Whole-course continuous short-process dyeing method for loose fibers

Abstract

The invention provides a whole-course continuous short-process dyeing method for loose fibers, and belongs to the technical field of fiber dyeing. The loose fibers are firstly subjected to cotton grabbing, dust removal, lapping, padding, leaching, squeezing and drying, and energy-saving and emission-reducing short-process and complete-process dyeing of the loose fibers from natural-color raw materials to finished products is completed.

Description

Technical Field

[0001] The present application relates to a loose fiber full-process continuous short-process dyeing method, belonging to the technical field of fiber dyeing. Background Art

[0002] Colored spun yarn products are made by first dyeing loose fibers and then spinning mixed colors. Multiple fibers are mixed and spun to achieve a unique mixed color and colorful single yarn style. They can achieve a soft three-dimensional effect and texture that is difficult to achieve with natural yarn products. Its rich colors and innovative spinning technology can provide a larger design space for downstream industries and bring more personalized and fashionable clothing products. In recent years, the overall scale of my country's colored spun yarn market has grown, the market share of mid-to-high-end textiles has gradually expanded, and the consumption potential of downstream customers has been continuously explored, which also makes the market penetration rate of colored spun yarn expected to continue to rise.

[0003] The key to the production of colored spun yarn lies in the dyeing of loose fibers. Compared with the overall dyeing method of traditional white yarn or white cloth, colored spun yarn is first dyed on part of the fibers and then blended with the original color fibers. It has obvious advantages in energy conservation, emission reduction and environmental protection. At present, domestic loose fiber dyeing processing usually adopts intermittent immersion dyeing such as dye vat dyeing. After dyeing, washing, dehydration, opening, drying, packaging and other processes are completed in different equipment. Not only is the processing flow long, the dyeing cycle is long, the immersion liquid and the cold pile are intermittently separated, and continuous operation cannot be achieved throughout the process. The operation is cumbersome, and the immersion tank is small, resulting in a short contact time between the dye solution and the fiber. A longer cold pile time is required to ensure the dyeing rate and dyeing uniformity. Summary of the invention

[0004] In view of this, the present application provides a loose fiber full-continuous short-process dyeing method, which not only realizes the full-process continuous operation of loose fibers from raw materials to finished products, but also ensures the uniformity of dyeing, thereby realizing energy-saving and emission-reducing short-process dyeing of loose fibers.

[0005] Specifically, the present application is implemented through the following scheme:

[0006] The whole process of loose fiber continuous short-process dyeing is completed from natural color raw materials to finished products through cotton grabbing → dust removal → net laying → padding dyeing → rinsing → squeezing → drying.

[0007] The padding dyeing device comprises an integrally arranged immersion tank and a re-rolling car. The laid loose fibers are clamped and conveyed by a group of mesh belts. After being immersed in the immersion tank by translational reciprocating movement, the loose fibers enter the re-rolling car. Excess immersion liquid in the loose fibers is squeezed out and 100% of it is returned to the immersion tank for reuse. The squeezed loose fibers are sent to a rinsing process connected to the padding dyeing for spray cleaning.

[0008] The overall process of this application includes cotton grabbing → dust removal → web laying → pad dyeing → rinsing → squeezing → drying → packaging, realizing a new production mode of continuous dyeing of loose fibers throughout the process. It has developed key technologies such as uniform web laying technology for loose fibers, mesh belt continuous conveying system, impurity removal, and pad dyeing, realizing efficient and short process of continuous dyeing line for loose fibers, improving product quality and production efficiency, and reducing labor and energy consumption.

[0009] Further, as a preference:

[0010] The re-rolling car is connected with the immersion tank, a group of mesh belts includes an upper mesh belt and a lower mesh belt, and a plurality of rollers at different heights are arranged in the immersion tank. After the upper mesh belt and the lower mesh belt are merged by the introduction roller, they are first moved down to the bottom of the dye liquid spray pipe, and then are set on the rollers and form a serpentine route in the immersion tank. The upper mesh belt and the lower mesh belt rotate with the rollers to realize translational reciprocation in the immersion tank. After the loose fibers clamped between the two are immersed in the liquid, they are sent between the liquid squeezing rollers of the re-rolling car with the upper mesh belt and the lower mesh belt. The upper mesh belt and the lower mesh belt are separated after leaving the liquid squeezing rollers. More preferably, the connection part between the re-rolling car and the immersion tank is located below the liquid squeezing roller.

[0011] The height of one end of the mesh belt outputting the re-rolling car is higher than the height of the guide belt in the rinsing process, and the guide belt speed in the rinsing process is higher than the mesh belt speed in the dip dyeing process.

[0012] One or more heaters are arranged in the immersion tank.

[0013] The rinsing process includes multiple washing units. The blanket-like loose fibers after pad dyeing are clamped and moved forward to the first washing unit of the spraying process by a high-throughput guide belt. The washing water is sprayed on the blanket-like fiber net from top to bottom. The loose fibers are first rinsed with the washing water, then squeezed, and then enter the next washing unit to repeat the rinsing and squeezing. More preferably, each washing unit is equipped with a fiber recovery device, and the collected fibers are sent to the blanket-like fibers through a micro-transport curtain and re-enter the rinsing process.

[0014] The padding and dyeing process and the spraying process are double mesh belt clamping and conveying, and the remaining processes and the loose fiber conveying between adjacent processes are all single mesh belt conveying. The double mesh belt clamping and conveying and the single mesh belt conveying realize the full-process continuous mesh belt conveying of the loose fibers.

[0015] Compared with the prior art, the beneficial effects of this application are summarized as follows:

[0016] (1) The dyeing method of the present application is mainly divided into seven steps, namely, cotton grabbing, dust removal, web laying, pad dyeing, rinsing, squeezing, and drying. The loose fibers are continuously transported by a mesh belt to achieve the continuous operation of dyeing. The entire dyeing process does not need to be interrupted and can be completed continuously in one line. The dyeing process omits the necessary steps of rolling, cold stacking, unwinding, etc. in the disclosed technology, simplifies the process flow, saves energy consumption and floor space.

[0017] (2) Dyeing adopts padding dyeing, equipped with a double mesh belt structure and multiple groups of rollers with different heights. The mesh belt is set on the roller to form a serpentine reciprocating path in the immersion tank. The power source (such as a motor) of the roller is started, and the roller rotates, driving the mesh belt to move accordingly, ensuring that the loose fibers can stay in the immersion tank for a relatively long time, and can maintain the loose fibers under the clamping of the mesh belt to continuously move back and forth in a horizontal manner, ensuring the uniformity of dyeing, and greatly saving the length and floor space of the assembly line. The heavy padding car is connected to the immersion tank and is set in an integrated manner, so that 100% of the dye treatment liquid rolled out can be returned to the immersion tank for reuse.

[0018] Compared with the conventional dyeing method in dyeing vats, the present application realizes continuous dyeing of the entire process from raw materials to finished products, eliminating the steps of pad dyeing, winding, cold stacking, unwinding, etc., uses less dye, and the dyeing is more uniform. In addition, no auxiliary dyeing agent needs to be added during the dyeing process, and no additional heat source needs to be provided for heating. The processing procedure is simplified, the intensity of washing and drying in post-processing is reduced, and the water consumption, energy consumption, steam and production costs are greatly reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic diagram of the dyeing process of this application;

[0021] Figure 2 It is a structural schematic diagram of the pad dyeing process in this application;

[0022] Figure 3 It is a structural schematic diagram of the impurity removal process in this application;

[0023] Figure 4 Another structural schematic diagram of the impurity removal process in this application;

[0024] Figure 5 It is a structural schematic diagram of the elution process in this application;

[0025] Figure 6This is a comparison chart of the color difference ΔE of different viscose fiber samples;

[0026] Figure 7 The following are the physical pictures of different viscose fiber samples;

[0027] Figure 8 This is a comparison chart of the fiber surface morphology after drying different viscose fibers;

[0028] Fig. 9 This is a comparison chart of energy consumption between the dyeing method of the present application and the conventional dyeing method.

[0029] Numbers in the figure: 1. Forward feeding roller; 2. Guide belt; 3. Upper guide belt; 4. Water squeeze roller; 5. Lower mesh belt; 6. Upper mesh belt; 7. Introducing roller; 8. Dye solution spray pipe; 9. Support roller; 10. Re-roller; 11. Squeeze roller; 12. Heater; 13. Lower guide belt; 14. Guide roller; 15. Cover plate; 16a. Conveyor belt; 16b. Taker-in roller; 17a. Nailed conveyor curtain; 17b. Cylinder; 18a. Cotton stripping beater; 18b. Movable cover plate; 19a. Cotton opening beater; 19b. Doffer. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer, the technical solutions in the embodiments of this application will be further described in detail below in conjunction with the drawings in the embodiments of this application. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit the technical solutions of this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] Example 1

[0032] The present application provides a method for dyeing loose fibers in a continuous short process. Figure 1 The loose fibers are successively subjected to cotton picking, dust removal, web laying, pad dyeing, leaching, squeezing, drying and packaging, completing the whole continuous short process dyeing of loose fibers from natural raw materials to finished products. Among them:

[0033] Combination Figure 2The stable blanket-like cotton web obtained in the web laying process is sent to the lower mesh belt 5 of the padding dyeing process through the combing mesh belt (single mesh belt structure). The device used in the padding dyeing process includes the lower mesh belt 5, the upper mesh belt 6, the immersion tank and the re-rolling car 10 and other components that are integrally arranged. A group of mesh belts, namely the upper mesh belt 6 and the lower mesh belt 5, are driven to rotate by different driving rollers respectively. An introduction roller 7 is arranged near the entrance of the immersion tank, and a dye liquid spray pipe 8 is arranged behind the introduction roller 7 (i.e., at an inner position). Several rows of rollers 9 are arranged at different heights in the immersion tank, and at least one group of heaters 12 is arranged at the bottom of the immersion tank; the re-rolling car 10 is located on the side of the immersion tank outlet and is connected to the immersion tank. A pair of squeezing rollers 11 are arranged in the re-rolling car 10.

[0034] The upper belt 6 and the lower belt 5 meet at the inlet roller 7, and first move down to the bottom of the dye spray pipe 8 to spray the dye for pre-wetting, and then put on the uppermost roller 13, and then put on the lower layers in turn, so as to form a liquid immersion tank. Figure 3 When the upper web belt 6 and the lower web belt 5 rotate with the roller 13 and realize translational reciprocation in the immersion tank, the loose fibers clamped between the two are contacted with the dye solution in the immersion tank and are immersed in the dye solution. The upper web belt 6 and the lower web belt 5 are sent to the liquid squeezing rollers 11 together to complete the squeezing. Since the re-squeezing car 10 and the immersion tank are an integrated structure and are interconnected, the excess immersion in the loose fibers is squeezed out and 100% of it is returned to the immersion tank for reuse. The upper web belt 6 and the lower web belt 5 leave the squeezing roller 11 and separate. The squeezing-finished loose fibers are taken out of the immersion and dyeing process by the lower web belt 5 and enter the lower guide belt 13 of the spraying process.

[0035] The padding dyeing is equipped with a double mesh belt structure and multiple groups of rollers 13 with different heights. The upper mesh belt 6 and the lower mesh belt 5 are mounted on the rollers 13 to form a serpentine reciprocating path in the immersion tank. The power source (such as a motor) of the rollers 13 is started, and the rollers 13 rotate, driving the upper mesh belt 6 and the lower mesh belt 5 to move accordingly, ensuring that the loose fibers can stay in the immersion tank for a relatively long time, greatly saving the length and floor space of the assembly line; and maintaining the loose fibers to continuously move back and forth in a horizontal manner under the clamping of the upper mesh belt 6 and the lower mesh belt 5, ensuring the uniformity of dyeing. The heavy padding car 10 is connected to the immersion tank and is integrally arranged to ensure that 100% of the dye treatment liquid rolled out can be returned to the immersion tank for reuse.

[0036] The implementation device of the spraying process is as follows Figure 5As shown: it mainly includes a lower guide belt 13, an upper guide belt 3 and multiple groups of squeezing rollers 4. The head of the lower guide belt 13 is close to the tail of the lower mesh belt 5, and the lower mesh belt 5 is at a high position relative to the lower guide belt 13. At the same time, the speed of the lower guide belt 13 is faster than that of the lower mesh belt 5, so that the loose fibers can fall smoothly and naturally on the lower guide belt 13. The upper guide belt 3 is arranged in coordination with the lower guide belt 13, and the squeezing roller 4 and a spray mechanism such as a spray head and other components (conventional structure, not shown in the figure) are also arranged in coordination with the upper guide belt 3 and the lower guide belt 13. The cleaning water is sprayed by the spray head on the loose fibers passing under the spray head. After the loose fibers are rinsed, they are squeezed out by the squeezing roller 4.

[0037] In this scheme, the rinsing process includes multiple washing units. The blanket-like loose fibers after dip-dyeing are clamped by the high-throughput upper guide belt 3 and the lower guide belt 13 and move forward to the first washing unit. After rinsing and squeezing, they enter the next washing unit to repeat rinsing and squeezing.

[0038] During the application process, each washing unit can be equipped with a fiber recovery device, and the collected fibers are sent to the blanket-like fibers through a micro-conveyor curtain and re-enter the washing process.

[0039] The pad dyeing process and the spraying process are both double mesh belt clamping and conveying, and the remaining processes and the loose fiber conveying between adjacent processes are all single mesh belt conveying. Double mesh belt clamping and conveying and single mesh belt conveying realize the full-process continuous mesh belt conveying of loose fibers. Each set of double mesh belt clamping and conveying units is equipped with two pairs of powered rollers and several unpowered rollers according to different lengths to support the upper and lower mesh belts to clamp the fiber web and move forward; at the same time, it is equipped with a mesh belt tension regulator and a deviation correction mechanism to ensure the appropriate tension and the mesh belt is always centered. Among them, the mesh belt structure includes two types: one uses felt as the mesh belt material, which is used for transportation in heavy rolling links, such as dip-dyeing, leaching, and squeezing processes. Because the felt has high strength and good elasticity, it has certain flexibility and permeability, which can not only ensure that the loose fibers pass through the rolling car smoothly, but also withstand a pressure of about 100 tons, and ensure that the moisture content of the fibers after rolling is controlled below 130%, meeting the process requirements; the other uses a mesh belt woven with high-strength engineering fibers such as high-strength polyester industrial yarn to ensure that the fibers fully absorb and discharge the working fluid, and the mesh belt life exceeds 6000h.

[0040] When viscose is used as loose fiber for dyeing, some viscose fiber samples are taken out at different process positions to test various structures and properties. The samples are shown in Table 1.

[0041] Table 1: Naming table of different viscose fiber samples

[0042]

[0043] Figure 6This is a comparison chart of the color difference ΔE of different viscose fiber samples. It can be seen that there are large differences in the color difference of different viscose fiber samples. The color difference ΔE of sample 1# is as high as 2.16, indicating that after only a single online dipping and padding, the dye has not been evenly penetrated in the fiber web, and the dye adsorption at different positions is quite different, resulting in large color difference.

[0044] Figure 7 The following are pictures of different viscose fiber samples. The observation results show that after the viscose fiber adsorbed the dye solution and fixed the color, the dye solution slowly flowed in the fiber (it can cooperate with gravity and rotating centrifugal force, such as rotating fixation) and was evenly distributed, so that the uniformity of fiber adsorption of dye solution at different positions was improved, and the color difference ΔE decreased, but there was also a large difference between the ΔE value without fixation. After repeated and extensive tests, the 24h fixation time can basically meet the requirements of level dyeing. After further elution and drying, the unreacted dye and hydrolyzed dye on the fiber surface were washed off, and the color difference of the above 3# and 4# samples was further reduced. The ΔE of the samples after 24h of fixation dropped to below 0.5, which has a certain degree of dyeing uniformity.

[0045] Table 2: Mechanical properties of different viscose fiber samples

[0046]

[0047] Table 2 shows the changes in mechanical properties such as breaking strength and breaking elongation of different viscose fiber samples. It can be seen from Table 2 that after a series of immersion dyeing and leaching, the breaking strength and breaking elongation of viscose fibers decreased slightly under the action of dyes and mechanical forces, among which the breaking strength decreased from (2.70±0.35) cN / dtex to (2.26±0.38) cN / dtex, a decrease of about 16%. The breaking elongation decreased from (16.45±2.20)% to (13.65±2.57)%, a decrease of about 17%. Although the breaking strength has decreased, it still meets the standards for cotton-type viscose staple fiber superior products in the FZ / T 52061-2021 "Dyed Viscose Staple Fiber" standard formulated by our unit.

[0048] Table 3: Physical indicators of dyed viscose fibers after elution (4#-48)

[0049]

[0050]

[0051] As can be seen from Table 3, the color fastness of dyed viscose fiber, such as alkali resistance, acid sweat color fastness, water fastness, wet and dry color fastness, rubbing color fastness, soaping color fastness and light color fastness, all reach level 4 or above, meeting the requirements of corresponding national standards.

[0052] Figure 8 This is a comparison chart of the surface morphology of different viscose fibers after drying. Figure 8 It can be seen that the surface of the untreated viscose fiber (a) is smooth and free of foreign matter, showing the typical groove structure of viscose fiber. After pad dyeing, a small amount of particles are attached to the fiber surface, such as (b), (c), and (d). The particles may be formed by the recrystallization of the dye after the dye solution is dried. After elution and drying, the particles on the fiber surface are removed and the fiber is basically restored to a smooth state, such as (e) and (f).

[0053] In terms of cost, combined Fig. 9 It can be seen that compared with the conventional dyeing method, the dyeing method of the present application completes the whole process from raw materials to finished products, eliminating the steps of rolling dyeing, rolling, cold stacking, unwinding, etc. in the disclosed technology. On the basis of achieving salt-free treatment (the amount of sodium sulfate is 0), the process is further shortened, the amount of dye is reduced (from the conventional 50kg / ton of loose fiber to 25kg / ton of loose fiber), the dyeing is more uniform, and no auxiliary dye is added during the dyeing process, and no additional heat source is provided for heating. The processing procedures are simplified, the intensity of leaching and drying in post-treatment is reduced, and the water consumption, energy consumption and production costs are greatly reduced. The water consumption per ton of loose fiber is about 6 tons, which is more than 80% lower than that of conventional dyeing methods; the steam consumption is reduced by about 40% compared with conventional methods, which greatly saves energy and water consumption and significantly improves the effectiveness. Compared with the traditional pad dyeing machine, reciprocating dyeing shortens the length, saves space, saves steam, and saves energy.

[0054] In the above scheme, for the impurity removal process, the following method can be used: Figure 3 The structure shown is completed, and it can also be Figure 4 The structure shown is completed.

[0055] When using Figure 3 In the structure shown in the figure, the loose fibers fed into the cotton grasping process are fed into the impurity removing process: the loose fibers fall onto the conveyor belt 16a and are fed to the conveying curtain 17a with nails for fine opening and impurity removal. The cotton stripping beaters 18a and the cotton opening beaters 19a are respectively arranged before and after the conveying curtain 17a with nails. The cotton stripping beaters 18a strip off the excess accumulated loose fibers on the conveying curtain 17a with nails to ensure the uniform supply of the loose fibers on the conveying curtain 17a with nails; the conveying curtain 17a with nails and the cotton opening beaters 19a perform fine opening on the loose fibers. In this process, impurities in the loose fibers are removed, and the loose fibers are opened into small and uniform pieces of smaller size. The loose fibers processed by the cotton stripping beaters 18a, the conveying curtain 17a with nails and the cotton opening beaters 19a are fed into the subsequent web laying process.

[0056] When using Figure 4In the structure shown, the impurity removal process includes three combing steps: the loose fibers are first introduced into a pair of licker-in rollers 16b through the combing fan and the forward feeding roller 1 to complete the first combing step, then the second combing step is completed through the cooperation of the cylinder 17b and the movable cover plate 18b, and finally the third combing step is completed through the doffer 19b. Then it is sent to the web laying process by the guide belt 2. The above structure can realize the impurity removal combing of viscose or raw cotton loose fibers containing 2% or more impurities. Among them, the movable cover plate 18b is located above the cylinder 17a, and is maintained in an arc shape around the upper part of the cylinder 17b by multiple guide rollers 14; a fixed cover plate 15 is set below the cylinder 17b.

[0057] The above-mentioned embodiments only express several feasible implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention, and the embodiments are not used to limit the scope of protection in the claims of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and all equivalent implementations or changes that do not depart from the present invention should be included in the technology of the present invention.

Claims

1. A loose fiber full-process continuous short-process dyeing method, characterized in that: The loose fibers are dyed in a continuous short process from natural raw materials to finished products through cotton grabbing, dust removal, web laying, padding, dyeing, rinsing, squeezing, and drying. The padding dyeing device includes an integral immersion tank and a re-rolling car. The laid loose fibers are clamped and conveyed by a group of mesh belts. After being immersed in the immersion tank by translational reciprocating movement, the loose fibers enter the re-rolling car. Excess immersion liquid in the loose fibers is squeezed out and all flows back to the immersion tank for reuse. The squeezed loose fibers are sent to a rinsing process connected to the padding dyeing for spray cleaning.

2. The method for dyeing loose fibers in a continuous short process according to claim 1, characterized in that: The re-rolling car is connected with the immersion tank, a group of mesh belts includes an upper mesh belt and a lower mesh belt, and a plurality of groups of rollers at different heights are arranged in the immersion tank. After the upper mesh belt and the lower mesh belt are merged by the introduction roller, they are first moved down to the bottom of the dye liquid spray pipe, and then put on the roller and form a serpentine route in the immersion tank. The upper mesh belt and the lower mesh belt rotate with the roller to realize translational reciprocating in the immersion tank. After the loose fibers clamped between the two are immersed in the liquid, they are sent into the liquid squeezing rollers of the re-rolling car along with the upper mesh belt and the lower mesh belt. The upper mesh belt and the lower mesh belt are separated after leaving the liquid squeezing rollers.

3. The method for dyeing loose fibers in a continuous short process according to claim 2, characterized in that: The communicating part between the re-rolling car and the immersion tank is located below the squeezing roller.

4. The method for dyeing loose fibers in a continuous short process according to claim 1, characterized in that: The height of one end of the mesh belt outputting the re-rolling car is higher than the height of the guide belt in the rinsing process, and the guide belt speed in the rinsing process is higher than the mesh belt speed in the dip dyeing process.

5. The method for dyeing loose fibers in a continuous short process according to claim 1, characterized in that: One or more heaters are arranged in the immersion tank.

6. The method for dyeing loose fibers in a continuous short process according to claim 1, characterized in that: The rinsing process includes multiple washing units. The blanket-like loose fibers after padding and dyeing are clamped and moved forward to the first washing unit of the spraying process by a high-throughput guide belt. The washing water is sprayed on the blanket-like fiber web from top to bottom. The loose fibers are first rinsed with the washing water and then squeezed. Then, they enter the next washing unit to repeat the rinsing and squeezing.

7. The method for dyeing loose fibers in a continuous short process according to claim 6, characterized in that: Each washing unit is equipped with a fiber recovery device. The collected fibers are sent onto the blanket-like fibers through a micro-conveyor curtain and re-enter the washing process.

8. The method for dyeing bulk fibers in a continuous short-process according to any one of claims 1 to 7, characterized in that: The padding and dyeing process and the spraying process use double mesh belt clamping and conveying, and the remaining processes and the loose fiber conveying between adjacent processes are all single mesh belt conveying. The double mesh belt clamping and conveying and the single mesh belt conveying realize the full-process continuous mesh belt conveying of the loose fibers.

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