High-strength carbon fiber plate processing technology for soles and soles

Abstract

The present invention relates to the technical field of shoe materials, and specifically discloses a high-strength carbon fiber plate processing technology for soles and soles, specifically including the following steps: S1, pretreatment of carbon fiber tows; S2, preparation of preforms; S3, vacuum impregnation; S4, hot pressing curing; S5, high-temperature carbonization. Wherein the pretreatment is that the carbon fiber tows are soaked and cleaned in acetone, and are divided into 15-30 strands by a mechanical yarn splitting process, and each strand is immersed in a dopamine modified liquid tank, a boron trifluoride ether complex liquid tank and an epoxy resin glue tank in sequence, and heated, flattened and ultrasonically treated in the dopamine modified liquid tank, the boron trifluoride ether complex liquid tank and the epoxy resin glue tank, respectively, and finally dried and bundled to obtain a modified carbon fiber tow with a boron trifluoride-polydopamine modified layer and an epoxy resin glue layer on the surface. The present invention is more conducive to the full infiltration and modification of carbon fiber monofilaments, and realizes that the resin permeates well outside the bundle of the preform and penetrates well inside the bundle.

Description

Technical Field

[0001] The invention relates to the technical field of shoe materials, and in particular to a processing technology of a high-strength carbon fiber plate for a sole and a sole. Background Art

[0002] As a composite material of resin and carbon fiber, carbon fiber plate can ensure the flexibility of the sole while enhancing its support and stability, especially when the wearer makes large turns, jumps, and runs, so that the sole will not be over-twisted, and the protection of the foot will be improved. Carbon fiber plate has been widely used in the sports shoe industry to improve sports performance. The application value of carbon fiber plate in the field of sports shoes is to strengthen the bottom of the midsole of sports shoes, improve structural rigidity, ensure the stability of the arch, and provide anti-torsion protection. Most carbon plate structures are in "X" or "Y" shapes.

[0003] There are many processing methods for carbon fiber boards, including a method that uses fiber felt or fabric as a fiber reinforcement and solidifies it with resin after laying. This method has a better control and grasp of the resin penetration outside the fiber reinforcement bundle, but because the fiber reinforcement generally uses a carbon fiber bundle containing thousands or even tens of thousands of carbon fiber filaments, the resin penetration operation in the bundle has high requirements and is prone to pores. In addition, there is also a method of first dividing the carbon fiber bundle into thousands of filaments through mechanical yarn separation and then impregnating it with glue. On the one hand, it is also easy to damage the filaments during yarn separation and transportation, and the glue is only impregnated with a mixture of epoxy resin and diluent, which does not contain beneficial components that are beneficial to the strength of the filaments and carbon fiber boards. On the other hand, sufficient yarn separation is required, otherwise it may lead to poor impregnation. Summary of the invention

[0004] The invention aims to provide a high-strength carbon fiber plate processing technology for soles and the soles, which can fully infiltrate and modify the carbon fiber bundles.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0006] The processing technology of high-strength carbon fiber plate for soles includes the following steps:

[0007] S1. Pretreatment of carbon fiber tows: After the carbon fiber tows are soaked and cleaned with acetone, they are divided into 15-30 strands by a mechanical yarn splitting process, and each strand is immersed in a dopamine modified liquid tank, a boron trifluoride ether complex liquid tank and an epoxy resin adhesive tank in turn, and heated, flattened and ultrasonically treated in the dopamine modified liquid tank, the boron trifluoride ether complex liquid tank and the epoxy resin adhesive tank respectively, and finally dried and bundled to obtain a modified carbon fiber tow with a boron trifluoride-polydopamine modified layer and an epoxy resin adhesive layer on the surface;

[0008] S2. Preparing a preform: Weaving the modified carbon fiber tow from step S1 into a non-weft unidirectional fabric with a surface density of 450-480 g / m 2 , then the non-weft unidirectional fabric is laid out in a mold sprayed with a release agent to obtain a preform;

[0009] S3, vacuum dipping: placing the preform of step S2 in a vacuum dipping bag, and performing dipping treatment under a vacuum degree of 0.8MPa-1.0MPa to obtain a prepreg;

[0010] S4, hot pressing curing: put the prepreg on the hot press, heat the hot pressing temperature to 170℃-180℃ and keep it for 50min-70min, then heat it to 275℃-285℃ and keep it for 90min-100min, and finally cool it naturally to room temperature to obtain hot pressing material;

[0011] S5, high temperature carbonization: carbonizing the hot pressed material in step S4 by adopting a stepwise temperature increase carbonization process to obtain a high-strength carbon fiber plate.

[0012] Preferably, the carbon fiber tow in step S1 is 12K.

[0013] Preferably, the carbon fiber tow in step S1 is polyacrylonitrile-based carbon fiber.

[0014] Preferably, the glue in the epoxy resin glue tank in step S1 is bisphenol F epoxy resin.

[0015] Preferably, the dopamine modification tank in step S1 contains a tris-hydrochloric acid buffer solution of dopamine, with a pH value of 8-9.

[0016] Preferably, the frequency of the ultrasonic treatment in step S1 is 250 MHz-300 MHz.

[0017] Preferably, each strand is pre-dried at 80°C-90°C before being immersed in the epoxy resin tank.

[0018] Preferably, the number of layers in step S2 is 8-12, and the order of layering is 0°, 45°, 90°, and 135° in a cycle.

[0019] Preferably, the step-by-step temperature carbonization in step S5 is as follows: under nitrogen protection, heating to 500°C-550°C at a heating rate of 6.0°C / min-6.5°C / min, and keeping warm for 1-1.5 hours; then heating to 800°C-850°C at a heating rate of 3.0°C / min-4.0°C / min, and keeping warm for 1-1.5 hours; then heating to 1150°C-1250°C at a heating rate of 2.0°C / min-2.5°C / min, and keeping warm for 2-3 hours; then step-by-step cooling to below 100°C.

[0020] The present invention also provides a shoe sole, comprising a high-strength carbon fiber plate for the shoe sole made by the processing technology.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention first performs surface modification and impregnation resin treatment on each carbon fiber monofilament in the carbon fiber tow before the preform layer is dipped, so that the resin can be well penetrated outside the bundle of the preform through vacuum dipping, and then the preform is mechanically divided into multiple strands in the pretreatment and then immersed in dopamine modified liquid tank, boron trifluoride ether complex liquid tank and epoxy resin glue tank in turn, and the carbon fiber strands are brought in and flattened by the pressure roller to expand the contact width, and at the same time, the relaxed flattened carbon fiber strands between the two groups of pressure rollers are ultrasonically spread and dopamine ultrasonic waves are helped to penetrate into each carbon fiber monofilament inside the carbon fiber strand, so as to be more conducive to the full infiltration and modification of the carbon fiber monofilament, and the resin is well penetrated in the bundle of the preform. The present invention greatly improves the penetration effect of epoxy resin in the preform bundle through the pretreatment process, and ensures a good penetration effect of epoxy resin outside the bundle through the vacuum dipping process, so that the epoxy resin in the prepreg is a continuous phase, effectively reducing the internal pore area of ​​the carbon fiber board and improving the density of the carbon fiber board, thereby enhancing the strength of the carbon fiber board.

[0023] In addition, the present invention polymerizes a boron trifluoride-polydopamine modified layer on the surface of the carbon fiber monofilament, wherein the polydopamine has the ability to deflect cracks and induce microcracks, can improve the interface toughness of the carbon fiber plate, and the tensile strength reaches more than 2800MPa, and the hydrogen connected to the nitrogen on the indole ring can produce hydrogen bonds with the hydroxyl group in the specific bisphenol F type epoxy resin to wet the resin; the boron trifluoride can weaken the room temperature curing effect of the amino group in the polydopamine molecule, so that the epoxy resin will not be cured before the hot pressing curing reaches a suitable high temperature, and dissociate and dehydrogenate when the high temperature is reached, and use hydrogen to attack the epoxy group to initiate the polymerization reaction to achieve rapid curing. DETAILED DESCRIPTION Example 1

[0024] This embodiment provides a sole, including a high-strength carbon fiber plate for the sole bonded to the midfoot position of the EVA midsole by adhesive. The carbon fiber plate provides arch support stability to prevent excessive twisting of the main body of the sole from causing excessive inward or outward rotation of the athlete's ankle, thereby causing physical injury.

[0025] The carbon fiber plate processing technology specifically includes the following steps: S1, pretreatment of carbon fiber tow; S2, preparation of preform; S3, vacuum impregnation; S4, hot pressing and curing; S5, high temperature carbonization.

[0026] In step S1, 12K polyacrylonitrile-based carbon fiber is soaked and cleaned in acetone for 24 hours and then dried at 60°C. It is then divided into 20 carbon fiber strands using a mechanical yarn splitting process. This greatly reduces the number of carbon fiber filaments per strand, which is more conducive to the full impregnation and modification of the carbon fiber filaments.

[0027] Each strand first enters the dopamine modification liquid tank, which contains tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution of dopamine, with a pH value of 8-9 and a liquid temperature of 40°C-50°C. Two groups of rollers are arranged in the tank along the conveying direction. The carbon fiber strands between the two groups of rollers are in a relaxed state, and the tension is controlled at 50mN / tex. The carbon fiber strands are brought into the dopamine modification liquid tank by the rollers and flattened to expand the contact width. At the same time, the ultrasonic generator in the dopamine modification liquid tank ultrasonically spreads the relaxed and flattened carbon fiber strands between the two groups of rollers and helps dopamine ultrasonic waves penetrate into each carbon fiber filament inside the carbon fiber strand. The frequency is 300MHz, and a polydopamine modified layer is polymerized on the surface of each carbon fiber filament.

[0028] After being output from the dopamine modified liquid tank, it enters the boron trifluoride ether complex liquid tank with a liquid temperature of 30°C-40°C. Similarly, two groups of pressing rollers and ultrasonic generators are arranged in the boron trifluoride ether complex liquid tank. The carbon fiber strands are brought into the boron trifluoride ether complex liquid tank by the pressing rollers and the carbon fiber strands are flattened to expand the contact width. At the same time, the ultrasonic generator in the boron trifluoride ether complex liquid tank ultrasonically spreads the flattened carbon fiber strands in a relaxed state between the two groups of pressing rollers and helps the boron trifluoride ether complex ultrasonically penetrate into each carbon fiber filament inside the carbon fiber strand. Then, the carbon fiber strands are output at a temperature of 80°C-90°C for pre-drying, thereby complexing on the surface of the carbon fiber filament to form a boron trifluoride-polydopamine modified layer.

[0029] Then it is immersed in an epoxy resin glue tank with a liquid temperature of 40℃-50℃, and the glue is bisphenol F type epoxy resin NPEF-170. Similarly, two sets of pressing rollers and ultrasonic generators are arranged in the epoxy resin glue tank. The carbon fiber strands are brought into the epoxy resin glue tank by the pressing rollers and the carbon fiber strands are flattened to expand the contact width. At the same time, the ultrasonic generator in the epoxy resin glue tank ultrasonically spreads the flattened carbon fiber strands in the relaxed state between the two sets of pressing rollers and helps the epoxy resin ultrasonically penetrate into each carbon fiber filament inside the carbon fiber strand. Finally, it is dried and bundled to obtain a modified carbon fiber bundle with a boron trifluoride-polydopamine modified layer and an epoxy resin glue layer on the surface.

[0030] In step S2, the modified carbon fiber tows of step S1 are used to weave a non-weft unidirectional fabric with a surface density of 480 g / m 2Then, the non-weft unidirectional fabric is laid in a mold sprayed with a release agent, the number of layers is 8, and the laying order is 0°, 45°, 90°, and 135° in a cycle to obtain a preform.

[0031] In step S3, the preform of step S2 is placed in a vacuum impregnation bag and is impregnated under a vacuum degree of 1.0 MPa to obtain a prepreg.

[0032] In step S4, the prepreg is placed on a hot press, and the hot pressing temperature is first raised to 180°C and kept for 60 minutes, then raised to 280°C and kept for 90 minutes, and finally naturally cooled to room temperature to obtain a hot pressed material; the hot pressing pressure is first increased to 16 MPa, and then increased to 20 MPa when the temperature rises to 180°C.

[0033] In step S5, the hot pressing material in step S4 is carbonized by a step-by-step temperature carbonization process to obtain a high-strength carbon fiber plate. The step-by-step temperature carbonization is specifically as follows: under nitrogen protection, the temperature is raised to 520°C at a heating rate of 6.0°C / min, and kept at this temperature for 1.5 hours; then the temperature is raised to 820°C at a heating rate of 4.0°C / min, and kept at this temperature for 1.5 hours; then the temperature is raised to 1200°C at a heating rate of 2.5°C / min, and kept at this temperature for 3 hours; then the temperature is lowered to below 100°C in a step-by-step manner. Example 2

[0034] This embodiment provides a sole, including a high-strength carbon fiber plate for the sole bonded to the midfoot position of the EVA midsole by adhesive. The carbon fiber plate provides arch support stability to prevent excessive twisting of the main body of the sole from causing excessive inward or outward rotation of the athlete's ankle, thereby causing physical injury.

[0035] The carbon fiber plate processing technology specifically includes the following steps: S1, pretreatment of carbon fiber tow; S2, preparation of preform; S3, vacuum impregnation; S4, hot pressing and curing; S5, high temperature carbonization.

[0036] In step S1, 12K polyacrylonitrile-based carbon fiber is soaked and cleaned in acetone for 24 hours and then dried at 60°C. It is then divided into 25 carbon fiber strands using a mechanical yarn splitting process. This greatly reduces the number of carbon fiber filaments per strand, which is more conducive to the full impregnation and modification of the carbon fiber filaments.

[0037] Each strand first enters the dopamine modified liquid tank, which contains tris(hydroxymethylaminomethane)-hydrochloric acid buffer solution of dopamine, with a pH value of 8-9 and a liquid temperature of 40°C-50°C. Two groups of rollers are arranged in the tank along the conveying direction. The carbon fiber strands between the two groups of rollers are in a relaxed state, and the tension is controlled at 50mN / tex. The carbon fiber strands are brought into the dopamine modified liquid tank by the rollers and flattened to expand the contact width. At the same time, the ultrasonic generator in the dopamine modified liquid tank ultrasonically spreads the relaxed and flattened carbon fiber strands between the two groups of rollers and helps dopamine ultrasonic waves penetrate into each carbon fiber filament inside the carbon fiber strand. The frequency is 300MHz, and a polydopamine modified layer is polymerized on the surface of each carbon fiber filament.

[0038] After being output from the dopamine modified liquid tank, it enters the boron trifluoride ether complex liquid tank with a liquid temperature of 30°C-40°C. Similarly, two groups of pressing rollers and ultrasonic generators are arranged in the boron trifluoride ether complex liquid tank. The carbon fiber strands are brought into the boron trifluoride ether complex liquid tank by the pressing rollers and the carbon fiber strands are flattened to expand the contact width. At the same time, the ultrasonic generator in the boron trifluoride ether complex liquid tank ultrasonically spreads the flattened carbon fiber strands in a relaxed state between the two groups of pressing rollers and helps the boron trifluoride ether complex ultrasonically penetrate into each carbon fiber filament inside the carbon fiber strand. Then, the carbon fiber strands are output at a temperature of 80°C-90°C for pre-drying, thereby complexing on the surface of the carbon fiber filament to form a boron trifluoride-polydopamine modified layer.

[0039] Then it is immersed in an epoxy resin glue tank with a liquid temperature of 40℃-50℃, and the glue is bisphenol F type epoxy resin NPEF-170. Similarly, two sets of pressing rollers and ultrasonic generators are arranged in the epoxy resin glue tank. The carbon fiber strands are brought into the epoxy resin glue tank by the pressing rollers and the carbon fiber strands are flattened to expand the contact width. At the same time, the ultrasonic generator in the epoxy resin glue tank ultrasonically spreads the flattened carbon fiber strands in the relaxed state between the two sets of pressing rollers and helps the epoxy resin ultrasonically penetrate into each carbon fiber filament inside the carbon fiber strand. Finally, it is dried and bundled to obtain a modified carbon fiber bundle with a boron trifluoride-polydopamine modified layer and an epoxy resin glue layer on the surface.

[0040] In step S2, the modified carbon fiber tows in step S1 are used to weave a non-weft unidirectional fabric with a surface density of 450 g / m 2 Then, the non-weft unidirectional fabric is laid in a mold sprayed with a release agent, the number of layers is 8, and the laying order is 0°, 45°, 90°, and 135° in a cycle to obtain a preform.

[0041] In step S3, the preform of step S2 is placed in a vacuum impregnation bag and is impregnated under a vacuum degree of 0.8 MPa to obtain a prepreg.

[0042] In step S4, the prepreg is placed on a hot press, and the hot pressing temperature is first raised to 175°C and kept for 60 minutes, then raised to 280°C and kept for 90 minutes, and finally naturally cooled to room temperature to obtain a hot pressed material; the hot pressing pressure is first increased to 15 MPa, and then increased to 20 MPa when the temperature rises to 175°C.

[0043] In step S5, the hot pressing material in step S4 is carbonized by a step-by-step temperature carbonization process to obtain a high-strength carbon fiber plate. The step-by-step temperature carbonization is specifically as follows: under nitrogen protection, the temperature is raised to 550°C at a heating rate of 6.0°C / min, and kept at this temperature for 1.5 hours; then the temperature is raised to 850°C at a heating rate of 4.0°C / min, and kept at this temperature for 1.5 hours; then the temperature is raised to 1250°C at a heating rate of 2.0°C / min, and kept at this temperature for 2.5 hours; then the temperature is lowered stepwise to below 100°C.

[0044] Comparative Example 1

[0045] The only difference between this comparative example and the above-mentioned embodiment 1 is the lack of step S1.

[0046] The carbon fiber tows modified by the dopamine modified liquid tank and the boron trifluoride ether complex liquid tank of Examples 1 and 2 were respectively woven into non-weft unidirectional fabrics, and the non-weft unidirectional fabrics were woven from the unmodified carbon fiber tows of Comparative Example 1. The permeability of the fabric was measured by the unidirectional method. A rectangular mold cavity was used, and the fluid viscosity was 0.059 Pa·s. The fluid was injected from one end of the mold. The flow rate of the fluid in the fabric and the one-dimensional flow pressure difference were measured, and the permeability was obtained by bringing Darcy's law into the fabric. Among them: the permeability of Example 1 is 7.74×10 -10 The permeability of Example 2 is 7.52×10 -10 The permeability of comparative example 1 is 3.29×10 -10 .

[0047] The flexural strengths of the carbon fiber plates prepared in Examples 1-2 and Comparative Example 1 were tested according to ASTM D7264 / D7264M-06 and were found to be 1855 MPa, 1872 MPa, and 1618 MPa, respectively.

[0048] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention shall be defined by the attached claims and their equivalents.

Claims

1. A process for processing high-strength carbon fiber plates for shoe soles, characterized in that: The specific steps include: S1. Pretreatment of carbon fiber tows: After the carbon fiber tows are soaked and cleaned with acetone, they are divided into 15-30 strands by a mechanical yarn splitting process, and each strand is immersed in a dopamine modified liquid tank, a boron trifluoride ether complex liquid tank and an epoxy resin adhesive tank in turn, and heated, flattened and ultrasonically treated in the dopamine modified liquid tank, the boron trifluoride ether complex liquid tank and the epoxy resin adhesive tank respectively, and finally dried and bundled to obtain a modified carbon fiber tow with a boron trifluoride-polydopamine modified layer and an epoxy resin adhesive layer on the surface; S2. Preparing a preform: Weaving the modified carbon fiber tow from step S1 into a non-weft unidirectional fabric with a surface density of 450-480 g / m 2 , then the non-weft unidirectional fabric is laid out in a mold sprayed with a release agent to obtain a preform; S3, vacuum dipping: placing the preform of step S2 in a vacuum dipping bag, and performing dipping treatment under a vacuum degree of 0.8MPa-1.0MPa to obtain a prepreg; S4, hot pressing curing: put the prepreg on the hot press, heat the hot pressing temperature to 170℃-180℃ and keep it for 50min-70min, then heat it to 275℃-285℃ and keep it for 90min-100min, and finally cool it naturally to room temperature to obtain hot pressing material; S5, high temperature carbonization: carbonizing the hot pressed material in step S4 by a step-by-step temperature carbonization process to obtain a high-strength carbon fiber plate; The dopamine modified liquid tank in step S1 contains a tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution of dopamine with a pH value of 8-9. The glue in the epoxy resin glue tank is bisphenol F epoxy resin. Each strand is pre-dried at 80°C-90°C before being immersed in the epoxy resin glue tank.

2. The process for processing high-strength carbon fiber plates for soles according to claim 1, characterized in that: The carbon fiber tow in step S1 is 12K.

3. The processing technology of high-strength carbon fiber plate for soles according to claim 1 is characterized in that: The carbon fiber tow in step S1 is polyacrylonitrile-based carbon fiber.

4. The process for processing high-strength carbon fiber plates for soles according to claim 1, characterized in that: The frequency of the ultrasonic treatment in step S1 is 250 MHz-300 MHz.

5. The process for processing high-strength carbon fiber plates for soles according to claim 1, characterized in that: The number of layers in step S2 is 8-12, and the order of layering is 0°, 45°, 90°, and 135° in a cycle.

6. The process for processing high-strength carbon fiber plates for soles according to claim 1, characterized in that: The step-by-step temperature carbonization in step S5 is specifically as follows: under nitrogen protection, the temperature is increased to 500°C-550°C at a heating rate of 6.0°C / min-6.5°C / min, and kept warm for 1-1.5 hours; then the temperature is increased to 800°C-850°C at a heating rate of 3.0°C / min-4.0°C / min, and kept warm for 1-1.5 hours; then the temperature is increased to 1150°C-1250°C at a heating rate of 2.0°C / min-2.5°C / min, and kept warm for 2-3 hours; then the temperature is step-down to below 100°C.

7. A shoe sole, characterized in that: The invention comprises a high-strength carbon fiber plate for soles made by the processing technology as claimed in any one of claims 1 to 6.