Yarn sizing agent as well as preparation method and application thereof

Abstract

The invention provides a yarn sizing agent and a preparation method and application thereof. The yarn sizing agent is prepared from the following raw materials: 40-60 wt% of an adhesive; 0.3 wt%-1 wt% of a smoothing agent; 0.3 wt%-1 wt% of a water-soluble edible pigment; 10 wt%-20 wt% of a nano cellulose aqueous solution; and the balance water. Compared with the prior art, the yarn sizing agent provided by the invention adopts components with specific contents, realizes better overall interaction, and can solve the problem of brittle and hard skin membrane after yarn sizing at high temperature by introducing new materials such as phosphate starch and nano cellulose to replace part of PVA main sizing agent; moreover, the strength enhancement rate of the yarn after single yarn sizing by adopting the yarn sizing agent provided by the invention can reach 10-35%, the yarn has better hairiness fit, the weavability of the wear-resistant yarn with a soft sizing film is improved, and the development range of a new product is widened.

Description

Technical Field

[0001] The invention relates to the technical field of textile sizing, and more specifically to a yarn sizing agent and a preparation method and application thereof. Background Art

[0002] Sizing is the process of applying sizing agent to the warp yarn to improve its weavability. Weavability refers to the ability of the warp yarn to withstand repeated friction, stretching, bending, etc. of the warp stop piece, heald, reed, etc. on the loom without a lot of fluff or even breakage. The fibers of the unsized single yarn are not firmly attached to each other, and there are more hairs on the surface, which is difficult to weave. After sizing, part of the sizing liquid penetrates between the fibers, and the other part adheres to the surface of the warp yarn. The sizing that mainly penetrates between the fibers is called penetration sizing, and the sizing that mainly adheres to the surface of the warp yarn is called covering sizing. There are six main methods of sizing warp yarn: warp beam sizing, weaving beam sizing, whole sizing combined sizing, dyeing sizing combined sizing, single yarn sizing, and hank yarn sizing. Among them, single yarn sizing is to withdraw the single yarn from the bobbin, and then wind it into a sized yarn bobbin after sizing by the single yarn sizing machine. The single yarn sizing machine is made by adding a sizing tank and a drying mechanism to a low-speed winding machine. Although this method has low output and high labor consumption, the sizing film quality is good. It adopts single yarn sizing method, which is suitable for small batch production such as yarn-dyed and ribbon. Single yarn sizing can be controlled according to the required length of warping to reduce material waste.

[0003] Nanocellulose is a nanoscale product obtained by processing cellulose fibers. Nanocellulose is a nanoscale fiber made by chemical or physical treatment of plant cellulose, and its diameter is usually between a few nanometers and a few hundred nanometers. It has high strength, high specific surface area and good biocompatibility. Since the hydroxyl group located at the flat bond position of the pyranose glucose ring on the nanocellulose chain is hydrophilic, while the C-H bond located at the axial position of cellulose is hydrophobic, nanocellulose is amphiphilic and is a nanoparticle widely used to stabilize Pickering emulsions; it is a green, non-toxic, abundant and renewable resource. Nanocellulose is suitable for stabilizing water-in-oil Pickering emulsions.

[0004] For example, Chinese Patent CN118668483A discloses a sizing agent for textiles and a sizing process for blended fabrics. This sizing agent for textiles, by weight percentage, comprises the following components: 10% - 20% of chitosan-graphene composite material, 15% - 20% of polyvinyl alcohol-conductive polymer composite material, 15% - 20% of nanocellulose-metal organic framework composite material, 10% - 15% of self-healing polymer, 3% - 5% of titanium dioxide nanoparticles, 2% - 4% of zinc oxide nanoparticles, 1% - 3% of silver nanoparticles, 3% - 5% of paraffin microcapsules, and 10% - 15% of aramid nanofibers. By introducing multifunctional nanomaterials, adopting the spin coating process, and performing heat setting and cold setting treatments, the mechanical strength, abrasion resistance, self-healing ability, antibacterial property, ultraviolet resistance, self-cleaning function, as well as the coating uniformity and permeability of the yarn are improved. The finished product has stable properties, is easy to store, and for the cotton and linen fiber fabric after pigment printing with the sizing agent composition of this invention, its wash resistance and sorption rate are significantly enhanced, and the printing is smooth, the color is bright, the coloring depth is appropriate, it is not easy to fade, and the rubbing fastness after printing is high. However, for the heat setting treatment in the sizing process of this patent, the temperature is set at 120 - 160°C and the time is 2 - 5 min. The temperature is relatively high, and at the above temperature, the problem of brittle and hard film on the yarn after sizing will occur. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a yarn sizing agent, its preparation method and application. The yarn sizing agent provided by the present invention can solve the problem of brittle and hard film on the yarn after sizing at high temperature by introducing new materials such as phosphate starch and nanocellulose to replace part of the PVA main sizing agent; moreover, for the yarn after single yarn sizing with the sizing agent provided by the present invention, the yarn strength enhancement rate can reach 10% - 35%, its hairiness is well adhered, the sizing film is soft and wear-resistant, and the weavability of the yarn is improved, broadening the scope of new product development.

[0006] The present invention provides a yarn sizing agent prepared from raw materials comprising the following components:

[0007] Adhesive 40wt% - 60wt%;

[0008] Smoothing agent 0.3wt% - 1wt%;

[0009] Water-soluble edible pigment 0.3wt% - 1wt%;

[0010] Aqueous solution of nanocellulose 10wt% - 20wt%;

[0011] Water as the balance.

[0012] Preferably, the adhesive is a mixture of a modifier and PVA; the modifier is selected from one or more of modified starch, cellulose derivatives, and acrylate multi-component copolymers.

[0013] Preferably, the adhesive is a mixture of modified starch and PVA, or NW-318 cold sizing agent; the modified starch is phosphate starch.

[0014] Preferably, the smoothing agent is selected from one or more of glycerol monostearate, silicone-based smoothing agents, polyoxyethylene-polyoxypropylene block copolymers, and wax emulsions.

[0015] Preferably, the solid content of the aqueous nano-cellulose solution is 0.5% - 2%.

[0016] The present invention also provides a method for preparing the sizing agent for yarn as described in the above technical solution, which includes the following steps:

[0017] Mix the adhesive, smoothing agent, water-soluble edible pigment, aqueous nano-cellulose solution and water to obtain the sizing agent for yarn.

[0018] Preferably, the mixing process is specifically as follows:

[0019] First mix the adhesive, smoothing agent, water-soluble edible pigment and water to obtain a first sizing paste;

[0020] Then add the aqueous nano-cellulose solution to the above first sizing paste for a second mixing to obtain the sizing agent for yarn.

[0021] Preferably, the first mixing is carried out by mechanical stirring at a temperature of 20°C - 35°C, a rotation speed of 700 rpm - 8000 rpm, and a time of 5 min - 15 min.

[0022] Preferably, the solid content of the sizing agent for yarn is 5% - 15%.

[0023] The present invention also provides a sizing process for warp, which includes the following steps:

[0024] Size the yarn using a single-yarn sizing machine, dry it at 45°C - 60°C, and then test the strength index;

[0025] The sizing agent for yarn used in the sizing is the sizing agent for yarn as described in the above technical solution.

[0026] The present invention provides a sizing agent for yarns, a preparation method thereof, and an application thereof; the sizing agent for yarns is prepared from raw materials including the following components: 40 wt% - 60 wt% of an adhesive; 0.3 wt% - 1 wt% of a smoothing agent; 0.3 wt% - 1 wt% of a water-soluble edible pigment; 10 wt% - 20 wt% of an aqueous nano-cellulose solution; and the balance being water. Compared with the prior art, the sizing agent for yarns provided by the present invention adopts components with specific contents to achieve good overall interaction. By introducing new materials such as phosphate starch and nano-cellulose to replace part of the main PVA sizing agent, the problem of brittle and hard film on the yarn after sizing at high temperature can be solved; moreover, after sizing single yarns with the sizing agent provided by the present invention, the yarn strength enhancement rate can reach 10% - 35%, the hairiness is well adhered, the sizing film is soft and wear-resistant, and the weavability of the yarn is improved, broadening the scope of new product development.

[0027] In addition, the preparation method provided by the present invention has simple process, mild and easy-to-control conditions, easily available raw materials and low cost, and has broad application prospects. Description of the Drawings

[0028] Figure 1 SEM diagram of the original yarn form;

[0029] Figure 2 SEM diagram after sizing with Sizing Agent B (Example 1);

[0030] Figure 3 SEM diagram after sizing with Sizing Agent A (Comparative Example 1);

[0031] Figure 4 Schematic diagram of the structures of linear and branched starches;

[0032] Figure 5 Conformation diagram of linear starch molecules in a dilute solution;

[0033] Figure 6 Schematic diagram of the complex structure formed by linear molecules and fatty acids;

[0034] Figure 7 Basic structural unit of nano-cellulose molecules;

[0035] Figure 8 Schematic diagram of the aggregated structure of nano-cellulose. Detailed Embodiments

[0036] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0037] The present invention provides a sizing agent for yarns, which is prepared from raw materials comprising the following components:

[0038] Adhesive: 40 wt% - 60 wt%;

[0039] Smoothing agent: 0.3 wt% - 1 wt%;

[0040] Water-soluble edible pigment: 0.3 wt% - 1 wt%;

[0041] Aqueous solution of nanocellulose: 10 wt% - 20 wt%;

[0042] Water: the balance.

[0043] The present invention provides a sizing agent for yarns containing nanocellulose, and its preparation and use methods. The sizing agent for yarns is prepared from raw materials comprising an adhesive, a smoothing agent, a water-soluble edible pigment, an aqueous solution of nanocellulose and water, and is preferably prepared from an adhesive, a smoothing agent, a water-soluble edible pigment, an aqueous solution of nanocellulose and water.

[0044] In the present invention, the adhesive is preferably a mixture of a modifier and PVA; the modifier is preferably selected from one or more of modified starch, cellulose derivatives, acrylate copolymers, and more preferably is modified starch, cellulose derivatives or acrylate copolymers. The present invention has no special restrictions on the source of the modifier, and commercially available products well-known to those skilled in the art can be used.

[0045] In the present invention, the modified starch may include oxidized starch oxidized with oxidants such as sodium hypochlorite, acidified starch generated under the action of inorganic acids, etherified starch reacted with ethylene oxide, and esterified starch reacted with esterifying agents, and also includes grafted starch formed by graft copolymerization with acrylic acids and adding long-chain structures to the starch side chains; the starch has the following basic molecular structural units:

[0046]

[0047] The starch is further divided into amylose and amylopectin, as shown in Figure 4 shown; among them, the molecular composition of amylose consists of 64% linear molecules and 36% slightly branched linear molecules, and amylose molecules exist in the form of helices in dilute solutions, such as Figure 4 ; due to the different molecular structures of amylose and amylopectin, the properties of the films formed by the two starches are different. Amylopectin molecules have one reducing end group and many non-reducing end groups, and the aggregated state is mostly amorphous structure, and the films made are very fragile. One end of the amylose molecule is a non-reducing end group, and the other end is a reducing end group with a highly crystalline structure. It has good molecular extensibility in solution and is easy to associate with polar organic compounds through hydrogen bonds, such as Figures 5 - 6, the polar groups of amylose form complexes with the polar molecules of fatty acids. Therefore, amylose can be made into fibers and films with very high strength. The modified starch described in the present invention is preferably the phosphate starch produced by Yujie Starch Factory in Zanhuang County, Shijiazhuang City, Hebei Province. As the main sizing agent partially replacing PVA, the viscosity of this starch is 4.5 mPa·s (measured at a concentration of 6% at 95°C), and specifically it can also be NW-318 cold sizing agent (Changzhou Lego Textile Co., Ltd., the general agent in the Pulcra Chemicaks region of Germany).

[0048] In a preferred embodiment of the present invention, the sizing agent is a mixture of modified starch and PVA, or NW-318 cold sizing agent (providing a flexible sizing film, enhancing the strength of the yarn, and imparting high smoothness to the yarn); the modified starch is phosphate starch; phosphate starch, or starch phosphate ester, refers to starch monophosphate ester, that is, only one acidic functional group in the phosphate ester molecule reacts with the hydroxyl group on the carbon atom of the anhydroglucose unit (AGE) in the starch molecule to obtain starch phosphate ester, which belongs to anionic starch derivatives. This molecular structure determines the properties of starch phosphate ester: (1) the gelatinization temperature is reduced, the viscosity and transparency are increased, and the paste filaments become longer; (2) it has good dispersion and emulsification properties.

[0049] In the present invention, the cellulose derivatives preferably include ether derivatives of cellulose, such as methylcellulose (Mc), ethylcellulose (Ec), carboxymethylcellulose (cMC), and carboxyethylcellulose (cEc), etc. The ester derivatives of cellulose mainly include nitrocellulose (Nc) and acetylcellulose (Ac). Nitrocellulose is also called cellulose nitrate.

[0050] In the present invention, the smoothing agent is preferably selected from one or more of glycerol monostearate (surfactant), silicone-based smoothing agents (such as methyl silicone oil), polyoxyethylene-polyoxypropylene homopolymer, and wax emulsion (special polyolefin emulsion, water-based fluorine-free waterproof wax emulsion, Nanjing Tianshi New Materials Technology Co., Ltd.). The present invention has no special restrictions on the source of the smoothing agent, and commercially available products well-known to those skilled in the art can be used. Adding a smoothing agent to the sizing agent aims to prevent the yarns from sticking together, play the roles of anti-sticking, increasing smoothness, and wear resistance, improve the weaving efficiency of the yarn, and reduce the abrasion of the steel reed.

[0051] In the present invention, the water-soluble food colorant can be obtained from commercially available sources well-known to those skilled in the art. The addition of the food colorant is to avoid the defect of dry sizing caused by the lack of sizing material in the sizing tank during sizing, and also to visually detect the uneven sizing on the left, middle and right in a timely manner, adjust the pressure of the pressure rollers on the left, middle and right, ensure uniform sizing, strictly control the quality of the production process, make the quality process controllable, and achieve quality visual management. The food colorant has no reactive activity with the fiber, but is only used to identify defects and prevent dry sizing, resulting in missed sizing and improve the quality of sized yarns.

[0052] In the present invention, the surface of the nanocellulose has a rich hydroxyl structure, such as Figure 7 , which enhances the hydrogen bond force, such as Figure 8 , making the crystalline region more solid, the starch film more firm after film formation, increasing the yarn strength, enhancing the strength and abrasion resistance of the yarn, and reducing the hairiness on the yarn surface; the combined effect of amylose and nanocellulose has an effect of 1 + 1 > 2; the solid content of the nanocellulose aqueous solution is preferably 0.5% to 2%, more preferably 1%.

[0053] In a preferred embodiment of the present invention, the nanocellulose is prepared by the Tempo oxidation method, including the following steps:

[0054] (1) Physical pulverization: The dried cotton fibers are pulverized by a pulverizer and screened with a 60-100 mesh sieve;

[0055] (2) Swelling treatment: The cotton fiber fluff obtained in step (1) is subjected to a swelling treatment with a solvent; the solvent is dimethyl sulfoxide; the mass-volume ratio of the cotton fiber fluff to the solvent is 2% to 5% (the mass-volume ratio means: 1 g of cotton fiber fluff is used with 10-50 ml of DMSO solvent).

[0056] (3) Oxidative defibrillation: 4-6 g / L of NaBr, 0.30-0.35 g / L of TEMPO and 40-60% of NaClO solution are successively added to the swollen cotton fiber fluff, stirred and then the pH value is adjusted to 10.5-11. After oxidation, 5-10 nl of absolute ethanol with a mass percentage of 3% to 5% is added to quench the reaction; this reaction process takes about 3-4 h;

[0057] (4) Centrifugal washing: The oxidized solution is centrifugally washed, and then a nanocellulose solution is obtained; the centrifugation parameters include: the rotation speed is 5000-8000 rpm, centrifuged for 10 min, and washed until the pH is neutral;

[0058] (5) Ultrasonic dispersion, the nanocellulose solution obtained in step (4); the ultrasonic dispersion is carried out by ultrasonic dispersion treatment with an ultrasonic cell disruptor for 30-60 min.

[0059] In the present invention, the water is preferably pure water, and there is no special limitation in the present invention.

[0060] The sizing agent for yarn provided by the present invention adopts components with specific contents to achieve good overall interaction. By introducing new materials such as phosphate starch and nanocellulose to replace part of the main PVA sizing agent, the problem of brittle and hard film on the yarn after sizing at high temperature can be solved; moreover, the strength enhancement rate of the yarn after single-yarn sizing with the sizing agent provided by the present invention can reach 10% - 35%. Its hairiness is well adhered, the sizing film is soft and wear-resistant, and the weavability of the yarn is improved, broadening the scope of new product development.

[0061] The present invention also provides a preparation method of the sizing agent for yarn described in the above technical solution, including the following steps:

[0062] Mix the adhesive, lubricant, water-soluble edible pigment, nanocellulose aqueous solution and water to obtain the sizing agent for yarn.

[0063] In the present invention, the adhesive, lubricant, water-soluble edible pigment, nanocellulose aqueous solution and water are the same as those in the above technical solution, and will not be elaborated here.

[0064] In the present invention, the mixing process is preferably specifically as follows:

[0065] First mix the adhesive, lubricant, water-soluble edible pigment and water to obtain the first sizing agent;

[0066] Add the nanocellulose aqueous solution to the above first sizing agent for a second mixing to obtain the sizing agent for yarn;

[0067] More preferably:

[0068] S1 Prepare sizing agent A: Calculate and accurately weigh each material and water according to the formula, put them into a beaker, stir evenly at room temperature, record it as sizing agent A, and use a sugar meter to test whether the solid content meets the index; S2 Prepare sizing agent B: Calculate and accurately weigh the nanocellulose aqueous solution, add it to the sizing agent A prepared in S1, stir evenly mechanically, and use a sugar meter to test that the solid content meets the index.

[0069] In the present invention, the first mixing method is preferably mechanical stirring, the temperature is preferably 20°C - 35°C, the rotation speed is preferably 700 rpm - 8000 rpm, and the time is preferably 5 min - 15 min.

[0070] In the present invention, the solid content of the sizing agent for yarn is preferably 5% - 15% to be qualified.

[0071] The preparation method provided by the present invention has simple process, mild and easy-to-control conditions, easily available raw materials and low cost, and has broad application prospects.

[0072] The present invention also provides a sizing process, comprising the following steps:

[0073] Sizing the yarn using a single-yarn sizing machine (room-temperature sizing), drying at 45°C to 60°C, and then testing the strength index;

[0074] The sizing agent used for sizing the yarn is the sizing agent for yarn as described in the above technical solution.

[0075] In the present invention, the sizing of the yarn uses a single-yarn sizing machine for low-temperature sizing process, the machine speed is preferably 40 to 60 meters per minute, and then drying is carried out. The drying temperature is preferably 45°C to 60°C, and finally the strength index is tested.

[0076] In the present invention, the sizing agent used for sizing the yarn is the sizing agent for yarn as described in the above technical solution. Dilute the sizing agent for yarn to the required concentration and stir for 10 minutes before use, without heating to 95°C, let alone boiling for 20 to 30 minutes before use.

[0077] The present invention provides a sizing agent for yarn, its preparation method and application, and the beneficial effects are as follows:

[0078] (1) The nano-cellulose introduced in the present invention has a rich hydroxyl structure on its surface, which enhances the hydrogen bond force, makes the starch crystalline region more solid, the starch film formed after filming is more firm, the yarn strength increases, the strength and wear resistance of the yarn are enhanced, and the hairiness on the yarn surface is reduced; the combined effect of amylose and nano-cellulose plays a role of 1 + 1 > 2.

[0079] (2) Starch phosphate ester is introduced. Since starch phosphate ester belongs to anionic starch derivatives and this starch phosphate ester belongs to a high-concentration and low-viscosity sizing agent, the sizing amount is large, the yarn strength enhancement rate is large, and the enhancement ratio of different yarns is different, generally the enhancement rate is 10% to 35%, the weavability is improved, and the scope of new product development is broadened.

[0080] (3) Sizing the yarn by single-yarn sizing method, accurately calculating the length of the sized yarn, reducing the waste of the yarn after sizing, and reducing the R & D cost.

[0081] (4) The temperature of the sizing process is low (the traditional high-temperature boiling process is to boil in a sizing bath at 95°C and keep warm for 1 h, and the present invention does not require high-temperature boiling), saving energy and reducing consumption, and being green, low-carbon and environmentally friendly.

[0082] (5) Adding water-soluble food coloring to prevent defective products from being produced, improving product quality, increasing the first-pass success rate, and reducing the rework and production costs.

[0083] The present invention provides a sizing agent for yarns, a preparation method thereof, and an application thereof. The sizing agent for yarns is prepared from raw materials including the following components: 40 wt% - 60 wt% of an adhesive; 0.3 wt% - 1 wt% of a smoothing agent; 0.3 wt% - 1 wt% of a water-soluble edible pigment; 10 wt% - 20 wt% of an aqueous nano-cellulose solution; and the balance of water. Compared with the prior art, the sizing agent for yarns provided by the present invention adopts components with specific contents to achieve good overall interaction. By introducing new materials such as phosphate starch and nano-cellulose to replace part of the PVA main sizing agent, the problem of brittle and hard film on the yarn after sizing at high temperature can be solved. Moreover, after single-yarn sizing with the sizing agent provided by the present invention, the yarn strength enhancement rate can reach 10% - 35%. The hairiness is well-adhered, the sizing film is soft and wear-resistant, and the weavability of the yarn is improved, broadening the scope of new product development.

[0084] In addition, the preparation method provided by the present invention has simple process, mild and easy-to-control conditions, easily available raw materials and low cost, and has broad application prospects.

[0085] To further illustrate the present invention, the following detailed description is provided through the following examples. All raw materials used in the following examples of the present invention are commercially available products. Among them, the smoothing agent used is glycerol monostearate, and the preparation method of the aqueous nano-cellulose solution used is as follows:

[0086] (1) Screening:

[0087] S1: Screen the dried cotton fibers with an 80-mesh sieve, weigh the powder that falls through the screening for the next step of treatment;

[0088] S2: First, pretreat the cotton fiber fluff obtained by screening in S1 with DMSO (dimethyl sulfoxide, analytical pure (AR), Fuchen (Tianjin) Chemical Reagent Co., Ltd.) to swell the fibers; then use the TEMPO / NaBr / NaClO oxidation system to selectively oxidize the surface of the swollen fluff; then centrifuge the oxidized solution to remove the reaction solvent; finally, perform ultrasonic crushing treatment on the obtained solution to obtain a nano-cellulose suspension (sodium hypochlorite solution, analytical pure AR, 6 - 14% active chlorine, Nacro);

[0089] The specific operation is as follows: Pour the DMSO solution into the cotton fibers obtained in S1, and magnetically stir at 60 °C for 5 h to swell the fibers. After the reaction, use a vacuum filtration device to wash the fluff clean. The main purpose of the DMSO pretreatment is to swell the fibers, and strong acids or other solvents penetrate into the amorphous region to untie the crystalline regions for subsequent oxidation reactions. The mass-volume ratio of the cotton fiber fluff to the DMSO solution is 2 - 5%; specifically 3%, and more specifically 1 g of fluff to 30 - 40 ml of DMSO.

[0090] (2) Oxidation reaction: Dissolve the swollen flower hair in water in an ice-water bath. After dispersing it evenly under magnetic stirring for 10 min, add reagents. Add 6 g / L NaBr and 0.30 - 0.32 g / L TEMPO (2,2,6,6-tetramethylpiperidine)-1-oxyl radical in sequence. Dropwise add the NaClO solution with a concentration of 40 - 60%. After stirring evenly, adjust the pH of the solution to 10.5 ± 0.5. After the oxidation reaction is completed, add 5 ml of 3 - 5% anhydrous ethanol to completely stop the reaction.

[0091] (3) Use a high-speed centrifuge (tabletop high-speed refrigerated centrifuge filing number: Hunan Chang Medical Equipment Preparation 20160150, Changsha Qile Instrument Co., Ltd.) to centrifuge the oxidized solution. After the centrifugation is completed, pour off the supernatant. Add deionized water and continue centrifugation until the pH of the solution is neutral. After centrifugation, pour off the supernatant. Leave the precipitate and add an appropriate amount of deionized water and stir evenly to obtain the aqueous solution of the nanocellulose as described.

[0092] Examples and comparative examples

[0093] As shown in Table 1, Table 1 shows the components and ratios (mass percentage) of the sizing agents for the yarns provided in Example 1 and Comparative Example 1.

[0094] Table 1

[0095]

[0096] Calculate and accurately weigh the weights of each component according to the formula table, and prepare the sizing agent and size the yarn according to the following steps:

[0097] S1 Prepare sizing agent A: Calculate and accurately weigh each material and water according to the formula and put them into a beaker. Stir evenly mechanically at room temperature, and record it as sizing agent A. Use a saccharimeter to test whether the solid content meets the index; the solid content is 8%. After stirring evenly, test the solid content and viscosity of the sizing agent, as shown in Table 2.

[0098] S2 Prepare sizing agent B: Calculate and accurately weigh 10 - 20% of the aqueous solution of nanocellulose with a solid content of 1% and put it into sizing agent A prepared in S1. Stir evenly mechanically, and record it as sizing agent B. Use a saccharimeter to test whether the solid content meets the index; the solid content is 8.2%. After stirring evenly, test the solid content and viscosity of the sizing agent, as shown in Table 2.

[0099] The above mechanical stirring process uses a DF101 thermostatic heating magnetic stirrer with heat collection, provided by Yuhua Instrument Co., Ltd., Gongyi City. Temperature: room temperature 25°C - 35°C, stirring speed 4500 rpm, time 10 min.

[0100] Sizing was carried out on the same sizing process using Sizing Agent A and Sizing Agent B respectively: sizing was performed using a single yarn sizing machine (pure cotton 21S, GA392 single yarn sizing machine, Jiangyin Tongyuan Textile Machinery Co., Ltd., machine speed 40 ± 5 m / min, drying temperature 50 ± 5 °C), the strength index was tested and the enhancement rate was calculated, as shown in Table 3; the SEM images of the products before and after sizing are shown in Figures 1 - 3 as shown; from Figures 1 - 3 it can be seen that after sizing with Sizing Agent B, the hairiness is more compliant and the diameter is smaller, while after sizing with Sizing Agent A, although the hairiness is compliant, the diameter is slightly larger.

[0101] Table 2 Data table of sizing agent concentration and viscosity configuration

[0102] Size Concentration (%) Viscosity (mPa·s) Yarn Strength (N) Enhancement Rate (%) 40s Pure Cotton Raw Yarn - - 235.4 - Size A (Comparative Example 1) 8.0 153.0 245.3 4.2 Size B (Example 1) 8.2 800.0 257.3 9.3

[0103] Table 3 Data table of yarn strength test after sizing with sizing agent configuration

[0104]

[0105] Note: Enhancement rate = strength enhancement value / original yarn breaking strength × 100%.

[0106] Analyzing the data in the above table, it can be obtained that after adding the nanocellulose solution, the viscosity of the sizing agent increases and the sizing agent becomes more viscous. After sizing the yarn with the sizing agent added with nanocellulose, the yarn strength has increased somewhat, and the average increase in the enhancement amount is 43.2, and the average enhancement rate is 11%. This is mainly because nanocellulose and starch macromolecules have the same basic structural units. According to the principle of similar compatibility of high molecular compounds, the compatibility between compound macromolecules is better, and the hydroxyl groups on the molecules are conducive to the formation of intermolecular hydrogen bonds, making the strength of the sizing film better after drying, which is conducive to the improvement of yarn strength. Analyzing the electron microscope pictures, it can be seen that after sizing with Sizing Agents A and B, the hairiness of the yarn is in good compliance, the warp yarn diameter decreases, and the fiber cohesion is closer; this is because the intermolecular hydrogen bonds between the long-chain alkyl groups on the macromolecular structure of the modified starch sizing agent, the surface hydroxyl groups of nanocellulose and the hydroxyl groups on the original starch long-chain and the hydroxyl groups on the original corn starch chain are weakened, playing the role of a plasticizer, reducing the surface tension of the sizing agent, enhancing the penetration performance of the sizing agent, facilitating the penetration of the sizing agent into the fibers of the yarn, and enhancing the cohesion between the fibers.

[0107] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sizing agent for yarn, characterized in that, Prepared from raw materials comprising the following components: Adhesive: 40wt% - 60wt%; Smoothing agent: 0.3wt% - 1wt%; Water-soluble edible pigment: 0.3wt% - 1wt%; Aqueous nano-cellulose solution: 10wt% - 20wt%; Water: the balance.

2. The sizing agent for yarn according to claim 1, characterized in that, The adhesive is a mixture of a modifier and PVA; the modifier is selected from one or more of modified starch, cellulose derivatives, and acrylate copolymers.

3. The sizing agent for yarn according to claim 2, characterized in that, The adhesive is a mixture of modified starch and PVA, or NW-318 cold sizing agent; the modified starch is phosphate starch.

4. The sizing agent for yarn according to claim 1, characterized in that, The smoothing agent is selected from one or more of glyceryl stearate, silicone-based smoothing agents, polyoxyethylene-polyoxypropylene homopolymers, and wax emulsions.

5. The sizing agent for yarn according to claim 1, wherein, The solid content of the aqueous nano-cellulose solution is 0.5% - 2%.

6. A method for preparing the sizing agent for yarn according to any one of claims 1 to 5, characterized in that, Comprising the following steps: Mix the adhesive, smoothing agent, water-soluble edible pigment, aqueous nano-cellulose solution, and water to obtain a yarn sizing agent.

7. The preparation method according to claim 6, characterized in that, The specific process of the mixing is as follows: First mix the adhesive, smoothing agent, water-soluble edible pigment, and water to obtain a first slurry; Add the aqueous nano-cellulose solution to the above first slurry for a second mixing to obtain a yarn sizing agent.

8. The preparation method according to claim 7, characterized in that, The first mixing is carried out by mechanical stirring at a temperature of 20°C - 35°C, a rotation speed of 700rpm - 8000rpm, and a time of 5min - 15min.

9. The preparation method according to claim 6, characterized in that, The solid content of the yarn sizing agent is 5% - 15%.

10. A sizing process, characterized in that, Comprising the following steps: Use a single-yarn sizing machine to size the yarn, dry it at 45°C - 60°C, and then test the strength index; The yarn sizing agent used for sizing is the yarn sizing agent according to any one of claims 1 - 5.

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