An antibacterial and flame-retardant yak wool yarn and its production method

Abstract

This invention discloses an antibacterial and flame-retardant yak wool yarn and its production method. The production steps are as follows: pretreatment; decolorization: the pretreated raw yak wool fibers are sequentially subjected to pre-mortar treatment, oxidative bleaching, and reduction bleaching to obtain white fibers; combing sliver; first comb: the combed sliver is processed through three first combs to obtain an antibacterial and flame-retardant combed sliver, wherein in the second first comb, ultraviolet light irradiation pretreatment is performed in the back drafting zone, and antibacterial liquid spraying treatment is performed in the front drafting zone; in the third first comb, flame-retardant liquid spraying treatment is performed in the drafting zone; wool combing; second comb; cotton spinning; cotton roving; cotton spinning yarn: the antibacterial and flame-retardant roving is processed through cotton spinning yarn to obtain the antibacterial and flame-retardant yak wool yarn, wherein flame-retardant liquid spraying treatment is performed between the front drafting rollers of the drafting system and the yarn guide hooks of the twisting system. The finished yarn of this invention has excellent and uniform antibacterial and flame-retardant properties.

Description

Technical Field

[0001] This invention belongs to the field of functional finishing technology of textiles, specifically relating to an antibacterial and flame-retardant yak wool yarn and its production method. Background Technology

[0002] Yak wool is a layer of fine downy hair that grows beneath the coarse hair of yaks. Because yaks live at altitudes of 3000-5000 meters, yak wool fibers possess excellent warmth retention. Compared to cashmere of the same fineness, yak wool fibers have a higher scale density, a smaller scale opening angle, and thinner scales, resulting in a softer, smoother, and less itchy feel, making them highly popular with consumers. Currently, yak wool is mainly used as a raw material to produce a range of products, including home decorations and clothing. Therefore, to further meet market demands, yak wool products undergo antibacterial and flame-retardant finishing processes.

[0003] Conventional antibacterial and flame-retardant finishing involves immersing textiles in a suitable finishing agent. However, this method can easily damage the yarn structure, reducing its softness. Furthermore, the finished yarn is not washable and has poor flame-retardant and antibacterial effects. Summary of the Invention

[0004] Technical problem solved: In view of the above-mentioned technical problem, the present invention provides an antibacterial and flame-retardant yak wool yarn and its production method. The finished yarn has excellent and uniform antibacterial and flame-retardant properties.

[0005] Technical solution: A method for producing antibacterial and flame-retardant yak wool yarn, comprising the following steps:

[0006] S1. Pretreatment: Remove impurities and foreign fibers from the original yak wool fibers;

[0007] S2. Decolorization: The pre-treated raw yak wool fibers are sequentially subjected to pre-mortar treatment, oxidative bleaching and reduction bleaching to obtain white fibers;

[0008] S3. Combing strip: White fibers are sequentially treated with oil and combing to obtain combing strips;

[0009] S4. First comb: The comb sliver is processed through three first combs to obtain antibacterial and flame-retardant comb sliver. In the second first comb, the sliver is pretreated with ultraviolet light in the back drafting zone and sprayed with antibacterial liquid in the front drafting zone. In the third first comb, the sliver is sprayed with flame-retardant liquid in the drafting zone.

[0010] S5. Wool Combing: Antibacterial and flame-retardant combed sliver is obtained by combing antibacterial and flame-retardant combed sliver.

[0011] S6. Second comb: The antibacterial and flame-retardant comb strip is processed by passing the antibacterial and flame-retardant comb strip through two second combs to obtain the antibacterial and flame-retardant comb strip;

[0012] S7. Cotton spinning and drawing: Antibacterial and flame-retardant combed sliver is obtained by cotton spinning and drawing;

[0013] S8. Cotton roving: Antibacterial and flame-retardant roving is made by spinning antibacterial and flame-retardant sliver through cotton roving.

[0014] S9. Cotton spinning: The antibacterial and flame-retardant yak wool yarn is obtained by spinning antibacterial and flame-retardant roving through cotton spinning, wherein flame-retardant liquid is sprayed between the front drafting rollers of the drafting system and the yarn guide hooks of the twisting system.

[0015] Preferably, the yak wool fiber in S1 is black yak wool fiber, purple yak wool fiber, brown yak wool fiber, green yak wool fiber, or brown yak wool fiber.

[0016] Preferably, the specific steps of the pretreatment in S1 are opening, washing, and pre-carding in sequence. Through pretreatment, the raw yak wool fibers can be loosened, and sand, impurities, and foreign fibers in the raw yak wool fibers can be removed to obtain clean raw materials.

[0017] Preferably, the pre-treatment step in S2 is as follows: Raw yak wool fibers are placed in a mixed solution of 8–16 g / L ferrous sulfate and 2–5 g / L sodium bisulfite, and heated for 30–45 minutes at a bath ratio of 1:50 and a temperature of 60°C, followed by washing. During this process, the Fe in the ferrous sulfate… 2+ It reacts with the colored pigment proteins in the original yak wool fibers to form a complex, and Fe adsorbed on the pigment proteins during the washing process... 2+ It is not easily washed off.

[0018] Preferably, the oxidative bleaching step in S2 is as follows: The pre-treated yak wool fibers are placed in a mixed solution of 20–40 g / L hydrogen peroxide and 5–8 g / L sodium pyrophosphate, the pH is adjusted to 8–8.5, and the mixture is reacted at 60°C for 60 minutes, followed by washing. During this process, when hydrogen peroxide reacts with the fibers, it preferentially complexes with a large amount of Fe... 2+ The pigment proteins are broken down, thereby destroying the pigment proteins and achieving the purpose of decolorization. (Fe) 2+ Selective bleaching promotes the destruction of pigment proteins while reducing damage to fibrous keratin, and then decomposes other pigment proteins, thereby destroying the pigment proteins and achieving fiber decolorization. After hydrogen peroxide decomposes the pigment proteins of yak wool fibers, the scale layer on the surface of yak wool fibers becomes looser.

[0019] Preferably, the reduction bleaching step in S2 is as follows: the oxidized bleached yak wool fibers are placed in a mixed solution of 6-10 g / L sodium hydrosulfite and 3-6 g / L sodium pyrophosphate, and reacted for 30 minutes in an environment with a bath ratio of 1:50, a temperature of 50°C, and a pH of 5-6, followed by washing. This process yields the desired white fibers.

[0020] Preferably, the overall oiling and wool-refining step in S3 is as follows: Based on the weight of the white fibers, add 0.5%–0.65% wool-refining oil, 0.2%–0.4% antistatic agent, and 0.5%–0.6% reinforcing agent. Control the moisture regain in the workshop at 20%–21%, and allow the equilibration time to exceed 8 hours to ensure uniform oil-water penetration. This step gives the fibers better flexibility, making them less prone to breakage under stress and reducing static electricity generated by friction in yak wool fibers.

[0021] Preferably, the combing step in S3 is set with the following conditions: feed roller speed of 1.5–3.0 r / min, cylinder speed of 90–120 r / min, doffer speed of 6–10 r / min, transfer roller speed of 110–140 r / min, and sliver weight of 5.0–8.0 g / m. This step can minimize fiber damage and breakage.

[0022] Preferably, the spraying device in S4 is located within the corresponding drawing zone and includes hollow comb needles, a rotating bearing, and a spray cylinder. The hollow comb needles are arranged alternately on the upper and lower needle plates within the drawing zone and penetrate the needle plates. One end of the hollow comb needle located between the upper and lower needle plates is connected to one end of the spray cylinder via the rotating bearing, and the other end is connected to an antibacterial liquid or a flame-retardant liquid via a pipeline. The spray cylinder is hollow inside, with one end closed, and spray holes are provided on its side along the circumference. When the spraying device rotates, the antibacterial liquid or flame-retardant liquid is ejected from the spray holes, and the spray force of the spray holes is proportional to the rotation speed of the device, thereby making the amount of liquid sprayed from the spray holes proportional to the rotation speed of the device, achieving the purpose of controlling the spray volume by utilizing the rotation speed.

[0023] Specifically, in the first pass of the first combing process, 4-6 yak wool comb slivers are fed together to produce yak wool comb slivers. These 4-6 yak wool comb slivers pass through a guide table, guide rollers, and guide bars, and then merge at the guide collection plate. This merging process mixes the individual yak wool comb slivers and effectively improves sliver unevenness. The merged yak wool comb slivers, in a roll structure, are then passed through a drafting system for drafting and combing. The drafting system includes front, middle, and rear rollers. Within the drafting zone formed by the front, middle, and rear rollers, a slowly moving row of needles is positioned, creating a relatively long intermediate control zone. The yak wool comb rolls in the drafting zone... During the drafting process, the fibers slip against each other due to the drafting force, which causes the fibers to be stretched and thinned. In this process, the needle plates of the upper and lower needle rows in the drafting zone continuously and crosswise penetrate into the fibers. As the carding sliver layer thins, the depth of the needle plates penetrating into the fibers gradually increases, thereby achieving effective control of the fiber movement in the drafting zone. As the fibers move forward in the drafting zone, the number of fibers gradually decreases, thereby continuously strengthening the control effect and achieving straightening and combing of the fibers during the drafting process. The drafted yak wool carding sliver is continuously wound into the sliver can by the sliver winding mechanism.

[0024] In the second stage of the first combing process, six yak wool comb slivers are fed together to produce antibacterial yak wool comb slivers. These six yak wool comb slivers pass through a guide platform, guide rollers, and guide bars before merging at the guide collection plate. This merging process mixes the individual yak wool comb slivers and effectively improves sliver unevenness. The merged yak wool comb slivers, in a roll structure, are then drawn and combed together by a drafting system. The drafting system includes front, middle, and rear rollers. Slow-moving needle rows are located in the drafting zone formed by the front, middle, and rear rollers. Ultraviolet (UV) emitting devices are installed on the upper and lower needle rows in the rear drafting zone between the middle and rear rollers. These UV emitting devices are evenly distributed in the gaps between the comb needles in the upper and lower needle rows of the rear drafting zone. During the drafting process in the rear drafting zone... During the process, the needle plates of the upper and lower needle rows in the back drafting zone continuously and crosswise penetrate between the yak wool fibers. Due to the penetration between the upper and lower needle rows, a certain gap is created between the fibers. Moreover, as the carding sliver layer thins, the depth of the needle plates crossing between the fibers gradually increases, and the gap between the fibers also gradually increases. At this time, the ultraviolet light emitting devices on the upper and lower needle rows simultaneously emit ultraviolet light, thereby directly generating ultraviolet light radiation on the fibers. As the yak wool fibers continue to move forward in the back drafting zone, the ultraviolet light radiation on the yak wool fibers gradually increases, thus completing the UV pretreatment process before the antibacterial finishing of the yak wool fibers. Antibacterial liquid spraying devices are respectively installed on the upper and lower needle rows in the front drafting zone between the middle and front rollers. During the drafting process in the pre-drafting zone, the needle plates of the upper and lower needle rows in the pre-drafting zone continuously and crosswise penetrate between the yak wool fibers. Due to the movement of the yak wool fibers in the pre-drafting zone, the sprayed antibacterial liquid is directly sprayed onto the surface of the yak wool fibers. Due to the rotation of the device, the antibacterial liquid is sprayed onto the yak wool fibers at a certain angle and force, thereby achieving uniform spraying. At this time, because the surface scale layer of the fiber after the decolorization treatment is loose, the antibacterial liquid continuously penetrates into the interior of the fiber under the action of the spraying force, thereby achieving antibacterial finishing of the yak wool fibers in the fiber state. As the combing sliver layer thins, the depth of the needle plates crossing between the fibers gradually increases, and the rotation speed of the device also increases accordingly, thereby gradually enhancing the antibacterial finishing of the yak wool fibers, thus completing the antibacterial finishing process of the yak wool fibers.

[0025] In the third stage of the first combing process, six yak wool antibacterial comb slivers are fed together to produce yak wool antibacterial and flame-retardant comb slivers. The six yak wool antibacterial comb slivers pass through the guide table, guide rollers, and guide rods, and then merge at the guide collection plate. This merging process mixes the various yak wool antibacterial comb slivers and effectively improves the unevenness of the slivers. The merged yak wool antibacterial comb slivers are then drawn and combed together by the drawing system in a roll structure. The drawing system includes front, middle, and rear rollers. Slow-moving needle rows are set in the drawing zone composed of the front, middle, and rear rollers. Flame-retardant liquid spraying devices are set on the upper and lower needle rows in the rear drawing zone between the middle and rear rollers and in the front drawing zone between the middle and front rollers. During the drafting process in the drafting zone, the needle plates of the upper and lower needle rows in the drafting zone continuously and crosswise penetrate between the yak wool fibers. Due to the movement of the yak wool fibers in the drafting zone, the sprayed flame retardant liquid is directly sprayed onto the surface of the yak wool fibers. Due to the rotation of the device, the flame retardant liquid is sprayed onto the yak wool fibers at a certain angle and force, thereby achieving uniform spraying. At this time, because the scale layer on the surface of the fiber after the decolorization treatment is loose, the flame retardant liquid continuously penetrates into the interior of the fiber under the action of the spraying force, thereby achieving antibacterial finishing of the yak wool fiber in its fibrous state. As the combing sliver layer thins, the depth of the needle plates crossing between the fibers gradually increases, and the rotation speed of the device also increases accordingly, thereby gradually enhancing the flame retardant finishing of the yak wool fiber, thus completing the flame retardant finishing process of the yak wool fiber. A self-adjusting leveling device is installed at the output end of the third-stage first comb. The self-adjusting leveling device includes a measuring mechanism, a memory delay mechanism, a conduction amplification mechanism, and an execution speed change mechanism. The self-adjusting leveling device automatically adjusts the draft ratio after detecting the change in the thickness of the fed sliver, thereby actively and effectively improving the uniformity of the output sliver and enhancing the consistency of the output yak wool antibacterial and flame-retardant comb sliver.

[0026] Preferably, the preparation steps of the antibacterial solution in S4 are as follows: prepare a chitosan aqueous solution at a bath ratio of 200:1, adjust the pH to 2-2.5, then add silver-loaded nano-SiO2 particles and stir, adjust the pH to 2-2.5 and let it stand.

[0027] Preferably, the preparation steps of the flame retardant liquid in S4 and S9 are as follows: prepare a potassium fluorozirconate solution with a mass fraction of 0.06%, add adipic acid at a molar ratio of 1:1, adjust the pH to 2-3, the temperature to 80-85℃, and the bath ratio to 1:20.

[0028] Preferably, the combing step in S5 is set with the following conditions: 8-12 fibers fed in, a draft ratio of 9.0-12.5, a spacing of 18-24 mm, a machine speed of 140-180 nipper strokes / min, and a sliver weight range of 8-12 g / m. Through combing, short fibers are separated from the antibacterial and flame-retardant yak wool sliver, while ensuring that the resulting combed sliver has uniform sliver and few fibers.

[0029] Preferably, the conditions for the second combing step in S6 are as follows: 3 to 6 strips are combined, the draw ratio is between 3.2 and 5.5 times, the spacing is 16 to 22 mm, the machine speed is 30 to 45 m / min, and the weight of the strips after the machine is controlled at 2.5 to 6.0 g / m.

[0030] Preferably, the conditions for the cotton spinning drawing step in S7 are as follows: 6 to 8 slivers are drawn together, the draw ratio is 5 to 10 times, and the design basis weight is 2.0 to 3.0 g / m.

[0031] Preferably, the cotton roving step in S8 is set with the following conditions: draft ratio of 5.2 to 8.5, back zone draft ratio of 1.15, roller spacing of 9×24×32mm, roller diameter of 28×28×25×28mm, roving weight of 3 to 6g / 10m, roving twist coefficient of 60 to 102 twists / m, and machine speed of 120 to 180m / min.

[0032] Preferably, the conditions for setting the cotton spinning step in S9 are as follows: a DTM129 spinning machine equipped with a full-polymer spinning device is used, the twist range of the yarn is 650 to 1380 twists / meter, the roller spacing is (10 to 13) × (27 to 32) mm, the roller diameter is 27 × 27 × 50 mm, the ring diameter is 42 mm, and the spindle speed is 8000 r / min.

[0033] Preferably, the spraying device in S9 is located between the front drafting roller pair and the yarn guide hook of the twisting system, and includes a connecting crossbar, a telescopic vertical bar and a spraying arc. The connecting crossbar is located on the frame of the spinning machine, and the telescopic vertical bar is distributed longitudinally along the connecting crossbar. One end is connected to the connecting crossbar and the other end is connected to the spraying arc. The spraying arc is hollow inside, with arc surfaces at the top and bottom. Flame retardant liquid is connected to both sides through pipelines, and spraying holes are provided on the arc surface of the spraying arc that contacts the yarn.

[0034] Furthermore, each jet arc corresponds to a spindle position on the spinning machine platform.

[0035] Furthermore, the contact point between the upper spray arc and the yarn is behind the contact point between the lower spray arc and the yarn. This ensures that the yak antibacterial and flame-retardant yarn first contacts the lower flame-retardant liquid spray hole. At this time, the yak antibacterial and flame-retardant yarn moves forward continuously, carrying away some air from the surface of the flame-retardant liquid spray hole during its movement. This reduces the surface pressure of the flame-retardant liquid spray hole, causing the flame-retardant liquid to be sprayed out and evenly onto the surface of the forward-moving yak antibacterial and flame-retardant yarn, thus completing the flame-retardant finishing of the yak antibacterial and flame-retardant yarn in its yarn-forming state.

[0036] Antibacterial and flame-retardant yak wool yarn prepared by the above method.

[0037] Beneficial effects: (1) Yak wool fiber is used as raw material for spinning. The yarn produced has a good hand feel and the product is high-end and elegant. By performing antibacterial and flame-retardant finishing on the yak wool in the fiber state and flame-retardant finishing on the yarn state, the yarn has functionality and the added value of the product is improved.

[0038] (2) By bleaching the original color of yak wool, on the one hand, it lays the foundation for further re-dyeing in the later process, thereby effectively expanding the application range of yak wool fiber; on the other hand, by bleaching, the fiber surface becomes loose, thereby providing conditions for flame retardants and antibacterial agents to penetrate into the fiber, thereby improving the flame retardant and antibacterial finishing effect, which has great market prospects. Detailed Implementation

[0039] The present invention will be further described below with reference to specific embodiments.

[0040] Example 1

[0041] Taking the production of antibacterial and flame-retardant yak wool yarn with an average fineness of 60Nm as an example, the original-color yak wool fiber used is black yak wool. The specific production process is as follows: First, the black yak wool fiber is pre-treated to remove residual impurities. The black yak wool fiber is then subjected to decolorization, wool oiling, combing, three first-needle combing processes, fine combing, two second-needle combing processes, and two cotton spinning processes to produce an antibacterial and flame-retardant sliver. Antibacterial finishing of the yak wool fiber is achieved in the first needle combing process of the second stage, and flame-retardant finishing in the first needle combing process of the third stage. The yarn is then roving with a certain strength, and then spun into fine yarn with a certain strength. Flame-retardant treatment is performed in the yarn-forming stage during the spinning process, ultimately yielding the antibacterial and flame-retardant yak wool yarn. The specific process configuration is as follows:

[0042] Pretreatment: First, the fibers are opened, cleaned and pre-carded to remove impurities and foreign fibers to ensure that the raw materials are clean.

[0043] Decolorization: (1) Pre-mordant treatment: Take yak wool fibers and place them in a mixed solution of 12 g / L ferrous sulfate and 3 g / L sodium bisulfite. Heat for 30 min at a bath ratio of 1:50 and a temperature of 60°C, and then wash. (2) Oxidative bleaching: Place the pre-mordant treated yak wool fibers in a mixed solution of 25 g / L hydrogen peroxide (35%) and 5 g / L sodium pyrophosphate. Adjust the pH value to 8.3 using acetic acid and sodium acetate buffer solution. Place the fibers in this solution and react for 60 min at a temperature of 60°C, and then wash. (3) Reduction bleaching: Take 6 g / L sodium hydrosulfite and 4 g / L sodium pyrophosphate to make a mixed solution. Place the yak wool fibers in this mixed solution and react for 30 min at a bath ratio of 1:50, a temperature of 50°C and a pH of 5.6, and then wash.

[0044] Wool oiling: Based on the weight of the bleached white fibers, add 0.6% CTA-1880 wool oil, 0.4% FX-AS20 antistatic agent, and 0.5% yarn reinforcing agent, control the moisture regain in the workshop at 20%–21%, and equilibrate for 10 hours.

[0045] Combing: The feed roller speed is 2.0 r / min, the cylinder speed is 100 r / min, the doffer speed is 6.8 r / min, the transfer roller speed is 115 r / min, and the sliver weight is 5.40 g / m.

[0046] First combing: The first combing uses 6 slivers combined, with a draw ratio set at 4.8 times, a spacing of 18mm, a machine speed of 30m / min, and a sliver weight of 6.75g / m. Second combing: 6 slivers combined, with a draw ratio set at 4.5 times, a spacing of 18mm, a machine speed of 30m / min, and a sliver weight of 9.00g / m. Third combing: 6 slivers combined, with a draw ratio set at 6 times, a spacing of 18mm, a machine speed of 30m / min, and a sliver weight of 9.00g / m.

[0047] Preparation of antibacterial solution: Chitosan was dissolved in water at a bath ratio of 200:1, and the pH was adjusted to 2.5. Then, silver-loaded nano-SiO2 particles were added, stirred evenly, and the pH was adjusted to 2 with 10% nitric acid. The mixture was allowed to stand for reaction. Preparation of flame retardant solution: A 0.06% potassium fluorozirconate solution was prepared. A certain amount of adipic acid was added at a molar ratio of potassium fluorozirconate to adipic acid of 1:1 to prepare a flame retardant. The pH of the flame retardant was adjusted to 2.5, the temperature was 80℃, and the bath ratio was 1:20.

[0048] Combing: 12 strands are fed in, the draft ratio is 12.2, the spacing is 20mm, the machine speed is 148 nips / min, and the weight of the sliver after combing is 8.85g / m.

[0049] Second comb: The first comb uses 3 strips combined together, with a draft ratio of 4.85, a spacing of 18mm, a machine speed of 30m / min, and a strip weight of 5.47g / m after finishing; the second comb uses 3 strips combined together, with a draft ratio of 4.50, a spacing of 18mm, a machine speed of 30m / min, and a strip weight of 3.65g / m after finishing.

[0050] Draw slivers: The first draw slivers consist of 8 slivers combined, with a draw ratio of 8.55 and a basis weight of 2.44 g / m; the second draw slivers consist of 6 slivers combined, with a draw ratio of 6.48 and a basis weight of 2.23 g / m.

[0051] Roving: The draft ratio of the roving process is 5.27 times, the draft ratio of the back zone is 1.15 times, the roller spacing is 9×24×32mm, the roller diameter is 28×28×25×28mm, the roving weight is 5.96g / 10m, the roving twist is controlled at 72 twists / m, and the machine speed is 150m / min.

[0052] Fine spinning: The yarn twist in the fine spinning process is 860T / M, the roller spacing is 11×29mm, the roller diameter is 27×27×50mm, the ring diameter is 42mm, and the spindle speed is 8000r / min.

[0053] The antibacterial and flame-retardant yak wool yarn produced according to the above method has been tested and the following indicators are obtained:

[0054]

[0055] Antibacterial properties test:

[0056] (1) The processed antibacterial and flame-retardant yak wool yarn is woven into a yarn with a horizontal density of 145 / 5cm and a weight of 155g / m². 2 Plain knit fabric.

[0057] (2) All instruments, equipment, yarn samples, biosafety cabinets, and reagents used in the experiment were sterilized. A "0" time group was set up in the experiment. The "0" time control was used to indicate the survival of pathogens during the experiment and to avoid the results being artificially high due to the decay of pathogens themselves.

[0058] (3) Dilute the bacterial suspension with PBS to a certain concentration.

[0059] (4) Put the sample to be tested and a certain concentration of bacterial solution into a flask. The bacterial solutions selected are Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 25922), and Candida albicans (ATCC 10231). Shake at 37°C for 18 hours to allow the sample to be fully inoculated.

[0060] (5) Dilute the inoculated bacterial solution to a certain multiple, inoculate the plate using the spreader method, make 2 parallel samples for each concentration gradient, and incubate in a 37℃ incubator for more than 24 hours (for fungal culture, more than 48 hours).

[0061] (6) The number of surviving colonies was calculated using the plate counting method. The inhibition rate and antibacterial rate were calculated according to the following formulas. The experiment was repeated 3 times and the average value was taken.

[0062]

[0063] In the formula: B is the antibacterial rate; b is the number of viable colonies in the control sample at time "0"; c is the number of viable colonies in the sample after 18 hours.

[0064] According to GB / T 20944.3—2008 "Evaluation of Antibacterial Properties of Yarn - Part 3: Vibration Method", antibacterial performance tests were conducted. If the yarn's inhibition rate against bacteria is ≥70%, the yarn is considered to have antibacterial properties. The antibacterial rate test after 18 hours of contact with pathogenic bacteria is as follows:

[0065]

[0066] Example 2

[0067] The difference between this embodiment and Embodiment 1 is that:

[0068] Similar to Example 1, taking the production of antibacterial and flame-retardant yak wool yarn with an average fineness of 60 Nm as an example, the speed of the two processes in the first combing was increased to 35 m / min, and the spindle speed of the fine yarn was increased to 8500 r / min, thereby increasing the amount of antibacterial liquid penetrating onto the fibers during processing. Various indicators of the produced antibacterial and flame-retardant yak wool yarn were tested, and the test results are as follows:

[0069]

[0070] The antibacterial and flame-retardant yak wool yarn of this embodiment was tested for antibacterial properties. The testing process was the same as in Example 1, and the test results are as follows:

[0071]

Claims

1. A method for producing antibacterial and flame-retardant yak wool yarn, characterized in that, The steps include the following: S1. Pretreatment: Remove impurities and foreign fibers from the original yak wool fibers; S2. Decolorization: White fibers are obtained by sequentially subjecting the pretreated raw yak wool fibers to pre-mortar treatment, oxidative bleaching and reduction bleaching. S3. Combing strip: White fibers are sequentially treated with oil and combing to obtain combing strips; S4. First comb: The comb sliver is processed through three first combs to obtain antibacterial and flame-retardant comb sliver. In the second first comb, the sliver is pretreated with ultraviolet light in the back drafting zone and sprayed with antibacterial liquid in the front drafting zone. In the third first comb, the sliver is sprayed with flame-retardant liquid in the drafting zone. S5. Wool Combing: Antibacterial and flame-retardant combed sliver is obtained by combing antibacterial and flame-retardant combed sliver. S6. Second comb: The antibacterial and flame-retardant comb strip is processed by passing the antibacterial and flame-retardant comb strip through two second combs to obtain the antibacterial and flame-retardant comb strip; S7. Cotton spinning and drawing: Antibacterial and flame-retardant combed sliver is obtained by cotton spinning and drawing; S8. Cotton roving: Antibacterial and flame-retardant roving is made by spinning antibacterial and flame-retardant sliver through cotton roving. S9. Cotton spinning: The antibacterial and flame-retardant yak wool yarn is obtained by spinning antibacterial and flame-retardant roving through cotton spinning. Flame-retardant liquid is sprayed between the front drafting rollers of the drafting system and the yarn guide hooks of the twisting system. The spraying device is located between the front drafting rollers and the yarn guide hooks of the twisting system, and includes a connecting crossbar, a telescopic vertical bar, and a spray arc. The connecting crossbar is located on the spinning machine frame. The telescopic vertical bar is distributed longitudinally along the connecting crossbar, with one end connected to the connecting crossbar and the other end connected to the spray arc. The spray arc is hollow inside, with curved surfaces at the top and bottom. Flame-retardant liquid is connected to both sides via pipes. Spray holes are provided on the curved surface of the spray arc that contacts the yarn. Each spray arc corresponds to a spindle position on the spinning machine frame. The contact point between the upper spray arc and the yarn is behind the contact point between the lower spray arc and the yarn.

2. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The pre-mortar treatment steps in S2 are as follows: Place the original yak wool fibers in a mixed solution of 8-16 g / L ferrous sulfate and 2-5 g / L sodium bisulfite, heat at a bath ratio of 1:50 and a temperature of 60℃ for 30-45 minutes, and then wash. The oxidative bleaching steps are as follows: Place the pre-mortar-treated yak wool fibers in a mixed solution of 20-40 g / L hydrogen peroxide and 5-8 g / L sodium pyrophosphate, adjust the pH to 8-8.5, react at 60℃ for 60 minutes, and then wash. The specific steps of the reduction bleaching process are as follows: Place the bleached yak wool fibers in a mixed solution of 6~10g / L sodium hydrosulfite and 3~6g / L sodium pyrophosphate, react for 30 minutes in an environment with a bath ratio of 1:50, a temperature of 50℃, and a pH of 5~6, and then wash them.

3. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The specific steps for the overall finishing and oiling process in S3 are as follows: Based on the weight of white fibers, add 0.5%~0.65% finishing oil, 0.2%~0.4% antistatic agent, and 0.5%~0.6% reinforcing agent, control the moisture regain in the workshop at 20%~21%, and the balancing time exceeds 8 hours; the carding process is set as follows: feed roller speed is 1.5~3.0 r / min, cylinder speed is 90~120 r / min, doffer speed is 6~10 r / min, transfer roller speed is 110~140 r / min, and sliver weight is 5.0~8.0 g / m.

4. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The preparation steps of the antibacterial solution in S4 are as follows: prepare a chitosan aqueous solution at a bath ratio of 200:1, adjust the pH to 2~2.5, then add silver-loaded nano-SiO2 particles and stir, adjust the pH to 2~2.5 and let it stand; the preparation steps of the flame retardant solutions in S4 and S9 are as follows: prepare a potassium fluorozirconate solution with a mass fraction of 0.06%, add adipic acid at a molar ratio of 1:1, adjust the pH to 2~3, the temperature to 80~85℃, and the bath ratio to 1:

20.

5. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The combing step in S5 is set with the following conditions: 8-12 feed strands, draft ratio of 9.0-12.5, spacing of 18-24mm, machine speed of 140-180 nips / min, and strip weight of 8-12g / m.

6. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The conditions for the second combing step in S6 are as follows: use 3 to 6 strips combined, the draw ratio is between 3.2 and 5.5 times, the spacing is 16 to 22 mm, the machine speed is 30 to 45 m / min, and the weight of the strips after the machine is controlled at 2.5 to 6.0 g / m.

7. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The conditions for the cotton spinning drawing step in S7 are as follows: 6 to 8 slivers are drawn together, the draft ratio is 5 to 10 times, and the design basis weight is 2.0 to 3.0 g / m.

8. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The following conditions are set for the cotton roving process in S8: draft ratio is 5.2 to 8.5, back zone draft ratio is 1.15, roller spacing is 9×24×32mm, roller diameter is 28×28×25×28mm, roving weight is 3 to 6g / 10m, roving twist coefficient is 60 to 102 twists / m, and machine speed is 120 to 180m / min.

9. The method for producing antibacterial and flame-retardant yak wool yarn according to claim 1, characterized in that, The following conditions are set for the cotton spinning fine yarn step in S9: the twist range of the yarn is 650~1380 twists / meter, the roller spacing is (10~13)×(27~32)mm, the roller diameter is 27×27×50mm, the ring diameter is 42mm, and the spindle speed is 8000r / min.

10. The antibacterial and flame-retardant yak wool yarn prepared by the method of claim 1.

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