Dyeing and finishing method of lyocell acrylic fiber blended fabric

Abstract

The invention relates to a dyeing and finishing method of a lyocell acrylic fiber blended fabric. The dyeing and finishing method comprises the steps of singeing, desizing, oxygen bleaching modification, dyeing, soft shaping, calendaring and preshrinking on the lyocell acrylic fiber blended fabric in sequence. Wherein before the dyeing procedure, the blended fabric is modified in the oxygen bleaching process, NaOH and NH4Cl are added, the number of hydroxyl groups and amino groups on the surfaces of acrylic fibers is increased, chitosan is added for modification, the number of amino groups on the surfaces of lyocell fibers and the surfaces of the acrylic fibers is further increased, and therefore subsequent dyeing can be smoothly carried out, and the dyeing quality is improved. The lyocell acrylic fiber blended fabric is dyed through a one-step dyeing method, and the fabric has good hand feeling and meanwhile has the antibacterial performance.

Description

Technical Field

[0001] The invention relates to the technical field of textiles, and in particular to a dyeing and finishing method for a lyocell-acrylic blended fabric. Background Art

[0002] As a textile product that combines the advantages of different fibers, blended fabrics occupy an important position in the market. Among them, acrylic fiber is widely favored for its superior elasticity, strength, warmth retention and sun resistance, and has the reputation of "artificial wool". However, the poor hygroscopicity and easy static electricity of acrylic fiber limit its in-depth application in the home textile industry. The emergence of lyocell fiber, with its good hygroscopicity, breathability, softness, drape, excellent touch and wear resistance, provides a possibility for improving the defects of acrylic fiber. Through the blending of lyocell and acrylic, the performance of the fabric is significantly improved.

[0003] However, the blended fabrics of lyocell and acrylic face severe challenges in the dyeing process. The dyeing properties of the two are very different. Lyocell fiber is mainly suitable for reactive dyes, while acrylic fiber is more suitable for cationic dyes. The traditional two-step bath dyeing process is not only time-consuming and energy-consuming, but also when dyeing acrylic fiber, the rapid combination of dye cations and dyeing sites on the fiber can easily lead to uneven dyeing. A large amount of sodium sulfate and leveling agent must be added to regulate the dyeing rate, which not only increases the cost, but also causes resource waste and environmental burden.

[0004] In addition, alkali is required in the dyeing process of reactive dyes, and the cyanide group on acrylic fibers is easily hydrolyzed under alkaline conditions, which affects the stability of cationic dyes and easily produces hydrolyzed dye residues, leading to floating color problems. These problems seriously restrict the widespread application of lyocell acrylic blended fabrics in the home textile industry.

[0005] Therefore, it is particularly urgent and necessary to develop a new dyeing process suitable for lyocell acrylic blended fiber fabrics. Summary of the invention

[0006] The invention aims to provide a new dyeing process suitable for lyocell-acrylic blended fiber fabrics, so as to solve the problems of uneven dyeing, floating color, time and cost waste, and realize one-bath dyeing of lyocell and acrylic.

[0007] To achieve the above objectives, this application is implemented through the following technical solutions: The present application provides a dyeing and finishing method for a lyocell-acrylic blended fabric, comprising the following steps: S1, blending lyocell fiber and acrylic fiber according to a preset ratio to obtain lyocell acrylic blended fiber, and manufacturing a mixed fabric with the lyocell acrylic blended fiber as warp and weft yarns; S2, the mixed fabric in step S1 is subjected to the steps of singeing, desizing, oxygen bleaching modification, dyeing, softening and shaping, calendering and pre-shrinking in sequence, wherein: The oxygen bleaching modification step is specifically as follows: the fabric after the desizing process is first placed in a first working solution containing NaOH, H2O2, and a hydrogen peroxide stabilizer at 90 to 95° C. for heat preservation treatment for 20 to 30 minutes, and the bath ratio of the fabric to the first working solution is 1:10 to 1:20 by mass ratio; NH4Cl is then added to the first working solution, and the heat preservation treatment is continued for 20 to 40 minutes; acetic acid is added for neutralization reaction, and the liquid is drained and washed with water; and then the fabric is placed in a second working solution containing chitosan and acetic acid at 80 to 90° C. for heat preservation treatment for 20 to 40 minutes, and the bath ratio of the fabric to the second working solution is 1:10 to 1:20 by mass ratio.

[0008] As a further improvement of the present application, in step S1, the ratio of the lyocell fiber to the acrylic fiber is 1:1 to 3:7, by mass, the warp density of the mixed fabric is 144 to 200 strands / inch, the weft density of the mixed fabric is 75 to 95 strands / inch, the weft structure of the mixed fabric is twill or satin, and the yarn twist of the mixed fabric is 110 twists / 10 cm.

[0009] As a further improvement of the present application, in the first working solution, the solvent is water, the concentration of NaOH is 1 to 5 g / L, the concentration of H2O2 is 1 to 5 g / L, the concentration of hydrogen peroxide stabilizer is 1 to 2 g / L, and the concentration of NH4Cl is 4 to 20 g / L; in the second working solution, the solvent is water, the concentration of chitosan is 4 to 20 g / L, and the concentration of acetic acid is 3 to 6 g / L.

[0010] As a further improvement of the present application, the mass ratio of the NH4Cl to the NaOH is 0.8-20, and the molecular weight of the chitosan is 6000-20000.

[0011] As a further improvement of the present application, the equipment used in the singeing process is a gas singeing machine, the speed of the gas singeing machine is 110-160 m / min, the burner flame intensity of the gas singeing machine is 10-15 mbar, and the singeing method of the singeing process is one forward and one reverse singeing.

[0012] As a further improvement of the present application, the desizing step is specifically as follows: placing the fabric after the singeing step in an enzyme working solution containing starch desizing enzyme and non-ionic penetrant at a temperature of 40 to 60°C, treating for 3 to 6 hours and then washing with water, and the bath ratio of the fabric to the enzyme working solution is 1:10 to 1:20 by mass ratio; wherein: in the enzyme working solution: the starch desizing enzyme is α-amylase, the concentration of the α-amylase is 5 to 10 g / L, and the concentration of the non-ionic penetrant is 1 to 2 g / L.

[0013] As a further improvement of the present application, the dyeing step is as follows: dissolve the dye in the dye liquor in advance, stir and mix thoroughly, then place the fabric treated by the oxygen bleaching modification step in the dye liquor, the bath ratio of the fabric to the dye liquor is 1:10-1:20 by mass ratio, add 1 / 3 of the preset amount of anhydrous sodium sulfate, heat to 60°C at 2-4°C / min, add 2 / 3 of the preset amount of anhydrous sodium sulfate, keep warm and dye for 2-4 times, then heat to 80°C, add 1 / 2 of the preset amount of sodium carbonate, keep warm and fix for 2-4 times, then add 1 / 2 of the preset amount of sodium carbonate, keep warm and fix for 2-4 times, drain the dye liquor and then soap and wash for 2-4 times, wash with water for 2-4 times, and then dry at 120-140°C. Preferably, the dye is a reactive dye, and the reactive dye can be but is not limited to reactive red X-3B.

[0014] As a further improvement of the present application, the mass of the dye is 1-5% of the mass of the fabric, the total concentration of the anhydrous sodium sulfate is 30-60 g / L, the total concentration of the sodium carbonate is 20-30 g / L, and the concentration of the soaping agent is 5-8 g / L.

[0015] As a further improvement of the present application, in the softening and setting step: the fabric is first immersed in a softener containing 40 to 60 g / L, and then the fabric is sent to a setting machine, the temperature of the heating zone of the setting machine is 130 to 180°C, and the speed of the setting machine is 40 to 70 m / mim.

[0016] As a further improvement of the present application, in the preshrinking step: the fabric after the softening and shaping step is fed into a preshrinking machine, the pressure of the pressure roller of the preshrinking machine is 12 to 15 kg, the temperature of the preshrinking machine is 100 to 120°C, and the speed of the preshrinking machine is 25 to 60 m / min.

[0017] The beneficial effect of the present application is that the present application provides a novel dyeing and finishing method for lyocell acrylic blended fabrics. Before the dyeing process, the acrylic in the blended fabric is modified during the oxygen bleaching process, and the number of hydroxyl groups and amino groups on the surface of the acrylic is increased by adding NaOH and NH4Cl. The number of amino groups on the surface of lyocell fiber and acrylic is further increased by adding chitosan, which is beneficial to the smooth dyeing of the subsequent dyeing, and realizes the dyeing of lyocell acrylic blended fabrics by a one-step dyeing method, and realizes that the lyocell acrylic blended fabrics have excellent dyeing rate and dyeing uniformity. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solution of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0019] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with specific implementation methods.

[0020] Example 1 This embodiment provides a dyeing and finishing method for a lyocell-acrylic blended fabric, comprising the following steps: S1. Blending lyocell fiber and acrylic fiber in a preset ratio to obtain lyocell-acrylic blended fiber, and using the lyocell-acrylic blended fiber as warp and weft yarns to manufacture a mixed fabric, specifically as follows: in parts by mass, the ratio of the lyocell fiber to the acrylic fiber is 1:1, the blended fiber is 32S, the warp density of the mixed fabric is 144 strands / inch, the weft density of the mixed fabric is 75 strands / inch, the weft structure of the mixed fabric is 2 / 1 twill weave, and the yarn twist of the mixed fabric is 110 twists / 10cm.

[0021] S2, the mixed fabric in step S1 is subjected to the steps of singeing, desizing, oxygen bleaching modification, dyeing, softening and shaping, calendering and pre-shrinking in sequence, wherein: The equipment used in the singeing process is a gas singeing machine, the speed of the gas singeing machine is 110m / min, the burner flame intensity of the gas singeing machine is 10mbar, and the singeing method of the singeing process is one forward and one reverse singeing.

[0022] The desizing step is specifically as follows: placing the fabric after the singeing step in an enzyme working solution at a temperature of 40-60°C, treating for 3 hours, washing twice with hot water at 70°C, each washing for 30 minutes, and the bath ratio of the fabric to the enzyme working solution is 1:10 by mass ratio; wherein: the solvent of the enzyme working solution is water, and includes α-amylase with a concentration of 5g / L and a non-ionic penetrant with a concentration of 1g / L, and the non-ionic penetrant is JFC.

[0023] The oxygen bleaching modification step is specifically as follows: the fabric after the desizing process is first placed in a first working solution at 90°C for heat preservation treatment for 20 minutes, and the bath ratio of the fabric to the first working solution is 1:10 by mass ratio; NH4Cl is added to the first working solution, and the heat preservation treatment is continued for 20 minutes; acetic acid is added for neutralization reaction, and the liquid is drained and washed; and then the fabric is placed in a second working solution containing chitosan and acetic acid at 80°C for heat preservation treatment for 20 minutes, and the bath ratio of the fabric to the second working solution is 1:10 by mass ratio. Among them: the solvent of the first working solution is water, and it includes NaOH with a concentration of 1g / L, H2O2 with a concentration of 1g / L and a hydrogen peroxide stabilizer with a concentration of 1g / L, the concentration of the added NH4Cl is 4g / L, and the hydrogen peroxide stabilizer is DM1403; the solvent of the second working solution is water, and it includes chitosan with a concentration of 4g / L and acetic acid with a concentration of 3g / L, and the molecular weight of chitosan is 8000-12000.

[0024] The dyeing step is specifically as follows: dissolving the dye in the dye liquor in advance, stirring it thoroughly to mix it evenly, then placing the fabric treated by the oxygen bleaching modification step in the dye removal liquor, the bath ratio of the fabric to the dye liquor is 1:10 by mass ratio, wherein the dye is Reactive Red X-3B, adding 1 / 3 of a preset amount of anhydrous sodium sulfate, heating to 60°C at 2°C / min, adding 2 / 3 of a preset amount of anhydrous sodium sulfate, keeping warm and dyeing for 4 times, then heating to 80°C, adding 1 / 2 of a preset amount of sodium carbonate, keeping warm and fixing for 2 times, adding 1 / 2 of a preset amount of sodium carbonate, keeping warm and fixing for 2 times, draining the dye liquor and then soaping twice, washing twice with water, and then drying at 140°C. Wherein: the total concentration of anhydrous sodium sulfate is 40g / L, the total concentration of sodium carbonate is 20g / L, the mass of the dye is 3% owf; the temperature of the soaping liquid is 90°C, the concentration of the soaping agent in the soaping liquid is 5g / L, and the washing temperature is 80°C.

[0025] In the softening and shaping step: the fabric is firstly placed in a softener containing 40g / L and immersed, the softener is RUCOFIN HHS of Rudolf Company, and then the fabric is sent to a shaping machine, the temperature of the heating zone of the shaping machine is 130°C, and the speed of the shaping machine is 40m / mim.

[0026] In the preshrinking step: the fabric after the softening and shaping step is sent to the preshrinking machine, the pressure of the pressure roller of the preshrinking machine is 12kg, the temperature of the preshrinking machine is 100°C, and the speed of the preshrinking machine is 25m / min.

[0027] Example 2 This embodiment provides a dyeing and finishing method for a lyocell-acrylic blended fabric, comprising the following steps: S1. Blending lyocell fiber and acrylic fiber in a preset ratio to obtain lyocell acrylic blended fiber, and using the lyocell acrylic blended fiber as warp and weft yarns to manufacture a mixed fabric, specifically as follows: in parts by mass, the ratio of the lyocell fiber to the acrylic fiber is 3:7, the blended fiber is 32S, the warp density of the mixed fabric is 144 strands / inch, the weft density of the mixed fabric is 75 strands / inch, the weft structure of the mixed fabric is 2 / 1 twill weave, and the yarn twist of the mixed fabric is 110 twists / 10cm.

[0028] S2, the mixed fabric in step S1 is subjected to the steps of singeing, desizing, oxygen bleaching modification, dyeing, softening and shaping, calendering and pre-shrinking in sequence, wherein: The equipment used in the singeing process is a gas singeing machine, the speed of the gas singeing machine is 160m / min, the burner flame intensity of the gas singeing machine is 15mbar, and the singeing method of the singeing process is one forward and one reverse singeing.

[0029] The desizing step is as follows: the fabric after the singeing step is placed in an enzyme working solution at a temperature of 70°C, and washed with water after treatment for 3 hours, each washing for 30 minutes, and the bath ratio of the fabric to the enzyme working solution is 1:20 by mass ratio. The enzyme working solution contains water as the solvent, 10 g / L α-amylase and 2 g / L non-ionic penetrant, and the model of the non-ionic penetrant is JFC.

[0030] The oxygen bleaching modification step is specifically as follows: the fabric after the desizing process is first placed in a first working solution at 95°C for heat preservation treatment for 30 minutes, and the bath ratio of the fabric to the first working solution is 1:20 by mass ratio; NH4Cl is added to the first working solution, and the heat preservation treatment is continued for 40 minutes; acetic acid is added for neutralization reaction, and the liquid is drained and washed; and then the fabric is placed in a second working solution containing chitosan and acetic acid at 90°C for heat preservation treatment for 40 minutes, and the bath ratio of the fabric to the second working solution is 1:20 by mass ratio. Among them: the solvent of the first working solution is water, and it contains NaOH with a concentration of 5g / L, H2O2 with a concentration of 5g / L, and a hydrogen peroxide stabilizer with a concentration of 1g / L. At the same time, the concentration of NH4Cl added is 20g / L, and the hydrogen peroxide stabilizer is DM1403; the solvent of the second working solution is water, and it contains chitosan with a concentration of 20g / L and acetic acid with a concentration of 6g / L, and the molecular weight of the chitosan is 6000-20000.

[0031] The dyeing step is specifically as follows: dissolving the dye in the dye liquor in advance, stirring it thoroughly to mix it evenly, then placing the fabric treated by the oxygen bleaching modification step in the dye liquor, the bath ratio of the fabric to the dye liquor is 1:20 by mass ratio, wherein the dye is Reactive Red X-3B, adding 1 / 3 of a preset amount of anhydrous sodium sulfate, heating to 60°C at 4°C / min, adding 2 / 3 of a preset amount of anhydrous sodium sulfate, keeping warm and dyeing for 4 times, then heating to 80°C, adding 1 / 2 of a preset amount of sodium carbonate, keeping warm and fixing for 2 times, then adding 1 / 2 of a preset amount of sodium carbonate, keeping warm and fixing for 2 times, draining the dye liquor and then soaping for 2 times, washing with water for 2 times, and then drying at 140°C. Wherein: the total concentration of anhydrous sodium sulfate is 40g / L, the total concentration of sodium carbonate is 20g / L, the mass of the dye is 3% owf; the temperature of the soaping liquid is 90°C, the concentration of the soaping agent in the soaping liquid is 8g / L, and the washing temperature is 80°C.

[0032] In the softening and shaping step: the fabric is firstly placed in a softener containing 60g / L and immersed, the softener is RUCOFIN HHS of Rudolf Company, and then the fabric is sent to a shaping machine, the temperature of the heating zone of the shaping machine is 180°C, and the speed of the shaping machine is 70m / mim.

[0033] In the preshrinking step: the fabric after the softening and shaping step is sent to the preshrinking machine, the pressure of the pressure roller of the preshrinking machine is 15kg, the temperature of the preshrinking machine is 120°C, and the speed of the preshrinking machine is 60m / min.

[0034] Example 3 This embodiment provides a dyeing and finishing method for a lyocell-acrylic blended fabric, comprising the following steps: S1. Blending lyocell fiber and acrylic fiber in a preset ratio to obtain lyocell-acrylic blended fiber, and using the lyocell-acrylic blended fiber as warp and weft yarns to manufacture a mixed fabric, specifically as follows: in parts by mass, the ratio of the lyocell fiber to the acrylic fiber is 1:1, the blended fiber is 32S, the warp density of the mixed fabric is 200 strands / inch, the weft density of the mixed fabric is 95 strands / inch, the weft structure of the mixed fabric is 4 / 1 satin weave, and the yarn twist of the mixed fabric is 110 twists / 10cm.

[0035] S2, the mixed fabric in step S1 is subjected to the steps of singeing, desizing, oxygen bleaching modification, dyeing, softening and shaping, calendering and pre-shrinking in sequence, wherein: The equipment used in the singeing process is a gas singeing machine, the speed of the gas singeing machine is 140m / min, the burner flame intensity of the gas singeing machine is 13mbar, and the singeing method of the singeing process is one forward and one reverse singeing.

[0036] The desizing step is specifically as follows: placing the fabric after the singeing step in an enzyme working solution containing starch desizing enzyme and non-ionic penetrant at a temperature of 50°C, treating for 4 hours and then washing with water, wherein the bath ratio of the fabric to the enzyme working solution is 1:12 by mass ratio; wherein: the solvent of the enzyme working solution is water, and contains α-amylase at a concentration of 8 g / L, and the concentration of the non-ionic penetrant is 2 g / L.

[0037] The oxygen bleaching modification step is as follows: the fabric after the desizing process is first placed in a first working solution at 95°C for 30 minutes of heat preservation, and the bath ratio of the fabric to the first working solution is 1:12 by mass ratio, and then NH4Cl is added to the first working solution, and the heat preservation treatment is continued for 30 minutes, acetic acid is added for neutralization reaction, and the liquid is washed with water, and then the fabric is placed in a second working solution containing chitosan and acetic acid at 90°C for 30 minutes of heat preservation, and the bath ratio of the fabric to the second working solution is 1:12 by mass ratio. Wherein: the solvent of the first working solution is water, and contains NaOH with a concentration of 3g / L, H2O2 with a concentration of 3g / L, and a hydrogen peroxide stabilizer with a concentration of 1g / L, and the concentration of NH4Cl added is 8g / L; the solvent of the second working solution is water, and contains chitosan with a concentration of 8g / L and acetic acid with a concentration of 4g / L, and the molecular weight of the chitosan is 6000-20000.

[0038] The dyeing step is as follows: dissolve the dye in the dyeing solution in advance, stir it thoroughly to mix it evenly, then place the fabric treated by the oxygen bleaching modification step in the dyeing solution, and the bath ratio of the fabric to the de-staining solution is 1:15 by mass ratio, wherein the dye is Reactive Red X-3B. After adding the fabric, add 1 / 3 of the preset amount of anhydrous sodium sulfate, heat to 60°C at 3°C / min, add 2 / 3 of the preset amount of anhydrous sodium sulfate, keep warm and dye for 4 times, then heat to 80°C, add 1 / 2 of the preset amount of sodium carbonate, keep warm and fix for 2 times, then add 1 / 2 of the preset amount of sodium carbonate, keep warm and fix for 2 times, drain the dyeing solution and then soap for 3 times, wash with water for 2 times, and then dry at 130°C. Wherein: the total concentration of anhydrous sodium sulfate is 40g / L, the total concentration of sodium carbonate is 20g / L, the mass of the dye is 3% owf; the temperature of the soaping liquid is 90°C, the concentration of the soaping agent in the soaping liquid is 6g / L, and the washing temperature is 80°C.

[0039] In the softening and shaping step: the fabric is firstly placed in a softener containing 50g / L and immersed, the softener is RUCOFIN HHS of Rudolf Company, and then the fabric is sent to a shaping machine, the temperature of the heating zone of the shaping machine is 150°C, and the speed of the shaping machine is 50m / min.

[0040] In the preshrinking step: the fabric after the softening and shaping step is sent to the preshrinking machine, the pressure of the pressure roller of the preshrinking machine is 13kg, the temperature of the preshrinking machine is 110°C, and the speed of the preshrinking machine is 40m / min.

[0041] Comparative Example 1 The difference between this comparative example and Example 3 is that the first working solution does not contain NaOH, NH4Cl is not added, and the chitosan modification step is omitted.

[0042] Comparative Example 2 The difference between this comparative example and Example 3 is that no NH4Cl is added to the first working solution.

[0043] Comparative Example 3 The difference between this comparative example and Example 3 is that the chitosan modification step is omitted.

[0044] Comparative Example 4 The difference between this comparative example and Example 3 is that no softener is used in the softening and setting process.

[0045] The breaking strength, moisture regain and antibacterial property of the grey cloths of the above embodiments and comparative examples were tested according to the following standards. The performance data are shown in Table 1.

[0046] 1. Color characteristics: Refer to GB / T 3979-2008 Object Color Measurement Method to test the color depth of the fabric.

[0047] 2. Breaking strength: refer to GB / T 3923-2013 Fabric tensile properties - Determination of breaking strength and elongation at break - Strip method to test the breaking strength of the fabric.

[0048] 3. Moisture regain: Refer to "GB / T 9994-2018 Standard Moisture Regain of Textiles" to test the moisture regain of the fabric.

[0049] 4. Antibacterial property: Refer to "GB / T 20944.3-2008 Evaluation of antibacterial properties of textiles" to test the antibacterial property of the fabric.

[0050] Table 1: Fabric performance data prepared by the dyeing and finishing methods of Examples 1-3 and Comparative Examples 1-4

[0051] In Table 1: By comparing Examples 1-3 with Comparative Example 1, it can be seen that adding NaOH, NH4Cl and chitosan in the oxygen bleaching modification step is beneficial to improving the color depth, moisture regain and antibacterial properties of the lyocell acrylic blended fabric.

[0052] By comparing Examples 1-3 with Comparative Examples 1-3, it can be seen that adding NaOH during the bleaching process will damage the strength of the fabric, while NH4Cl can avoid a significant decrease in the strength of the fabric fibers and is beneficial for improving the color depth of the lyocell acrylic blended fabric. Chitosan modification can further improve the color depth of the lyocell acrylic blended fabric and make the fabric have antibacterial properties.

[0053] By comparing Examples 1-3 with Comparative Example 4, it can be seen that the use of a hydrophilic softener in the softening and shaping process is beneficial to improving the moisture regain of the lyocell acrylic blended fabric.

[0054] The specific reaction principle of the present application is as follows: In the step of oxygen bleaching modification, the acrylic fiber in the fabric is hydrolyzed by the cyanide group under the action of NaOH to form hydrophilic groups such as COOH, as shown in the following reaction formula I: Formula I, On the other hand, NaOH will form a large number of pores on the surface of acrylic fibers in the fabric, which can greatly improve the hygroscopicity of the fibers.

[0055] After adding NH4Cl, NH4Cl reacts with NaOH to generate NH4OH, which reacts with acrylic fiber under alkaline conditions as shown in Formula II: Formula II, The addition of NH4Cl not only gives the acrylic fibers in the fabric highly hydrophilic amino and hydroxyl groups, further improving the hydrophilicity of the fibers and providing reactive dye-dyeable groups for the acrylic fibers, but also acts as a pH buffer, avoiding the yellowing problem of acrylic fibers caused by long-term NaOH treatment.

[0056] After adding chitosan, the hydroxyl and amino groups on the chitosan molecules can react with the carboxyl groups on acrylic fibers and the hydroxyl groups in lyocell fibers. On the other hand, after chitosan is grafted onto the fibers, the number of amino groups on the fibers can be further increased, increasing the adsorption of reactive dyes on the fabric and improving its dyeability.

[0057] The softener used in the softening and shaping step of the present application is a hydrophilic softener, which can keep the fabric dry during use and bring a better skin-friendly experience.

[0058] Although this specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation mode may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0059] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present application. They are not intended to limit the scope of protection of the present application. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present application should be included in the scope of protection of the present application.

Claims

1. A dyeing and finishing method for lyocell acrylic blended fabric, characterized in that: The steps include: S1, blending lyocell fiber and acrylic fiber according to a preset ratio to obtain lyocell acrylic blended fiber, and manufacturing a mixed fabric with the lyocell acrylic blended fiber as warp and weft yarns; S2, the mixed fabric in step S1 is subjected to the steps of singeing, desizing, oxygen bleaching modification, dyeing, softening and shaping, calendering and pre-shrinking in sequence, wherein: The oxygen bleaching modification step is specifically as follows: the fabric after the desizing process is first placed in a first working solution containing NaOH, H2O2, and a hydrogen peroxide stabilizer at 90 to 95° C. for heat preservation treatment for 20 to 30 minutes, and the bath ratio of the fabric to the first working solution is 1:10 to 1:20 by mass ratio; NH4Cl is then added to the first working solution, and the heat preservation treatment is continued for 20 to 40 minutes; acetic acid is added for neutralization reaction, and the liquid is drained and washed with water; and then the fabric is placed in a second working solution containing chitosan and acetic acid at 80 to 90° C. for heat preservation treatment for 20 to 40 minutes, and the bath ratio of the fabric to the second working solution is 1:10 to 1:20 by mass ratio.

2. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 1, characterized in that: In step S1, the ratio of the lyocell fiber to the acrylic fiber is 1:1 to 3:7 in parts by mass, the warp density of the mixed fabric is 144 to 200 strands / inch, the weft density of the mixed fabric is 75 to 95 strands / inch, the weft structure of the mixed fabric is twill or satin, and the yarn twist of the mixed fabric is 110 twists / 10 cm.

3. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 1, characterized in that: In the first working solution: the solvent is water, the concentration of NaOH is 1-5 g / L, the concentration of H2O2 is 1-5 g / L, the concentration of hydrogen peroxide stabilizer is 1-2 g / L, and the concentration of NH4Cl is 4-20 g / L; In the second working solution: the solvent is water, the concentration of the chitosan is 4-20 g / L, and the concentration of the acetic acid is 3-6 g / L.

4. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 3, characterized in that: The mass ratio of the NH4Cl to the NaOH is 0.8-20, and the molecular weight of the chitosan is 6000-20000.

5. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 1, characterized in that: The equipment used in the singeing process is a gas singeing machine, the speed of the gas singeing machine is 110-160m / min, the burner flame intensity of the gas singeing machine is 10-15mbar, and the singeing method of the singeing process is one forward and one reverse singeing.

6. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 1, characterized in that: The desizing step is specifically as follows: placing the fabric after the singeing step in an enzyme working solution containing starch desizing enzyme and non-ionic penetrant at a temperature of 40 to 60° C., treating for 3 to 6 hours and then washing with water, wherein the bath ratio of the fabric to the enzyme working solution is 1:10 to 1:20 by mass ratio; Wherein: in the enzyme working solution: the starch desizing enzyme is α-amylase, the concentration of the α-amylase is 5-10 g / L, and the concentration of the non-ionic permeabilizer is 1-2 g / L.

7. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 1, characterized in that: The dyeing step is specifically as follows: placing the fabric treated by the oxygen bleaching modification step in a dyeing solution, wherein the bath ratio of the fabric to the dyeing solution is 1:10-1:20 by mass ratio, wherein the dye is added to the dyeing solution in advance, fully stirred and mixed, then adding 1 / 3 of a preset amount of anhydrous sodium sulfate, heating to 60°C at 2-4°C / min, then adding 2 / 3 of a preset amount of anhydrous sodium sulfate, keeping warm and dyeing for 2-4 times, then heating to 80°C, adding 1 / 2 of a preset amount of sodium carbonate, keeping warm and fixing for 2-4 times, then adding 1 / 2 of a preset amount of sodium carbonate, keeping warm and fixing for 2-4 times, draining the dyeing solution and then soaping for 2-4 times, washing with water for 2-4 times, and then drying.

8. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 7, characterized in that: The mass of the dye is 1-5% of the mass of the fabric, the total concentration of the anhydrous sodium sulfate is 30-60 g / L, the total concentration of the sodium carbonate is 20-30 g / L, and the concentration of the soaping agent is 5-8 g / L.

9. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 1, characterized in that: In the softening and shaping step: firstly, the fabric is dipped in a softener containing 40-60 g / L, and then the fabric is sent to a shaping machine, the temperature of the shaping machine is 130-180°C, and the speed of the shaping machine is 40-70 m / mim.

10. The dyeing and finishing method of lyocell acrylic blended fabric according to claim 1, characterized in that: In the preshrinking step: the fabric after the softening and shaping step is sent to the preshrinking machine, the pressure of the pressure roller of the preshrinking machine is 12-15kg, the temperature of the rubber blanket of the preshrinking machine is 100-120°C, and the speed of the preshrinking machine is 25-60m / min.

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