阅读说明：本技术 一种莱赛尔/棉纤维混纺纱线及其制备方法 (Lyocell/cotton fiber blended yarn and preparation method thereof ) 是由 宫怀瑞 徐良平 何留根 张红艳 张磊 于 2021-11-09 设计创作，主要内容包括：本发明涉及家用纺织品技术领域,特别涉及一种莱赛尔/棉纤维混纺纱线及其制备方法。所述制备方法包括以下步骤：S1.棉纤维改性处理：将棉纤维置于溶胀剂中浸泡后洗涤、烘干,用氦等离子体处理后,隔绝氧环境下置于甲基丙烯酸缩水甘油酯的醇溶液中反应,随后洗涤、干燥,得到改性棉纤维；S2.将莱赛尔纤维和改性棉纤维分别梳理后混合,随后进行纺纱,得到所述混纺纱线。通过以上接枝反应,将难以被氧化的酯基接枝到棉纤维上,进而解决了棉纤维在空气中长时间日晒氧化生成二氧化碳和水,分子内氢键作用减弱、机械性能下降的问题。由本发明的混纺纱线制得的纺织品,手感柔软,舒适性好。(The invention relates to the technical field of household textiles, in particular to a lyocell/cotton fiber blended yarn and a preparation method thereof. The preparation method comprises the following steps: s1, cotton fiber modification treatment: placing the cotton fiber in a swelling agent for soaking, washing and drying, treating with helium plasma, placing in an alcohol solution of glycidyl methacrylate for reaction under the condition of isolating oxygen, and then washing and drying to obtain modified cotton fiber; s2, respectively carding and mixing the lyocell fibers and the modified cotton fibers, and then spinning to obtain the blended yarn. Through the grafting reaction, ester groups which are difficult to oxidize are grafted to the cotton fibers, so that the problems that carbon dioxide and water are generated by long-time solarization and oxidation of the cotton fibers in the air, the hydrogen bonding effect in molecules is weakened, and the mechanical performance is reduced are solved. The textile prepared from the blended yarn has soft hand feeling and good comfort.)

1. A preparation method of Lyocell/cotton fiber blended yarn is characterized by comprising the following steps:

s1, cotton fiber modification treatment: placing the cotton fiber in a swelling agent for soaking, washing and drying, treating with helium plasma, placing in an alcohol solution of glycidyl methacrylate for reaction under the condition of isolating oxygen, and then washing and drying to obtain modified cotton fiber;

s2, respectively carding and mixing the lyocell fibers and the modified cotton fibers, and then spinning to obtain the blended yarn.

2. The method according to claim 1, wherein in step S1, the swelling agent is an aqueous solution of 3-methyl-1-allylimidazole chloride salt;

and/or in step S1, the swelling temperature is 20-40 ℃, and the swelling time is 18-25 h;

and/or in step S1, the discharge mode of the helium plasma treatment is glow discharge, the pressure is 30-40Pa, the discharge power is 30-60W, and the discharge time is 5-10 min.

3. The method according to claim 2, wherein the 3-methyl-1-allylimidazole chloride salt is contained in the 3-methyl-1-allylimidazole chloride salt aqueous solution at a concentration of 20 to 30 wt%.

4. The method according to claim 3, wherein the mass ratio of the 3-methyl-1-allylimidazole chloride salt to the cotton fiber is 5-10: 100.

5. the method according to claim 1, wherein in step S1, the concentration of the glycidyl methacrylate is 10 wt% to 15 wt%;

and/or in step S1, the mass ratio of the glycidyl methacrylate to the cotton fibers is 1: 5-8;

and/or in step S1, the alcoholic solution further contains dicumyl peroxide;

and/or, in step S1, the alcoholic solution further contains xylene;

and/or, in step S1, the alcohol is one or more of methanol, ethanol and n-propanol;

and/or in the step S1, the reaction temperature is 120-130 ℃, and the reaction time is 5-8 h;

and/or in step S1, the drying temperature is 60-80 ℃, and the drying time is 30-40 min;

and/or in step S1, the drying temperature is 80-90 ℃, and the drying time is 15-25 min.

6. The method according to claim 5, wherein the mass ratio of dicumyl peroxide to cotton fiber is 1.5-2.1: 100;

and/or the mass ratio of the xylene to the glycidyl methacrylate is 1-5: 100.

7. the method according to claim 1, wherein in step S2, the mass percentage of the lyocell fibers and the modified cotton fibers is 33 wt% to 67 wt%: 67 wt% -33 wt%;

and/or in step S2, the spinning includes: opening and picking, cotton carding, drawing, roving, spinning and spooling.

8. The method as claimed in claim 7, wherein in the opening and picking process, the carding needle beater speed is 400-540r/min, and the comprehensive beater speed is 850-900 r/min;

and/or, in the cotton carding process, the quantitative rate is 17-22g/5m, the cylinder rotating speed is 290-340r/min, the cover plate speed is 80-90mm/min, and the doffer speed is 15-25 r/min;

and/or in the drawing process, 6-8 pieces of drawing are adopted, and two times of drawing are adopted; wherein the head doubling ration is 15-19g/5m, the number of combined roots is 6-8, the drafting multiple of the rear zone is 1-2 times, the total drafting multiple is 5-8 times, and the sliver-out speed is 200-500 m/min; the quantitative ratio of two strips is 15-18g/5m, the number of combined strips is 6-8, the drafting multiple of the rear zone is 1-2 times, the total drafting multiple is 5-8 times, and the strip-discharging speed is 200-500 m/min;

and/or in the roving process, the quantitative amount is 4-6g/10m, the spindle speed is 650-fold/min, the front roller speed is 170-fold/min, the rear zone stretching multiple is 1-2-fold, and the twist coefficient is 75-90;

and/or in the spinning process, the quantitative amount is 1-2g/100m, the spindle speed is 13000-;

and/or in the spooling process, the spooling rotating speed is 900-1200 r/min.

9. The production method according to claim 1, wherein the fineness of the lyocell fiber is 1.35 to 1.40 dtex.

10. A lyocell/cotton fiber blended yarn produced by the production method according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of household textiles, in particular to a lyocell/cotton fiber blended yarn and a preparation method thereof.

Background

The cotton fiber is seed fiber formed by stretching and thickening epidermal cells of fertilized ovules, and is one of the most widely applied natural fibers in the textile field. The main component of the cotton fiber is cellulose, the cellulose content in the normal mature cotton fiber is about 94%, and in addition, the cotton fiber also contains a small amount of components such as protein, fat, wax, water-soluble substances, ash and the like.

The cotton fiber has the following excellent properties: the fabric has the advantages of high strength, good air permeability, heat resistance, easy dyeing, good hygroscopicity, wear resistance, light weight, softness, low cost, biodegradability, good spinnability, capability of being blended with various fibers such as viscose, rich fiber, terylene, vinylon, polypropylene, lyocell and the like, good comfort, soft hand feeling, excellent heat retention, good air permeability and the like, and can be widely applied to the fields of household textiles, electromagnetic protection, pollution control, medical sanitation and the like.

The lyocell fiber is cellulose fiber prepared by taking natural plant cellulose as a raw material through an NMMO solvent spinning process, and a textile prepared from the lyocell fiber has natural luster, smooth hand feeling, stable size, crease resistance, high strength, moisture permeability, air permeability and good comfort.

In order to improve the antibacterial properties of lyocell fibers and cotton fibers, attempts have been made to blend cotton fibers and lyocell fibers to obtain lyocell/cotton fiber blended yarns having antibacterial properties. However, the light resistance of the conventional lyocell/cotton blended yarn is poor, the strength is easy to reduce under long-time sunlight irradiation, and the dimensional stability of the prepared textile is poor.

Disclosure of Invention

In view of the above, the present invention provides a lyocell/cotton fiber blended yarn and a method for preparing the same, wherein the stability of the sun-proof strength of a textile made of the blended yarn is significantly improved.

In order to solve the problems, the invention is realized by the following technical scheme:

a method for preparing lyocell/cotton fiber blended yarns comprises the following steps:

s1, cotton fiber modification treatment: placing the cotton fiber in a swelling agent for soaking, washing and drying, treating with helium plasma, placing in an alcohol solution of glycidyl methacrylate for reaction under the condition of isolating oxygen, and then washing and drying to obtain modified cotton fiber;

s2, respectively carding and mixing the lyocell fibers and the modified cotton fibers, and then spinning to obtain the blended yarn.

Further, in step S1, the swelling agent is an aqueous solution of 3-methyl-1-allylimidazole chloride salt.

Further, in the 3-methyl-1-allyl imidazole chloride aqueous solution, the concentration of the 3-methyl-1-allyl imidazole chloride is 20 wt% to 30 wt%, preferably 24 wt% to 28 wt%.

Further, in step S1, the mass ratio of the 3-methyl-1-allylimidazole chloride salt to the cotton fiber is 5 to 10:100, preferably 5 to 8: 100.

Further, in step S1, the swelling temperature is 20-40 ℃, preferably 30-40 ℃; the swelling time is 18-25h, preferably 20-25 h.

Further, in step S1, the discharge mode of the helium plasma treatment is glow discharge, and the pressure is 30 to 40Pa, preferably 30 to 33 Pa; the discharge power is 30-60W, preferably 40-50W; the discharge time is 5-10min, preferably 5-8 min.

Further, the concentration of glycidyl methacrylate is 10 to 15 wt%, preferably 12 to 15 wt%.

Further, in step S1, the mass ratio of glycidyl methacrylate to cotton fiber is 1: 5-8, preferably 1: 5-6.

Further, in step S1, the alcohol solution further contains dicumyl peroxide.

Further, the mass ratio of dicumyl peroxide to cotton fiber is 1.5-2.1:100, preferably 1.8-2.0: 100.

Further, in step S1, the alcohol solution further contains xylene.

Further, the mass ratio of the xylene to the glycidyl methacrylate is 1-5: 100, preferably 2 to 5: 100.

further, in step S1, the alcohol is one or more of methanol, ethanol, and n-propanol.

Further, in step S1, the reaction temperature is 120-130 ℃, preferably 125-130 ℃; the reaction time is 5-8h, preferably 6-7 h.

Further, in step S1, the drying temperature is 60-80 ℃, more preferably 65-75 ℃; the drying time is 30-40min, preferably 33-38 min.

Further, in step S1, the drying temperature is 80-90 ℃, preferably 84-88 ℃; the drying time is 15-25min, preferably 20-25 min.

Further, in step S2, the mass percentage of the lyocell fibers and the modified cotton fibers is 33 wt% to 67 wt%: 67-33 wt%, preferably 40-60 wt%: 60 to 40 weight percent.

Further, in step S2, the spinning includes opening picking, carding, drawing, roving, spinning and spooling.

Further, in the opening and picking process, the carding needle beater speed is 400-; the comprehensive hand-beating speed is 850-900r/min, preferably 860-880 r/min.

Further, in the cotton carding process, the quantitative content is 17-22g/5m, preferably 18-20g/5 m; the rotating speed of the cylinder is 290-340r/min, preferably 300-330 r/min; the cover plate speed is 80-90mm/min, preferably 82-87 mm/min; the doffer speed is 15-25r/min, preferably 18-23 r/min.

Furthermore, in the drawing process, 6-8 pieces of combination are adopted, and 6-7 pieces of combination are preferably adopted; twice merging, wherein the head sum is 15-19g/5m, preferably 16-18g/5 m; the number of the combined root is 6-8, preferably 6-7; the drafting multiple of the rear zone is 1 to 2 times, preferably 1.2 to 1.5 times; the total draft multiple is 5 to 8 times, preferably 5.5 to 7.5 times; the strip discharging speed is 200-500m/min, preferably 300-450 m/min; the two-strip basis weight is 15-18g/5m, preferably 15-16g/5 m; the number of the combined root is 6-8, preferably 6-7; the drafting multiple of the rear zone is 1 to 2 times, preferably 1.3 to 1.5 times; the total draft multiple is 5 to 8 times, preferably 5.5 to 6.5 times; the strip-out speed is 200-500m/min, preferably 300-450 m/min.

Further, in the roving process, the basis weight is 4-6g/10m, preferably 4.5-5.5g/10 m; the spindle speed is 620-650r/min, preferably 630-640r/min, the front roller speed is 170-200r/min, preferably 180-190 r/min; the stretching ratio of the rear zone is 1-2 times, preferably 1.5-1.9 times; the twist multiplier is 75-90, preferably 80-85.

Further, in the spinning step, the basis weight is 1 to 2g/100m, preferably 1.2 to 1.8g/100 m; the ingot speed is 13000-; the speed of the front roller is 185-200r/min, preferably 190-195 r/min; the stretching ratio of the rear zone is 1-2 times, preferably 1.2-1.8 times; the total draft multiple is 25 to 30 times, preferably 26 to 28 times; the twist factor is 320-340, preferably 325-330; the distance between the jaws is 2.5-3mm, 2.6-2.8 mm.

Further, in the winding process, the winding rotation speed is 900-.

Further, the fineness of the lyocell fiber is 1.3 to 1.40dtex, preferably 1.3 to 1.33 dtex.

Under the condition of the fineness, the cotton fiber and the lyocell fiber can better meet the requirement of the blending process condition.

The invention also aims to protect the lyocell/cotton fiber blended yarn prepared by the preparation method.

As described above, the lyocell/cotton fiber blended yarn and the preparation method thereof provided by the present invention have the following beneficial effects:

according to the invention, the cotton fibers are swelled through the swelling effect, and the pores among the swollen cotton fibers are increased, so that glycidyl methacrylate in the solution in the next reaction is easier to enter the cotton fibers.

In the present invention, the helium plasma can generate radicals on the surface of the cotton fiber, thereby initiating the graft polymerization reaction by the radicals.

In the invention, ester groups in glycidyl methacrylate are grafted to cotton fibers through free radical graft polymerization, hydroxyl groups on the surfaces of the cotton fibers are reduced, and the ester groups are difficult to be oxidized by oxygen in the air, so that the oxidation resistance of the cotton fibers is improved, and further, the oxidation and cracking of cellulose caused by long-time sunlight irradiation of cotton fiber textiles in the air are avoided, the molecular chain is shortened, the intra-molecular and inter-molecular forces are weakened, and the physical and mechanical properties such as breaking strength and the like are reduced.

In the invention, dicumyl peroxide can generate more free radicals through thermal decomposition, and the graft polymerization reaction of glycidyl methacrylate and cotton fibers is further promoted, so that the sun-proof mechanical strength stability of the fabric made of the cotton fibers and the lyocell fibers is further improved.

According to the invention, the xylene can reduce the interfacial tension between the cotton fiber and the alcohol solution, improve the affinity between the cotton fiber and the alcohol solution, and enable more glycidyl methacrylate to permeate and diffuse into the cotton fiber, so that the graft polymerization reaction is promoted, the grafting rate is increased, and the sunlight-resistant mechanical strength stability of the fabric made of the cotton fiber and the lyocell fiber is further improved.

The lyocell fiber and the cotton fiber have soft hand feeling and good comfort, so the lyocell/cotton fiber blended yarn has soft hand feeling and good comfort.

Detailed Description

The present invention is further illustrated by the following specific examples, but it should be noted that the specific material ratios, process conditions, results, etc. described in the examples of the present invention are only for illustrating the present invention and should not be construed as limiting the present invention

All changes and modifications that come within the spirit of the invention are desired to be protected

Within the scope of protection. It is to be noted that "wt%" as indicated in the description herein means "mass fraction" unless otherwise specified.

The invention provides a preparation method of lyocell/cotton fiber blended yarn, which comprises the following steps:

s1, cotton fiber modification treatment: placing the cotton fiber in a 3-methyl-1-allyl imidazole chloride aqueous solution for soaking, then washing and drying, treating with helium plasma, then placing in an alcohol solution of glycidyl methacrylate for reaction under the condition of isolating oxygen, and then washing and drying to obtain modified cotton fiber;

in the 3-methyl-1-allyl imidazole chloride aqueous solution, the concentration of the 3-methyl-1-allyl imidazole chloride is 20 to 30 weight percent, preferably 24 to 28 weight percent; the mass ratio of the 3-methyl-1-allyl imidazole chloride salt to the cotton fiber is 5-10:100, preferably 5-8: 100;

the swelling temperature is 20-40 ℃, preferably 30-40 ℃; the swelling time is 18-25h, preferably 20-25 h.

The discharge mode of the helium plasma treatment is glow discharge, and the pressure is 30-40Pa, preferably 30-33 Pa; the discharge power is 30-60W, preferably 40-50W; the discharge time is 5-10min, preferably 5-8 min;

the concentration of glycidyl methacrylate is 10 to 15 wt%, preferably 12 to 15 wt%; the mass ratio of the glycidyl methacrylate to the cotton fiber is 1: 5-8, preferably 1: 5-6;

the alcohol is one or more of methanol, ethanol and n-propanol;

the reaction temperature is 120-130 ℃, preferably 125-130 ℃; the reaction time is 5-8h, preferably 6-7 h;

the drying temperature is 60-80 ℃, and more preferably 65-75 ℃; the drying time is 30-40min, preferably 33-38 min;

the drying temperature is 80-90 ℃, preferably 84-88 ℃; drying for 15-25min, preferably 20-25 min;

in another embodiment of the present invention, the alcoholic solution further contains dicumyl peroxide, and the mass ratio of dicumyl peroxide to cotton fiber is 1.5-2.1:100, preferably 1.8-2.0: 100;

in another embodiment of the present invention, the alcohol solution further contains xylene, and the mass ratio of xylene to glycidyl methacrylate is 1 to 5:100, preferably 2 to 5:100, respectively;

s2, respectively carding and mixing the lyocell fibers and the modified cotton fibers, and then sequentially performing opening and picking, cotton carding, drawing, roving, spinning and spooling processes to obtain the blended yarn;

wherein the fineness of the lyocell fiber is 1.3-1.40dtex, preferably 1.3-1.33 dtex;

the mass percentage of the lyocell fiber and the modified cotton fiber is 33-67 wt%: 67-33 wt%, preferably 40-60 wt%: 60-40 wt%;

in the opening and picking process, the carding needle beating speed is 400-; the comprehensive starting speed is 850-;

in the cotton carding process, the quantitative content is 17-22g/5m, preferably 18-20g/5 m; the rotating speed of the cylinder is 290-340r/min, preferably 300-330 r/min; the cover plate speed is 80-90mm/min, preferably 82-87 mm/min; the doffer speed is 15-25r/min, preferably 18-23 r/min;

in the drawing process, 6-8 pieces of the raw materials are combined, preferably 6-7 pieces of the raw materials are combined, and the two times of combination are adopted; wherein the head sum is 15-19g/5m, preferably 16-18g/5 m; the number of the combined root is 6-8, preferably 6-7; the drafting multiple of the rear zone is 1 to 2 times, preferably 1.2 to 1.5 times; the total draft multiple is 5 to 8 times, preferably 5.5 to 7.5 times; the strip discharging speed is 200-500m/min, preferably 300-450 m/min; the two-strip basis weight is 15-18g/5m, preferably 15-16g/5 m; the number of the combined root is 6-8, preferably 6-7; the drafting multiple of the rear zone is 1 to 2 times, preferably 1.3 to 1.5 times; the total draft multiple is 5 to 8 times, preferably 5.5 to 6.5 times; the strip discharging speed is 200-500m/min, preferably 300-450 m/min;

in the roving step, the basis weight is 4-6g/10m, preferably 4.5-5.5g/10 m; the ingot speed is 620-650r/min, preferably 630-640 r/min; the speed of the front roller is 170-200r/min, preferably 180-190 r/min; the stretching ratio of the rear zone is 1-2 times, preferably 1.5-1.9 times; a twist multiplier of 75 to 90, preferably 80 to 85;

in the spinning step, the basis weight is 1-2g/100m, preferably 1.2-1.8g/100 m; the ingot speed is 13000-; the speed of the front roller is 185-200r/min, preferably 190-195 r/min; the stretching ratio of the rear zone is 1-2 times, preferably 1.2-1.8 times; the total draft multiple is 25 to 30 times, preferably 26 to 28 times; the twist factor is 320-340, preferably 325-330; the distance between the jaws is 2.5-3mm, preferably 2.6-2.8 mm;

in the winding process, the winding speed is 900-.

In another embodiment of the present invention, the alcoholic solution further contains dicumyl peroxide, and the mass ratio of dicumyl peroxide to cotton fiber is 1.5-2.1:100, preferably 1.8-2.0: 100.

In another embodiment of the present invention, the alcohol solution further contains xylene, and the mass ratio of xylene to glycidyl methacrylate is 1 to 5:100, preferably 2 to 5: 100.

example 1

A method for preparing lyocell/cotton fiber blended yarns comprises the following steps:

s1, cotton fiber modification treatment: soaking long stapled cotton in 20 wt% concentration 3-methyl-1-allyl imidazole chloride aqueous solution at 20 deg.c for 22 hr, washing with anhydrous ethanol for 3 times, stoving at 60 deg.c for 40min, glow discharge with helium plasma at 35Pa and 40W pressure for 6min, reaction in methanol solution of glycidyl methacrylate at 123 deg.c for 5 hr in oxygen-isolated environment, washing with methanol for 3 times, and drying at 84 deg.c for 20min to obtain modified long stapled cotton;

wherein the mass ratio of the 3-methyl-1-allyl imidazole chloride salt to the cotton fiber is 8: 100; the mass ratio of the glycidyl methacrylate to the long stapled cotton is 1: 7; the mass ratio of dicumyl peroxide to cotton fiber is 2.1:100, respectively;

s2, the lyocell fiber with the fineness of 1.40dtex and the modified long stapled cotton are mixed according to the mass percentage of 67 wt%: respectively carding 33 wt% and mixing, then performing opening and picking treatment under the conditions that the carding speed is 400r/min and the comprehensive carding speed is 850r/min, and then carding under the conditions that the ration is 17g/5m, the rotating speed of a cylinder is 290r/min, the cover plate speed is 80mm/min and the doffer speed is 18 r/min; then carrying out drawing, roving, spinning and spooling processes in sequence to obtain the blended yarn;

in the drawing process, 7 pieces of yarn are combined, two times of yarn combination are carried out, the head combined quantity is 19g/5m, the number of the combined yarn is 7, the back zone drafting multiple is 1.28 times, the total drafting multiple is 7.8 times, the yarn discharging speed is 450m/min, the two pieces of yarn quantity is 16g/5m, the number of the combined yarn is 7, the back zone drafting multiple is 1.36 times, the total drafting multiple is 6.3 times, and the yarn discharging speed is 450 m/min;

in the roving process, the quantitative rate is 6g/10m, the spindle speed is 650r/min, the front roller speed is 200r/min, the rear zone stretching multiple is 1.9 times, and the twist factor is 90;

in the spinning process, the fixed quantity is 1.8g/100m, the spindle speed is 14000r/min, the speed of a front roller is 200r/min, the stretching multiple of a rear area is 1.8 times, the total stretching multiple is 30 times, the twist coefficient is 340, and the nip distance is 3 mm;

in the spooling process, the spooling rotating speed is 1200 r/min.

Example 2

A method for preparing lyocell/cotton fiber blended yarns comprises the following steps:

s1, cotton fiber modification treatment: soaking long stapled cotton in 30 wt% 3-methyl-1-allyl imidazole chloride aqueous solution at 40 deg.C for 20h, washing with anhydrous ethanol for 2 times, oven drying at 80 deg.C for 30min, glow discharging with helium plasma at 33Pa and 40W for 10min, reacting in ethanol solution of glycidyl methacrylate at 130 deg.C for 7h in oxygen-isolated environment, washing with ethanol for 3 times, and drying at 80 deg.C for 25min to obtain modified long stapled cotton;

wherein the mass ratio of the 3-methyl-1-allyl imidazole chloride salt to the long stapled cotton is 6: 100; the mass ratio of glycidyl methacrylate to long stapled cotton is preferably 1: 5;

s2, the lyocell fiber with the fineness of 1.33dtex and the modified long stapled cotton are mixed according to the mass ratio of 33 wt%: respectively carding 67 wt% and mixing, then performing opening and picking treatment under the conditions that the carding speed of a card wire is 540r/min and the comprehensive carding speed is 900r/min, and then carding under the conditions that the ration is 22g/5m, the rotating speed of a cylinder is 340r/min, the cover plate speed is 90mm/min and the doffer speed is 25 r/min; then carrying out drawing, roving, spinning and spooling processes in sequence to obtain the blended yarn;

in the drawing process, 6 pieces of drawing are adopted, two times of drawing are carried out, the head drawing ration is 15g/5m, the number of the drawn pieces is 6, the back zone drafting multiple is 1.5 times, the total drafting multiple is 5.5 times, the drawing speed is 300m/min, the two pieces of drawing ration is 15g/5m, the number of the drawn pieces is 6, the back zone drafting multiple is 1.3 times, the total drafting multiple is 5.5 times, and the drawing speed is 300 m/min;

in the roving process, the quantitative rate is 46g/10m, the spindle speed is 620r/min, the front roller speed is 170r/min, the rear zone stretching multiple is 1.6 times, and the twist factor is 75;

in the spinning process, the ration is 1.2g/100m, the spindle speed is 13000r/min, the speed of a front roller is 185r/min, the stretching multiple of a rear zone is 1.4 times, the total stretching multiple is 25 times, the twist coefficient is 320, and the nip distance is 2.5 mm;

in the spooling process, the spooling rotating speed is 900 r/min.

Example 3

A method for preparing lyocell/cotton fiber blended yarns comprises the following steps:

s1, cotton fiber modification treatment: soaking long stapled cotton in 28 wt% 3-methyl-1-allyl imidazole chloride aqueous solution at 30 ℃ for 18h, washing with absolute ethyl alcohol for 2 times, drying at 75 ℃ for 35min, performing glow discharge with helium plasma under the pressure of 40Pa and the discharge power of 50W for 5min, reacting in n-propanol solution of glycidyl methacrylate at 125 ℃ for 8h in an oxygen-isolated environment, washing with n-propanol for 2 times, and drying at 90 ℃ for 15min to obtain modified long stapled cotton;

wherein the mass ratio of the 3-methyl-1-allyl imidazole chloride salt to the long stapled cotton is 5: 100; the mass ratio of the glycidyl methacrylate to the long stapled cotton is 1: 8;

s2, the lyocell fiber with the fineness of 1.32dtex and the modified long stapled cotton are mixed according to the mass percentage of 40 percent: 60 wt% of the cotton fibers are respectively carded and then mixed, then opening and picking treatment is carried out under the conditions that the carding speed of a card wire is 500r/min and the comprehensive carding speed is 860r/min, and then cotton carding is carried out under the conditions that the ration is 20g/5m, the rotating speed of a cylinder is 300r/min, the cover plate speed is 82mm/min and the doffer speed is 23 r/min; then carrying out drawing, roving, spinning and spooling processes in sequence to obtain the blended yarn;

in the drawing process, 8 pieces of drawing are adopted, two times of drawing are carried out, the head drawing ration is 16g/5m, the number of the drawn pieces is 8, the back zone drafting multiple is 1.2 times, the total drafting multiple is 5.5 times, the drawing speed is 400m/min, the two pieces of drawing ration is 17g/5m, the number of the drawn pieces is 8, the back zone drafting multiple is 1.4 times, the total drafting multiple is 6 times, and the drawing speed is 400 m/min;

in the roving process, the quantitative rate is 4.5g/10m, the spindle speed is 630r/min, the front roller speed is 190r/min, the rear zone stretching multiple is 1.6 times, and the twist coefficient is 80;

in the spinning process, the fixed weight is 1.2g/100m, the spindle speed is 13500r/min, the speed of a front roller is 190r/min, the stretching multiple of a rear area is 1.5 times, the total stretching multiple is 26 times, the twist coefficient is 330, and the nip distance is 2.6 mm;

in the winding process, the winding speed is 980 r/min.

Example 4

The other parameter settings of this example were the same as in example 3, except for the following conditions: dicumyl peroxide is also added into the n-propanol solution, and the mass ratio of the dicumyl peroxide to the cotton fiber is 1.5: 100.

example 5

The other parameter settings of this example were the same as in example 3, except for the following conditions: dicumyl peroxide is also added into the n-propanol solution, and the mass ratio of the dicumyl peroxide to the cotton fiber is 2.1: 100.

example 6

The other parameter settings of this example were the same as in example 4 except for the following conditions: xylene is also added into the n-propanol solution, and the mass ratio of the xylene to the glycidyl methacrylate is 5: 100.

example 7

The other parameter settings of this example were the same as in example 4 except for the following conditions: xylene is also added into the n-propanol solution, and the mass ratio of the xylene to the glycidyl methacrylate is 1: 100.

comparative example 1

A lyocell/cotton fiber blended yarn was prepared in the same manner as in example 3, except that long stapled cotton was not modified.

Performance detection

The blended yarns from examples 1-7 and comparative example 1 were processed into white fabrics, and 100mm by 100mm samples were taken according to GB/T3923.2-2008, part 2 of tensile properties of textile fabrics: measuring the radial fracture strength of the test sample (sample grabbing method), wherein the spacing length of a tensile tester is 100 mm; then, a xenon lamp is adopted, the black standard temperature is 48 ℃, the relative humidity is 40 percent, and the irradiance is 42W/m²Irradiating for 192h under the condition; again according to GB/T3923.2-2008 textile fabric tensile Properties part 2: measuring the radial fracture strength of the test sample (sample grabbing method), wherein the spacing length of a tensile tester is 100 mm; then according to the formulaThe breaking strength retention rate was calculated and the results are shown in table 1; in the formula, M_{Front side}Measured before irradiation, breaking strength in units of N, M_{Rear end}The breaking strength measured after irradiation is given in N.

Table 1 results of performance testing

Source	Retention rate of breaking strength/%)
		Example 1	88.7
Example 2	88.4
		Example 3	88.6
Example 4	94.1
		Example 5	96.2
Example 6	97.5
		Example 7	95.3
Comparative example 1	67.9

As can be seen from table 1, the retention of breaking strength of the fabrics made of the lyocell/cotton fiber blended yarns of examples 1 to 7 was significantly improved as compared with that of comparative example 1.

The retention of breaking strength of the face fabric made of the lyocell/cotton fiber blended yarn of example 3 was improved by about 30.4% as compared with that of comparative example 1.

Compared with example 3, the retention rate of breaking strength of the fabrics made of the lyocell/cotton fiber blended yarns of examples 4 and 5 was improved by 5.5% and 7.6%, respectively.

Compared with example 4, the retention rate of breaking strength of the fabrics made of the lyocell/cotton fiber blended yarns of examples 6 and 7 was improved by 3.4% and 1.2%, respectively.

In conclusion, the invention obviously improves the stability of the sun-proof strength of the fabric made of the lyocell/cotton fiber blended yarn.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.