Three-dimensional knitted fabric and preparation process thereof

Abstract

The invention relates to the technical field of knitted fabrics, in particular to a three-dimensional knitted fabric and a preparation process thereof. The preparation method comprises the following steps: taking 4, 4 '-diphenyl ether dicarboxylic acid, a dicarboxyl flame retardant, ethylene glycol and butanediol as raw materials, carrying out melt polycondensation reaction to prepare a modified polyester material, and carrying out melt spinning, winding and stretching treatment on the modified polyester material to obtain the modified polyester fiber. Blending the modified polyester fibers and the modified viscose fibers to obtain blended yarns; the blended yarn and the spandex filaments are subjected to a double-face weft knitting process, and gray fabric is obtained; the three-dimensional knitted fabric is obtained by sequentially performing scutching, washing and deoiling, blank fixing, dyeing, reducing and washing, dewatering and drying and shaping on gray fabric. The prepared three-dimensional knitted fabric not only has excellent flame retardant property, can effectively resist flame spreading and ensure safety, but also has excellent hydrophilicity, and the wearing comfort is remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of knitted fabrics, in particular to a three-dimensional knitted fabric and a preparation process thereof. Background Art

[0002] Three-dimensional knitted fabrics are widely used in clothing, sports equipment and home textiles due to their unique texture and structure, and have become an important choice for modern textile design. With the advancement of technology, the development of three-dimensional knitted fabrics has been constantly innovating, especially in terms of comfort and functionality, and has become more and more popular in the market. Its rich three-dimensional sense and elegant appearance not only enhance the visual appeal of the product, but also give the wearer more personalized choices.

[0003] Polyester fiber (PET) is widely used in the production of three-dimensional knitted fabrics due to its excellent strength, wear resistance and wrinkle resistance. However, due to the chemical structure and combustion characteristics of polyester fiber itself, its limiting oxygen index (LOI) is usually less than 22%, which is a flammable material. This flammability makes polyester fiber easy to burn in high temperature environments, resulting in safety hazards, greatly limiting its application in safety protective clothing, home textiles and other fields. In addition, polyester fiber has low hydrophilicity and poor hygroscopicity, which makes the fabric prone to discomfort in a humid environment, affecting the wearing experience. The existence of these problems restricts the application of three-dimensional knitted fabrics in certain specific fields.

[0004] Therefore, we propose a three-dimensional knitted fabric and a preparation process thereof. Summary of the invention

[0005] The purpose of the present invention is to provide a three-dimensional knitted fabric and a preparation process thereof to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A preparation process of a three-dimensional knitted fabric comprises the following steps:

[0008] Step S1: blending modified polyester fiber and modified viscose fiber to obtain blended yarn;

[0009] Step S2: the blended yarn and the spandex filament are subjected to a double-sided weft knitting process to obtain a grey fabric;

[0010] Step S3: The grey cloth is sequentially subjected to the steps of opening, water washing and degreasing, blank setting, dyeing, reduction water washing, dehydration and drying to obtain a three-dimensional knitted fabric.

[0011] Furthermore, the mass ratio of the modified polyester fiber to the modified viscose fiber in the blended yarn is 1:(1-3).

[0012] Furthermore, the mass ratio of the blended yarn to the spandex filament is (8-10):1.

[0013] Furthermore, the preparation method of the modified polyester fiber is as follows:

[0014] Step (1): 4,4'-diphenyl ether dicarboxylic acid, dicarboxyl flame retardant, ethylene glycol, butanediol and zinc acetate are uniformly mixed, esterification reaction is carried out at 230-250°C for 2-4h, antimony trioxide is added, polycondensation reaction is carried out at 270-280°C for 1-2h, cooling to room temperature, washing and drying to obtain a modified polyester material;

[0015] Step (2): melt spinning, winding and stretching the modified polyester material to obtain modified polyester fibers.

[0016] Furthermore, the modified polyester fiber comprises the following components by weight: 80-100 parts of 4,4'-diphenyl ether dicarboxylic acid, 5-15 parts of dicarboxyl flame retardant, 30-50 parts of ethylene glycol, 60-80 parts of butanediol, 0.13-0.2 parts of zinc acetate, and 0.05-0.07 parts of antimony trioxide.

[0017] Furthermore, the preparation method of the dicarboxyl flame retardant is as follows:

[0018] Under nitrogen protection, triallyl isocyanurate, DOPO and DMF are mixed evenly, heated to 70-80°C, reacted for 4-6 hours, heated to 85-95°C, 3,4-dimethoxycinnamic acid and azobisisobutyronitrile are added, reacted for 10-12 hours, cooled to room temperature, filtered, washed and dried to obtain modified DOPO;

[0019] The modified DOPO, L-cysteine ​​and a photoinitiator are uniformly mixed, and after ultraviolet irradiation, filtration, washing and drying, a dicarboxyl flame retardant is obtained.

[0020] Furthermore, the mass ratio of triallyl isocyanurate, DOPO and DMF is 1:(0.8-0.9):(4-6).

[0021] Furthermore, the mass of the 3,4-dimethoxycinnamic acid is 0.7-0.8 times the mass of triallyl isocyanurate.

[0022] Furthermore, the mass of the azobisisobutyronitrile is 0.03-0.05 of the mass of triallyl isocyanurate.

[0023] Furthermore, the mass ratio of the modified DOPO, L-cysteine ​​and photoinitiator is 1:(0.5-0.8):(0.01-0.03).

[0024] Furthermore, the photoinitiator is 2-hydroxy-2-methyl-1-phenyl-1-propanone, and the process conditions of ultraviolet irradiation are: irradiation wavelength 360-400nm, irradiation time 30-50min, irradiation intensity 25-35mW / cm 2 .

[0025] In the above technical scheme, a carbon-carbon double bond in triallyl isocyanurate reacts with the PH bond of DOPO, and then, under the action of an initiator, the remaining carbon-carbon double bond in triallyl isocyanurate reacts with the double bond of 3,4-dimethoxycinnamic acid to obtain a modified DOPO; finally, a thiol-ene click reaction occurs between the remaining double bond in the modified DOPO and L-cysteine ​​to obtain a dicarboxyl flame retardant.

[0026] Furthermore, the temperature of the melt spinning is 290-300° C., the winding rate is 600-900 m / mim, the stretching multiple is 3-5 times, and the stretching rate is 700-900 m / mim.

[0027] Furthermore, the preparation method of the modified viscose fiber is as follows:

[0028] Step A: placing raw silk from mulberry silk in a sodium carbonate solution, treating it at 90-100° C. for 4-6 hours, cooling it to room temperature, and dialyzing it to obtain a sericin solution;

[0029] Step B: Evenly mix the sericin solution and epichlorohydrin, add tetrabutylammonium bromide, heat to 40-50° C., react for 2-3 hours, add sodium hydroxide solution to adjust the system pH to 8-9, react for 1-2 hours, and dialyze to obtain an epoxidized sericin solution;

[0030] Step C: adding the epoxidized sericin solution to the viscose fiber stock solution, stirring at room temperature for 1-2 hours, standing to degas, and spinning into a fiber, and washing and drying to obtain a modified viscose fiber.

[0031] Furthermore, in step A, the concentration of the sodium carbonate solution is 0.5-0.8 g / L, and the bath ratio is 1:50.

[0032] Furthermore, the epoxidized sericin solution comprises the following components by weight: 20-40 parts of sericin solution, 2-4 parts of epichlorohydrin, and 0.3-0.5 parts of tetrabutylammonium bromide.

[0033] Furthermore, the concentration of the sericin solution is 25 g / L.

[0034] Furthermore, the mass of the epoxidized sericin solution is 15-25% of the mass of the viscose fiber stock solution.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. A three-dimensional knitted fabric and a preparation process thereof of the present invention, wherein a carbon-carbon double bond in triallyl isocyanurate reacts with a PH bond of DOPO, and then, under the action of an initiator, a remaining carbon-carbon double bond in triallyl isocyanurate reacts with a double bond of 3,4-dimethoxycinnamic acid to introduce N, S elements and a carboxyl group to obtain a modified DOPO; finally, a thiol-ene click reaction is carried out between the remaining other double bond in the modified DOPO and L-cysteine ​​to introduce a carboxyl group, an amino group and an S element to obtain a dicarboxyl flame retardant containing N, P and S; through the introduced N, P and S elements, the material can form a carbon layer during the combustion process, delay heat transfer, and reduce the flame diffusion rate, and the synergistic effect of each element helps to improve the flame retardant properties of the material;

[0037] Using 4,4'-diphenyl ether dicarboxylic acid, dicarboxyl flame retardant, ethylene glycol and butanediol as raw materials, a modified polyester material is prepared through melt polycondensation reaction. This not only improves the flame retardancy of the material, but also enhances its hydrophilicity, thereby achieving an excellent combination of functionality and comfort.

[0038] 2. A three-dimensional knitted fabric and its preparation process of the present invention, sericin has good hydrophilicity, biosafety and biocompatibility; epichlorohydrin is used to modify sericin, epoxy groups are introduced to obtain epoxidized sericin solution; the epoxidized sericin solution is blended with viscose fiber stock solution, and sericin modified viscose fiber is prepared by traditional viscose fiber preparation process, the excellent performance of sericin can be effectively integrated into viscose fiber, effectively improving the hygroscopicity of viscose fiber, and at the same time, after epoxidation modification, sericin can be firmly grafted onto modified polyester fiber containing amino groups to form stable chemical bonds, thereby improving its adhesion in the fiber. Not only the hydrophilicity and safety of the fabric are improved, but also excellent flame retardant properties are given to it. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In this embodiment, the mulberry silk raw silk: 5A grade, sourced from Jiangsu Xinyuan Cocoon Silk Group Co., Ltd.; the viscose fiber stock solution: industrial grade, sourced from Weifang Xinlong Biomaterial Co., Ltd.; the spandex filament: item number JF36, sourced from Dongguan Jinfeng Textile Co., Ltd.

[0041] In the following examples and comparative examples, 1 part is equal to 10 g.

[0042] Embodiment 1: A process for preparing a three-dimensional knitted fabric, comprising the following processes:

[0043] Step S1: blending 50 parts of modified polyester fiber and 50 parts of modified viscose fiber to obtain blended yarn;

[0044] Step S2: 80 parts of the blended yarn and 10 parts of spandex filaments are subjected to a double-sided weft knitting process to obtain a grey fabric;

[0045] Step S3: the grey cloth is sequentially subjected to the steps of opening, washing and degreasing, setting, dyeing, reduction washing, dehydration and drying to obtain a three-dimensional knitted fabric;

[0046] The preparation method of modified polyester fiber is as follows:

[0047] Step (1): 80 parts of 4,4'-diphenyl ether dicarboxylic acid, 5 parts of dicarboxyl flame retardant, 30 parts of ethylene glycol, 60 parts of butanediol and 0.15 parts of zinc acetate are mixed uniformly, and esterification reaction is carried out at 230°C for 2 hours, 0.05 parts of antimony trioxide are added, and polycondensation reaction is carried out at 270°C for 1 hour, and the mixture is cooled to room temperature, washed and dried to obtain a modified polyester material;

[0048] Step (2): melt spinning (temperature of 290° C.), winding (winding rate of 600 m / mim) and stretching (stretching ratio of 3 times, stretching rate of 700 m / mim) the modified polyester material to obtain modified polyester fiber;

[0049] The preparation method of dicarboxyl flame retardant is as follows:

[0050] Under nitrogen protection, 5 parts of triallyl isocyanurate, 4 parts of DOPO and 20 parts of DMF were mixed evenly, heated to 70°C, reacted for 4 hours, heated to 85°C, and then 3.5 parts of 3,4-dimethoxycinnamic acid and 0.15 parts of azobisisobutyronitrile were added, reacted for 10 hours, cooled to room temperature, filtered, washed and dried to obtain modified DOPO;

[0051] 5 parts of modified DOPO, 2.5 parts of L-cysteine ​​and 0.05 parts of photoinitiator were mixed evenly and irradiated with ultraviolet light (irradiation wavelength 360nm, irradiation time 30min, irradiation intensity 25mW / cm 2 ), filtering, washing and drying to obtain a dicarboxyl flame retardant;

[0052] The preparation method of modified viscose fiber is as follows:

[0053] Step A: 50 parts of raw silk from mulberry silk are placed in a 0.5 g / L sodium carbonate solution at a bath ratio of 1:50, treated at 90° C. for 4 h, cooled to room temperature, and dialyzed to obtain a sericin solution;

[0054] Step B: 20 ​​parts of 25 g / L sericin solution and 2 parts of epichlorohydrin were mixed evenly, 0.3 parts of tetrabutylammonium bromide were added, the temperature was raised to 40° C., the reaction was carried out for 2 hours, sodium hydroxide solution was added to adjust the system pH to 8, the reaction was carried out for 1 hour, and after dialysis, an epoxidized sericin solution was obtained;

[0055] Step C: Add 15 parts of epoxidized sericin solution to 100 parts of viscose fiber stock solution, stir at room temperature for 1 hour, let stand to degas, and then spin into fibers. After washing and drying, modified viscose fibers are obtained.

[0056] Embodiment 2: A process for preparing a three-dimensional knitted fabric, comprising the following processes:

[0057] Step S1: blending 50 parts of modified polyester fiber and 100 parts of modified viscose fiber to obtain blended yarn;

[0058] Step S2: 90 parts of the blended yarn and 10 parts of spandex filaments are subjected to a double-sided weft knitting process to obtain a grey fabric;

[0059] Step S3: the grey cloth is sequentially subjected to the steps of opening, washing and degreasing, setting, dyeing, reduction washing, dehydration and drying to obtain a three-dimensional knitted fabric;

[0060] The preparation method of modified polyester fiber is as follows:

[0061] Step (1): 90 parts of 4,4'-diphenyl ether dicarboxylic acid, 10 parts of dicarboxyl flame retardant, 40 parts of ethylene glycol, 70 parts of butanediol and 0.2 parts of zinc acetate are mixed uniformly, and esterification reaction is carried out at 240°C for 3 hours, 0.08 parts of antimony trioxide is added, and polycondensation reaction is carried out at 275°C for 1.5 hours, and the mixture is cooled to room temperature, washed and dried to obtain a modified polyester material;

[0062] Step (2): melt spinning (temperature of 295° C.), winding (winding rate of 800 m / mim) and stretching (stretching ratio of 4 times, stretching rate of 800 m / mim) the modified polyester material to obtain modified polyester fiber;

[0063] The preparation method of dicarboxyl flame retardant is as follows:

[0064] Under nitrogen protection, 10 parts of triallyl isocyanurate, 8.5 parts of DOPO and 50 parts of DMF were mixed evenly, heated to 75°C, reacted for 5 hours, heated to 90°C, and then 7.5 parts of 3,4-dimethoxycinnamic acid and 0.4 parts of azobisisobutyronitrile were added, reacted for 11 hours, cooled to room temperature, filtered, washed and dried to obtain modified DOPO;

[0065] 10 parts of modified DOPO, 7 parts of L-cysteine ​​and 0.2 parts of photoinitiator were mixed evenly and irradiated with ultraviolet light (irradiation wavelength 380nm, irradiation time 40min, irradiation intensity 30mW / cm 2 ), filtering, washing and drying to obtain a dicarboxyl flame retardant;

[0066] The preparation method of modified viscose fiber is as follows:

[0067] Step A: 50 parts of raw silk from mulberry silk are placed in a 0.6 g / L sodium carbonate solution at a bath ratio of 1:50, treated at 95° C. for 5 h, cooled to room temperature, and dialyzed to obtain a sericin solution;

[0068] Step B: 30 parts of 25 g / L sericin solution and 3 parts of epichlorohydrin were mixed evenly, 0.4 parts of tetrabutylammonium bromide were added, the temperature was raised to 45° C., the reaction was carried out for 2.5 hours, sodium hydroxide solution was added to adjust the system pH to 8.5, the reaction was carried out for 1.5 hours, and after dialysis, an epoxidized sericin solution was obtained;

[0069] Step C: Add 20 parts of epoxidized sericin solution to 100 parts of viscose fiber stock solution, stir at room temperature for 1.5 hours, let stand to degas, and then spin into fibers. After washing and drying, modified viscose fibers are obtained.

[0070] Embodiment 3: A process for preparing a three-dimensional knitted fabric, comprising the following processes:

[0071] Step S1: blending 50 parts of modified polyester fiber and 150 parts of modified viscose fiber to obtain blended yarn;

[0072] Step S2: 100 parts of the blended yarn and 10 parts of spandex filaments are subjected to a double-sided weft knitting process to obtain a grey fabric;

[0073] Step S3: the grey cloth is sequentially subjected to the steps of opening, washing and degreasing, setting, dyeing, reduction washing, dehydration and drying to obtain a three-dimensional knitted fabric;

[0074] The preparation method of modified polyester fiber is as follows:

[0075] Step (1): 100 parts of 4,4'-diphenyl ether dicarboxylic acid, 15 parts of dicarboxyl flame retardant, 40 parts of ethylene glycol, 80 parts of butanediol and 0.30 parts of zinc acetate are mixed uniformly, and esterification reaction is carried out at 250°C for 4 hours, 0.10 parts of antimony trioxide are added, and polycondensation reaction is carried out at 280°C for 2 hours, and the mixture is cooled to room temperature, washed and dried to obtain a modified polyester material;

[0076] Step (2): melt spinning (temperature of 300° C.), winding (winding rate of 900 m / mim) and stretching (stretching ratio of 5 times, stretching rate of 900 m / mim) the modified polyester material to obtain modified polyester fiber;

[0077] The preparation method of dicarboxyl flame retardant is as follows:

[0078] Under nitrogen protection, 15 parts of triallyl isocyanurate, 13.5 parts of DOPO and 90 parts of DMF were mixed evenly, heated to 80°C, reacted for 6 hours, heated to 95°C, and then 12 parts of 3,4-dimethoxycinnamic acid and 0.75 parts of azobisisobutyronitrile were added, reacted for 12 hours, cooled to room temperature, filtered, washed and dried to obtain modified DOPO;

[0079] 15 parts of modified DOPO, 12 parts of L-cysteine ​​and 0.45 parts of photoinitiator were mixed and irradiated with ultraviolet light (irradiation wavelength 400nm, irradiation time 50min, irradiation intensity 35mW / cm 2 ), filtering, washing and drying to obtain a dicarboxyl flame retardant;

[0080] The preparation method of modified viscose fiber is as follows:

[0081] Step A: placing 100 parts of raw silk into a 0.8 g / L sodium carbonate solution at a bath ratio of 1:50, treating at 100° C. for 6 hours, cooling to room temperature, and dialyzing to obtain a sericin solution;

[0082] Step B: 40 parts of 25 g / L sericin solution and 4 parts of epichlorohydrin were mixed evenly, 0.5 parts of tetrabutylammonium bromide were added, the temperature was raised to 50° C., the reaction was carried out for 3 hours, sodium hydroxide solution was added to adjust the system pH to 9, the reaction was carried out for 2 hours, and after dialysis, an epoxidized sericin solution was obtained;

[0083] Step C: adding 40 parts of epoxidized sericin solution into 160 parts of viscose fiber stock solution, stirring at room temperature for 2 hours, standing to degas, spinning into fibers, washing with water, and drying to obtain modified viscose fibers.

[0084] Comparative Example 1: A process for preparing a three-dimensional knitted fabric, comprising the following processes:

[0085] Compared with Example 2, in Comparative Example 1, the modified polyester fiber is replaced with polyester fiber of the same quality (article number ENSON, sourced from Shishi Yingsheng Wire and Tape Trading Co., Ltd.), and the other steps are the same as those in Example 2.

[0086] Comparative Example 2: A process for preparing a three-dimensional knitted fabric, comprising the following processes:

[0087] Compared with Example 2, the modified viscose fiber in Comparative Example 2 is replaced with viscose fiber of the same mass, and the other steps are the same as those in Example 2.

[0088] Comparative Example 3: A process for preparing a three-dimensional knitted fabric, comprising the following processes:

[0089] Step S1: blending 50 parts of modified polyester fiber and 25 parts of modified viscose fiber to obtain blended yarn;

[0090] Step S2: 90 parts of the blended yarn and 10 parts of spandex filaments are subjected to a double-sided weft knitting process to obtain a grey fabric;

[0091] Step S3: the grey cloth is sequentially subjected to the steps of opening, washing and degreasing, setting, dyeing, reduction washing, dehydration and drying to obtain a three-dimensional knitted fabric;

[0092] Compared with Example 2, the mass ratio of the modified polyester fiber to the modified viscose fiber in the blended yarn of Comparative Example 3 is 1:0.5, and the other steps are the same as those in Example 2.

[0093] Comparative Example 4: A preparation process of a three-dimensional knitted fabric, comprising the following processes:

[0094] The preparation method of dicarboxyl flame retardant is as follows:

[0095] Under nitrogen protection, 10 parts of triallyl isocyanurate, 8.5 parts of DOPO and 50 parts of DMF were mixed evenly, heated to 75°C, reacted for 5 hours, heated to 90°C, and then 20 parts of 3,4-dimethoxycinnamic acid and 0.4 parts of azobisisobutyronitrile were added, reacted for 11 hours, cooled to room temperature, filtered, washed and dried to obtain modified DOPO;

[0096] 10 parts of modified DOPO, 7 parts of L-cysteine ​​and 0.2 parts of photoinitiator were mixed evenly and irradiated with ultraviolet light (irradiation wavelength 380nm, irradiation time 40min, irradiation intensity 30mW / cm 2 ), filtering, washing and drying to obtain a dicarboxyl flame retardant;

[0097] Compared with Example 2, the mass of 3,4-dimethoxycinnamic acid in Comparative Example 4 is twice the mass of triallyl isocyanurate, and the other steps are the same as those in Example 2.

[0098] Comparative Example 5: A process for preparing a three-dimensional knitted fabric, comprising the following processes:

[0099] The preparation method of modified polyester fiber is as follows:

[0100] Step (1): 90 parts of 4,4'-diphenyl ether dicarboxylic acid, 2 parts of dicarboxyl flame retardant, 40 parts of ethylene glycol, 70 parts of butanediol and 0.2 parts of zinc acetate are mixed uniformly, and esterification reaction is carried out at 240°C for 3 hours, 0.08 parts of antimony trioxide is added, and polycondensation reaction is carried out at 275°C for 1.5 hours, and the mixture is cooled to room temperature, washed and dried to obtain a modified polyester material;

[0101] Step (2): melt spinning (temperature of 295° C.), winding (winding rate of 800 m / mim) and stretching (stretching ratio of 4 times, stretching rate of 800 m / mim) the modified polyester material to obtain modified polyester fiber;

[0102] Compared with Example 2, only 2 parts of dicarboxyl flame retardant were added to the modified polyester fiber of Comparative Example 5, and the other steps were the same as those of Example 2.

[0103] Experiment: Take the three-dimensional knitted fabrics obtained in Examples 1-3 and Comparative Examples 1-5, prepare samples, test their properties respectively and record the test results:

[0104] With reference to GB / T 5454-1997 “Textile Combustion Performance Test - Oxygen Index Method”, the LOI value was determined using a LFY-606B Limiting Oxygen Index Instrument with a sample size of 150mm×58mm.

[0105] The hydrophilicity of the fabric is evaluated by the water drop absorption time. Referring to the standard of GB / T 21655.1, a drop of 0.2 mL of deionized water is dropped with a dropper vertically above the fabric at a distance of about 1 cm. The time for the water drop to completely diffuse is recorded as the water drop absorption time. The experiment is repeated five times for each piece of fabric and the average value is taken.

[0106] The test results are as follows:

[0107] LOI value / % Water drop absorption time / s Example 1 32.1 4.8 Example 2 33.5 3.3 Example 3 32.6 5.2 Comparative Example 1 20.2 20.5 Comparative Example 2 31.8 15.4 Comparative Example 3 31.6 10.7 Comparative Example 4 30.5 7.2 Comparative Example 5 29.4 8.6

[0108] According to the data in the above table, we can clearly draw the following conclusions:

[0109] 1. Compared with Examples 1-3, the LOI value of the product obtained in Comparative Example 1 decreases and the water droplet absorption time increases, indicating that the modified polyester fiber prepared by the present invention has better flame retardant effect and hydrophilicity than the unmodified polyester fiber, thereby effectively improving the flame retardant properties and mechanical properties of the fabric.

[0110] 2. Compared with Examples 1-3, the water drop absorption time of the products obtained in Comparative Examples 2 and 3 increased, which indicates that the modified viscose fiber prepared by the present invention has excellent hydrophilicity and can effectively improve the water absorbency; at the same time, when the addition amount of modified viscose fiber is reduced, the overall hydrophilicity of the fabric will decrease.

[0111] 3. Compared with Examples 1-3, the flame retardant properties and hydrophilic properties of the products obtained in Comparative Examples 4 and 5 are reduced. It can be seen that when an excess of 3,4-dimethoxycinnamic acid is added, the remaining carbon-carbon double bonds in triallyl isocyanurate will react completely, thereby affecting the subsequent reaction and further affecting the flame retardancy and hydrophilicity of the material; at the same time, when the amount of dicarboxylic flame retardant added is reduced, the flame retardant properties and hydrophilicity of the material will also decrease, indicating that the modified polyester fiber prepared by the present invention is affected by its component ratio. By selecting the component ratio within the range, a fabric with excellent flame retardancy and hydrophilicity can be prepared.

[0112] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A process for preparing a three-dimensional knitted fabric, characterized in that: The steps include: Step S1: blending modified polyester fiber and modified viscose fiber to obtain blended yarn; Step S2: the blended yarn and the spandex filament are subjected to a double-sided weft knitting process to obtain a grey fabric; Step S3: The grey cloth is sequentially subjected to the steps of opening, water washing and degreasing, blank setting, dyeing, reduction water washing, dehydration and drying to obtain a three-dimensional knitted fabric.

2. The process for preparing a three-dimensional knitted fabric according to claim 1, characterized in that: The mass ratio of the modified polyester fiber to the modified viscose fiber in the blended yarn is 1:(1-3).

3. The process for preparing a three-dimensional knitted fabric according to claim 2, characterized in that: The preparation method of the modified polyester fiber is as follows: Step (1): 4,4'-diphenyl ether dicarboxylic acid, dicarboxyl flame retardant, ethylene glycol, butanediol and zinc acetate are uniformly mixed, esterification reaction is carried out at 230-250°C for 2-4h, antimony trioxide is added, polycondensation reaction is carried out at 270-280°C for 1-2h, cooling to room temperature, washing and drying to obtain a modified polyester material; Step (2): melt spinning, winding and stretching the modified polyester material to obtain modified polyester fibers.

4. The process for preparing a three-dimensional knitted fabric according to claim 3, characterized in that: The modified polyester fiber comprises the following components by weight: 80-100 parts of 4,4'-diphenyl ether dicarboxylic acid, 5-15 parts of dicarboxyl flame retardant, 30-50 parts of ethylene glycol, 60-80 parts of butanediol, 0.15-0.30 parts of zinc acetate and 0.05-0.10 parts of antimony trioxide.

5. The process for preparing a three-dimensional knitted fabric according to claim 4, characterized in that: The preparation method of the dicarboxyl flame retardant is as follows: Under nitrogen protection, triallyl isocyanurate, DOPO and DMF are mixed evenly, heated to 70-80°C, reacted for 4-6 hours, heated to 85-95°C, 3,4-dimethoxycinnamic acid and azobisisobutyronitrile are added, reacted for 10-12 hours, cooled to room temperature, filtered, washed and dried to obtain modified DOPO; The modified DOPO, L-cysteine ​​and a photoinitiator are uniformly mixed, and after ultraviolet irradiation, filtration, washing and drying, a dicarboxyl flame retardant is obtained.

6. The process for preparing a three-dimensional knitted fabric according to claim 2, characterized in that: The preparation method of the modified viscose fiber is as follows: Step A: placing raw silk from mulberry silk in a sodium carbonate solution, treating it at 90-100° C. for 4-6 hours, cooling it to room temperature, and dialyzing it to obtain a sericin solution; Step B: Evenly mix the sericin solution and epichlorohydrin, add tetrabutylammonium bromide, heat to 40-50° C., react for 2-3 hours, add sodium hydroxide solution to adjust the system pH to 8-9, react for 1-2 hours, and dialyze to obtain an epoxidized sericin solution; Step C: adding the epoxidized sericin solution to the viscose fiber stock solution, stirring at room temperature for 1-2 hours, standing to degas, and spinning into a fiber, and washing and drying to obtain a modified viscose fiber.

7. The process for preparing a three-dimensional knitted fabric according to claim 6, characterized in that: The epoxidized sericin solution comprises the following components by weight: 20-40 parts of sericin solution, 2-4 parts of epichlorohydrin, and 0.3-0.5 parts of tetrabutylammonium bromide.

8. The process for preparing a three-dimensional knitted fabric according to claim 6, characterized in that: The mass of the epoxidized sericin solution is 15-25% of the mass of the viscose fiber stock solution.

9. The process for preparing a three-dimensional knitted fabric according to claim 1, characterized in that: The mass ratio of the blended yarn to the spandex filament is (8-10):

1.

10. A three-dimensional knitted fabric obtained according to the preparation process according to any one of claims 1 to 9.