White discharge printing style knitted fabric and preparation method thereof

Abstract

The invention relates to the technical field of knitted fabrics, and particularly discloses a white discharge printing style knitted fabric and a preparation method thereof. Comprising the following steps: S1, pre-treating and drying a knitted fabric gray fabric; s2, treating a wax printing material on the dried fabric through a stencil scraping printing or stencil brush printing method to form a required pattern design, and cooling to solidify the wax printing material; s3, performing cold pad-batch dyeing on the fabric subjected to wax printing by using a reactive dye; s4, performing soaping to remove flooding on the surface of the fabric, so that wax adhered to the fabric falls off and is removed; s5, drying the fabric to obtain the white discharge printing style knitted fabric. According to the method, a white discharge printing style similar to that of a traditional woven fabric can be obtained without adopting a traditional white discharge auxiliary or a special vat-intolerant dye, the white discharge printing pattern is clear, the whiteness of uncolored base cloth is good, the sewage treatment cost is lower, the production mode is more environment-friendly, semi-continuous production can be realized, and the production efficiency is higher.

Description

Technical Field

[0001] The invention relates to the technical field of knitted fabrics, and particularly discloses a white discharge printing style knitted fabric and a preparation method thereof. Background Art

[0002] Whitening fabrics have always been an important part of the printing category. The traditional production method of whitening fabrics requires dyeing the fabrics with reactive dyes that are not resistant to reduction, and then treating the whitening additives on the fabrics through printing to form different patterns and textures. This processing method: on the one hand, requires the use of strong reducing agents such as carved white powder, and the dyes that are broken by the reduced dyes are washed down and discharged in the form of sewage. The production method is not environmentally friendly. On the other hand, the whitening effect is greatly affected by the dyes. If the performance of the dyes is good, the pattern will be clearer when whitening, otherwise the whitening pattern will appear blurred.

[0003] For the problem of whitening fabrics at present, or use the method of batik printing to resist dyeing, but this technology is greatly affected by dyes, and it is necessary to use low-temperature dyeable dyes such as indigo dye or vat dyes to make whitening effect. Especially for corresponding knitted fabrics, traditional knitted fabrics generally use rope-shaped overflow dyeing, if dyeing is adopted after waxing, due to washing and roller friction, wax is easily destroyed and falls off, so the batik of traditional knitted fabrics needs to use vat dyes to dye, fabrics or ready-made clothes are waxed, and then put into vat dye leuco body, static soaking, so that the position of waxing can be guaranteed not to be affected by external force and fall off to affect the style of batik. Such a production method, on the one hand, the quantity of each production is small, and on the other hand, the reducing auxiliary agent and oxidizing auxiliary agent used during vat dyeing have large pollution to the environment.

[0004] The invention provides a new solution, reduces the dependence on the dye performance, abandons the use of white discharge auxiliary agents, and takes into account the production of knitted fabrics with white discharge printing effects. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a white-printed style knitted fabric and a preparation method thereof.

[0006] On the one hand, the present invention discloses a method for preparing a white-printed style knitted fabric, which adopts the following technical scheme:

[0007] A method for preparing a white-printed knitted fabric comprises the following steps:

[0008] S1, pre-treating and drying the knitted fabric grey cloth;

[0009] S2, the dried fabric is processed with wax printing material onto the fabric by stencil scraping or stencil brushing to form the required pattern design, and then cooled to solidify;

[0010] S3, using reactive dyes to cold pad-batch dye the wax-printed fabric;

[0011] S4. Soap wash to remove the floating color on the surface of the fabric and remove the wax adhering to the fabric;

[0012] S5, drying the fabric to obtain a white-printed style knitted fabric.

[0013] Preferably, the pre-treatment in S1 includes: using an open-width scouring and bleaching machine for pre-treatment.

[0014] Preferably, the process parameters of the open width scouring and bleaching machine are:

[0015] Machine speed 20~60m / min;

[0016] Demining box: stacking at 60-90℃ for 3-10min;

[0017] Demineralization box additive formula: fatty alcohol penetrant: 1-10g / L;

[0018] Stacking box: stack at 101℃ for 5 to 15 minutes;

[0019] Stacking box additive formula: 18g / L caustic soda solution, 23g / L H 2 O 2 (50%), 3g / L fatty alcohol penetrant;

[0020] Rinse box: 90℃ for 5 to 15 minutes.

[0021] Preferably, the grey cloth is singed by a singeing machine before using the open-width scouring and bleaching machine; the fabric after pre-treatment by the open-width scouring and bleaching machine is shaped by a shaping machine, and the cloth is dried under the conditions of a set temperature of 175° C. and a machine speed of 35 m / min.

[0022] Preferably, the process parameters of cold pad-batch dyeing in S3 are:

[0023] Machine speed 10~60m / min;

[0024] Temperature: 26±2℃;

[0025] Reactive dye solution: 1~150g / L;

[0026] Sodium silicate alkali solution: 5-80g / L;

[0027] Left, middle and right PADDER pressure: 2bar, 3bar, 2bar.

[0028] Preferably, the water temperature during the cold pad-batch dyeing soaping and wax removal in S4 is 90°C to 100°C.

[0029] Preferably, the grey cloth fabric is pure cotton or regenerated cellulose fiber.

[0030] Preferably, the wax printing material is yellow wax, white wax or a mixture thereof.

[0031] Preferably, the wax printing material further comprises one or a mixture of mortar, gum or lithopone.

[0032] On the other hand, the present invention discloses a white-printed style knitted fabric, which is prepared by the above preparation method.

[0033] Compared with the prior art, the present invention has at least the following beneficial effects:

[0034] The invention adopts a new process of wax printing and cold pad batch dyeing to print knitted fabrics, and does not need to use traditional white discharge auxiliaries or special vat-intolerant dyes, so that a white discharge printing style similar to that of traditional woven fabrics can be obtained, and not only the white discharge printing pattern is clear, but also the whiteness of the uncolored base fabric is good, and no auxiliaries harmful to the environment such as carved white powder need to be used in the dyeing process, and the anti-dyeing effect of batik can be retained, the sewage treatment cost is lower, the production method is more environmentally friendly, semi-continuous production can be realized, and the production efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a picture showing the fabric whitening effect obtained by the method for preparing whitening printed style knitted fabric in Example 1;

[0036] Figure 2 This is a picture of the fabric whitening effect obtained by the traditional whitening process of comparative example 1. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] A white-printed knitted fabric and a preparation method thereof, the preparation method comprising the following steps:

[0040] (S1) pre-treating and drying the knitted fabric grey cloth:

[0041] (S1.1) Use a circular knitting machine to produce 40S / 1 fine cotton yarn + 30D spandex cotton double-sided fabric (starch cut edges) (96% cotton 4% spandex).

[0042] (S1.2) The woven grey cloth is singed using a singeing machine, and the surface of the fabric is smooth after singeing.

[0043] (S1.3) The singed fabric is pre-processed using an open-width scouring and bleaching machine. The process parameters of the open-width scouring and bleaching machine are:

[0044] Machine speed: 40m / min;

[0045] Demining box: stacking at 80℃ for 5min;

[0046] Demineralization box additive formula: fatty alcohol penetrant: 5g / L;

[0047] Stacking box: stack at 101℃ for 14 minutes;

[0048] Stacking box additive formula: 18g / L caustic soda solution, 23g / L H 2 O 2 (50%), 3g / L fatty alcohol type penetrant;

[0049] Rinse box: 90℃ for 8min.

[0050] (S1.3) The pre-treated fabric is dried using a setting machine at a set temperature of 175°C and a set speed of 35 m / min;

[0051] (S2) The dried fabric is wax-printed on a printing machine to print a pattern, and the wax-printing process parameters are:

[0052] The yellow wax is heated and melted, and then coated onto the fabric through a printing machine at a speed of 20m / min, and then cooled to solidify the yellow wax.

[0053] (S3) The fabric printed with yellow wax is dyed by cold pad batch method, and the cold pad batch dyeing process parameters are:

[0054] Machine speed: 40m / min;

[0055] Reactive dye solution: 30g / L;

[0056] Sodium silicate alkali solution: 50g / L;

[0057] Left, middle and right PADDER pressure: 2bar, 3bar, 2bar.

[0058] (S4) After the fabrics are dipped in the dye solution, they are piled in a constant temperature room at 26°C for 18 hours, and then washed with soap using a rope washing machine at 80°C to remove the floating color on the surface of the fabrics. At the same time, the water temperature and time of the last section of the boiling water tank of the soap washing machine are set to 95°C*10min, so that the wax adhering to the fabrics can be removed without affecting the subsequent wearing performance of the fabrics.

[0059] (S5) The soap-washed fabric is dried in a setting machine at a temperature of 175° C. and a machine speed of 35 m / min to obtain a whitening printing style knitted fabric.

[0060] The knitted fabric is treated by adopting the innovative process of open-width bleaching + wax printing + cold pad-batch dyeing in this scheme, which overcomes the problem that knitted fabric is more fluffy than woven fabric and is not conducive to wax coating. In addition, the fabric after wax printing is subjected to cold pad-batch dyeing with any active dye. Because the presence of wax hinders the diffusion of dye into the dye at room temperature, the wax-printed position cannot be colored, while the non-wax-printed position is dyed, finally forming a more distinct color contrast, and the fabric whitening printing effect is obvious. Figure 1 The method for preparing the white-discharging printed style knitted fabric of the present invention does not require a white-discharging auxiliary agent or a special dye that is not resistant to reduction, and can obtain a white-discharging style fabric, and the production method is more environmentally friendly.

[0061] Comparative Example 1

[0062] Traditional whitening printed knitted fabric and preparation method thereof, the preparation method comprising the following steps:

[0063] (S1) pre-treating the knitted fabric:

[0064] (S1.1) Use a circular knitting machine to produce 40S / 1 fine cotton yarn + 30D spandex cotton double-sided fabric (starch cut edges) (96% cotton 4% spandex).

[0065] (S1.2) The woven grey cloth is singed using a singeing machine, and the surface of the fabric is smooth after singeing.

[0066] (S1.3) The singed fabric enters the rope-shaped overflow dyeing tank for boiling and bleaching. The process parameters are: H 2 O 2 (50%): 5g / L, caustic soda tablets: 1g / L, penetrant: 1g / L, bath ratio: 1:6, temperature: 105℃, time: 30min, pre-treat the fabric.

[0067] (S2) The pre-treated fabric is subjected to acid HAC: 1g / L, 50℃*2min to neutralize the caustic soda on the fabric, and then hydrogen peroxide deoxygenase: 0.1g / L, 50℃*10min is added to remove the hydrogen peroxide on the fabric.

[0068] (S3) Adding reactive dyes that can be whitened into the dye vat:

[0069] Red: owf0.15%,

[0070] Yellow: owf0.63%,

[0071] Blue: owf0.16%,

[0072] Sodium bicarbonate: 0.5g / L

[0073] Sodium carbonate: 10g / L

[0074] Sodium sulfate: 40g / L

[0075] Bath ratio: 1:6

[0076] The dyeing was carried out at 50°C for 30 min.

[0077] (S4) The dyed fabric is subjected to acid treatment, HAC: 0.7 g / L, bath ratio: 1:6, temperature: 60°C, time: 8 min, and the fabric is subjected to acid treatment.

[0078] (S5) The acid-treated fabric is soaped in a soaping agent of 1 g / L, bath ratio of 1:6, temperature of 90°C, and time of 15 min to remove the floating color on the fabric.

[0079] (S6) The fabric is dried using a setting machine at a set temperature of 175°C and a set speed of 35 m / min.

[0080] (S7) using strong reducing agent to destroy the chromophore of the background color, and processing the whitening slurry onto the fabric by rotary screen printing, and the whitening process parameters are:

[0081] Machine speed: 30m / min,

[0082] Whitening paste: composed of Rongbai powder, urea, water and printing paste;

[0083] Steaming in a steamer: 102°C, 5min;

[0084] Water washing - soap washing - water washing, soap washing agent: 1g / L, temperature 90℃, time 2min.

[0085] The white discharge printed knitted fabric obtained in Comparative Example 1 is shown in Figure 2 The whiteness of the white discharge printing is good, but the wastewater generated in the production process needs to be strictly treated before being discharged by using strong reducing agents such as Rongbai powder, which is not environmentally friendly and has high wastewater treatment costs. Moreover, the edges of the fabric printing have problems such as jagged and blurred. The white discharge printing effect is not as good as that of Example 1. The fabric pattern obtained in Example 1 using the preparation method of this scheme is clearer, and the corresponding uncolored base fabric will be whiter.

[0086] The technical solution provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a white-printed knitted fabric, characterized in that: The steps include: S1, pre-treating and drying the knitted fabric grey cloth; S2, the dried fabric is processed with wax printing material onto the fabric by stencil scraping or stencil brushing to form the required pattern design, and then cooled to solidify; S3, using reactive dyes to cold pad-batch dye the wax-printed fabric; S4. Soap wash to remove the floating color on the surface of the fabric and remove the wax adhering to the fabric; S5, drying the fabric to obtain a white-printed style knitted fabric.

2. The method for preparing the white-printed knitted fabric according to claim 1, wherein: The pre-treatment in S1 includes: using an open width scouring and bleaching machine for pre-treatment.

3. The method for preparing the white discharge printing style knitted fabric according to claim 2, wherein: The process parameters of the open width scouring and bleaching machine are: Machine speed 20~60m / min; Demining box: stacking at 60-90℃ for 3-10min; Demineralization box additive formula: fatty alcohol penetrant: 1-10g / L; Stacking box: stack at 101℃ for 5 to 15 minutes; Stacking box additive formula: 18g / L caustic soda solution, 23g / L H2O2 (50%), 3g / L fatty alcohol penetrant; Rinse box: 90℃ for 5 to 15 minutes.

4. The method for preparing the white-printed style knitted fabric according to claim 2, wherein: Before using the open-width scouring and bleaching machine, the grey cloth is singed using a singeing machine; the fabric treated before using the open-width scouring and bleaching machine is shaped using a shaping machine.

5. The method for preparing the white discharge printing style knitted fabric according to claim 1, wherein: Process parameters of cold pad-batch dyeing in S3: Machine speed 10~60m / min; Temperature: 26±2℃; Reactive dye solution: 1~150g / L; Sodium silicate alkali solution: 5-80g / L; Left, middle and right PADDER pressure: 2bar, 3bar, 2bar.

6. The method for preparing the white discharge printing style knitted fabric according to claim 1, wherein: The water temperature during the cold pad-batch dyeing soaping and wax removal in S4 is 90°C to 100°C.

7. The method for preparing the white-printed style knitted fabric according to claim 1, wherein: The grey cloth fabric is pure cotton or regenerated cellulose fiber.

8. The method for preparing the white discharge printing style knitted fabric according to claim 1, wherein: The wax printing material is yellow wax, white wax or a mixture thereof.

9. The method for preparing the white discharge printing style knitted fabric according to claim 8, wherein: The wax printing material also includes one or a mixture of mortar, gum or lithopone.

10. A white-printed knitted fabric, characterized in that: The knitted fabric is prepared by the method for preparing the white discharge printing style knitted fabric according to any one of claims 1 to 9.

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