Reactive discharge printing process

Abstract

The invention discloses an active discharge printing process, comprising: S1, cold-batch dyeing of semi-bleached cloth, wherein the dyeing liquid formula is: vinyl sulfone type dye: 20-60 g / L; bubble cloth: 85-100 g / L; caustic soda with a mass percentage of 40%: 13-25 g / L; the rest is water, so as to obtain a dyed base cloth; S2, printing the dyed base cloth, wherein the printing slurry formula is: monochloro-s-triazine active dye: 5-60 g / L; seaweed paste: 400-700 g / L; potassium carbonate: 40-60 g / L; sodium sulfite: 5-35 g / L; baking soda: 10-30 g / L; resist salt: 1-3 g / L; urea: 20-60 g / L; the rest is water, so as to obtain a printed cloth; S3, steaming, cleaning and finishing the printed cloth in sequence, so as to obtain a finished product. The invention has the advantages of improving the softness, color fastness and color light stability of fabrics; and is easy to operate, has low steaming requirements and is pollution-free to the environment.

Description

Technical Field

[0001] The invention relates to a printing process, in particular to an active discharge printing process. Background Art

[0002] The engraving printing process is also called discharge printing. It is a technology for pattern processing on textiles. The basic principle of this process is to destroy the base color of colored fabrics through reducing agents and oxidizing agents, thereby obtaining a printing method of various patterns and patterns that are partially decolorized or colored. The steps of engraving printing include dyeing the base color: dyeing the fabric into a single color - printing: printing the pattern on the fabric - color discharge printing.

[0003] The engraving and printing process has the characteristics of rich patterns, fullness and brightness, strong color contrast, clear and delicate outlines, and rich background colors. The presentation of flower effects cannot be shown or replaced by direct printing.

[0004] However, the traditional paint engraving printing uses engraving blocks in the printing paste, which cause great environmental pollution. In addition, the paint is bonded with adhesive to fix the color, which has the problems of easy agglomeration, poor appearance, hard feel and poor friction fastness. Especially for flannel, it is easy to stick the flannel together, affecting the quality of the flannel and having great limitations on its use.

[0005] In the traditional reactive engraving and printing process, the base color is not fixed separately but is fixed by high-temperature steaming together with the printed color. During the process, the dyed base cloth will be exposed to the air to varying degrees without being fixed, resulting in problems such as unstable color light, difficulty in process control, color difference between edges and centers, windshield printing, etc. The defective rate is high and large-scale production cannot be carried out normally.

[0006] The steaming time of reduction engraving printing is 15 minutes, the steaming temperature is 100℃~103℃, and the steaming humidity is 85%. Once the steaming conditions are immature or unstable, it will lead to failure of color development. The strong reducing substances in the engraving white block are oxidized after steaming, and re-steaming is ineffective, resulting in the failure of the flower pattern to appear and product failure. In addition, since the engraving white block is used in printing, it pollutes the environment greatly, and it cannot be produced in the same steamer as the active production process, and the production operation is very inconvenient. Therefore, there are problems such as long steaming time, high requirements for steaming conditions, inconvenient operation, and pollution. Summary of the invention

[0007] The purpose of the present invention is to provide a reactive discharge printing process, which has the characteristics of improving the softness, color fastness and color light stability of fabrics, and is easy to operate, has low steaming requirements and is environmentally friendly.

[0008] The technical solution of the present invention is an active discharge printing process, comprising the following steps: S1, cold-batch dyeing of a semi-bleached cloth, wherein the dyeing solution formula is: vinyl sulfone dye: 20-60 g / L; sodium carbonate: 85-100 g / L; caustic soda with a mass percentage of 40%: 13-25 g / L; the rest is water, to obtain a dyed base cloth;

[0009] S2, printing the dyed base cloth, wherein the printing slurry formula is: monochlorotriazine reactive dye: 5-60g / L; seaweed paste: 400-700g / L; potassium carbonate: 40-60g / L; sodium sulfite: 5-35g / L; baking soda: 10-30g / L; resist salt: 1-3g / L; urea: 20-60g / L; the rest is water, to obtain printed cloth;

[0010] S3, steaming, cleaning and finishing the printed cloth in sequence to obtain a finished product.

[0011] In the aforementioned reactive discharge printing process, in step S1, the cold batch dyeing method is specifically as follows:

[0012] A. After the semi-bleached cloth is evenly dipped into the dye solution, it is rolled directly and the fabric on the roll rack is sealed with a film to obtain product A;

[0013] B. Place product A at 20-30 rpm at 20-40°C, stack it for 12-16 hours, then wash with high-temperature soap to fix the color, and obtain the dyed base fabric.

[0014] In the aforementioned reactive discharge printing process, in step S3, the cleaning step includes room temperature acid washing, high temperature soap washing and clean water washing.

[0015] In the above-mentioned reactive discharge printing process, the cleaning solution for room temperature pickling contains 1 to 3 g / L of glacial acetic acid, and the washing time is 2 to 5 minutes.

[0016] In the above-mentioned reactive discharge printing process, the soaping liquid of high temperature soaping contains 2-5 g / L of soaping agent, the soaping time is 5-15 min, and the soaping temperature is 95-98°C.

[0017] In the above-mentioned reactive discharge printing process, in step S3, the evaporation temperature is 100-105° C., the evaporation time is 8-10 minutes, and the evaporation humidity is above 60%.

[0018] In the aforementioned reactive discharge printing process, the semi-bleached cloth is a fabric containing hydroxyl groups.

[0019] In the aforementioned reactive discharge printing process, the semi-bleached cloth comprises cotton fiber fabric, kapok fiber fabric or silk fabric.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The active engraving and active printing process of the present invention adopts the steps of cold batch dyeing to fix the base color and then engraving and printing with active dyes, so that the steaming time only needs 8 minutes and the steaming humidity can be 60%, which not only solves the problems of hard feel and low color fastness of the fabric, but also solves the problems of unstable base color and surface color, high production cost and inconvenient steaming. The fabric pattern effect obtained after printing is clear and three-dimensional, the color is stable and uniform, the fabric quality is high, the defective rate is low, and the process time of discharge printing in the past is shortened, the work cost is reduced, and the work efficiency and work benefit are improved.

[0022] This process has been washed many times to improve the color fastness. The color fastness of dark colors is above 2.5, the dry friction is above 3, the soap fastness is above 3.5, and the multi-fiber staining is above 3.5. The color fastness of medium and light colors is one level higher than that of dark colors.

[0023] The dyeing and printing formulas used are non-toxic, non-polluting materials and are environmentally friendly.

[0024] If the discharge printing color development is not good after steaming in the printing process of the present invention, re-steaming can be performed to improve the discharge printing color development effect and stability performance, and there is no situation where the flower pattern cannot be displayed.

[0025] Therefore, the invention has the characteristics of improving the softness, color fastness and color light stability of the fabric, and is easy to operate, has low steaming requirements and is pollution-free to the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is the printed fabric prepared in Example 2 of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the embodiments, but they are not intended to limit the present invention.

[0028] Embodiment 1:

[0029] The reactive discharge printing process comprises the following steps: cold-batch dyeing of semi-bleached cloth to obtain dyed base cloth; printing of dyed base cloth to obtain printed cloth; and sequentially steaming, washing and finishing the printed cloth to obtain the finished product. The semi-bleached cloth is a fabric containing hydroxyl groups, including cotton fiber fabric, kapok fiber fabric, silk fabric, etc.

[0030] The dyeing process adopts cold dyeing process, and the dyeing liquid formula is:

[0031] Vinyl sulfone type (KN type) dye: 20-60 g / L; sodium silicate (water glass): 85-100 g / L; caustic soda with a mass percentage of 40%: 13-25 g / L; the rest is water.

[0032] The specific dyeing method is:

[0033] A. After the semi-bleached cloth is dipped into the dye solution, it is rolled directly and the fabric on the roll rack is sealed with a film to obtain product A;

[0034] B. Place product A in a heat preservation room at 20℃~40℃, rotate the roll rack at 20~30 rpm, stack it for 12~16h, then wash it with soap at 96~99℃ for 8~10min to wash away the floating color and fix the color at the same time to obtain the dyed base fabric. At this time, the base color of the dyed base fabric is stable.

[0035] The dyeing in the printing process of the present invention is cold dyeing, and the dyeing process only needs to be stacked under the condition of 20℃~40℃, which saves energy and cost. For the engraving process, the whitening is cleaner, and the color is directly fixed after cold, and the base color is stable and will not change. However, the current continuous long-wheel pad dyeing needs to roll saturated salt water at a high temperature of 100℃~103℃ to fix the color, and the base color is unstable. For the engraving process, the whitening is not easy to be clean, and the high-temperature fixation consumes a lot of energy and has high cost.

[0036] The printing slurry formula is: monochlorotriazine (K type) reactive dye: 5-60g / L; seaweed paste (original paste concentration 7%): 400-700g / L; potassium carbonate: 40-60g / L; sodium sulfite: 5-35g / L; baking soda: 10-30g / L; resist salt: 1-3g / L; urea: 20-60g / L; the rest is water.

[0037] In this process, vinyl sulfone type (KN type) dyes are selected for base dyeing during dyeing, and slurry containing sodium sulfite and potassium carbonate is selected for printing. The slurry containing potassium carbonate and sodium sulfite is printed on the fabric to react with the dye on the base color of the fabric. The vinyl sulfone group of the vinyl sulfone type dye can react with the hydroxyl group on the cotton fiber of the fabric to generate an ether bond, thereby fixing the dye. However, when sodium sulfite is present, it can react with the vinyl sulfone group in a competitive nucleophilic addition reaction to generate a stable sodium salt derivative of vinyl sulfone sulfonic acid, resulting in a change in the structure of the vinyl sulfone type dye molecule, a loss of active groups, and no longer being able to react with the hydroxyl group on the fiber, and losing the bonding effect with the fiber, thereby achieving the purpose of destroying the base color and preventing the base color from staining, and the cold dyeing method is easier to print.

[0038] The potassium carbonate is used to adjust the pH value of the reaction to 8-9.5, providing dyeing conditions for monochlorotriazine-type reactive dyes and reducing the reaction rate of the vinyl sulfone group with the reducing sodium sulfite. This allows the reactive dye to be evaporated again if the color is not deep during evaporation, and also allows the sodium sulfite to react more fully, which helps with printing.

[0039] The monochlorotriazine (K type) reactive dye in the printing paste will not react with sodium sulfite. Therefore, the monochlorotriazine (K type) reactive dye can combine with the hydroxyl group on the fabric fiber to color and print normally, promote the penetration performance and color fastness of the printing dye on the fiber, produce better solubility and moisture absorption, and the printed fabric feels soft.

[0040] The potassium carbonate and sodium sulfite used in the printing paste are environmentally friendly.

[0041] The evaporation temperature is 100-105° C., the evaporation time is 8-10 minutes, and the evaporation humidity is above 60%.

[0042] The cleaning comprises sequentially performing room temperature pickling, high temperature soap washing and clean water washing, wherein the cleaning solution of room temperature pickling contains 1-3 g / L of glacial acetic acid, and the water washing time is 2-5 min.

[0043] The soaping liquid for high temperature soaping contains 2 to 5 g / L of soaping agent, the soaping time is 5 to 15 minutes, and the soaping temperature is 95 to 98°C.

[0044] The overall process of the invention is relatively simple, easy to operate and has stable color and light.

[0045] Embodiment 2:

[0046] The invention discloses an active discharge printing process for cotton fiber fabrics, comprising the following steps: cold dyeing of semi-bleached cotton cloth, printing, steaming, washing and finishing to obtain printed cotton cloth.

[0047] The dyeing liquid formula is as follows: vinyl sulfone type (KN type) dye: 30g / L; water glass: 90g / L; caustic soda with a mass percentage of 40%: 20g / L; and the rest is water.

[0048] The specific dyeing method is:

[0049] A. After the semi-bleached cloth is dipped into the dye solution, it is rolled directly and the fabric on the roll rack is sealed with a film to obtain product A;

[0050] B. Place product A in a 30℃ heat preservation room, rotate the roll rack at 25 rpm, stack it for 14 hours, and then wash it with soap at 96-99℃ for 10 minutes to obtain the dyed base fabric.

[0051] The printing slurry formula is: monochlorotriazine (K type) reactive dye: 30g / L; seaweed paste (original paste concentration 7%): 500g / L; potassium carbonate: 50g / L; sodium sulfite: 20g / L; baking soda: 20g / L; resist salt: 2g / L; urea: 30g / L; the rest is water.

[0052] The evaporation temperature is 102° C., the evaporation time is 8 minutes, and the evaporation humidity is 70%.

[0053] The water washing comprises acid washing at room temperature, soap washing at high temperature and clean water washing in sequence, wherein the cleaning solution of the acid washing at room temperature contains 2 g / L of glacial acetic acid, and the water washing time is 3 minutes.

[0054] The soaping liquid for high temperature soaping contains 3 g / L of soaping agent, the soaping time is 10 min, and the soaping temperature is 98°C.

[0055] Embodiment 2 obtains calico after finishing, as Figure 1 As shown, the pattern effect is clear and three-dimensional.

[0056] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. Reactive discharge printing process, characterized by: The following steps are involved: S1, cold-batch dyeing the semi-bleached cloth, wherein the dyeing solution formula is: vinyl sulfone dye: 20-60 g / L; sodium carbonate: 85-100 g / L; caustic soda with a mass percentage of 40%: 13-25 g / L; the rest is water, to obtain a dyed base cloth; S2, printing the dyed base cloth, wherein the printing slurry formula is: monochlorotriazine reactive dye: 5-60g / L; seaweed paste: 400-700g / L; potassium carbonate: 40-60g / L; sodium sulfite: 5-35g / L; baking soda: 10-30g / L; resist salt: 1-3g / L; urea: 20-60g / L; the rest is water, to obtain printed cloth; S3, steaming, cleaning and finishing the printed cloth in sequence to obtain a finished product.

2. The reactive discharge printing process according to claim 1, characterized in that: In step S1, the cold batch dyeing method is specifically as follows: A. Evenly dip the semi-bleached cloth into the dye solution and roll it up, and seal the fabric on the roll rack with a film to obtain product A; B. Place product A at 20-30 rpm at 20-40°C, stack it for 12-16 hours, then wash with high-temperature soap to fix the color, and obtain the dyed base fabric.

3. The reactive discharge printing process according to claim 1, characterized in that: In step S3, the cleaning step includes room temperature acid cleaning, high temperature soap cleaning and clean water cleaning.

4. The reactive discharge printing process according to claim 3, characterized in that: The cleaning solution for room temperature pickling contains 1 to 3 g / L of glacial acetic acid, and the washing time is 2 to 5 minutes.

5. The reactive discharge printing process according to claim 3, characterized in that: The soaping liquid for high temperature soaping contains 2 to 5 g / L of soaping agent, the soaping time is 5 to 15 minutes, and the soaping temperature is 95 to 98°C.

6. The reactive discharge printing process according to claim 1, characterized in that: In step S3, the evaporation temperature is 100-105° C., the evaporation time is 8-10 min, and the evaporation humidity is above 60%.

7. The reactive discharge printing process according to claim 1, characterized in that: The semi-bleached cloth is a fabric containing hydroxyl groups.

8. The reactive discharge printing process according to claim 1, characterized in that: The semi-bleached cloth includes cotton fiber fabric, kapok fiber fabric or silk fabric.

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