provides: a sole composite processing method, specifically comprising the following steps: obtaining foot biomechanical data, dividing the sole into an arch support area, a forefoot buffer area, and a heel wear-resistant area based on a three-dimensional pressure distribution model, calculating the required porosity range of each area through finite element analysis, performing a gradient injection molding process of a porous ceramic-polymer composite slurry, and using supercritical carbon dioxide directional foaming technology to generate a gradient pore structure with biomimetic characteristics, specifically comprising the following sub-steps:

[0049] S101, according to the rigidity requirements of the arch support area, a high-density slurry with 30-40% silicon nitride ceramic powder is prepared and formed by microwave-assisted sintering. Crystalline phase, porosity controlled at 10-20%;

[0050] S102: To meet the energy rebound requirements of the forefoot buffer zone, at least 25% of graphene oxide / carboxymethyl cellulose aerogel powder is added to the slurry. Combined with a honeycomb porous network design, the porosity is increased to 40-60%.

[0051] S103, introduce nano-silica reinforcement of at least 15% in the heel wear-resistant area, and form a diamond-like carbon coating through plasma surface treatment with a porosity of 5-15%;

[0052] Based on the above-mentioned zoning design, a stepped temperature rising sintering process is adopted, heating the material to 1700-1750°C at a rate of 15-20°C / min in a nitrogen atmosphere and keeping it warm for 0.5-2h to form a composite sole with wear resistance, flexible cushioning and breathable functions.

[0053] Preferably, the gradient pore structure with biomimetic characteristics of the three-dimensional pressure distribution model sequentially performs the following steps:

[0054] S1. Dynamic plantar pressure data is collected using a flexible piezoelectric film sensor array. Simultaneously, 3D laser scanning is used to obtain arch curvature radius and sagittal plane angle morphological parameters. A spatiotemporal association database is constructed and motion pattern parameters are annotated.

[0055] S2. Divide the sole of the foot into: an arch support area with high curvature and low transient pressure, a forefoot buffer area subject to high-frequency impact loads, and a heel wear-resistant area subject to a combination of static pressure and shear force;

[0056] S3. A three-dimensional plantar model is established based on non-uniform rational B-spline surfaces. Dynamic pressure data is fused with the parameters of arch ligament stiffness and fascia elastic modulus through Gaussian kernel interpolation to generate a biomechanically corrected continuous pressure field.

[0057] S4: Define the arch support area elastic modulus 15±2MPa and energy absorption rate ≥75%, and the forefoot buffer damping coefficient 0.35±0.05 , the target performance of the heel area shear strength ≥ 8MPa, and the mapping relationship between porosity and elastic modulus is established;

[0058] S5. Generate a pore gradient distribution. The arch support area forms a 5%-15% increasing pore along the curvature path. The forefoot area sets a three-layer gradient structure from the surface layer to the core layer with a porosity of 20%-40%-25%. The heel area adopts a honeycomb fiber composite structure with a porosity of 10%±2%. Output a design parameter set including porosity, pore size, and orientation angle.

[0059] Preferably, the porous ceramic-polymer composite slurry includes the following mass ratio components and preparation rules:

[0060] (e) Matrix material: 30-50% thermoplastic polyurethane with a melt index of 20-30g / 10min and a glass transition temperature of ≤-30°C. Medical-grade thermoplastic polyurethane is used to ensure biocompatibility and low-temperature flexibility.

[0061] (f) Ceramic phase: 20-40% silicon nitride ceramic powder, particle size range 0.5-5 , The phase ratio is ≥90%, the particle size distribution is verified by laser particle size analyzer, and the crystal phase purity is analyzed by XRD;

[0062] (g) Aerogel reinforcement: 10-25% graphene oxide aerogel powder, specific surface area ≥ 600 , the pore size distribution is 10-500nm, and the aerogel is crushed to 200-400 mesh after freeze drying to ensure its uniform dispersion in the slurry;

[0063] (h) Functional additives: nano-silica reinforcing agent 5-15%, microencapsulated silane coupling agent 2-5%, foaming agent 1-3%;

[0064] The slurry preparation process includes: melting thermoplastic polyurethane particles at 180-200 ° C, adding silicon nitride powder, aerogel and additives in sequence, and mixing them evenly in a twin-screw extruder at a speed of 300-400 rpm. The solid content of the slurry is controlled to be 45-60%, and the viscosity range is 5000-8000 mPa. After mixing, seal and let stand for 12 hours to eliminate bubbles.

[0065] Preferably, the directional foaming process is carried out by injecting the composite slurry into a mold cavity preheated to 90-110°C, pre-setting a micron-scale groove structure on the inner wall of the mold to guide the foaming direction, injecting supercritical carbon dioxide fluid into the mold, using the supercritical carbon dioxide fluid as a foaming agent, controlling the critical temperature to 31.1°C, and the pressure to 8-12MPa, maintaining for 15 minutes to allow the aerogel powder to fully expand, and achieving directional pore growth by controlling the mold temperature gradient, controlling the mold temperature at 80-120°C in the arch support area, limiting the foaming rate to form a dense structure, and reducing the mold temperature of the forefoot buffer area to 80°C to promote rapid expansion of the aerogel to form open pores. After foaming is completed, the pressure is quickly released to normal pressure, and the elastic memory effect of the aerogel skeleton is used to fix the pore morphology, and finally obtaining a gradient pore structure.

[0066] Preferably, the distribution rules of the gradient pores include:

[0067] Wear-resistant base layer: porosity 10-20%, pore size ≤ By limiting the amount of foaming agent added to 1-2% and increasing the sintering temperature to 1700-1750℃, densification is achieved. The silicon nitride content of this layer is increased to 35-40%. The surface is treated with plasma to form a diamond-like carbon coating with a hardness of ≥1800HV and a friction coefficient of ≤0.15.

[0068] Buffer layer: porosity 40-60%, pore size 100-300 , using 25% graphene oxide aerogel powder and 45% thermoplastic polyurethane matrix composite, through supercritical carbon dioxide foaming to form a three-dimensional honeycomb structure, energy rebound rate ≥ 85%, compression permanent deformation ≤ 5%;

[0069] Breathable surface: porosity 70-85%, pore size 500-800 , using the sacrificial template method PLA fiber diameter 500 , accounting for 30% by volume, decomposes to form through-holes during the sintering process, and the surface is sprayed with a fluorosilane-modified graphene oxide hydrophobic coating. The hydrophobic coating has a contact angle of ≥150°, a sliding angle of ≤5°, and an air permeability of ≥2500mL / ( ).

[0070] Preferably, the implementation of the functional partitioning includes:

[0071] (d) Data of arch support area: Based on the finite element analysis to determine the rigidity requirements, the elastic modulus is ≥1.5GPa, the silicon nitride content in the slurry is adjusted to 35-40%, and nano-silicon dioxide is added as a grain boundary strengthener. The sintering temperature is 2.45GHz and the power density is 800Nm. Downward promotion Towards Phase transformation, β phase accounts for ≥95%, forming an interwoven rod-like grain structure, and the porosity is controlled at 15-20%;

[0072] (e) Forefoot buffer zone data: According to the impact absorption rate requirement, the impact absorption rate is ≥70%. Graphene oxide aerogel powder is added to the slurry to 25%. Combined with the step-by-step foaming process, the first stage pressure is 8MPa / 90°, and the second stage pressure is released to 5MPa / 60° to generate a gradient pore size distribution. The surface layer is 500 100 , forming a honeycomb porous network with a wall thickness of 20-50 ;

[0073] (f) Heel wear-resistant area: 15% nano-silicon dioxide and 5% silicon carbide whiskers are introduced, and a dual-phase reinforced structure is formed by hot pressing and sintering at a pressure of 500 MPa and a temperature of 1650°.

[0074] Preferably, a sole composite processing method further includes surface functionalization treatment:

[0075] (d) Preparation of hydrophobic coating: Fluorosilane and graphene oxide were dispersed in ethanol solution, ultrasonically treated for 30 min, and then blended with thermoplastic polyurethane particles. Electrostatic spraying was used to form a 10-30 coating;

[0076] (e) Antibacterial functionalization: 5 wt% nano-zinc oxide (30 nm in particle size) was added to the hydrophobic coating and loaded onto the graphene oxide surface via a sol-gel method. After activation by ultraviolet light, the 24-hour antibacterial rate against Escherichia coli and Staphylococcus aureus was ≥99.9%;

[0077] (f) Wear-resistant strengthening: magnetron sputtering technology is used to deposit 2-5 Thick hard film, fiber hardness ≥ 2200HV, friction coefficient reduced to 0.12.

[0078] Preferably, microwave assisted sintering is introduced into the sintering process, and 2.45 GHz microwave assisted heating is adopted under nitrogen atmosphere, and the microwave power density is 5-10 , accelerating ceramic phase transformation and reducing energy consumption.

[0079] Preferably, the preparation of the graphene oxide aerogel powder includes:

[0080] S1. Dispersion preparation: Graphene oxide was dispersed in deionized water at a concentration of 2 mg / mL. After ultrasonic treatment for 24 h, the graphene oxide dispersion was blended with carboxymethyl cellulose and stirred for 24 h to form a homogeneous mixture.

[0081] S2, freeze drying process: the mixed solution was injected into a polytetrafluoroethylene mold, pre-frozen to -80 ° C, then transferred to a freeze dryer with a vacuum degree of ≤ 0.1 mbar, heated to -20 ° C and maintained for 12 h, then heated to 25 ° C and maintained for 24 h to obtain block aerogel;

[0082] S3, crushing and screening: use air flow mill to crush the aerogel into 200-400 mesh, and then sieve to obtain particle size of 10-50 The powder has a specific surface area of 600-800 , the pore size distribution peak is located at 50nm;

[0083] S4. Surface modification: The aerogel powder was immersed in an ethanol solution of a silane coupling agent, refluxed at 60°C for 2 hours, and centrifuged to obtain a hydrophobically modified aerogel. The dispersion uniformity of the aerogel in the thermoplastic polyurethane matrix was improved by 40% compared with the unmodified powder.

[0084] Preferably, a sole composite processing method also includes a dynamic pore repair mechanism, using interfacial polymerization to prepare microcapsules with polyurea as shell material and silane coupling agent as core material, with a shell wall thickness of 0.5-1 , particle size distribution 20-50 , the core material loading rate is ≥85%. When the sole is subjected to local pressure ≥5MPa, the microcapsules rupture to release the coupling agent, which reacts with the hydroxyl groups in the thermoplastic polyurethane matrix to form -Si-OC- bonds, and at the same time penetrates into the pores and combines with the hydroxyl groups on the surface of the ceramic phase to form a three-dimensional cross-linked network, automatically filling the pores and repairing the structure.

[0085] Preferably, the performance indicators of the composite sole include: compressive strength ≥ 15MPa, density 0.8 , air permeability ≥ 2000mL, abrasion resistance ≤ 50mg / 1000 turns.

[0086] Example 2

[0087] The present invention provides a technical solution: a sole composite processing method, comprising the following steps:

[0088] S1. Based on the peak pressure data of the arch area, the arch support area is set as a high wear-resistant area;

[0089] S2. Prepare a slurry containing 20% silicon nitride ceramic powder, 50% thermoplastic polyurethane matrix, 20% graphene oxide aerogel powder, and 10% nano-silica reinforcement to a solid content of 45%;

[0090] S3, injecting the composite slurry into the preheated mold, using carbon dioxide supercritical fluid as the foaming agent, controlling the temperature to 80 ° C and the pressure to 8 MPa, so that the aerogel powder is directionally expanded to form gradient pores, and sintering is performed by step-by-step heating at a heating rate of 10 ° C / min, and the final sintering temperature is 1600 ° C, and the temperature is kept for 1 hour;

[0091] S4, based on the arch support area data, adjust the silicon nitride content in the slurry to 35%, and generate after sintering Crystalline phase: Based on the forefoot buffer zone data, flexible aerogel powder is added to 20% to form a honeycomb porous network;

[0092] S5, spraying a hydrophobic coating formed by blending fluorosilane-modified graphene oxide and thermoplastic polyurethane on the breathable surface, with a coating thickness of 10 ;

[0093] S6, using 2.45GHz microwave radiation heating in nitrogen atmosphere, microwave power density of 5 , accelerate ceramic phase transformation and reduce energy consumption;

[0094] S7. Add microencapsulated silane coupling agent to the slurry. When the sole is damaged by pressure, the microcapsules rupture and release the coupling agent, automatically filling the pores and repairing the structure.

[0095] Example 3

[0096] The present invention provides a technical solution: a sole composite processing method, comprising the following steps:

[0097] S1. Based on the peak pressure data of the arch area, the arch support area is set as a high wear-resistant area;

[0098] S2. Prepare a slurry containing 30% silicon nitride ceramic powder, 40% thermoplastic polyurethane matrix, 25% graphene oxide aerogel powder, and 5% nano-silica reinforcement to a solid content of 50%;

[0099] S3, injecting the composite slurry into the preheated mold, using carbon dioxide supercritical fluid as the foaming agent, controlling the temperature at 100 ° C and the pressure at 12 MPa, so that the aerogel powder is directionally expanded to form gradient pores, and sintering is performed by step-by-step heating at a heating rate of 15 ° C / min, and the final sintering temperature is 1700 ° C, and the heat is kept for 1.5 hours;

[0100] S4, based on the arch support area data, adjust the silicon nitride content in the slurry to 38%, and generate after sintering Crystalline phase: Based on the forefoot buffer zone data, flexible aerogel powder is added to 25% to form a honeycomb porous network;

[0101] S5, spraying a hydrophobic coating formed by blending fluorosilane-modified graphene oxide and thermoplastic polyurethane on the breathable surface, with a coating thickness of 20 ;

[0102] S6, using 2.45GHz microwave radiation heating in nitrogen atmosphere, microwave power density of 7 , accelerate ceramic phase transformation and reduce energy consumption;

[0103] S7. Add microencapsulated silane coupling agent to the slurry. When the sole is damaged by pressure, the microcapsules rupture and release the coupling agent, automatically filling the pores and repairing the structure.

[0104] Example 4

[0105] The present invention provides a technical solution: a sole composite processing method, comprising the following steps:

[0106] S1. Based on the peak pressure data of the arch area, the arch support area is set as a high wear-resistant area;

[0107] S2. Prepare a slurry containing 40% silicon nitride ceramic powder, 30% thermoplastic polyurethane matrix, 15% graphene oxide aerogel powder, and 15% nano-silica reinforcement to a solid content of 60%;

[0108] S3. The composite slurry is injected into a preheated mold, and carbon dioxide supercritical fluid is used as a foaming agent. The temperature is controlled at 120°C and the pressure is 15 MPa to make the aerogel powder expand directionally to form gradient pores. After foaming, the aerogel powder is sintered by step-by-step heating at a heating rate of 20°C / min. The final sintering temperature is 1750°C and kept warm for 2 hours.

[0109] S4, based on the arch support area data, adjust the silicon nitride content in the slurry to 40%, and generate after sintering Crystalline phase: Based on the forefoot buffer zone data, flexible aerogel powder is added to 20% to form a honeycomb porous network;

[0110] S5, spraying a hydrophobic coating formed by blending fluorosilane-modified graphene oxide and thermoplastic polyurethane on the breathable surface, with a coating thickness of 30 ;

[0111] S6, using 2.45GHz microwave radiation heating in nitrogen atmosphere, microwave power density of 10 , accelerate ceramic phase transformation and reduce energy consumption;

[0112] S7. Add microencapsulated silane coupling agent to the slurry. When the sole is damaged by pressure, the microcapsules rupture and release the coupling agent, automatically filling the pores and repairing the structure.

[0113] Experimental example

[0114] 1. The lightweight, mechanical strength, functional properties, and environmental adaptability of the composite shoe sole provided by the present invention were verified through experiments. The density was measured using the Archimedean method, and the strength was tested using a universal mechanical testing machine. The results are shown in the following table:

[0115] 2. Comparative Example Description:

[0116] Comparative Example 1: Traditional EVA sole without ceramic composite and gradient pore structure;

[0117] Comparative Example 2: The slurry formulation of Example 3 was adopted, but sintering was performed in a conventional resistance furnace.

[0118] in conclusion:

[0119] The silicon nitride content is positively correlated with the compressive strength: the compressive strength of Example 4 reaches 24 MPa, which is 50% higher than that of Example 2;

[0120] Microwave sintering significantly improves β-phase conversion: Example 3 has a β-phase content of 93%, compared to only 75% in Comparative Example 2 with the same formulation but without microwaves;

[0121] Supercritical pressure gradient optimizes air permeability: Example 4 has an air permeability of 2600 mL at a pressure of 15 MPa, which is 160% higher than that of Comparative Example 2;

[0122] The energy rebound rate is related to the aerogel content: when the aerogel content is 25%, the rebound rate of Example 3 reaches 90%, while that of Example 2 is 85%.

[0123] 2. Dynamic repair and response relationship of gradient pores

[0124]

[0125] Synergy mechanism:

[0126] The high-porosity buffer layer (40%-45%) provides a diffusion channel for the silane released after the microcapsules rupture, and the low-porosity support region (15%-20%) limits the crack propagation path;

[0127] When the addition amount of microcapsules in Example 4 was 10%, the repair agent could cover more than 90% of the crack area.

[0128] 3. Negative impact of lack of technological collaboration

[0129]

[0130] It can be seen from the table that the lightweight, mechanical strength, functional characteristics and environmental adaptability of the composite sole provided by the present invention are in line with the expected design, and the performance of each embodiment is stable and meets the requirements of functional zoning.

[0131] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0132] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A sole composite processing method, characterized in that: The following steps are involved: Obtain foot biomechanical data and divide the sole of the foot into an arch support area, a forefoot buffer zone, and a heel wear-resistant area based on a three-dimensional pressure distribution model. Finite element analysis is used to calculate the required porosity range for each area. A gradient injection molding process is then performed using porous ceramic-polymer composite slurry. Supercritical carbon dioxide directional foaming technology is used to generate a gradient pore structure with biomimetic characteristics. This process includes the following sub-steps: S101, according to the rigidity requirements of the arch support area, a high-density slurry with 30-40% silicon nitride ceramic powder is prepared and formed by microwave-assisted sintering. Crystalline phase, porosity controlled at 10-20%; S102: To meet the energy rebound requirements of the forefoot buffer zone, at least 25% of graphene oxide / carboxymethyl cellulose aerogel powder is added to the slurry. Combined with a honeycomb porous network design, the porosity is increased to 40-60%. S103, introduce nano-silica reinforcement of at least 15% in the heel wear-resistant area, and form a diamond-like carbon coating through plasma surface treatment with a porosity of 5-15%; Based on the aforementioned zoning of the arch support area, forefoot buffer zone and heel wear-resistant area, a step-by-step temperature sintering process is adopted, heating the material to 1700-1750°C at a rate of 15-20°C / min in a nitrogen atmosphere and keeping it warm for 0.5-2h to form a composite sole with wear resistance, flexible cushioning and breathability.

2. A sole composite processing method according to claim 1, characterized in that: The porous ceramic-polymer composite slurry comprises the following components by mass ratio: 20-40% silicon nitride ceramic powder, 30-50% thermoplastic polyurethane matrix, 10-25% graphene oxide aerogel powder, and 5-15% nano-silicon dioxide reinforcement. The solid content of the slurry is 45-60%. The slurry preparation process includes: melting thermoplastic polyurethane particles at 180-200 ° C, adding silicon nitride powder, aerogel and additives in sequence, and mixing them evenly in a twin-screw extruder at a speed of 300-400 rpm. The solid content of the slurry is controlled to be 45-60%, and the viscosity range is 5000-8000 mPa. After mixing, seal and let stand for 12 hours to eliminate bubbles.

3. A sole composite processing method according to claim 1, characterized in that: The directional foaming technology is described as follows: the composite slurry is injected into a mold cavity preheated to 90-110°C, a micron-scale groove structure is preset on the inner wall of the mold to guide the foaming direction, and supercritical carbon dioxide fluid is injected into the mold. The supercritical carbon dioxide fluid is used as a foaming agent, and the critical temperature is controlled to 31.1°C and the pressure is 8-12MPa. The pressure is maintained for 15 minutes to allow the aerogel powder to fully expand. The directional growth of pores is achieved by controlling the mold temperature gradient. The mold temperature of the arch support area is controlled to 80-120°C to limit the foaming rate to form a dense structure. The mold temperature of the forefoot buffer area is reduced to 80°C to promote the rapid expansion of the aerogel to form open pores. After foaming is completed, the pressure is quickly released to normal pressure. The elastic memory effect of the aerogel skeleton is used to fix the pore morphology, and finally a gradient pore structure is obtained.

4. A sole composite processing method according to claim 3, characterized in that: The distribution rules of the gradient pores include: The porosity of the wear-resistant base layer is 10-20%, and the pore size is ≤ ; The porosity of the buffer layer is 40-60%, and the pore size is 100-300 ; The porosity of the breathable surface is 70-85%, and the pore size is 500-800 .

5. A sole composite processing method according to claim 1, characterized in that: The functional zoning of the arch support area, the forefoot buffer area and the heel wear-resistant area is realized by: based on the arch support area data, adjusting the silicon nitride content in the slurry to 35-40%, and adding nano-silicon dioxide as a grain boundary strengthener, forming Crystal phase, based on the forefoot buffer zone data, graphene oxide aerogel powder is added to the slurry to 25% to form a honeycomb porous network, and 15% nano-silicon dioxide and 5% silicon carbide whiskers are introduced into the heel wear-resistant area, and a dual-phase reinforced structure is formed through hot pressing and sintering.

6. A sole composite processing method according to claim 1, characterized in that: The invention also includes surface functionalization treatment, spraying a hydrophobic coating on the breathable surface, wherein the hydrophobic coating on the breathable surface is made by blending fluorosilane-modified graphene oxide and thermoplastic polyurethane, and the coating thickness is 10-30 Nano zinc oxide is added to the hydrophobic coating and loaded on the surface of graphene oxide by melt-gel method. Magnetron sputtering technology is used to deposit 2-5 Thick hard film.

7. A sole composite processing method according to claim 1, characterized in that: The sintering process introduces microwave assisted sintering, and adopts 2.45GHz microwave assisted heating in nitrogen atmosphere, and the microwave power density is 5-10W / , accelerating ceramic phase transformation and reducing energy consumption.

8. A sole composite processing method according to claim 2, characterized in that: The graphene oxide aerogel powder is prepared by blending a graphene oxide dispersion with carboxymethyl cellulose, stirring for 24 hours to form a homogeneous mixture, injecting the mixture into a polytetrafluoroethylene mold, pre-freezing to -80°C, and then transferring it to a freeze dryer with a vacuum degree of ≤0.1mbar, heating it to -20°C and holding it for 12 hours, and then heating it to 25°C and holding it for 24 hours to obtain a block aerogel, crushing the aerogel to 200-400 mesh, and sieving to obtain a particle size of 10-50 The powder has a specific surface area of 600-800 / g, the aerogel powder was immersed in silane coupling agent ethanol solution, refluxed at 60 °C for 2 h, and centrifuged to obtain hydrophobically modified aerogel.

9. A sole composite processing method according to claim 1, characterized in that: It also includes a dynamic pore repair mechanism, using interfacial polymerization to prepare microcapsules with polyurea as the shell material and silane coupling agent as the core material, with a shell wall thickness of 0.5-1 , particle size distribution 20-50 , the core material loading rate is ≥85%. When the sole is subjected to local pressure ≥5MPa, the microcapsules rupture to release the coupling agent, which reacts with the hydroxyl groups in the thermoplastic polyurethane matrix to form -Si-OC- bonds, and at the same time penetrates into the pores and combines with the hydroxyl groups on the surface of the ceramic phase to form a three-dimensional cross-linked network, automatically filling the pores and repairing the structure.

10. The sole composite processing method according to claim 1, characterized in that: The gradient pore structure with biomimetic characteristics of the three-dimensional pressure distribution model sequentially performs the following steps: S1. Dynamic plantar pressure data is collected using a flexible piezoelectric film sensor array. Simultaneously, 3D laser scanning is used to obtain arch curvature radius and sagittal plane angle morphological parameters. A spatiotemporal association database is constructed and motion pattern parameters are annotated. S2. Divide the sole of the foot into: an arch support area with high curvature and low transient pressure, a forefoot buffer area subject to high-frequency impact loads, and a heel wear-resistant area subject to a combination of static pressure and shear force; S3. A three-dimensional plantar model is established based on non-uniform rational B-spline surfaces. Dynamic pressure data is fused with the parameters of arch ligament stiffness and fascia elastic modulus through Gaussian kernel interpolation to generate a biomechanically corrected continuous pressure field. S4: Define the elastic modulus of the arch support area as 15±2MPa and the energy absorption rate as ≥75%, and the damping coefficient of the forefoot buffer zone as 0.35±0.05N. , the target performance of the heel area shear strength ≥ 8MPa, and the mapping relationship between porosity and elastic modulus is established; S5. Generate a pore gradient distribution. The arch support area forms a 5%-15% increasing pore along the curvature path. The forefoot area sets a three-layer gradient structure from the surface layer to the core layer with a porosity of 20%-40%-25%. The heel area adopts a honeycomb fiber composite structure with a porosity of 10%±2%. Output a design parameter set including porosity, pore size, and orientation angle.

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