Foot-correcting and height-increasing insole for children

Abstract

The invention relates to the field of insoles, in particular to a child foot-correcting height-increasing insole which comprises a nano bamboo charcoal fiber layer, a foam layer, an anti-skid layer and a damping layer which are sequentially arranged from top to bottom. The nano bamboo charcoal fiber layer is obtained by weaving modified nano bamboo charcoal fibers in a plain weaving manner; wherein the monofilament fineness of the modified nano bamboo charcoal fibers is 2.2-3.5 dtex, the warp density of the fabric is 55-85 pieces per inch, and the weft density of the fabric is 46-78 pieces per inch. The nano bamboo charcoal fiber layer is improved, so that the strength and the wear resistance of the surface layer are enhanced, and the phenomenon that the use of the insole is influenced by the wear of the surface layer is reduced. And the surface strength and the wear resistance of the improved nano bamboo charcoal fiber layer are greatly enhanced, and the nano bamboo charcoal fiber layer also has excellent moisture absorption and antibacterial properties.

Description

Technical Field

[0001] The invention relates to the field of insoles, in particular to a foot height-enhancing insole for children and adolescents. Background Art

[0002] After years of research, the organization found that 67% of children and adolescents have different degrees of adverse foot development: they cannot exert force normally when standing for a long time or exercising, and they will feel fatigue or even pain in a short time. The manifestations of bad foot shape are: flat feet, inversion, eversion, O-shaped legs, X-shaped legs, etc. In addition to congenital inheritance, the above symptoms are caused by the rapid physical development of children in recent years, and their weight and height have increased significantly compared with the past. However, the development of children's foot bones is relatively lagging behind that of the body. In the case that the joints of the feet are not completely healed during the development process, they cannot normally bear the heavy pressure of the heavy body. In addition, the insoles in the shoes on the market are all made of a single material and a single thickness, which is only a thin layer. They cannot provide scientific support and protection for the feet of children during their development period, which can easily cause the arch of the child's foot to collapse, and the foot joints to twist and deform, and then flat feet, inversion, eversion, O-shaped legs, and X-shaped legs will appear.

[0003] The insole is a component inside the shoe. Its main function is to increase comfort, protect the foot, reduce friction and provide support. Therefore, it is possible to correct the bad phenomena of children's feet through the correct insole. The correct insole corrects gait problems caused by flat feet, X / O-shaped legs, and inversion of the foot by supporting the arch of the foot and wrapping the heel, helping the normal development of bones and muscles and reducing the negative impact on height growth. For example, the insole designed with HPSX shaping material and U-shaped root cup can stabilize the ankle, evenly disperse the pressure on the sole of the foot, adjust the body's vertical line, and promote blood circulation. The insole of reasonable height (usually 1.5-3cm is recommended) can raise the heel position, optimize the body proportions through visual stretching, and avoid being too high to cause unstable center of gravity or foot fatigue. At present, many insoles on the market use bamboo charcoal fiber as the surface material of the insoles. Bamboo charcoal fiber can release far-infrared energy light waves, and at the same time has the functions of penetrating the sole of the foot to promote blood circulation, absorbing odor, inhibiting bacteria and deodorizing. However, bamboo charcoal fiber has the problem of being brittle in texture and easily worn and deformed after frequent friction or strenuous exercise. Moreover, as the bamboo charcoal insoles wear and deform, the adsorption and antibacterial effects will be greatly weakened. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a foot height-enhancing insole for children and adolescents.

[0005] The purpose of the present invention is achieved by adopting the following technical solutions:

[0006] A foot heightening insole for children and adolescents, comprising a nano bamboo charcoal fiber layer, a foam layer, an anti-slip layer and a shock-absorbing layer arranged in sequence from top to bottom;

[0007] Preferably, the nano bamboo charcoal fiber layer is woven from modified nano bamboo charcoal fibers in a plain weave manner; wherein the monofilament fineness of the modified nano bamboo charcoal fibers is 2.2-3.5 dtex, the warp density of the fabric is 55-85 strands / inch, and the weft density of the fabric is 46-78 strands / inch.

[0008] Preferably, the foam layer is polyurethane foam, and the brand is any one of TPU-385SX, TPU-1175A10W, and TPU-1154D.

[0009] Preferably, the anti-slip layer is woven from natural plant fibers, and the natural plant fibers are at least one of wormwood fibers, flax fibers, coconut shell fibers, and bamboo fibers.

[0010] Preferably, the shock-absorbing layer is made of Covestro polyurethane material with a brand name of FPU-79A.

[0011] Preferably, the preparation method of the modified nano bamboo charcoal fiber comprises:

[0012] S1, mixing nano bamboo charcoal powder, ethanol and deionized water, adding silane coupling agent KH-550, condensing and refluxing at a temperature of 60-70°C for 3-10h, cooling, centrifuging, washing with water and drying to obtain amino nano bamboo charcoal powder;

[0013] S2, mixing 2,2-dihydroxymethylbutyric acid and thionyl chloride, stirring in an ice water bath for 0.5-1.5h, then gradually heating to 50-60°C, keeping warm and stirring for 2-3h, after the reaction is completed, removing excess thionyl chloride to obtain 2,2-dihydroxymethylbutyryl chloride;

[0014] S3, mixing the aminated nano bamboo charcoal powder and 2,2-dihydroxymethylbutyryl chloride into tetrahydrofuran, adding an acid binding agent dropwise, stirring at room temperature for 4-8 hours, and removing the solvent after the reaction to obtain activated nano bamboo charcoal powder;

[0015] S4. Weigh terephthalic acid and 1,4-butanediol, mix them, stir until uniform, add activated nano bamboo charcoal powder, disperse them evenly, then add a catalyst under the protection of nitrogen, first stir and react at a temperature of 220-240°C for 2-5h, then reduce the pressure to less than 150Pa, raise the temperature to 245-265°C, and keep the temperature for 3-6h. After the reaction is completed, a melt is obtained, which is introduced into a spinning box. After spinning, cooling, stretching and shaping, modified nano bamboo charcoal fibers are obtained.

[0016] Preferably, in S1, the particle size of the nano bamboo charcoal powder is 100-200 nm, and the mass ratio of the nano bamboo charcoal powder, the silane coupling agent KH-550, ethanol and deionized water is 1:0.1-0.5:10-15:5-10.

[0017] Preferably, in S2, the mass ratio of 2,2-dihydroxymethylbutyric acid to thionyl chloride is 0.7-1.4:10.

[0018] Preferably, in S3, the mass ratio of the amination nano bamboo charcoal powder, 2,2-dihydroxymethylbutyryl chloride and tetrahydrofuran is 1:0.2-0.6:10-20.

[0019] Preferably, in S3, the acid binding agent is triethylamine, and the amount of triethylamine added is 0.01%-0.1% of the mass of the amination nano bamboo charcoal powder.

[0020] Preferably, in S4, the mass ratio of terephthalic acid, activated nano bamboo charcoal powder and 1,4-butanediol is 1.3-1.8:0.1-1:1.

[0021] Preferably, in S4, the catalyst is tetrabutyl titanate, and the added amount is 0.2%-0.4% of the mass of terephthalic acid.

[0022] Preferably, in S4, the spinning temperature is 250-270°C, the speed is 1000-1500 m / min; the cooling is air cooling, the wind speed is 0.3-0.8 m / s; the stretching temperature is 130-180°C, the multiple is 3-5 times; the setting temperature is 160-180°C.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention prepares a kind of insole for children to increase their height. The surface layer of the insole is provided with a nano bamboo charcoal fiber layer, and then the foam layer, the anti-skid layer and the shock-absorbing layer are provided downward in sequence. Among them, the present invention improves the nano bamboo charcoal fiber layer, enhances the strength and wear resistance of the surface layer, and reduces the phenomenon that the insole is affected by the wear of the surface layer. The nano bamboo charcoal fiber layer after the improvement not only has greatly enhanced surface strength and wear resistance, but also has excellent moisture absorption and antibacterial properties.

[0025] 2. Bamboo charcoal fiber material has good moisture absorption and deodorization effect, and also has excellent far infrared function, with a far infrared emissivity of 85%, thereby promoting blood circulation in the feet. However, the traditional bamboo charcoal fiber has poor hardness and is easy to break. The present invention modifies the surface of the bamboo charcoal fiber and then participates in the preparation of the PBT fiber. The strength and hardness of the prepared modified nano bamboo charcoal fiber are well enhanced, and it also maintains excellent moisture absorption and antibacterial properties.

[0026] 3. The modification process of bamboo charcoal fiber includes: firstly, the surface of nano bamboo charcoal powder is treated with amino by hydrolysis of coupling agent, and then acyl chloride-amino combination reaction is carried out with 2,2-dihydroxymethylbutyryl chloride to obtain activated nano bamboo charcoal powder containing multiple hydroxyl groups and amide groups; then, PTA and BDO are used as reaction raw materials, activated nano bamboo charcoal powder is added as reactant at the same time, and modified nano bamboo charcoal fiber is obtained after esterification reaction.

[0027] 4. Compared with the fibers obtained by directly spinning bamboo charcoal into PBT resin, the modified nano bamboo charcoal fibers prepared by the present invention have more excellent compatibility, and the strength and wear resistance are enhanced. More importantly, the long-term antibacterial property is significantly enhanced. DETAILED DESCRIPTION

[0028] In order to better understand the above technical scheme, the exemplary embodiments of the present invention are described in more detail below. Although exemplary embodiments of the present invention are shown, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to enable the scope of the present invention to be fully communicated to those skilled in the art.

[0029] The present invention will be further described below in conjunction with the following examples.

[0030] Example 1

[0031] A foot heightening insole for children and adolescents comprises a nano bamboo charcoal fiber layer, a foam layer, an anti-skid layer and a shock-absorbing layer which are arranged in sequence from top to bottom; the nano bamboo charcoal fiber layer is woven from modified nano bamboo charcoal fibers in a plain weave manner; wherein the monofilament fineness of the modified nano bamboo charcoal fibers is 2.8 dtex, the warp density of the fabric is 72 strands / inch, and the weft density of the fabric is 60 strands / inch; the foam layer is polyurethane foam with a brand name of TPU-385SX; the anti-skid layer is woven from natural plant fibers, and the natural plant fibers are flax fibers; the shock-absorbing layer is a Covestro polyurethane material with a brand name of FPU-79A.

[0032] Wherein, the preparation method of modified nano bamboo charcoal fiber comprises:

[0033] S1. Aminated nano bamboo charcoal powder:

[0034] Nano bamboo charcoal powder with a particle size of 100-200 nm, ethanol and deionized water are mixed, and silane coupling agent KH-550 is added, the mass ratio of nano bamboo charcoal powder, silane coupling agent KH-550, ethanol and deionized water is 1:0.3:12:8, condensed and refluxed at a temperature of 65°C for 6 hours, cooled to room temperature, centrifuged to collect solids, washed three times with water and then dried to obtain amino nano bamboo charcoal powder;

[0035] S2, preparation of 2,2-dihydroxymethylbutyryl chloride:

[0036] 2,2-dihydroxymethylbutyric acid and thionyl chloride are mixed in a mass ratio of 1.1:10, stirred in an ice water bath for 1 hour, then gradually heated to 55°C, kept warm and stirred for 3 hours, and after the reaction is completed, excess thionyl chloride is removed by vacuum distillation to obtain 2,2-dihydroxymethylbutyryl chloride;

[0037] S3, activated nano bamboo charcoal powder:

[0038] The aminated nano bamboo charcoal powder and 2,2-dihydroxymethylbutyryl chloride are mixed in tetrahydrofuran, wherein the mass ratio of the aminated nano bamboo charcoal powder, 2,2-dihydroxymethylbutyryl chloride and tetrahydrofuran is 1:0.4:15, and an acid-binding agent triethylamine is added dropwise in an amount of 0.05% of the mass of the aminated nano bamboo charcoal powder. The mixture is stirred at room temperature for 6 hours. After the reaction is completed, the solvent is removed by reduced pressure distillation to obtain activated nano bamboo charcoal powder.

[0039] S4, modified nano bamboo charcoal fiber:

[0040] Weigh terephthalic acid (PTA) and 1,4-butanediol (BDO) and mix them. After stirring until uniform, add activated nano bamboo charcoal powder. The mass ratio of terephthalic acid, activated nano bamboo charcoal powder and 1,4-butanediol is 1.5:0.5:1. Disperse evenly. Then, under the protection of nitrogen, add 0.3% of tetrabutyl titanate of the mass of terephthalic acid as a catalyst. First, stir and react at a temperature of 230°C for 3h. During the reaction, separate the generated water in time. Then, reduce the pressure to less than 150Pa, raise the temperature to 2455°C, and keep the reaction for 4h. After the reaction, a melt is obtained, which is introduced into a spinning box for spinning. The spinning temperature is 260°C and the speed is 1200m / min. After air cooling, the filament is formed. The wind speed is 0.5m / s. Then, it is stretched 4 times at 150°C and shaped at 170°C to obtain modified nano bamboo charcoal fiber.

[0041] Example 2

[0042] A normal height-enhancing insole for children and adolescents, which is different from the embodiment 1 in that the preparation method of the modified nano bamboo charcoal fiber is different.

[0043] Wherein, the preparation method of modified nano bamboo charcoal fiber comprises:

[0044] S1. Aminated nano bamboo charcoal powder:

[0045] Nano bamboo charcoal powder with a particle size of 100-200 nm, ethanol and deionized water are mixed, and silane coupling agent KH-550 is added, the mass ratio of nano bamboo charcoal powder, silane coupling agent KH-550, ethanol and deionized water is 1:0.1:10:5, and condensation reflux is performed at a temperature of 60°C for 3 hours. After cooling to room temperature, solids are collected by centrifugation, washed three times with water and then dried to obtain amino nano bamboo charcoal powder;

[0046] S2, preparation of 2,2-dihydroxymethylbutyryl chloride:

[0047] 2,2-dihydroxymethylbutyric acid and thionyl chloride are mixed in a mass ratio of 0.7:10, stirred in an ice-water bath for 0.5 h, then gradually heated to 50° C., kept warm and stirred for 2 h, and after the reaction is completed, excess thionyl chloride is removed by vacuum distillation to obtain 2,2-dihydroxymethylbutyryl chloride;

[0048] S3, activated nano bamboo charcoal powder:

[0049] The aminated nano bamboo charcoal powder and 2,2-dihydroxymethylbutyryl chloride are mixed in tetrahydrofuran, wherein the mass ratio of the aminated nano bamboo charcoal powder, 2,2-dihydroxymethylbutyryl chloride and tetrahydrofuran is 1:0.2:10, and an acid-binding agent triethylamine is added dropwise in an amount of 0.01% of the mass of the aminated nano bamboo charcoal powder. The mixture is stirred at room temperature for 4 hours. After the reaction is completed, the solvent is removed by reduced pressure distillation to obtain activated nano bamboo charcoal powder.

[0050] S4, modified nano bamboo charcoal fiber:

[0051] Weigh terephthalic acid (PTA) and 1,4-butanediol (BDO) and mix them. After stirring until uniform, add activated nano bamboo charcoal powder. The mass ratio of terephthalic acid, activated nano bamboo charcoal powder and 1,4-butanediol is 1.3:0.1:1. Disperse evenly. Then, under the protection of nitrogen, add 0.2% of tetrabutyl titanate of the mass of terephthalic acid as a catalyst. First, stir and react at a temperature of 220°C for 2h. During the reaction, separate the generated water in time. Then, reduce the pressure to less than 150Pa, raise the temperature to 245°C, and keep the reaction for 3h. After the reaction, a melt is obtained, which is introduced into a spinning box for spinning. The spinning temperature is 250°C and the speed is 1000m / min. After air cooling, the filament is formed. The wind speed is 0.3m / s. Then, it is stretched 3 times at 130°C and shaped at 160°C to obtain modified nano bamboo charcoal fiber.

[0052] Example 3

[0053] A normal height-enhancing insole for children and adolescents, which is different from the embodiment 1 in that the preparation method of the modified nano bamboo charcoal fiber is different.

[0054] Wherein, the preparation method of modified nano bamboo charcoal fiber comprises:

[0055] S1. Aminated nano bamboo charcoal powder:

[0056] Nano bamboo charcoal powder with a particle size of 100-200 nm, ethanol and deionized water are mixed, and silane coupling agent KH-550 is added, and the mass ratio of nano bamboo charcoal powder, silane coupling agent KH-550, ethanol and deionized water is 1:0.5:15:10. At a temperature of 70°C, condensation reflux is performed for 10 hours, and after cooling to room temperature, solids are collected by centrifugation, washed three times with water and then dried to obtain amino nano bamboo charcoal powder;

[0057] S2, preparation of 2,2-dihydroxymethylbutyryl chloride:

[0058] 2,2-dihydroxymethylbutyric acid and thionyl chloride are mixed in a mass ratio of 1.4:10, stirred in an ice-water bath for 1.5 hours, then gradually heated to 60°C, kept warm and stirred for 3 hours, and after the reaction is completed, excess thionyl chloride is removed by vacuum distillation to obtain 2,2-dihydroxymethylbutyryl chloride;

[0059] S3, activated nano bamboo charcoal powder:

[0060] The aminated nano bamboo charcoal powder and 2,2-dihydroxymethylbutyryl chloride are mixed in tetrahydrofuran, wherein the mass ratio of the aminated nano bamboo charcoal powder, 2,2-dihydroxymethylbutyryl chloride and tetrahydrofuran is 1:0.6:20, and an acid-binding agent triethylamine is added dropwise in an amount of 0.1% of the mass of the aminated nano bamboo charcoal powder. The mixture is stirred at room temperature for 8 hours. After the reaction is completed, the solvent is removed by reduced pressure distillation to obtain activated nano bamboo charcoal powder.

[0061] S4, modified nano bamboo charcoal fiber:

[0062] Weigh terephthalic acid (PTA) and 1,4-butanediol (BDO) and mix them. After stirring until uniform, add activated nano bamboo charcoal powder. The mass ratio of terephthalic acid, activated nano bamboo charcoal powder and 1,4-butanediol is 1.8:1:1. Disperse evenly. Then, under the protection of nitrogen, add 0.4% of tetrabutyl titanate of the mass of terephthalic acid as a catalyst. First, stir and react at a temperature of 240°C for 5h. During the reaction, separate the generated water in time. Then, reduce the pressure to less than 150Pa, raise the temperature to 265°C, and keep the reaction for 6h. After the reaction, a melt is obtained, which is introduced into a spinning box for spinning. The spinning temperature is 270°C and the speed is 1500m / min. After air cooling, the filament is formed. The wind speed is 0.8m / s. Then, it is stretched 5 times at 180°C and shaped at 180°C to obtain modified nano bamboo charcoal fiber.

[0063] Example 4

[0064] A children's foot heightening insole comprises a nano bamboo charcoal fiber layer, a foam layer, an anti-skid layer and a shock-absorbing layer which are arranged in sequence from top to bottom; the nano bamboo charcoal fiber layer is woven from modified nano bamboo charcoal fibers in a plain weave manner; wherein the preparation of the modified nano bamboo charcoal fibers is the same as that in Example 1, the warp density of the modified nano bamboo charcoal fibers is 55 strands / inch, and the weft density of the modified nano bamboo charcoal fibers is 46 strands / inch; the foam layer is polyurethane foam with a brand name of TPU-1175A10W; the anti-skid layer is woven from natural plant fibers, and the natural plant fibers are wormwood fibers; the shock-absorbing layer is a Covestro polyurethane material with a brand name of FPU-79A.

[0065] Example 5

[0066] A foot heightening insole for children and adolescents comprises a nano bamboo charcoal fiber layer, a foam layer, an anti-skid layer and a shock-absorbing layer which are sequentially arranged from top to bottom; the nano bamboo charcoal fiber layer is obtained by weaving modified nano bamboo charcoal fibers in a plain weave manner; wherein the preparation of the modified nano bamboo charcoal fibers is the same as that in Example 1, the warp density of the fabric of the modified nano bamboo charcoal fibers is 85 strands / inch, and the weft density of the fabric is 78 strands / inch; the foam layer is polyurethane foam with a brand name of TPU-1154D; the anti-skid layer is obtained by weaving natural plant fibers, and the natural plant fibers are at least one of wormwood fibers, flax fibers, coconut shell fibers and bamboo fibers; the shock-absorbing layer is a Covestro polyurethane material with a brand name of FPU-79A.

[0067] Comparative Example 1

[0068] A nano bamboo charcoal fiber cloth is different from Example 1 in that the preparation method of the modified nano bamboo charcoal fiber in the composition is different (aminated nano bamboo charcoal powder is used to replace the activated nano bamboo charcoal powder in Example 1).

[0069] The preparation method of the nano bamboo charcoal fiber in this comparative example comprises:

[0070] S1, amination nano bamboo charcoal powder, the same as in Example 1.

[0071] S2, modified nano bamboo charcoal fiber:

[0072] Weigh terephthalic acid (PTA) and 1,4-butanediol (BDO) and mix them. After stirring until uniform, add aminated nano bamboo charcoal powder. The mass ratio of terephthalic acid, aminated nano bamboo charcoal powder and 1,4-butanediol is 1.5:0.5:1. Disperse evenly. Then, under the protection of nitrogen, add 0.3% of tetrabutyl titanate of the mass of terephthalic acid as a catalyst. First, stir and react at a temperature of 230°C for 3h. During the reaction, separate the generated water in time. Then, reduce the pressure to less than 150Pa, raise the temperature to 2455°C, and keep the reaction for 4h. After the reaction, a melt is obtained, which is introduced into a spinning box for spinning. The spinning temperature is 260°C and the speed is 1200m / min. After air cooling, the filament is formed. The wind speed is 0.5m / s. Then, it is stretched 4 times at 150°C and shaped at 170°C to obtain modified nano bamboo charcoal fiber.

[0073] Comparative Example 2

[0074] A nano bamboo charcoal fiber cloth is different from Example 1 in that the preparation method of the modified nano bamboo charcoal fiber in the composition is different (nano bamboo charcoal powder and 2,2-dihydroxymethylbutyric acid are used to replace the activated nano bamboo charcoal powder in Example 1).

[0075] The preparation method of the nano bamboo charcoal fiber in this comparative example comprises:

[0076] Weigh terephthalic acid (PTA) and 1,4-butanediol (BDO) and mix them. After stirring until uniform, add nano bamboo charcoal powder and 2,2-dihydroxymethylbutyric acid. The mass ratio of terephthalic acid, nano bamboo charcoal powder, 2,2-dihydroxymethylbutyric acid and 1,4-butanediol is 1.5:0.35:0.15:1. Disperse them uniformly. Then, under the protection of nitrogen, add 0.3% tetrabutyl titanate of the mass of terephthalic acid as a catalyst. First, at 23 The reaction was stirred at 0°C for 3 hours, during which the generated water was separated in time, and then the pressure was reduced to less than 150Pa, the temperature was raised to 2455°C, and the reaction was kept warm for 4 hours. After the reaction, a melt was obtained, which was introduced into a spinning box for spinning. The spinning temperature was 260°C and the speed was 1200m / min. After air cooling, the filaments were formed at a wind speed of 0.5m / s, and then stretched 4 times at 150°C and shaped at 170°C to obtain modified nano bamboo charcoal fibers.

[0077] The properties of the nano bamboo charcoal fibers prepared in Example 1, Comparative Example 1 and Comparative Example 2 and the fabrics prepared using the fibers were tested. The fiber breaking strength was referenced to GB / T 13835.5-2009, the fabric wear resistance was referenced to GBT 21196.2-2007, the fiber regain was referenced to GB / T 9994-2018, and the fabric antibacterial property was referenced to QB / T 2881-2013.

[0078] The results are as follows:

[0079]

[0080] It can be seen from the above table that the fabric prepared in Example 1 has excellent strength and wear resistance. In addition, the antibacterial rate of Escherichia coli after washing 30 times can still reach more than 97%, indicating that its long-term antibacterial performance is better.

[0081] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A kind of insole for children's feet to increase height, characterized in that: It includes a nano bamboo charcoal fiber layer, a foam layer, an anti-slip layer and a shock-absorbing layer arranged in sequence from top to bottom; The nano bamboo charcoal fiber layer is obtained by weaving modified nano bamboo charcoal fibers in a plain weave manner; wherein the monofilament fineness of the modified nano bamboo charcoal fibers is 2.2-3.5 dtex, the warp density of the fabric is 55-85 strands / inch, and the weft density of the fabric is 46-78 strands / inch.

2. The insole for increasing the height of children's feet according to claim 1, characterized in that: The foam layer is polyurethane foam, and the brand is any one of TPU-385SX, TPU-1175A10W, and TPU-1154D.

3. The insole for increasing the height of children's feet according to claim 1, characterized in that: The anti-slip layer is woven from natural plant fibers, and the natural plant fibers are at least one of wormwood fibers, flax fibers, coconut shell fibers, and bamboo fibers.

4. The insole for increasing the height of children's feet according to claim 1, characterized in that: The shock-absorbing layer is made of Covestro polyurethane material with the brand name FPU-79A.

5. The insole for increasing the height of children's feet according to claim 1, characterized in that: The preparation method of the modified nano bamboo charcoal fiber comprises: S1, mixing nano bamboo charcoal powder, ethanol and deionized water, adding silane coupling agent KH-550, condensing and refluxing at a temperature of 60-70°C for 3-10h, cooling, centrifuging, washing with water and drying to obtain amino nano bamboo charcoal powder; S2, mixing 2,2-dihydroxymethylbutyric acid and thionyl chloride, stirring in an ice water bath for 0.5-1.5h, then gradually heating to 50-60°C, keeping warm and stirring for 2-3h, after the reaction is completed, removing excess thionyl chloride to obtain 2,2-dihydroxymethylbutyryl chloride; S3, mixing the aminated nano bamboo charcoal powder and 2,2-dihydroxymethylbutyryl chloride into tetrahydrofuran, adding an acid binding agent dropwise, stirring at room temperature for 4-8 hours, and removing the solvent after the reaction to obtain activated nano bamboo charcoal powder; S4. Weigh terephthalic acid and 1,4-butanediol, mix them, stir until uniform, add activated nano bamboo charcoal powder, disperse them evenly, then add a catalyst under the protection of nitrogen, first stir and react at a temperature of 220-240°C for 2-5h, then reduce the pressure to less than 150Pa, raise the temperature to 245-265°C, and keep the temperature for 3-6h. After the reaction is completed, a melt is obtained, which is introduced into a spinning box. After spinning, cooling, stretching and shaping, modified nano bamboo charcoal fibers are obtained.

6. The insole for increasing the height of children's feet according to claim 5, characterized in that: In S1, the particle size of the nano bamboo charcoal powder is 100-200 nm, and the mass ratio of the nano bamboo charcoal powder, the silane coupling agent KH-550, ethanol and deionized water is 1:0.1-0.5:10-15:5-10.

7. The insole for increasing the height of children's feet according to claim 1, characterized in that: In the S2, the mass ratio of 2,2-dihydroxymethylbutyric acid to thionyl chloride is 0.7-1.4:

10.

8. The insole for increasing the height of children's feet according to claim 1, characterized in that: In the S3, the mass ratio of the amination nano bamboo charcoal powder, 2,2-dihydroxymethylbutyryl chloride and tetrahydrofuran is 1:0.2-0.6:10-20.

9. The insole for increasing the height of children's feet according to claim 1, characterized in that: In the S4, the mass ratio of terephthalic acid, activated nano bamboo charcoal powder and 1,4-butanediol is 1.3-1.8:0.1-1:

1.

10. The insole for increasing the height of children's feet according to claim 1, characterized in that: In the S4, the spinning temperature is 250-270°C, the speed is 1000-1500 m / min; the cooling is air cooling, the wind speed is 0.3-0.8 m / s; the stretching temperature is 130-180°C, the multiple is 3-5 times; the setting temperature is 160-180°C.

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