Method for reducing damage by reactive deep dyeing of cashmere strip wool

Abstract

The invention provides a method for reducing damage by reactive deep dyeing of cashmere strip wool, and belongs to the technical field of dyeing processes. The method comprises the following steps: firstly, in a cylinder loading link, padding screen cloth with specific specifications between a material and a dyeing core and between the material and a dyeing cage; the impact of double-circulation back-and-forth penetration of the dye liquor on the cashmere is relieved, and meanwhile felt merging is avoided. On the basis, the circulation mode and flow of dye liquor are controlled in the dyeing process; damage to fibers in the dyeing process is relieved in a low-flow and small-circulation dyeing mode, meanwhile, cashmere is continuously shifted, and therefore dye liquor evenly permeates. In addition, the acid-base change in the post-treatment process of the dye liquor is gradually adjusted, damage caused by too fast pH change is reduced, and meanwhile the fastness of the dyed cashmere is improved. The dyeing damage of the cashmere strips is obviously reduced, meanwhile, the physical and chemical indexes are not reduced, the subsequent carding and yarn production efficiency is improved, and meanwhile, the stability of the finishing process and the taking process is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of dyeing technology, and in particular relates to a method for reducing damage to cashmere strips by active dyeing of dark colors. Background Art

[0002] Cashmere strips are inevitably damaged in the dyeing process due to the fiber structure and fineness of the raw material itself, and the frequent impact of long-term high-speed liquid flow causes fiber entanglement and even felting. The direct manifestation is the reduction of fiber strength and fiber elasticity, especially for dark colors that take a long time to dye, which has a greater impact. It is impossible to completely avoid damage to cashmere strips during the dyeing process, but it is possible to reduce fiber damage as much as possible.

[0003] The existing technologies mainly reduce fiber damage by carrying out relevant physical and chemical protection on cashmere fibers, optimizing dyes and chemicals, optimizing dyeing processes (such as reducing dyeing time, lowering dyeing temperature, using chemicals to prevent harmful chemical reactions, etc.), and using automation and machinery. Although the existing cashmere strip low-damage dyeing technology can reduce fiber damage during the dyeing process to a certain extent, the effect is not obvious, and it often leads to a decline in physical and chemical indicators, at the expense of certain indicators. Summary of the invention

[0004] The first technical problem to be solved by the present invention is: how to reduce the dyeing damage of cashmere strips without losing physical and chemical indicators.

[0005] The second technical problem to be solved by the present invention is that the conventional method has an insignificant effect on alleviating the dyeing damage of cashmere strips.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: A method for reducing damage to cashmere strips by active dyeing to a dark color, comprising: 1) Before loading the material to be dyed into the dyeing vat, a layer of polyester mesh with a mesh size of 2 mm is placed between the inner dye core and the material, and a layer of polyester mesh with a mesh size of 3 mm is placed between the material and the outer dyeing cage; 2) In the dyeing process, the method first drives the dye liquid to penetrate from the core of the dye vat to the outer layer for 2 minutes, then drives the dye liquid to penetrate from the outside to the core of the dye vat for 5 minutes, and then drives the dye liquid to penetrate from the core of the dye vat to the outer layer for 2 minutes, which is a cycle; several cycles are performed; during the execution, the dye liquid flow rate is controlled at 8-10 L / kg∙min; 3) During the color fixing process, this method goes through the following nodes A, B, C, D, and E in sequence: Add a leveling agent to the A node and adjust the pH to 4.0-5.5 with formic acid; Adding dye to the B node; At the C node, the pH is adjusted to 6.5-7.5 with aqueous ammonia; At the D node, adjust the pH to 8-8.5 with aqueous ammonia; At the E node, the pH is adjusted to 6-6.5 with formic acid.

[0007] Preferably, the material is cashmere strips.

[0008] Preferably, the material is a hollow cashmere ball pre-wound by cashmere strips.

[0009] Preferably, the hollow cashmere ball is in a rope shape.

[0010] Preferably, the diameter of the flower tube on the inner dye core is 4 mm; the diameter of the flower tube on the outer dye cage is 4 mm.

[0011] Preferably, the mesh is in the shape of a bag.

[0012] Preferably, in the method, the cylinder loading process is implemented by a cylinder loading machine; the dyeing process is implemented by a dyeing machine; and the execution process is implemented on the dyeing machine by industrial control.

[0013] Preferably, the dye is a reactive dye for wool; and the leveling agent is a low-temperature dyeing accelerator.

[0014] Preferably, the reactive dye for wool is a dye produced by Hunstman Company with the trade name of LANASOL CE; the low-temperature dyeing accelerator is a low-temperature auxiliary agent produced by Hunstman Company with the trade name of LTD.

[0015] As a preference: The temperature from node A to node B is kept at 50°C for 5 minutes; The path from node B to node C is divided into four sections: the first section is a constant temperature section, where the temperature is maintained at 50°C for 5 minutes; the second section is a temperature rise section, where the temperature rise rate is 1°C / min, and the start and end temperatures of this section are 50°C and 90°C respectively; the third section is a constant temperature section, where the temperature is maintained at 90°C for 60-90 minutes; the fourth section is a temperature drop section, where the start and end temperatures of this section are 90°C and 80°C respectively, and the duration is 10 minutes; The path from node C to node D is divided into two sections: the first section is a constant temperature section, where the temperature is maintained at 80°C for 20 minutes; the second section is a cooling section, where the starting and ending temperatures are 80°C and 50°C respectively, and the duration is 10 minutes; The distance from node D to node E is divided into three sections: the first section is the temperature rise section, with the starting and ending temperatures of 50°C and 80°C respectively, and the duration is 15 minutes; the second section is the constant temperature section, with the temperature maintained at 80°C, and the duration is 20 minutes; the third section is the temperature drop section, with the starting and ending temperatures of 80°C and 50°C respectively, and the duration is 10 minutes; The E node is then kept at 40°C for 20 minutes.

[0016] The present invention provides a method for reducing damage to cashmere strips by active dyeing of dark colors. The technical solution has made innovative improvements in terms of the cylinder loading method, the circulation method and flow control of the dye solution, and the dyeing technology of adjusting the low-temperature buffered pH dye solution. On this basis, the physical and chemical indexes of the cashmere strips after dyeing are tested, which fully confirms the technical effect. The present invention significantly reduces the dyeing damage of the cashmere strips while the physical and chemical indexes do not decrease, improves the efficiency of the subsequent combing and yarn production, and ensures the stability of the finishing process and the wearing process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the cylinder mounting structure of the present invention.

[0018] Figure 2 It is a process curve diagram of the dyeing process of the present invention.

[0019] Figure 3 This is a physical picture of dyed foot water in a specific embodiment of the present invention.

[0020] Figure 4 This is a real picture of the dyed foot water after being diluted 10 times in a specific embodiment of the present invention.

[0021] Figure 5 It is a color fastness test record diagram in a specific implementation manner of the present invention.

[0022] In the figure: 1. Inner dyeing cylinder honeycomb tube 2. Inner polyester mesh cloth 3. Cashmere balls 4. Outer polyester mesh cloth 5. Dyeing cage. DETAILED DESCRIPTION

[0023] The specific embodiments of the present invention will be described in detail below. In order to avoid too much unnecessary details, the well-known structures or functions will not be described in detail in the following examples. The approximate language used in the following examples can be used for quantitative expression, indicating that the quantity can be allowed to have a certain change without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following examples have the same meaning as those generally understood by those skilled in the art to which the present invention belongs.

[0024] A method for reducing damage to cashmere strips by active dyeing of dark colors: 1. Double bag cashmere filling technology: Before the cashmere strips are made into rope-shaped hollow cashmere balls and loaded into the dye core, a polyester mesh is used to form a layer of separation between the inner dye core and the cashmere ball, and between the cashmere ball and the outer dye cage to slow down the impact of the double circulation of dye on the cashmere and avoid the formation of felting. Figure 1 shown.

[0025] The bag material is made of polyethylene terephthalate fiber, that is, polyester, so that the cashmere balls will not be stained by dye. The diameter of the flower tube on the inner dye core is 4mm, and the diameter of the flower tube on the outer dye cage is also 4mm. In order to ensure that the dye can slowly and evenly penetrate the cashmere balls, the diameter of the bag mesh close to the dye core is selected to be 2mm, and the diameter of the bag mesh close to the dye cage is selected to be 3mm.

[0026] 2. Low-flow and small-circulation dyeing method: Put the cashmere balls loaded into the dyeing cage into the dyeing tank, and adopt the double circulation method of inside → outside → inside, with a time of 2min → 5min → 2min, and the dyeing liquid flow rate is controlled at 8-10 L / (kg∙min).

[0027] Adopting the double circulation method of inside → outside → inside, the dye liquid flows from inside to outside at the beginning, the dye liquid penetrates from the core to the outer layer, and the cashmere is squeezed from the inner layer to the outer layer, and it lasts for a set time, and then the valve is switched, the dye liquid is switched to outside to inside, that is, the cashmere penetrates from the outer layer to the inner layer, and the inner layer cashmere is squeezed, and it lasts for a set time, and then the valve is switched to inside to outside, and the cycle repeats. Each cashmere is constantly changing position, so that the dye liquid penetrates evenly.

[0028] The above process is realized by cylinder loading equipment and dyeing equipment. In this embodiment, the cylinder loading machine uses the cylinder loading machine of model WXT3-2 produced by Wuxi Satellite Company; the dyeing machine uses the dyeing machine of model Eco-Bloc-X produced by This Company of Germany. In terms of operation, in the process editing module of the computer terminal, select the cycle mode "inside and outside", and enter the corresponding time as 2 / 5 / 2, then put the cashmere ball loaded with the dye core into the dyeing cylinder, cover the cylinder cover and call out the edited process, and it will run according to the set parameters.

[0029] 3. pH adjustment technology of buffered dye solution in the color fixing process: select the above circulation mode and flow rate, select wool reactive dyes and corresponding low-temperature dyeing accelerators, and gradually adjust the pH value of the dye solution during the post-treatment process to reduce the damage caused by rapid changes in pH, while improving the fastness of dyed cashmere. Figure 2 As shown. Among them: A: Leveling agent 2%, formic acid to adjust pH 4.0-5.5; B: dye; C: Ammonia water to adjust pH 6.5-7.5; D: Ammonia water to adjust pH 8-8.5; E: Formic acid adjusts pH to 6-6.5.

[0030] Among them, reactive dyes for wool can use Hunstman's LANASOL CE series dyes; leveling agents can use Hunstman's low-temperature auxiliary agent LTD.

[0031] The specific operation process of this method is as follows: Double bagging cylinder: Before loading, check that the inner dyeing honeycomb tube is not bent, deformed or blocked, and put the specified inner polyester mesh cloth (2mm in diameter) on the dye core as the inner bag. Handle the cashmere balls gently in the raw material warehouse to prevent the rope from falling off. After unpacking the cashmere balls from the original plastic bag, put them into the bagged inner dyeing honeycomb tube through the bullet head of the cylinder, and control the height of the cashmere balls by moving the piston rod of the ball press up and down. Then use the outer polyester mesh cloth (3mm in diameter) as the outer bag to wrap the entire cashmere ball from top to bottom and tie the mouth, and finally put it into the dyeing cage to form a multi-layer protection for the cashmere.

[0032] Low-damage dyeing: According to the above process curve, edit the improved process on the computer terminal, and pay attention to modifying the individual parameters of the traditional dyeing process module, that is, switch the traditional single cycle of dye liquid to double cycle, select the cycle mode "inside and outside", and enter the corresponding time as 2 / 5 / 2. In the subsequent color fixation link, the process curve has also been improved accordingly. The traditional one-time addition of soda ash to adjust the pH to 8-8.5 has been improved to adding ammonia water twice to adjust the pH to 8-8.5.

[0033] Drying: After the dyeing process is completed, the cotton wool will enter the re-washing and drying process, using a low speed and low temperature method to meet the moisture regain requirements and finally enter the next combing process.

[0034] The technical effects of the present invention are investigated as follows: 1. Color difference between inside and outside of dyeing As shown in Table 1 below: Table 1 Results of color difference detection inside and outside dyeing

[0035] Note: Standard sample 1 is a cashmere strip dyed close to the inner bag, and sample 1 is a cashmere strip dyed close to the outer bag. The color difference between the two is not large, indicating that the dye solution penetrates evenly.

[0036] 2. Foot water after dyeing (1) Sampling foot water The status of the sampled foot water is as follows Figure 3 shown.

[0037] The pH value during feeding operation is 4.15 → pH value at the end of insulation is 4.45 → pH value during the first alkali treatment is 6.55 → pH value during the second alkali treatment is 8.15 → pH value of the hair balls out of the tank is 6.53.

[0038] (2) Foot water diluted 10 times In order to better reflect the coloring rate, dilute the above foot water 10 times before taking pictures. Figure 4 As shown in the figure, the dye uptake rate is high, the foot water is clear, and the dyeing effect is achieved.

[0039] 3. Fastness According to GB / T 251-2008 “Grey Scale for Assessing Staining of Textiles - Tests for Colour Fastness”, the staining of the rubbing cloth is rated as 4-5 for dry rubbing and 4 for wet rubbing.

[0040] Fastness test results are as follows Figure 5 As shown in the figure, the dry and wet rubbing fastnesses meet the requirements.

[0041] 4. Alkali solubility of fiber The solubility of cashmere in alkali under different dyeing processes was investigated. The results are shown in Table 2 below.

[0042] Table 2 Analysis results of solubility in cashmere alkali of different dyeing processes

[0043] Note 1: The applicable standards for the determination method: GB / T601 Preparation of standard titrant for chemical reagents; GB / T6682 Specifications and test methods for water for analytical experiments (neqGB / T6682-1992, ISO3696:1987); GB / T7570 Determination of acid content in wool (GB / T7570-2008, ISO3073:1975, MOD); GB / T 8170 Numerical rounding rules.

[0044] Note 2: The experiment adopts parallel experiment, and the cashmere raw materials are from the same batch. The solubility value of white cashmere raw materials in alkali before dyeing is 7.482%. The drying is carried out for the same batch. The test data can accurately reflect the loss degree of cashmere in the dyeing process of the same color.

[0045] Note 3: K8001 to K8005 indicate the degree of deep black (dye dosage is 5%, 5.5%, 6%, 6.5%, 7% respectively).

[0046] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for reducing damage to cashmere strips by active dyeing of dark colors, characterized in that: include: 1) Before loading the material to be dyed into the dyeing vat, a layer of polyester mesh with a mesh size of 2 mm is placed between the inner dye core and the material, and a layer of polyester mesh with a mesh size of 3 mm is placed between the material and the outer dyeing cage; 2) In the dyeing process, the method first drives the dye liquid to penetrate from the core of the dye vat to the outer layer for 2 minutes, then drives the dye liquid to penetrate from the outside to the core of the dye vat for 5 minutes, and then drives the dye liquid to penetrate from the core of the dye vat to the outer layer for 2 minutes, which is a cycle; several cycles are performed; during the execution, the dye liquid flow rate is controlled at 8-10 L / kg∙min; 3) During the color fixing process, this method goes through the following nodes A, B, C, D, and E in sequence: Add a leveling agent to the A node and adjust the pH to 4.0-5.5 with formic acid; Adding dye to the B node; At the C node, the pH is adjusted to 6.5-7.5 with aqueous ammonia; At the D node, adjust the pH to 8-8.5 with aqueous ammonia; At the E node, the pH is adjusted to 6-6.5 with formic acid.

2. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 1, characterized in that: The material is cashmere strips.

3. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 1, characterized in that: The material is a hollow cashmere ball formed by winding cashmere strips in advance.

4. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 3, characterized in that: The hollow cashmere ball is in a rope shape.

5. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 1, characterized in that: The diameter of the flower tube on the inner dye core is 4 mm; the diameter of the flower tube on the outer dye cage is 4 mm.

6. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 1, characterized in that: The mesh cloth is in a bag shape.

7. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 1, characterized in that: In the method, the cylinder loading process is realized by a cylinder loading machine; the dyeing process is realized by a dyeing machine; and the execution process is realized on the dyeing machine by industrial control.

8. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 1, characterized in that: The dye is a reactive dye for wool; and the leveling agent is a low-temperature dyeing accelerator.

9. A method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 8, characterized in that: The reactive dye for wool is a dye produced by Hunstman Company with the trade name of LANASOL CE; the low-temperature dyeing accelerator is a low-temperature auxiliary agent produced by Hunstman Company with the trade name of LTD.

10. The method for reducing damage to cashmere strips by active dyeing of dark colors according to claim 1, characterized in that: The temperature from node A to node B is kept at 50°C for 5 minutes; The path from node B to node C is divided into four sections: the first section is a constant temperature section, where the temperature is maintained at 50°C for 5 minutes; the second section is a temperature rise section, where the temperature rise rate is 1°C / min, and the start and end temperatures of this section are 50°C and 90°C respectively; the third section is a constant temperature section, where the temperature is maintained at 90°C for 60-90 minutes; the fourth section is a temperature drop section, where the start and end temperatures of this section are 90°C and 80°C respectively, and the duration is 10 minutes; The path from node C to node D is divided into two sections: the first section is a constant temperature section, where the temperature is maintained at 80°C for 20 minutes; the second section is a cooling section, where the starting and ending temperatures are 80°C and 50°C respectively, and the duration is 10 minutes; The distance from node D to node E is divided into three sections: the first section is the temperature rise section, with the starting and ending temperatures of 50°C and 80°C respectively, and the duration is 15 minutes; the second section is the constant temperature section, with the temperature maintained at 80°C and the duration is 20 minutes; the third section is the temperature drop section, with the starting and ending temperatures of 80°C and 50°C respectively, and the duration is 10 minutes; The E node is then kept at 40°C for 20 minutes.

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