A method for molding a foamed material assembly with nylon support.

Abstract

This invention provides a method for molding a foamed material assembly with a nylon support, comprising: S10 providing a rigid nylon support with through holes and a foamed material preform; S20 selecting a heat-activated adhesive that is in a gel state at room temperature, heating and liquefying it, and then coating it onto the nylon support and the inner wall of the through holes, drying it to form a solid dry film; S30 placing the nylon support with the solid dry film and the foamed preform into a mold; S40 closing the mold, heating and pressurizing to melt the solid dry film, causing the foamed preform to expand and fill the through holes and bond with the molten adhesive; S50 cooling and solidifying before opening the mold. The foamed material assembly produced by this molding method has better shear resistance.

Description

Technical Field

[0001] This invention relates to the field of foam material component molding technology, and more specifically to a method for molding foam material components with nylon supports. Background Technology

[0002] In the manufacturing of high-performance athletic shoe soles, it is typically necessary to combine high-rigidity nylon support components with high-elasticity thermoplastic elastomer foam materials (such as EVA and PEBA) to balance the support stability and cushioning rebound performance of the sole. Current technology generally employs an in-mold molding process, where pre-fabricated nylon components are placed in a mold, followed by the addition of foam material for compression molding, using heat and pressure to bond the two together. However, this process results in foam material components with insufficient physical and mechanical interlocking and weak shear resistance. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects or problems in the prior art and to provide a method for molding a foamed material component with nylon support members, wherein the foamed material component produced by this molding method has better shear resistance.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: Technical Solution 1: A method for molding a foamed material component with a nylon support, comprising the following steps: S10: providing a nylon support and a foamed material preform; the nylon support is made of nylon material as a rigid component, having a bonding surface perpendicular to its thickness direction, and having a plurality of through holes penetrating the nylon support along the thickness direction; the foamed material preform is made of thermoplastic elastomer foamed material; S20: selecting a heat-activated adhesive that is in a gel state at room temperature and whose chemical system is compatible with the foamed material preform, heating the heat-activated adhesive to convert it into a liquefied state, and then applying it to the bonding surface of the nylon support and the inner wall of the through holes. The coated nylon support is dried to form a solid dry film of heat-activated adhesive on the surface of the nylon support; S30: The nylon support with the solid dry film is placed in the positioning structure of the molding mold, and the foamed material preform is placed in the molding mold and covers the mating surface of the nylon support; S40: The molding mold is closed, the molding mold is heated and a mold closing pressure is applied, so that the solid dry film melts, and the foamed material preform expands due to heat and fills into the through hole and contacts the molten heat-activated adhesive; S50: After cooling the molding mold to the set temperature, the mold is opened to obtain a foamed material assembly with nylon support.

[0005] Technical Solution 2 based on Technical Solution 1: In step S20, the method of heating the thermally activated adhesive into a liquefied state is as follows: the container containing the room temperature gel-state thermally activated adhesive is placed in a water bath environment at 100°C and heated and stirred until the adhesive is converted into a fluid. Then, the fluid adhesive is filtered through an 80-mesh to 100-mesh filter.

[0006] Technical Solution 3 based on Technical Solution 1: In step S20, the drying process is as follows: drying in an environment of 75°C to 80°C for 4 to 6 minutes until the thickness of the solid dry film formed is 0.08 mm to 0.12 mm.

[0007] Technical Solution 4 based on Technical Solution 1: In step S20, before applying the heat-activated adhesive, the method further includes: cleaning the mating surface and inner wall of the through hole of the nylon support with an organic solvent, then applying a layer of nylon treatment agent containing isocyanate curing agent, and drying at 75°C to 80°C for 3 to 5 minutes.

[0008] Technical solution five based on technical solution one: In step S10, the material of the nylon support is glass fiber reinforced nylon 6 with a glass fiber content of 30%, and the heat distortion temperature of this material under a load of 0.45MPa is greater than or equal to 190℃.

[0009] Technical Solution Six based on Technical Solution One: In step S10, the diameter of the through hole is 3.0mm to 5.0mm, and the edge of the through hole on one side of the mating surface is machined with a rounded corner with a radius of 0.5mm.

[0010] Technical solution seven based on technical solution one: In step S30, the initial volume of the selected foamed material preform is 85% to 95% of the volume of the molding mold cavity.

[0011] Technical solution eight based on technical solution seven: In step S40, the parameters for heating the molding die and applying the mold closing pressure are: heating the molding die to 175℃±3℃ and applying a mold closing gauge pressure greater than or equal to 170kg / cm².

[0012] Technical Solution Nine based on Technical Solution One: In step S50, the cooling method of the molding die is as follows: while keeping the mold closing pressure constant, a cooling medium is introduced for continuous cooling for 450 seconds ± 20 seconds, and the set temperature at the time of mold opening is less than or equal to 45°C.

[0013] Technical solution ten based on technical solution one: The molding method further includes step S60: the foamed material component with nylon support obtained after mold opening is subjected to cold light source ultraviolet irradiation treatment, and then the component is bonded to the rubber outsole using a polyurethane system adhesive. As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects: Conventional in-mold molding processes typically involve directly applying liquid adhesives to the insert surface. When the mold closes and the foamed material rapidly expands and flows upon heating, a high-intensity shear flow is generated within the mold cavity. This fluid scouring force can peel or disperse the liquid or incompletely dried adhesive layer from the bonding surface, resulting in adhesive-deficient areas or adhesive overflow at the bonding interface, preventing the formation of a continuous and uniform adhesive layer. The process steps employed in the first technical solution of this invention involve selecting a heat-activated adhesive that is in a gel state at room temperature. This adhesive is first liquefied by heating to reduce its viscosity, achieving wetting and coverage of the nylon surface and the inner walls of the through-holes. This solves the problems of uneven coating and poor penetration of micropores by gel-state adhesives. Subsequently, a drying process transforms the adhesive into a solid dry film before mold entry. During the initial stage of in-mold molding and the intense flow of the foamed material, the solid dry film adhering to the nylon surface possesses sufficient cohesion and adhesion to resist the shear scouring of the foaming fluid, maintaining the stability of the adhesive layer's position and thickness. Only when the mold temperature rises to the activation temperature range of the adhesive and the internal pressure stabilizes does the solid dry film melt in situ, contacting and chemically cross-linking with the foamed material, which is also in a molten state. This avoids the adhesion failure caused by fluid erosion in conventional liquid adhesive application processes. Furthermore, conventional mechanical bonding usually relies on injection pressure to force the material into the pores. However, in foam molding processes, the low material density and uneven pressure transmission make it difficult to fill deep pores. In this solution, the volume expansion of the foamed preform within the confined space generates uniform isotropic pressure, forcing the softened foamed material to flow towards the through-hole region of least resistance. Simultaneously, the adhesive film layer pre-placed on the inner wall of the through-hole melts synchronously, acting as a high-temperature lubricating medium to facilitate the smooth filling of the through-hole by the foamed material. After cooling and solidification, the foamed material filling the through-hole forms a rivet-like physical interlocking structure, and this interlocking structure also achieves chemical bonding at the interface through the molten adhesive. Compared to the simple shear stress at the interface in conventional structures, it transforms into a composite stress mode of physical interlocking and chemical bonding, which can withstand the peeling stress generated by the rebound of foamed materials.

[0014] In technical solution two, a 100℃ water bath heating method combined with mechanical stirring is used to ensure that the heat-activated adhesive is heated evenly during the liquefaction process, avoiding localized overheating failure or colloid aging that may occur with direct heating. The filtration step with an 80-100 mesh screen effectively traps unmelted skin, gel clumps, or external impurities that may be generated during heating, eliminating the particle feel in the adhesive and ensuring that the adhesive layer coated on the surface of the nylon support is fine and uniform, thus improving the consistency of bonding.

[0015] In technical solution three, the temperature range and time range of the drying process are limited to ensure that the solvent in the adhesive layer completely evaporates before entering the mold, while the resin remains active, preventing bubble defects caused by the vaporization of residual solvent during high-temperature molding in the mold. At the same time, the thickness of the solid dry film is controlled between 0.08 mm and 0.12 mm, which ensures that there is sufficient adhesive volume to fill the interfacial gaps and wet the through holes after melting, while avoiding the formation of a weak cohesive layer due to excessive adhesive layer thickness.

[0016] In technical solution four, a cleaning and priming process is introduced before applying the heat-activated adhesive. This not only removes release agents or oil stains that hinder adhesion, but also chemically modifies the nylon surface using a treatment agent containing isocyanate hardeners. The isocyanate groups can react with the amide groups on the nylon surface, disrupting the crystalline structure of the nylon surface and introducing active groups, thereby increasing the surface energy of the nylon surface. This enhances the affinity between the nylon substrate and the subsequent heat-activated adhesive layer, significantly improving the interfacial bonding strength.

[0017] In technical solution five, glass fiber reinforced nylon with a heat distortion temperature greater than or equal to 190℃ is selected as the material for the support component. This ensures that the support component maintains high modulus and rigidity even under the high-temperature environment of in-mold molding at around 175℃, without softening or creeping. During the component cooling and shaping stage, the nylon support component can also act as an internal constraint skeleton, effectively resisting the internal shrinkage stress caused by thermal expansion and contraction of the foamed material, and preventing warping and deformation of the composite component after demolding.

[0018] In technical solution six, the 0.5mm rounded corner structure at the edge of the through hole acts as a fluid guide, reducing the flow resistance of the foam material during expansion and filling. This avoids the shearing obstruction of the foam fluid by sharp edges, allowing the softened foam material to fill the through hole more smoothly and completely, forming a full rivet head structure. Simultaneously, the rounded corner transition eliminates the stress concentration effect caused by right-angled edges, preventing the rivet structure from breaking at the root during subsequent stress, and improving the fatigue resistance of the physically interlocking structure.

[0019] In technical solution seven, the initial volume of the foamed material preform is set to be slightly smaller than the volume of the mold cavity, so that the foamed material preform will expand to a certain extent after being heated. This isotropic internal expansion pressure constitutes the main driving force for the material to flow and fill the nylon through holes, ensuring that the foamed material can achieve dense filling of the through holes on the nylon support by its own expansion energy without the need for complex flow channel design.

[0020] In technical solution eight, the heating temperature and mold closing pressure parameters are limited. A mold temperature of 175℃ can simultaneously trigger the cross-linking reaction of the adhesive and the melting flow of the foam material. A high-pressure environment of more than 170kg / cm² can make the molten adhesive and the foam material come into close contact and diffuse with each other at the molecular level, ensuring the density of physical riveting and the degree of cross-linking of chemical bonding, and avoiding false adhesion caused by insufficient temperature or loose structure caused by insufficient pressure.

[0021] In technical solution nine, the relevant process parameters for cooling are limited, and the mold opening temperature is controlled below 45°C. This allows the thermoplastic foam material to recrystallize and release stress under the forced constraint of the mold and nylon skeleton, eliminating residual thermal stress and gas expansion pressure inside the foam material. This avoids springback deformation due to internal and external pressure differences or thermal shrinkage during mold opening, ensuring the shape stability of the final product.

[0022] In technical solution ten, a cold light source UV irradiation is used to activate the surface of the component, thereby increasing its surface energy without causing thermal deformation of the foam material. Then, polyurethane adhesive is used to bond the outsole, ensuring the functional integrity of the foam material component when used as a shoe sole. Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0024] In the claims and description of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0025] This invention relates to a method for molding a foamed material assembly with a nylon support member, which mainly includes the following steps: S10: Provide a nylon support and a foam material preform; the nylon support is made of nylon material into a rigid component, has a mating surface perpendicular to its thickness direction, and is provided with a plurality of through holes penetrating the nylon support along the thickness direction; the foam material preform is made of thermoplastic elastomer foam material. S20: Select a heat-activated adhesive that is in a gel state at room temperature and whose chemical system is compatible with the foamed material preform. After heating the heat-activated adhesive to a liquefied state, apply it to the bonding surface of the nylon support and the inner wall of the through hole. Then, dry the coated nylon support to form a solid dry film of the heat-activated adhesive on the surface of the nylon support. S30: Place the nylon support with solid dry film in the positioning structure of the molding die, and place the foam material preform inside the molding die and cover the mating surface of the nylon support. S40: Close the molding mold, heat the molding mold and apply mold closing pressure to melt the solid dry film, and the foamed material preform expands under heat and fills the through hole to contact the molten heat-activated adhesive. S50: After cooling the molding die to the set temperature, the die is opened to obtain a foamed material assembly with nylon support components; S60: The foam material assembly with nylon support obtained after mold opening is subjected to cold light source ultraviolet irradiation treatment, and then the assembly is bonded to the rubber outsole using polyurethane system adhesive.

[0026] The following is a detailed explanation of each of the above steps.

[0027] In step S10, two components for subsequent integrated molding need to be prepared: a nylon support component serving as a rigid skeleton and a pre-formed foam material component serving as a buffer. For the nylon support component, a high-modulus and heat-resistant nylon material is selected and manufactured using injection molding. To ensure the nylon support component maintains structural stability and does not soften or creep under the subsequent high-temperature and high-pressure in-mold molding environment, glass fiber reinforced nylon 6 material with a glass fiber content of 30% is specifically selected. The heat distortion temperature of this material under a 0.45 MPa load must be strictly controlled at 190°C or higher to ensure that the nylon support component maintains high rigidity at a molding temperature of approximately 175°C, thus effectively resisting the thermal shrinkage stress of the foam material during the cooling stage.

[0028] In terms of structural design, the nylon support has a flat or curved mating surface perpendicular to its thickness direction. This mating surface is the main area for subsequent chemical bonding and physical interlocking with the foam material. To achieve physical interlocking, several through holes are formed along the thickness direction on the nylon support. The diameter of the through holes is set in the range of 3.0mm to 5.0mm. This diameter size is optimized to ensure that the molten foam material can pass through smoothly while avoiding weakening the mechanical strength of the nylon support due to excessively large hole diameters. In addition, a rounded corner structure with a radius of 0.5mm is specially machined on the edge of the through holes on the mating surface side of the nylon support. This rounded corner design can effectively reduce the flow resistance of the foam fluid when entering the through holes and prevent the sharp edges from shearing and impeding the fluid, thereby helping to form a full and stress-free rivet-like interlocking structure.

[0029] For foamed material preforms, thermoplastic elastomer foamed materials are selected for preparation, such as ethylene-vinyl acetate copolymers or polyether block amide preforms obtained using supercritical physical foaming processes. During the preparation of these preforms, their geometric dimensions and volume are precisely cut so that their initial volume is 85% to 95% of the final mold cavity volume. This allows space for the thermal expansion of the foamed material within the mold, ensuring that after mold closure and heating, the preform can generate appropriate internal pressure through its own volume expansion. This pressure will serve as the primary driving force to propel the softened foamed material into the nylon through-holes where resistance is minimal, preventing difficulties in mold closing due to excessive initial volume or insufficient filling pressure due to insufficient initial volume.

[0030] In step S20, the physical state conversion of the thermally activated adhesive, the surface pretreatment of the nylon support, and the coating and curing pre-setting of the adhesive layer are mainly completed. First, based on the chemical properties of the foam material preform, a thermally activated adhesive with a chemical system compatible with it is selected. For example, for foam materials based on ethylene-vinyl acetate copolymer, an adhesive with an ethylene-vinyl acetate copolymer modified system is selected. This type of adhesive exhibits a highly thixotropic gel state at room temperature, making it difficult to directly and uniformly coat. Therefore, it needs to be liquefied first. The specific liquefaction operation involves placing a container containing the room-temperature gel-state thermally activated adhesive in a water bath at a constant temperature of 100°C for heating, accompanied by mechanical stirring, to ensure uniform heating of the adhesive until it is completely transformed into a fluid state with good flowability. To remove unmelted skin, gel clumps, or external impurities that may be generated during the heating process, the fluid adhesive needs to be filtered through an 80-100 mesh filter to obtain a fine-textured adhesive solution.

[0031] Before applying the liquefied adhesive to the nylon support, the nylon support needs to undergo surface cleaning and chemical modification to improve the interfacial bonding strength. The bonding surfaces and inner walls of the through-holes of the nylon support are wiped clean with an organic solvent to remove mold release agent, oil, and dust. Subsequently, a layer of nylon treatment agent containing an isocyanate hardener is applied to the cleaned bonding surfaces and inner walls of the through-holes. After coating, the nylon support is dried at 75°C to 80°C for 3 to 5 minutes, utilizing the reaction between the isocyanate groups and the nylon surface to introduce active sites and complete the initial drying of the treatment agent layer.

[0032] After the pretreatment layer dries, the filtered liquefied heat-activated adhesive is evenly applied to the mating surfaces of the nylon support and the inner walls of the through holes. Following coating, the nylon support undergoes a second drying process, being placed in a drying environment of 75°C to 80°C for 4 to 6 minutes. This process aims to evaporate the solvent components in the adhesive, transforming it from a liquid to a solid dry film. The thickness of the dried solid film is controlled between 0.08 mm and 0.12 mm; at this point, the adhesive surface is slightly tacky to the touch but does not exhibit stringiness. This solid dry film state ensures that the adhesive layer adheres firmly to the nylon surface without displacement or loss under the high-pressure impact of subsequent in-mold molding, while retaining its reactivity for remelting at high temperatures.

[0033] In step S30, the main operations involve mold loading and spatial positioning of each component. First, a molding mold with a specific cavity structure is prepared. This mold has internal positioning structures designed to match the geometry of the nylon support, such as positioning countersunk holes or limiting slots. The nylon support, which has been treated in step S20 and has a solid dry film of heat-activated adhesive on its surface, is placed into the positioning structure of the mold. During placement, the orientation of the nylon support must be strictly confirmed, ensuring that the side without adhesive is tightly fitted against the inner wall of the mold, while the mating surface with the solid dry film and the through-hole openings face the interior of the mold cavity to facilitate subsequent contact with the foaming material.

[0034] After positioning the nylon support, the selected foam material preform is placed inside the cavity of the molding die. The foam material preform directly covers the mating surface of the nylon support, ensuring physical contact between its bottom surface and the surface of the nylon support with its solid dry film. In this step, the initial volume of the selected foam material preform is controlled between 85% and 95% of the total volume of the molding die cavity. This volume setting allows the preform to be smoothly installed into the die without generating excessive initial interference resistance, while also reserving appropriate space for thermal expansion within the die cavity.

[0035] In step S40, a high-temperature, high-pressure in-mold integrated molding operation is performed. First, the upper and lower mold plates of the molding die are closed, and then the heating and hydraulic pressurization systems are activated. During this process, the temperature of the molding die is heated and precisely controlled within the range of 175℃±3℃, while a mold closing pressure greater than or equal to 170 kg / cm² is applied. As the mold temperature rises, the solid dry film of the heat-activated adhesive adhering to the surface of the nylon support and the inner wall of the through-hole reaches its activation melting point, rapidly transforming from a solid state into a highly reactive molten liquid. Simultaneously, the thermoplastic elastomer foam preform placed in the mold cavity expands in volume upon heating. Because the mold is in a closed and locked state, the free expansion of the foam material is restricted, thereby generating isotropic internal pressure inside the mold cavity. Driven by this expanding internal pressure and the external mold closing pressure, the softened foam material flows towards the area of ​​least resistance, filling the through-hole of the nylon support. The foamed material entering the through-hole comes into close contact with and is mutually wetting with the molten, heat-activated adhesive layer on the inner wall. Under high temperature and pressure, the two complete a chemical cross-linking reaction at the interface, while the foamed material fills the through-hole to form a rivet-like physical entity.

[0036] In step S50, the main operations are cooling, shaping, and demolding of the component. After the high-temperature, high-pressure molding stage is completed, the cooling process begins. During this process, the pressure applied in step S40 is maintained constant, and the pressure is not prematurely released during cooling to utilize the rigidity of the mold cavity and nylon support to constrain the foamed material. While maintaining high-pressure mold locking, a cooling medium, such as cooling water, is introduced into the circulation pipe of the molding mold to continuously exchange heat and cool the mold. The duration of this cooling process is set to 450 seconds ± 20 seconds. This long-cycle pressurized cooling ensures that the thermoplastic foamed material can recrystallize and release stress under constrained conditions. By monitoring the mold temperature in real time, when the temperature of the molding mold drops to a set value, specifically less than or equal to 45°C, the cooling medium is stopped, the mold is depressurized, and the mold is opened. Subsequently, the integrated and dimensionally stable foamed material component with nylon support is removed from the mold cavity.

[0037] In step S60, the foam material assembly with nylon support members removed from the mold undergoes subsequent surface treatment and outsole assembly processes. First, the assembly is placed under ultraviolet irradiation for surface activation. During this process, a cold light source ultraviolet light is specifically chosen as the radiation source to avoid secondary thermal deformation or dimensional shrinkage of the thermoplastic foam material caused by the high temperatures generated by traditional hot light sources. Subsequently, a rubber outsole is prepared, and a polyurethane adhesive is selected as the interlayer bonding medium. The polyurethane adhesive is applied to the bonding surface of the assembly and the corresponding surface of the rubber outsole. After the adhesive is activated, the two are pressed together.

[0038] To more intuitively illustrate the technological advancements of the present invention in solving the problem of in-mold bonding failure of heterogeneous materials compared with existing technologies, the present invention specification provides the following embodiments and comparative examples.

[0039] First, the key raw materials used in the embodiments and comparative examples are specifically described. The nylon support component is made of glass fiber reinforced nylon 6 granules, grade CM1017XL, manufactured by Toray Industries, Ltd. of Japan, with a glass fiber content of 30%. The foamed material preform is made of thermoplastic elastomer substrate, grade Polyketone M330A, manufactured by Hyosung Corporation of South Korea, obtained through a supercritical nitrogen foaming process, with a density of approximately 0.18 g / cm³. The heat-activated adhesive is EVA modified resin adhesive, grade P983, manufactured by Nan Pao Resin Co., Ltd., which is gel-like at room temperature. The nylon treatment agent is treatment agent, grade JW-043, manufactured by Nan Pao Resin Co., Ltd., used in conjunction with isocyanate curing agent, grade RFE, manufactured by Bayer AG of Germany, with the curing agent addition ratio being 3%-4%. The polyurethane adhesive used in this system is PU adhesive with the grade 6580S produced by Nanpao Resin Company, used in conjunction with a hardener with the grade 6048.

[0040] Example 1 This embodiment provides a method for molding a foamed material assembly with nylon supports. The specific operation steps are as follows: S10: Component Preparation. Nylon support components are injection molded using CM1017XL nylon granules, with a tested heat distortion temperature (0.45 MPa) of 210℃. A 4.0 mm diameter through-hole is pre-drilled on the mating surface of the support component, with the hole edges machined with a radius of R0.5. A supercritical foam preform is prepared, its initial volume cut to 90% of the mold cavity volume.

[0041] S20: Adhesive layer pre-application. Place the P983 adhesive (which is in a gel state at room temperature) along with its container in a 100°C water bath and heat for 10 minutes with stirring until completely liquefied. Filter through an 80-mesh nylon filter. First, clean the surface of the nylon support with methyl ethyl ketone (MEK), then apply a JW-043 treatment agent mixed with RFE hardener and dry at 75°C for 4 minutes. Next, apply the liquefied P983 adhesive to the mating surfaces and inner walls of the through-holes of the nylon support and dry in a 75°C oven for 5 minutes. After removal, a solid dry film approximately 0.1 mm thick will form on the nylon surface; it will be slightly sticky to the touch and will not string.

[0042] S30: Mold Filling. Place the nylon support with solid dry film into the positioning groove at the bottom of the mold, ensuring the adhesive-free side adheres to the mold. Place the foamed preform into the mold cavity, covering the nylon support.

[0043] S40: In-mold molding. Close the mold, set the mold temperature to 175℃, and the mold closing pressure to 175 kg / cm². Maintain this high temperature and high pressure for 450 seconds to allow the foam material to expand, fill the pores, and bond with the molten adhesive film.

[0044] S50: Cooling and Shaping. Maintain constant mold closing pressure and circulate cooling water for 450 seconds. Open the mold and remove the component when the mold temperature drops to 40°C.

[0045] S60: Post-processing. The component is irradiated with cold light source UV (energy 1000mJ / cm²), and then bonded to the rubber outsole using 6580S adhesive.

[0046] Example 2 The only difference between this embodiment and Embodiment 1 is the diameter of the through hole in step S10.

[0047] In this embodiment, the diameter of the through hole on the nylon support is set to 3.0 mm. The remaining material specifications, processing technology, and molding parameters (temperature 175℃, pressure 175 kg / cm², cooling time 450 seconds) are consistent with those in Example 1.

[0048] Example 3 The only difference between this embodiment and Embodiment 1 is the diameter of the through hole in step S10.

[0049] In this embodiment, the diameter of the through hole on the nylon support is set to 5.0 mm. All other material specifications, processing techniques, and molding parameters remain consistent with those in Example 1.

[0050] Example 4 The only difference between this embodiment and Embodiment 1 is the initial volume of the foamed preform in step S30.

[0051] In this embodiment, the initial volume of the foamed material preform is cut to 85% of the volume of the molding mold cavity. The remaining material specifications and process parameters are consistent with those in Example 1.

[0052] Example 5 The only difference between this embodiment and Embodiment 1 is the initial volume of the foamed preform in step S30.

[0053] In this embodiment, the initial volume of the foamed material preform is cut to 95% of the volume of the molding mold cavity. All other material specifications and process parameters are consistent with those in Example 1.

[0054] Comparative Example 1 The difference between this comparative example and Example 1 lies in step S20. In Comparative Example 1, after the P983 adhesive is liquefied and coated, it is not dried to form a film. Instead, the nylon support is directly placed into the mold in a wet adhesive state (liquid) for subsequent operations S30 to S50. The remaining materials, structure (including through holes), and molding parameters are completely consistent with those of Example 1.

[0055] Comparative Example 2 The difference between this comparative example and Example 1 lies in step S10. In Comparative Example 2, the mating surface of the nylon support is a complete plane without any through holes. All other adhesive treatments (solid dry film process), molding parameters, etc., are completely consistent with Example 1.

[0056] Comparative Example 3 The difference between this comparative example and Example 1 lies in step S50. In Comparative Example 3, after molding, no pressure holding and cooling are performed; instead, the mold is opened directly while still hot (mold temperature approximately 170°C), and the component is removed and allowed to cool naturally in a natural environment. All other materials and processes are the same as in Example 1.

[0057] Comparative Example 4 The difference between this comparative example and Example 1 lies in the choice of nylon material in step S10. This comparative example uses ordinary nylon 6 (unreinforced), whose heat distortion temperature (0.45 MPa) is approximately 160°C. The remaining structure and process are consistent with Example 1.

[0058] The performance of the above embodiments and comparative examples was tested according to the following standards: Peel strength test: The test was conducted according to GB / T 3903.3-2011 "Test Methods for Peel Strength of Whole Footwear". A sample containing the interface between nylon and foam material was cut from the molded component, and the peel strength (unit: N / mm) was tested. The failure mode (interface failure or material bulk failure) was observed.

[0059] Dimensional stability test: Derived from the dimensional measurement methods in GB / T 3903.2-2017 "Test Methods for Abrasion Resistance of Whole Footwear". The length of the molded component is measured after 24 hours of storage and compared with the designed dimensions of the mold cavity to calculate the shrinkage rate (%). A lower shrinkage rate indicates better dimensional stability.

[0060] The test results are shown in the table below:

[0061] The test results of Examples 1 to 5 show that the components prepared by the method of the present invention have excellent performance, with peel strengths all above 3.8 N / mm, and the failure mode is material body tearing, indicating that the interfacial bonding force exceeds the material's own strength. Meanwhile, the dimensional shrinkage rate of each example is controlled within 1.0%, and the appearance is smooth with no excess adhesive, proving the stability of the process.

[0062] Comparing Example 1 and Comparative Example 1, it can be seen that the physical state of the adhesive has a significant impact on the bonding quality. Comparative Example 1, due to the direct liquid injection into the mold, experienced adhesive loss under high-pressure fluid flushing within the mold, resulting in a significant drop in peel strength to 1.5 N / mm and severe adhesive overflow. This confirms that pre-setting the adhesive as a solid dry film is crucial for preventing adhesive layer erosion and ensuring effective bonding. Comparing Example 1 and Comparative Example 2, it is evident that the introduction of physical structures significantly improves the bonding strength. Comparative Example 2, although chemically bonded, lacks a through-hole structure, resulting in a peel strength of only 2.2 N / mm. Example 1, by filling the through-holes with foam material to form physical interlocking, increased the strength to 4.2 N / mm, demonstrating the synergistic enhancement effect of physical interlocking and chemical bonding. The results of Comparative Examples 3 and 4 verify the effectiveness of the dimensional control methods. Comparative Example 3 eliminated pressure holding and cooling, and Comparative Example 4 used ordinary nylon with poor heat resistance, resulting in shrinkage rates as high as 4.5% and 3.2%, respectively, and severe component deformation. Example 1 utilizes a high heat-resistant nylon skeleton combined with in-mold pressure holding and cooling to control the shrinkage rate at 0.6%, effectively overcoming the problem of thermal shrinkage of foamed materials.

[0063] The foregoing description of the specifications and embodiments is intended to explain the scope of protection of this invention, but does not constitute a limitation on the scope of protection of this invention. Modifications, equivalent substitutions, or other improvements to the embodiments of this invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of this invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of this invention.

Claims

1. A method for molding a foamed material assembly with nylon supports, characterized in that, Includes the following steps: S10: Provide a nylon support and a foam material preform; the nylon support is made of nylon material into a rigid component, has a mating surface perpendicular to its thickness direction, and is provided with a plurality of through holes penetrating the nylon support along the thickness direction; the foam material preform is made of thermoplastic elastomer foam material. S20: Select a heat-activated adhesive that is in a gel state at room temperature and whose chemical system is compatible with the foamed material preform. After heating the heat-activated adhesive to a liquefied state, apply it to the bonding surface of the nylon support and the inner wall of the through hole. Then, dry the coated nylon support to form a solid dry film of the heat-activated adhesive on the surface of the nylon support. S30: Place the nylon support with solid dry film in the positioning structure of the molding die, and place the foam material preform inside the molding die and cover the mating surface of the nylon support. S40: Close the molding mold, heat the molding mold and apply mold closing pressure to melt the solid dry film, and the foamed material preform expands under heat and fills the through hole to contact the molten heat-activated adhesive. S50: After cooling the molding die to the set temperature, the die is opened to obtain a foamed material assembly with nylon support.

2. The method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, In step S20, the method of heating the thermally activated adhesive to a liquefied state is as follows: the container containing the room temperature gel-state thermally activated adhesive is placed in a water bath environment at 100°C and heated and stirred until the adhesive is converted into a fluid. Then, the fluid adhesive is filtered through an 80-mesh to 100-mesh filter.

3. The method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, In step S20, the drying process is carried out by drying in an environment of 75°C to 80°C for 4 to 6 minutes until the thickness of the solid dry film formed is 0.08 mm to 0.12 mm.

4. The method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, In step S20, before applying the heat-activated adhesive, the method further includes: cleaning the mating surfaces and inner walls of the through holes of the nylon support with an organic solvent, then applying a layer of nylon treatment agent containing an isocyanate hardener, and drying at 75°C to 80°C for 3 to 5 minutes.

5. The method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, In step S10, the nylon support is made of glass fiber reinforced nylon 6 with a glass fiber content of 30%, and the heat distortion temperature of this material under a load of 0.45MPa is greater than or equal to 190℃.

6. The method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, In step S10, the diameter of the through hole is 3.0 mm to 5.0 mm, and the edge of the through hole on the mating surface is machined with a rounded corner with a radius of 0.5 mm.

7. The method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, In step S30, the initial volume of the selected foam material preform is 85% to 95% of the volume of the molding die cavity.

8. The method for molding a foamed material assembly with a nylon support as described in claim 7, characterized in that, In step S40, the parameters for heating the molding die and applying the clamping pressure are as follows: heating the molding die to 175℃±3℃ and applying a clamping gauge pressure greater than or equal to 170kg / cm².

9. A method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, in In step S50, the cooling method for the molding die is as follows: while keeping the mold closing pressure constant, a cooling medium is introduced for continuous cooling for 450 seconds ± 20 seconds, and the set temperature at the time of mold opening is less than or equal to 45°C.

10. A method for molding a foamed material assembly with a nylon support as described in claim 1, characterized in that, The molding method further includes step S60: subjecting the foamed material component with nylon support obtained after mold opening to cold light source ultraviolet irradiation treatment, and then using polyurethane system adhesive to bond the component to the rubber outsole.

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