Uniform dyeing technology of wool and silk fabrics

Abstract

The present invention relates to the technical field of textile printing and dyeing, and specifically to a wool silk fabric uniformity dyeing process, comprising the following steps: placing the wool silk fabric in a sealed box for negative pressure treatment, and then gently degreasing to obtain a pre-treated fabric; putting the wool silk fabric into a dyeing device, dyeing with active dyes, adding a retarder and a softener in the bath, and adjusting the pH value with a pH buffer; washing and post-treatment after dyeing to obtain a dyed wool silk fabric. The present invention adopts physical negative pressure and gentle degreasing pre-treatment, and by placing the physical negative pressure for a long time, the silk fibroin oil and residual sericin in the silk fabric are precipitated to the fabric surface, and then combined with subsequent gentle degreasing treatment, the grease and impurities on the silk surface can be effectively removed, and the dyeing uniformity of the wool silk fabric can be improved. At the same time, the damage to the fiber caused by dyeing under traditional alkaline conditions is avoided, the silk fibroin dyeing performance is protected, and the fluctuation of the proportion of fabric components is reduced, thereby improving the dyeing fullness effect and overall high-end feeling of the wool silk fabric.

Description

Technical Field

[0001] The invention relates to the technical field of textile printing and dyeing, and in particular to a process for uniform dyeing of wool and silk fabrics. Background Art

[0002] Wool silk fabric is a high-end textile that combines two natural fibers, wool and silk. It is widely favored by consumers for its unique performance and texture. Wool has excellent moisture absorption, warmth retention and elasticity, which brings excellent comfort and durability to the fabric; silk gives the fabric a natural luster, smooth feel and good breathability, making wool silk fabric not only have a luxurious appearance, but also a comfortable wearing experience.

[0003] In the dyeing process of wool and silk fabrics, reactive dyes are preferred in order to balance dye fastness, color brightness and process operability. Wool and raw silk need to be scour and bleached to remove impurities before textile processing. Due to the difference in the content of amino dyeing groups in the two fibers, the balanced dyeing amount of wool is higher than that of silk. In addition, some silk fibroin oil and impurities still exist in the cooked silk after scouring and bleaching, which further hinders the dyeing of dyeing reaction groups and affects the dyeing performance and color depth of silk, so pre-dyeing treatment is required.

[0004] Traditional dyeing pretreatment is carried out under alkaline conditions, but this will damage wool and silk fibers, and the alkalinity will be further enhanced when dyeing dark series, resulting in greater fiber damage, reducing the dyeing effect and durability of the fabric, and due to the difference in fiber damage and dyeing effect, the proportion of fabric components fluctuates, deviating from the original design requirements, affecting the quality and appearance of the fabric, and causing uneven dyeing of wool and silk fabrics. Therefore, the present invention provides a uniform dyeing process for wool and silk fabrics to solve the above problems. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to solve the problem of uniform dyeing process for wool and silk fabrics.

[0006] The uniform dyeing process of wool and silk fabrics includes the following steps:

[0007] S1: Pre-processing stage

[0008] The wool and silk fabric blanks are placed in a sealed box, the negative pressure is adjusted to perform negative pressure treatment, and the storage time is set to allow the silk fibroin oil and residual sericin to naturally precipitate onto the surface of the fabric;

[0009] After negative pressure treatment, mild degreasing is used to remove the precipitated grease and impurities to prepare for subsequent dyeing and pre-treat the fabric;

[0010] S2: Staining stage

[0011] The pretreated fabric is put into a dyeing device, dyed with a reactive dye, a retarder is added to the same bath, and a pH buffer is used to adjust the dyeing pH value to 5-5.5, and the dyeing process is carried out;

[0012] S3: Washing stage

[0013] After dyeing is completed, washing and post-treatment are carried out to ensure that unbound dyes and chemical auxiliaries are removed to obtain dyed wool silk fabrics.

[0014] Furthermore, the negative pressure is 0.1 kpa-101 kpa, and the storage time is 1-10 days.

[0015] Furthermore, the wool silk fabric grey cloth is obtained by selecting 150G circular knitted sweat cloth of 50NM wool and 20D silk of specific specifications, mixing wool and silk in a ratio of 90:10, adopting the spinning method of silk-coated wool yarn, and weaving using special equipment under a standard wet temperature environment.

[0016] Furthermore, the mild degreasing adopts a mild wool pre-treatment method, avoiding strong alkali, strong reducing agent and high temperature.

[0017] Furthermore, the mild degreasing method includes one or more of protease degreasing, baking soda weak alkali degreasing, vegetable soap degreasing, mild detergent degreasing, and ultrasonic cleaning.

[0018] Furthermore, the dyeing equipment used in the dyeing stage is a downflow overflow dyeing machine, and the bath softener BRL-30 is continuously added during the dyeing process.

[0019] Furthermore, the reactive dye is LANASOL wool-specific reactive dye, the retarding agent is sodium sulfate, and the pH buffer is one of a citric acid-sodium citrate buffer pair and an acetic acid-sodium acetate buffer pair.

[0020] Furthermore, the amount of the sodium sulfate added is 2-10% of the weight of the LANASOL wool-specific reactive dye.

[0021] Furthermore, the washing stage includes at least two cold water rinses and one hot water rinse.

[0022] Furthermore, the initial temperature of the dyeing stage is 28-32°C, which is increased to 40-45°C at a rate of 1-3°C / min and maintained for 15-30min; then increased to 55-60°C at a rate of 1°C / min and maintained for 20-40min; finally increased to 75-80°C at a rate of 1°C / min and maintained for 40-60min. After dyeing is completed, the temperature is cooled to room temperature at a rate of 1-3°C / min to discharge the liquid.

[0023] The technical solution provided by the present invention includes the following beneficial effects:

[0024] 1. The present invention provides a wool silk fabric uniform dyeing process, which can effectively remove grease and impurities on the silk surface through physical negative pressure and mild degreasing pre-treatment, while protecting the silk dyeing performance. Through long-term physical negative pressure placement, the silk fibroin grease and residual sericin in the silk fabric are precipitated to the fabric surface, and then combined with subsequent mild degreasing treatment, the grease and impurity removal efficiency is improved, the dyeing uniformity of the wool silk fabric is improved, and the numbness is reduced. At the same time, the damage to the fiber caused by dyeing under traditional alkaline conditions is avoided, and the fluctuation of the proportion of fabric components is reduced, thereby improving the dyeing effect and overall high-end feeling of the wool silk fabric.

[0025] 2. After the wool silk fabric of the present invention is treated with negative pressure and left for a certain period of time, silk grease and residual sericin are precipitated to the surface to varying degrees, and the purpose of degreasing can be achieved by a general mild degreasing method, so that the dyeing resistance of the dye is reduced, and the dyeing performance of silk is improved to a level close to the dyeing rate of wool, thereby achieving the purpose of uniformity of the dyed cloth surface.

[0026] 3. The present invention adopts a pre-dyeing treatment method different from the traditional one. By changing the storage method of the grey cloth, that is, adopting negative pressure storage and combining it with mild oil removal, it can achieve more effective removal of silk sericin and grease than the traditional process, and optimize the pre-dyeing conditions of the fabric.

[0027] 4. The present invention can improve the dyeing synchronization of wool and silk by selecting specific active dyes, adding sodium sulfate as a retarding agent, and using a pH buffer to adjust the dyeing pH. At the same time, it can slow-release acid and dye under weak acid conditions, reduce the probability of color spots in dyeing processing, and avoid alkaline damage to wool and silk protein fibers.

[0028] 5. The present invention comprehensively utilizes physical negative pressure treatment, mild oil removal, pretreatment methods, and optimization of specific dyes and dyeing conditions to achieve significant improvement in dyeing uniformity of wool and silk fabrics from multiple dimensions, overcome the limitations of traditional dyeing technology, and enhance the overall quality and visual effect of the fabrics. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a schematic flow chart of a wool and silk fabric uniformity dyeing process adopted in an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0031] Example 1: Uniform dyeing process of wool and silk fabrics, such as Figure 1 As shown, the following steps are included:

[0032] S1: Pre-processing stage

[0033] Select 150G circular knitted jersey of 50NM wool and 20D silk of specific specifications, mix them in a ratio of 90:10, adopt the spinning method of silk-covered wool yarn, and weave them with special equipment under standard humidity and temperature environment to obtain wool silk fabric;

[0034] The wool silk fabric blank is placed in a sealed box, the negative pressure is adjusted to 0.1 kPa for negative pressure treatment, and the storage time is set to 1 day, so that the silk fibroin oil and residual sericin are naturally precipitated to the surface of the fabric;

[0035] Prepare an enzyme solution with a content of 1 g / L, immerse the wool and silk fabric after negative pressure treatment in the enzyme solution, the solution temperature is 40°C, the time is 30 minutes, and the enzyme solution is gently degreased to prepare for subsequent dyeing, thereby obtaining a pretreated fabric;

[0036] S2: Staining stage

[0037] The pretreated fabric was put into a down-flow overflow dyeing machine, and LANASOL wool-specific reactive dye was used at a dosage of 3% of the pretreated fabric weight. Sodium sulfate was added in the same bath at a weight of 2% of the reactive dye as a retarder. Acetic acid-sodium acetate pH buffer was used to adjust the dyeing pH value to 5, and the dyeing process was carried out. Softener BRL-30 was added before dyeing, and the total amount of softener was 3% of the fabric weight.

[0038] The initial temperature of the dyeing stage is 30℃, which is then raised to 45℃ at a rate of 2℃ / min and maintained for 20min; then raised to 55℃ at a rate of 1℃ / min and maintained for 25min; finally, raised to 75℃ at a rate of 3℃ / min and maintained for 50min. After dyeing is completed, the temperature is lowered to room temperature at a rate of 3℃ / min to drain the liquid;

[0039] S3: Washing stage

[0040] After dyeing is completed, two cold water rinses and one hot water rinse are performed, the hot water temperature is 50°C, and the total washing time is 50 minutes to ensure that unbound dyes and chemical auxiliaries are removed to obtain dyed wool silk fabrics.

[0041] Example 2: Wool and silk fabric uniformity dyeing process, such as Figure 1 As shown, the following steps are included:

[0042] S1: Pre-processing stage

[0043] Select 150G circular knitted jersey of 50NM wool and 20D silk of specific specifications, mix them in a ratio of 90:10, adopt the spinning method of silk-covered wool yarn, and weave them with special equipment under standard humidity and temperature environment to obtain wool silk fabric;

[0044] The wool silk fabric blank is placed in a sealed box, the negative pressure is adjusted to 1 kPa for negative pressure treatment, and the storage time is set to 3 days, so that the silk fibroin oil and residual sericin are naturally precipitated to the surface of the fabric;

[0045] A mixed solution is prepared by mixing baking soda and water in a volume ratio of 1:10, and the wool and silk fabric treated with negative pressure is immersed in the mixed solution at a solution temperature of 40°C for 30 minutes to perform mild degreasing with baking soda weak alkali to prepare for subsequent dyeing, thereby obtaining a pretreated fabric;

[0046] S2: Staining stage

[0047] The pretreated fabric was put into a down-flow overflow dyeing machine, and LANASOL wool-specific reactive dye was used at a dosage of 3% of the weight of the pretreated fabric. 5% of the weight of the reactive dye was added to the same bath as a retarder, and the pH value of the dyeing was adjusted to 5.2 using citric acid-sodium citrate pH buffer. The softener BRL-30 was added before dyeing, and the total amount of the softener was 3% of the weight of the fabric.

[0048] The initial temperature of the dyeing stage was 28°C, which was then raised to 40°C at a rate of 1°C / min and maintained for 15 minutes; then raised to 57°C at a rate of 1.5°C / min and maintained for 20 minutes; finally, raised to 77°C at a rate of 2°C / min and maintained for 40 minutes. After dyeing was completed, the temperature was lowered to room temperature at a rate of 3°C / min and the liquid was discharged;

[0049] S3: Washing stage

[0050] After dyeing is completed, a cold water rinse and a hot water rinse are performed, the hot water temperature is 50°C, and the total washing time is 50 minutes to ensure that unbound dyes and chemical auxiliaries are removed to obtain dyed wool silk fabrics.

[0051] Example 3: Wool and silk fabric uniformity dyeing process, such as Figure 1 As shown, the following steps are included:

[0052] S1: Pre-processing stage

[0053] Select 150G circular knitted jersey of 50NM wool and 20D silk of specific specifications, mix them in a ratio of 65:35, adopt the spinning method of silk-covered wool yarn, and weave them with special equipment under standard humidity and temperature environment to obtain wool silk fabric;

[0054] The wool silk fabric blank is placed in a sealed box, the negative pressure is adjusted to 10 kPa for negative pressure treatment, and the storage time is set to 7 days, so that the silk fibroin oil and residual sericin are naturally precipitated to the surface of the fabric;

[0055] Prepare a 3% vegetable soap solution, immerse the wool and silk fabric after negative pressure treatment in the soap solution, the solution temperature is 40°C, the time is 30 minutes, and the vegetable soap is used for mild degreasing to prepare for subsequent dyeing, thereby obtaining a pretreated fabric;

[0056] S2: Staining stage

[0057] The pretreated fabric was put into a down-flow overflow dyeing machine, and LANASOL wool-specific reactive dye was used at a dosage of 3% of the weight of the pretreated fabric. 7% of the weight of the reactive dye was added to the same bath as a retarder. Acetic acid-sodium acetate pH buffer was used to adjust the dyeing pH value to 5.3, and the dyeing process was carried out. Softener BRL-30 was added before dyeing, and the total amount of softener was 3% of the weight of the fabric.

[0058] The initial temperature of the dyeing stage was 32°C, which was then raised to 42°C at a rate of 2°C / min and maintained for 18 minutes; then raised to 60°C at a rate of 3°C / min and maintained for 30 minutes; finally, raised to 80°C at a rate of 1.5°C / min and maintained for 45 minutes. After dyeing was completed, the temperature was lowered to room temperature at a rate of 2°C / min and the liquid was discharged;

[0059] S3: Washing stage

[0060] After dyeing, two cold water soakings and two hot water rinses are performed, the hot water temperature is 50°C, and the total washing time is 50 minutes to ensure that unbound dyes and chemical auxiliaries are removed to obtain dyed wool silk fabrics.

[0061] Embodiment 4: wool silk fabric uniformity dyeing process, such as Figure 1 As shown, the following steps are included:

[0062] S1: Pre-processing stage

[0063] Select 150G circular knitted jersey of 50NM wool and 20D silk of specific specifications, mix them in a ratio of 90:10, adopt the spinning method of silk-covered wool yarn, and weave them with special equipment under standard humidity and temperature environment to obtain wool silk fabric;

[0064] The wool silk fabric blank is placed in a sealed box, the negative pressure is adjusted to 50 kPa for negative pressure treatment, and the storage time is set to 10 days, so that the silk fibroin oil and residual sericin are naturally precipitated to the surface of the fabric;

[0065] A mild detergent without strong alkaline or strong acidic components is selected and dissolved in 35°C warm water to prepare a 3% concentration detergent solution. The wool and silk fabrics treated with negative pressure are immersed in the detergent solution for 30 minutes to remove oil with the mild detergent in preparation for subsequent dyeing to obtain pretreated fabrics.

[0066] S2: Staining stage

[0067] The pretreated fabric was put into a down-flow overflow dyeing machine, and LANASOL wool-specific reactive dye was used at a dosage of 3% of the weight of the pretreated fabric. 10% of the weight of the reactive dye was added to the same bath as a retarder, and the pH value of the dyeing was adjusted to 5.5 using citric acid-sodium citrate pH buffer. The softener BRL-30 was continuously added during the dyeing process, and the total amount of the softener was 3% of the weight of the fabric.

[0068] The initial temperature of the dyeing stage is 30℃, which is then raised to 45℃ at a rate of 1.5℃ / min and maintained for 25min; then raised to 58℃ at a rate of 2.5℃ / min and maintained for 40min; finally, raised to 78℃ at a rate of 3℃ / min and maintained for 55min. After dyeing is completed, the temperature is lowered to room temperature at a rate of 3℃ / min and the liquid is discharged;

[0069] S3: Washing stage

[0070] After dyeing, two cold water soakings and one hot water rinse are performed, the hot water temperature is 50°C, and the total washing time is 50 minutes to ensure that unbound dyes and chemical auxiliaries are removed to obtain dyed wool silk fabrics.

[0071] Comparative Example 1: Compared with Example 4, in this comparative example, the wool and silk fabric grey cloth is not subjected to negative pressure treatment, and only mild oil removal is performed. The remaining operating steps and conditions are consistent with Example 4.

[0072] Comparative Example 2: Compared with Example 4, in this comparative example, the wool and silk fabric grey cloth is not subjected to mild oil removal after negative pressure treatment, and the remaining operating steps and conditions are consistent with those of Example 4.

[0073] Performance testing: dye uptake, dyeing uniformity, wool and silk color difference and bursting strength of wool and silk fabrics dyed in the examples and comparative examples;

[0074] 1. Use a spectrophotometer to test the dyeing rate of wool and silk fabrics;

[0075] The absorbance A of the original solution and the residual solution after dyeing was measured using a 722N visible spectrophotometer. 0 and A n The formula for calculating the percentage of dye uptake on the fiber is: dye uptake % = (1-A n N n / A0 N 0 )×100;

[0076] A n ——absorbance of the residual liquid;

[0077] A 0 ——Absorbance of blank dye solution;

[0078] N n ——Dilution multiple of residual liquid;

[0079] N 0 ——Dilution multiple of blank dye solution.

[0080] 2. Use visual inspection combined with simple color difference assessment;

[0081] Using D65 standard light source, the wool and silk fabrics are laid flat on a white background. The quality inspectors observe them from multiple angles, including the front, side and upper side, and compare them with the standard color card to observe the color depth, glossiness or uneven areas, and evaluate the color difference level (1-5, 1 means no color difference and uniform dyeing; 5 means obvious color difference and uneven dyeing) to quantify the dyeing uniformity.

[0082] 3. Use Datacolor SF600 spectrophotometer to test the color difference of wool and silk;

[0083] Cut a small sample from each embodiment and comparative example, place the standard sample and the test sample in a standard light box, use a spectrophotometer to measure the Lab* value of each sample in turn, calculate the color difference (ΔEab) between each test sample and the standard sample, and evaluate the color difference grade according to the ΔEab value, ΔEab≤1 indicates no color difference or very slight color difference, 1<ΔEab≤2 indicates slight color difference, 2<ΔEab≤3 indicates obvious color difference, and ΔE*ab>3 indicates severe color difference.

[0084] 4. Use an electronic fabric strength testing machine to cut a small round sample (diameter 50 mm) from each embodiment and comparative example, clamp the sample in the upper and lower clamps of the testing machine, set the testing machine to the bursting strength test mode, set the test speed to 200 cm³ / min and the maximum load, and record the maximum load value (N) when the sample bursts, i.e. the bursting strength.

[0085] The test results of items 1-4 above are shown in the table below:

[0086] Table 1 Test results of dye uptake, dyeing uniformity, wool and silk color difference and wool and silk fabric bursting strength in the examples and comparative examples

[0087]

[0088] As can be seen from Table 1, the use of negative pressure treatment combined with mild oil removal in the pre-treatment stage can maximize the dyeing rate and dyeing uniformity of wool and silk fabrics. In addition, the fabrics of the embodiments all show lower color difference values, indicating that the color control during the dyeing process is very accurate, and have higher strength values ​​in terms of bursting strength, indicating that sufficient pre-treatment steps help to enhance the physical properties and structural strength of the fabric. The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with this technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A wool and silk fabric uniformity dyeing process, characterized in that: The following steps are involved: S1: Pre-processing stage The wool and silk fabric blanks are placed in a negative pressure sealed box, the negative pressure is adjusted to 0.1 kpa-101 kpa for negative pressure treatment, and the storage time is set to 1-10 days, so that the silk fibroin oil and residual sericin are naturally precipitated to the surface of the fabric; After negative pressure treatment, mild degreasing is used to remove the precipitated grease and impurities to prepare for subsequent dyeing and pre-treat the fabric; S2: Staining stage The pretreated fabric is put into a dyeing device, dyed with a reactive dye, a retarder is added to the same bath, and a pH buffer is used to adjust the dyeing pH value to 5-5.5, and the dyeing process is carried out; S3: Washing stage After dyeing is completed, washing and post-treatment are carried out to ensure that unbound dyes and chemical auxiliaries are removed to obtain dyed wool and silk fabrics; The initial temperature of the dyeing stage is 28-32°C, which is then increased to 40-45°C at a rate of 1-3°C / min and maintained for 15-30min; then increased to 55-60°C at a rate of 1°C / min and maintained for 20-40min; finally increased to 75-80°C at a rate of 1°C / min and maintained for 40-60min. After dyeing is completed, the temperature is lowered to room temperature at a rate of 1-3°C / min to discharge the liquid.

2. The wool and silk fabric uniformity dyeing process according to claim 1, characterized in that: The wool silk fabric grey cloth is obtained by selecting 150G circular knitted sweat cloth of 50NM wool and 20D silk of specific specifications, mixing wool and silk in a ratio of 90:10, adopting a spinning method of silk-covered wool yarn, and weaving using special equipment under a standard wet temperature environment.

3. The wool and silk fabric uniformity dyeing process according to claim 1, characterized in that: The mild degreasing adopts a mild pre-treatment method for wool, avoiding strong alkali, strong reducing agents and high temperature.

4. The wool and silk fabric uniformity dyeing process according to claim 3, characterized in that: The mild degreasing method includes one or more of protease degreasing, baking soda weak alkali degreasing, vegetable soap degreasing, mild detergent degreasing, and ultrasonic cleaning.

5. The wool and silk fabric uniformity dyeing process according to claim 1, characterized in that: The dyeing equipment used in the dyeing stage is a down-flow overflow dyeing machine, and the bath softener BRL-30 is continuously added during the dyeing process.

6. The wool and silk fabric uniformity dyeing process according to claim 1, characterized in that: The reactive dye is a LANASOL wool-specific reactive dye, the retarding agent is sodium sulfate, and the pH buffer is one of a citric acid-sodium citrate buffer pair and an acetic acid-sodium acetate buffer pair.

7. The wool and silk fabric uniformity dyeing process according to claim 6, characterized in that: The amount of sodium sulfate added is 2-10% of the weight of the LANASOL wool-specific reactive dye.

8. The wool and silk fabric uniformity dyeing process according to claim 1, characterized in that: The washing stage includes at least two cold water rinses and one hot water rinse.

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