A method of dyeing a knitted fabric

Abstract

The application provides a dyeing method of knitted fabric, and relates to the technical field of fabric dyeing. The dyeing method comprises the following steps: firstly, cotton fabric is subjected to singeing, scouring and bleaching, and then subjected to cold pad dyeing by using reactive dyes; secondly, the cotton fabric is subjected to repeated hot-cold alternating treatment by using an aqueous solution of disodium EDTA; thirdly, the cotton fabric is dried and subjected to secondary temperature rising dyeing; and finally, the cotton fabric is rinsed, soaped and spun dry. The dyeing method overcomes the defects of the prior art, and can be used for the industrial continuous production of irregular pattern dyed fabric. The finally dyed fabric is not prone to color fading, and has high market value.

Description

Technical Field

[0001] This invention relates to the field of fabric dyeing technology, and more specifically to a method for dyeing knitted fabrics. Background Technology

[0002] Knitted cotton fabric is a common fabric with characteristics such as moisture absorption, warmth retention, heat resistance, alkali resistance, and hygiene. Generally speaking, pure cotton fabric is widely popular in the clothing industry because of its good moisture absorption and heat resistance, as well as its comfortable wearing. Based on this, the requirements for cotton fabric are getting higher and higher, and the corresponding demand for dyeing knitted cotton fabric is also getting higher and higher, requiring fabrics of different colors and patterns to meet market demand.

[0003] Currently, the mainstream dyeing method for cotton fabrics is still based on single solid colors. However, solid-color fabrics can no longer satisfy people's pursuit of clothing aesthetics. At present, the production process of fabrics has gradually developed different patterns from solid colors. Existing pattern preparation includes printing and dyeing, tie-dyeing / batik, and dip-dyeing. Tie-dyeing is often used to achieve irregular changes. However, tie-dyeing is a manual process with disadvantages such as non-repeatability, low efficiency, high cost, poor color fastness, and limited patterns. It is difficult to achieve the same pattern effect on the same batch of fabrics. Based on this, the development of new irregular patterned fabrics that can be industrialized and continuously produced has a broad market prospect. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a dyeing method for knitted fabrics that enables continuous factory production of irregularly patterned fabrics. The dyed fabrics are also less prone to fading and have high market value.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A dyeing method for knitted fabric, the dyeing method comprising the following steps: S1. The raw knitted cotton fabric is singed, boiled, and then bleached to obtain pre-treated raw fabric for later use. S2. The pretreated fabric is subjected to cold-batch treatment with the first dye. The formula of the first dye is as follows: reactive dye: 5-40 g / L, soda ash: 40-50 g / L, sodium silicate: 30-40 g / L, sodium sulfate: 30-60 g / L, urea: 10-20 g / L, hydroxypropyl cyclodextrin: 10-15 g / L, polysorbate-80: 4-10 g / L. S3. After the fabric has been cooled and piled up, place it in an aqueous solution containing disodium EDTA at 95-100℃ for 20-30 minutes, and then immediately place it in cold water at 10-20℃ for 5-10 minutes. Repeat the above operation of treating the fabric with the aqueous solution containing disodium EDTA at 95-100℃ followed by cold water treatment at 10-20℃ 3-5 times. Then take out the pretreated fabric for later use. S4. After squeezing out the moisture from the pretreated fabric, stretch it to the preset width and heat it to 160-180℃ for drying to obtain the dried fabric. S5. Place the above-mentioned dried fabric in the second dye and heat it for dyeing. The formula of the second dye is: reactive dye: 1-8g / L, soda ash: 8-10g / L, sodium sulfate: 30-60g / L, urea: 10-20g / L, penetrant JFC: 1-2g / L. S6. Rinse the dyed fabric until it is neutral, then soap it, and finally spin dry to complete the dyeing process.

[0006] Preferably, the scouring method in step S1 is to use a scouring agent with the following formula: NaOH: 5-10g / L, penetrant JFC: 1-2g / L, refining agent 065: 2-3g / L, and the remainder being water. The singed blank is placed in the scouring agent at a bath ratio of 1:15-20 and heated to 95-100℃ for 40-60 minutes, followed by washing with water 2-3 times.

[0007] Preferably, the bleaching treatment in step S2 is carried out as follows: the cooked blanks are placed in a hydrogen peroxide solution with a concentration of 2-6 g / L, treated at 95-100℃ for 40-60 min, then neutralized with acetic acid to neutrality and washed with water 2-3 times.

[0008] Preferably, the temperature of the cold reactor treatment in step S2 is 20-30°C, and the treatment time is 6-8 hours.

[0009] Preferably, the amount of disodium EDTA in the aqueous solution containing disodium EDTA in step S3 is 15-20 g / L.

[0010] Preferably, the drying time in step S4 is 20-30 minutes.

[0011] In step S5, the temperature for heating and staining is 60-70℃, the staining time is 30-40 minutes, and the bath ratio is 1:15-20.

[0012] Preferably, the content of reactive dye in the second dye is 1 / 4 to 1 / 5 of the content of reactive dye in the first dye.

[0013] Preferably, the solution formula used in step S6 for soaping is: soaping agent 209: 2-3 g / L, soda ash: 1-2 g / L, glacial acetic acid: 1.2-1.5 mL / L. The soaping method is to place the fabric in the soaping solution and heat it to 90-95℃ for 10-20 minutes, then cool it down to 70-75℃ and continue to treat it for 40-60 minutes, then cool it down to 40-60℃ and continue to treat it for 1-2 hours, and then cool it to room temperature.

[0014] This invention provides a dyeing method for knitted fabrics, which has the following advantages compared with the prior art: This invention uses reactive dyes to dye cotton fabric in two stages: cold piling and heating. Between the two dyeing stages, the fabric is repeatedly washed with EDTA disodium aqueous solution at high and low temperatures. The amount of pigment added is reduced during the heating dyeing stage. The final fabric product will have an irregular pattern with a blurred effect. At the same time, the dyed fabric is not easy to fade and has good stability, making it suitable for large-scale production. This invention provides a new type of irregular patterned fabric with high market application value. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the fabric after dyeing according to Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the fabric after dyeing in Comparative Example 1 of the present invention; Figure 3 This is a schematic diagram of the fabric after dyeing in Comparative Example 2 of the present invention; Figure 4 This is a schematic diagram of the fabric after dyeing in Comparative Example 3 of the present invention; Figure 5 This is a schematic diagram of the fabric after dyeing in Comparative Example 4 of the present invention; Figure 6 This is a schematic diagram of the fabric after dyeing in Comparative Example 5 of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The following uses reactive deep blue KN-RP as the reactive dye, and the knitted fabric used is 26-count pure cotton greige fabric.

[0018] Example 1: Fabric dyeing methods: (1) The front and back sides of the fabric were singed with gas at a speed of 100 m / min and a temperature of 1050℃. The singed fabric was then treated with a scouring agent (NaOH: 8 g / L, penetrant JFC: 1.5 g / L, scouring agent 065: 2.5 g / L, the remainder being water) at a bath ratio of 1:18, heated to 95℃ for 50 min, then washed twice with water, and then placed in a hydrogen peroxide solution with a concentration of 4 g / L, treated at 95℃ for 50 min, then neutralized to neutral with acetic acid and washed three times with water to obtain the pretreated fabric. (2) The formulation of the first dye components is as follows: reactive dye: 25 g / L, soda ash: 45 g / L, sodium silicate: 35 g / L, sodium sulfate: 45 g / L, urea: 15 g / L, hydroxypropyl cyclodextrin: 12 g / L, polysorbate-80: 8 g / L; the pretreated fabric is cold-batch treated with the first dye for 7 h. (3) After the cold stacking, the fabric is placed in an aqueous solution containing disodium EDTA (disodium EDTA concentration of 18g / L) at 95℃ for 25min, and then immediately placed in cold water at 15℃ for 8min. The above hot and cold alternation operation is repeated 4 times and the pre-treated fabric is taken out for use. (4) After squeezing out the moisture from the pretreated fabric, stretch it to the preset width and heat it to 170°C for 25 minutes to dry it, and obtain the dried fabric. (5) Place the dry fabric in the second dye (liquor ratio of 1:18) and heat to 60°C for 35 min. The formula of the second dye is: reactive dye: 5 g / L, soda ash: 9 g / L, sodium sulfate: 40 g / L, urea: 15 g / L, penetrant JFC: 1.5 g / L; and the soda ash is added in three portions after 10 min of heating to 60°C.

[0019] (6) Rinse the dyed fabric with cold water until it is neutral, and then use soaping agent (soaping agent 209: 2.5g / L, soda ash: 1.5g / L, glacial acetic acid: 1.3mL / L) for soaping. The soaping method is to first heat the fabric to 92℃ for 15min, then cool it to 72℃ for 50min, then cool it to 50℃ for 1.5h, and then cool it to room temperature and use a blast dryer to dry it to complete the dyeing.

[0020] Comparative Example 1: Comparative Example 1 is basically the same as Example 1, except that the formulation of the first dye in step (2) is different. The formulation of the first dye in this comparative example is: reactive dye: 25g / L, soda ash: 45g / L, sodium silicate: 35g / L, sodium sulfate: 45g / L, urea: 15g / L.

[0021] Comparative Example 2: Comparative Example 2 is basically the same as Example 1, except for step (3). The specific operation of step (3) is as follows: (3) After the cold stacking, the fabric is placed in hot water at 95°C for 25 minutes, and then immediately placed in cold water at 15°C for 8 minutes. The above hot and cold alternation operation is repeated 4 times before the pre-treated fabric is taken out for use. Comparative Example 3: Comparative Example 2 is basically the same as Example 1, except for step (3). The specific operation of step (3) is as follows: (3) Place the cold-stacked fabric in hot water at 95°C for 1.5 hours to obtain pretreated fabric for later use; Comparative Example 4: Comparative Example 2 is basically the same as Example 1, except for step (3). The specific operation of step (3) is as follows: (3) The fabric after cold stacking is placed in an aqueous solution of disodium EDTA at 95°C (the concentration of disodium EDTA is 18g / L) for 1.5h to obtain pretreated fabric for use. Comparative Example 5: Comparative Example 2 is basically the same as Example 1, except that steps (5) and (6) are omitted, and the dried fabric obtained in step (4) is used as the finished product.

[0022] Detection: The finished fabrics after dyeing in each group are as follows: Figures 1-6 As shown, where Figures 1-6 The following figures respectively represent the finished dyed fabrics of Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4, and Comparative Example 5. Figure 1 Example 1 Figure 2 Comparative Example 1 Figure 3 Comparative Example 2 and Figure 5 The finished fabric obtained in Comparative Example 4 has a brighter color, but overall... Figure 1 The patterns are more uniform; Figure 4 Comparative Example 3 and Figure 6 Comparative Example 3 has a lighter overall color, and Figure 6 There are white marks in the pattern, indicating poor stability.

[0023] The colorfastness of each component of the fabric was tested, and the specific test results are shown in the table below: As can be seen from the table above, the fabric dyed by the method in Example 1 has better color fastness, and according to Figure 1-6 As can be seen from the images, the pattern of Example 1 is more uniform and stable.

[0024] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dyeing method for knitted fabrics, characterized in that, The staining method includes the following steps: S1. The raw knitted cotton fabric is singed, boiled, and then bleached to obtain pre-treated raw fabric for later use. S2. The pretreated fabric is subjected to cold-batch treatment with the first dye. The formula of the first dye is as follows: reactive dye: 5-40 g / L, soda ash: 40-50 g / L, sodium silicate: 30-40 g / L, sodium sulfate: 30-60 g / L, urea: 10-20 g / L, hydroxypropyl cyclodextrin: 10-15 g / L, polysorbate-80: 4-10 g / L. S3. After the fabric has been cooled and piled up, place it in an aqueous solution containing disodium EDTA at 95-100℃ for 20-30 minutes, and then immediately place it in cold water at 10-20℃ for 5-10 minutes. Repeat the above operation of treating the fabric with the aqueous solution containing disodium EDTA at 95-100℃ followed by cold water treatment at 10-20℃ 3-5 times. Then take out the pretreated fabric for later use. S4. After squeezing out the moisture from the pretreated fabric, stretch it to the preset width and heat it to 160-180℃ for drying to obtain the dried fabric. S5. Place the above-mentioned dried fabric in the second dye and heat it for dyeing. The formula of the second dye is: reactive dye: 1-8g / L, soda ash: 8-10g / L, sodium sulfate: 30-60g / L, urea: 10-20g / L, penetrant JFC: 1-2g / L. S6. Rinse the dyed fabric until it is neutral, then soap it, and finally spin dry to complete the dyeing process.

2. The staining method according to claim 1, characterized in that: In step S1, the scouring method involves using a scouring agent with the following formula: NaOH: 5-10 g / L, penetrant JFC: 1-2 g / L, refining agent 065: 2-3 g / L, and the remainder being water. The scouring agent is prepared at a bath ratio of 1:15-20. The singed blanks are placed in the scouring agent and heated to 95-100℃ for 40-60 minutes, followed by 2-3 water washes.

3. The staining method according to claim 1, characterized in that: The specific method of bleaching treatment in step S2 is as follows: the cooked blanks are placed in a hydrogen peroxide solution with a concentration of 2-6 g / L, treated at 95-100℃ for 40-60 min, then neutralized with acetic acid to neutral, and washed with water 2-3 times.

4. The staining method according to claim 1, characterized in that: In step S2, the temperature of the cold reactor treatment is 20-30℃, and the treatment time is 6-8 hours.

5. The staining method according to claim 1, characterized in that: In step S3, the amount of disodium EDTA in the aqueous solution is 15-20 g / L.

6. The staining method according to claim 1, characterized in that: The drying time in step S4 is 20-30 minutes.

7. The staining method according to claim 1, characterized in that: In step S5, the temperature for heating and staining is 60-70℃, and the staining time is 30-40 minutes.

8. The staining method according to claim 1, characterized in that: The content of reactive dye in the second dye is 1 / 4 to 1 / 5 of the content of reactive dye in the first dye.

9. The staining method according to claim 1, characterized in that: The solution formula used in step S6 for soaping is as follows: soaping agent 209: 2-3 g / L, soda ash: 1-2 g / L, glacial acetic acid: 1.2-1.5 mL / L. The soaping method is to place the fabric in the soaping solution and heat it to 90-95℃ for 10-20 minutes, then cool it down to 70-75℃ and continue to treat it for 40-60 minutes, then cool it down to 40-60℃ and continue to treat it for 1-2 hours, and then cool it to room temperature.

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