A method for regenerating waste polyester textiles to prepare polyester fibers

Abstract

The invention discloses a method for preparing polyester fiber by regenerating waste polyester textiles, belongs to the technical field of polyester recycling, and is used to solve the technical problem that the antibacterial property and wear resistance of regenerated polyester fiber in the prior art need to be further improved; the invention comprises the following steps: using a roller oiler to evenly coat high-temperature wear-resistant oil on spinning fibers, solidifying, and obtaining polyester fibers; the invention prepares a modified titanium filler and high-temperature wear-resistant oil, and the modified titanium filler hybridizes polyester segments while improving the efficiency of double-stage filtration, and serves as a skeleton of the wear-resistant high-temperature oil and a bridge connecting the wear-resistant high-temperature oil and the polyester fiber to stabilize the oil layer structure and reduce the loss of the polyester fiber during the winding process, wherein the titanium dioxide particles inside the polyester fiber and in the high-temperature wear-resistant oil can excite electrons under ultraviolet light irradiation to generate a strong oxidant, achieve effective sterilization, and finally obtain a wear-resistant and antibacterial polyester fiber.

Description

Technical Field

[0001] The invention relates to the technical field of polyester recycling, and in particular to a method for preparing polyester fibers by regenerating waste polyester textiles. Background Art

[0002] Under the current background of sustainable development, the recycling of waste polyester textiles has become increasingly important. Polyester fibers, especially polyester fibers, are favored for their excellent wear resistance and wide application. However, traditional polyester fibers are often insufficient in terms of bactericidal ability and wear resistance. By recycling waste polyester textiles, it is possible to effectively reduce resource waste and open up new paths for improving fiber performance.

[0003] In the process of recycling and regenerating polyester materials, impurity filtration is one of the key links, which directly affects the quality and production efficiency of recycled polyester. However, traditional filtration systems often face the problems of easy clogging of filter screens and reduced filtration efficiency. Especially when the melt contains large particles of impurities, the filtration device is frequently blocked, resulting in shutdowns, cleaning and other problems. This not only increases maintenance costs but also reduces overall production efficiency.

[0004] Prior art CN115449919A discloses a regenerated polyester antibacterial deodorizing fiber and a production process thereof, comprising the following raw materials in parts by weight: 100-120 parts of regenerated polyester masterbatch, 8-12 parts of tea polyphenol modifier, 10-12 parts of inorganic antibacterial powder, 0.5-2 parts of dispersant and 0.1-0.3 parts of thickener. The patent greatly improves the antibacterial property and antibacterial durability of polyester fiber through the coordinated synergistic effect of tea polyphenol modifier and inorganic antibacterial powder, activates and modifies tea polyphenol, and can effectively inhibit the growth of microorganisms through the cross-linking activation of polyvinyl alcohol and potassium polyacrylate. The activated tea polyphenol can also complex with metal ions to inactivate metal enzymes and achieve an antibacterial effect. Nano zirconium dioxide can be used as a functional material for antibacterial regenerated polyester fiber to achieve the functions of heat storage, heating and antibacterial. Medical stone powder is loaded with silver antibacterial agent to increase the surface area of ​​contact between medical stone powder and loaded silver, thereby improving the antibacterial property of polyester fiber.

[0005] However, the above patent is to obtain antibacterial and deodorizing fibers by melt-treating waste polyester and mixing it with auxiliary materials. However, after the waste polyester is melt-treated, it is not filtered to remove impurities in the melt, and the impurities in the melt will have a negative impact on subsequent processing. In addition, the antibacterial substance in this solution is a mixture of inorganic materials and organic materials to achieve a bactericidal effect. Due to the large difference in polarity between the two, the interfacial bonding force between the two is weak, which affects the mutual coordination between the two, resulting in the antibacterial and wear-resistant properties of the fiber prepared by the invention need to be further improved.

[0006] In view of the technical defects in this aspect, a solution is now proposed. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing polyester fibers by regenerating waste polyester textiles, so as to solve the technical problem in the prior art that the antibacterial property and wear resistance of the regenerated polyester fibers need to be further improved.

[0008] The purpose of the present invention can be achieved by the following technical solution: A method for preparing polyester fiber by regenerating waste polyester textiles, comprising the following steps:

[0009] S1, adding pre-treated waste polyester, modified titanium filler and auxiliary materials into a twin-screw extruder for melt extrusion to obtain a molten body, and then filtering the molten body in two stages to obtain molten polyester;

[0010] S2, adding molten polyester into a spinning manifold, and obtaining homogenized molten polyester after homogenization and distribution;

[0011] S3, extruding the homogenized molten polyester through a spinneret and transferring it to a side-blowing chamber, and obtaining spun fibers after air cooling and solidification;

[0012] S4. Use a roller oiler to evenly apply high-temperature wear-resistant oil on the spun fibers, and then solidify them to obtain polyester fibers.

[0013] Furthermore, in step S1, the auxiliary materials include: a heat stabilizer, a lubricant and an antioxidant, and the amount ratio of the pre-treated waste polyester, the modified titanium filler, the heat stabilizer, the lubricant and the antioxidant is 80-100g: 20-30g: 5-8g: 3-5g: 5-8g, and the pre-treatment step is: putting the waste polyester textile into a drum and preheating it with 150°C steam, evaporating the water and extracting the water vapor with the help of a vacuum system, vacuuming for 8-10 hours to remove the water, completing drying, and obtaining the pre-treated waste polyester.

[0014] Furthermore, the heat stabilizer is one or more of dibutyltin dilaurate, triphenyl phosphate and epoxy soybean oil; the lubricant is one or more of calcium stearate, zinc stearate and polyethylene wax; the antioxidant is one or more of antioxidant 1010, triphenyl phosphite and dilauryl sulfide; the temperatures of the eight temperature zones of the twin-screw extruder from the feed port toward the discharge port are 280°C, 280, 285°C, 295°C, 295°C, 300°C, and 300°C respectively, the main engine speed of the twin-screw extruder is 80-120rpm, and the pressure is 100-150bar.

[0015] Further, in step S1, the operation of double-stage filtration is: the melt is first filtered through a primary filter with a particle size of 10-30 μm at a pressure of 1-2 MPa, and then filtered through a secondary filter with a particle size of 5-8 μm at a pressure of 2-4 MPa to obtain molten polyester, wherein the primary filter is replaced at a frequency of 500-750 h / time, and the secondary filter is replaced at a frequency of 1000-1500 h / time, and the filter is replaced in advance when the pressure difference reaches 0.4 MPa; wherein the preparation method of the modified titanium filler comprises the following steps:

[0016] A1. Add tetraisopropyl titanate and ethanol to a reactor, stir at room temperature for 10-15 min, add deionized water and 0.1-0.3 M hydrochloric acid solution to the reactor, continue stirring for 2-4 h, and let stand for 12-16 h to obtain an aged gel, which is then post-treated to obtain titanium dioxide particles;

[0017] The reaction principle for preparing titanium dioxide particles is as follows: at room temperature, tetraisopropyl titanate reacts with deionized water to undergo hydrolysis to generate a titanate intermediate. The hydrochloric acid solution provides hydrogen ions to promote the formation of more hydroxy titanium compounds. As the reaction proceeds, condensation reactions occur between the formed hydroxy titanium compounds to generate polymer chains, ultimately forming an aged gel with a network structure, which is then calcined and ground to obtain titanium dioxide particles.

[0018] A2, dispersing titanium dioxide particles and deionized water in a hydrothermal reactor, controlling the temperature of the hydrothermal reactor to 120-150° C., the pressure to 2-3 MPa, keeping the reaction temperature for 1-2 hours, and post-treating to obtain a hydroxylated filler;

[0019] The reaction principle for preparing hydroxylated fillers is as follows: under the conditions of 120-150°C and 2-3MPa, the physical and chemical properties of water change, showing higher solubility and reactivity. Under high temperature and high pressure, the surface of titanium dioxide particles dissolves to form titanate ions (TiO 6 2- ) and react with hydroxyl ions (OH - ) reaction to form a hydroxylated titanium compound to prepare a hydroxylated filler.

[0020] A3. Add hydroxylated filler, N-aminoethyl-3-aminopropyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, triethylamine and deionized water into a reactor, keep the reaction warm for 1-2 hours, and post-treat to obtain modified titanium filler.

[0021] The reaction equation for preparing modified titanium filler is:

[0022]

[0023] Where: Indicates hydroxylated filler.

[0024] The reaction principle for preparing the modified titanium filler is as follows: under the catalysis of alkaline conditions, the silane coupling agent is hydrolyzed to form silanol bonds that cross-link with the hydroxylated filler to form a stable structure, and finally the modified titanium filler is prepared.

[0025] Further, in step A1, the stirring rate of the reactor is 60-80rpm, the amount ratio of tetraisopropyl titanate, ethanol, deionized water and 0.1-0.3M hydrochloric acid solution is 8-10g:30-40mL:20-30mL:5-6mL, and the post-treatment includes: adding the aged sol to a drying oven at a temperature of 60°C and vacuum drying for 2-4h, placing the material in a tubular furnace, passing nitrogen protection, heating to 400-600°C at a heating rate of 5°C / min, keeping warm for 1-2h, and naturally cooling to obtain crystalline titanium dioxide particles, and grinding and passing through a 10000 mesh sieve to obtain titanium dioxide particles; in step A2, the amount ratio of titanium dioxide particles to deionized water is 3- 5g:15-20mL, post-treatment includes: after the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is placed in a drying oven at a temperature of 80°C for vacuum drying until the filter cake has a constant weight, and a hydroxylated filler is obtained; in step A3, the amount ratio of the hydroxylated filler, N-aminoethyl-3-aminopropyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, triethylamine and deionized water is 8-10g:2-3g:2-3g:0.3-0.5g:40-60mL, and post-treatment includes: after the reactor is lowered to room temperature, the reaction liquid is filtered to collect the filter cake, the filter cake is placed in a drying oven at a temperature of 80°C for vacuum drying until the filter cake has a constant weight, and a modified titanium filler is obtained.

[0026] Furthermore, in step S2, the operation of averaging and distributing includes the following steps:

[0027] B1. Use gas phase heat medium to keep the melt warm, control the melt temperature at 285-290°C, and set the heat medium system circulation at 100-120°C to maintain uniform heat transfer to obtain a uniformly heated melt;

[0028] B2. Use a metering pump to introduce the homogenized melt into a static mixer for homogenization to obtain a homogenized polyester.

[0029] Furthermore, in step B1, the gas phase heat medium is biphenyl-biphenyl ether; in step B2, the flow rate of the homogenized melt is 500-1000 kg / h, the static mixer is one of a spiral static mixer and a honeycomb static mixer, the homogenization time is 30-60 s, and the homogenized polyester should meet the temperature of 285-290 ° C, the dynamic viscosity of 250-280 Pa·s, the dispersion uniformity of 95-99% and the impurity content of 0.001-0.005%.

[0030] Furthermore, in step S3, the holes of the spinneret are circular, the mesh number is 32-64, the pore size is 0.1-0.5 mm and the spinning pressure is 80-150 bar; the cold wind is air, the relative humidity is 30-50%, the temperature is 20-30°C and the flow rate is maintained at 5-10 m / s.

[0031] Furthermore, in step S4, the roller diameter in the roller oiler is 50-100 mm, the rotation speed is 200-300 rpm, the spinning fiber contact pressure is 0.5-1 N, the high temperature wear-resistant oil flow rate is 10-30 ml / min and the temperature is maintained at 20-25°C.

[0032] Further, in step S4, the preparation method of high temperature wear-resistant oil is:

[0033] C1, dihydroxydibenzocyclohexanone, 1,3-dichlorobenzene, potassium carbonate and diphenyl sulfone are added into a reaction kettle, the temperature of the reaction kettle is raised to 300-340°C, the reaction is kept warm for 2-3 hours, and modified polyetheretherketone is obtained by post-treatment;

[0034] The reaction equation for preparing modified polyetheretherketone is:

[0035]

[0036] The reaction principle for preparing modified polyetheretherketone is as follows: at high temperature, dihydroxydibenzocyclohexanone can undergo a decarboxylation reaction to generate active aromatic compounds; 1,3-dichlorobenzene, as a nucleoside, reacts with the generated aromatic intermediates through a nucleophilic substitution reaction to form a basic unit of the copolymer; potassium carbonate, as an alkaline catalyst, can promote the nucleophilic substitution reaction and enhance the reaction rate; at a high temperature of 300-340°C, a condensation reaction occurs between the reactants to form a polymer chain to prepare modified polyetheretherketone.

[0037] C2, adding modified polyetheretherketone and modified titanium filler into a reactor and stirring, raising the temperature of the reactor to 350-360° C., keeping the temperature and stirring for 1-2 hours, and post-treating to obtain modified polyetheretherketone powder;

[0038] The reaction principle for preparing the modified polyetheretherketone powder is as follows: at high temperature, the amino group and the imino group on the surface of the modified titanium filler react to form a stable cross-linked structure, which is then pulverized after cooling to obtain the modified polyetheretherketone powder.

[0039] C3. Add modified polyetheretherketone powder, polyvinyl pyrrolidone and N-methylpyrrolidone into a reactor and stir. The temperature of the reactor is increased to 150-170°C. The reactor is stirred for 1-2 hours at this temperature. After natural cooling, high-temperature wear-resistant oil is obtained.

[0040] Further, in step C1, the amount ratio of dihydroxydibenzocyclohexanone, 1,3-dichlorobenzene, potassium carbonate and diphenyl sulfone is 8-10g:3-5g:0.8-1.2g:45-60mL, and the post-treatment includes: after the reaction is completed, after the temperature of the reactor is lowered to room temperature, the material is washed 3-5 times with deionized water at a temperature of 50-60°C, and the material is placed in a rotary evaporator with a salt bath temperature of 150-160°C, and decompressed and distilled until no liquid is extracted, Modified polyetheretherketone is obtained; in step C2, the dosage ratio of modified polyetheretherketone and modified titanium filler is 8-10g:3-4g, and the post-treatment is: after the reactor is cooled to room temperature, the material is ground through a 300-600 mesh sieve to obtain modified polyetheretherketone powder; in step C3, the stirring rate of the reactor is 80-120rpm, and the dosage ratio of modified polyetheretherketone powder, polyvinylpyrrolidone and N-methylpyrrolidone is 8-10g:2-3g:40-60mL.

[0041] Furthermore, the produced polyester fiber is drawn through double drafting rollers and then wound, the temperature of the first drafting roller is 80-90°C, the temperature of the second drafting roller is 100-120°C, the draft ratio is 3.5-4.5, the speed of the first drafting roller is 300-400m / min, and the speed of the second drafting roller is adjusted proportionally according to the draft ratio, and the speed of the winding head is 1500-2000m / min; a wire detector is provided in front of the winding machine to detect the broken ends of the tow, activate the cutter, the tow collection device and the waste wire suction system, The detection sensitivity is 0.3-0.7mm, the signal response time is ≤30ms, the activation cutter delay time is 50-150ms, the pressure of the waste wire suction system is maintained at 0.3-0.5MPa and the capacity of the wire bundle collection device is 1-3m³. The finished silk cakes are respectively packaged in large cartons according to product varieties and grades after physical inspection, appearance inspection and grading. After manual boxing, manual bundling, weighing and labeling, they are transported to the finished product warehouse by manual forklifts and stacked in the finished product warehouse by internal combustion forklifts.

[0042] The present invention has the following beneficial effects:

[0043] 1. The present invention provides a method for preparing polyester fibers by regenerating waste polyester textiles, and prepares a modified titanium filler and high-temperature wear-resistant oil. The modified titanium filler improves the efficiency of double-stage filtration while hybridizing polyester segments, and serves as a skeleton of the wear-resistant high-temperature oil and a bridge connecting the wear-resistant high-temperature oil and the polyester fiber to stabilize the properties of the polyester fiber and reduce the loss of the polyester fiber during the winding process. A large amount of titanium dioxide particles inside the fiber and in the high-temperature wear-resistant oil can excite electrons under ultraviolet light to generate strong oxidants, destroy bacterial cell membranes and genetic material, thereby achieving effective sterilization, and finally preparing a wear-resistant and antibacterial polyester fiber.

[0044] 2. The present invention provides a method for regenerating waste polyester textiles to prepare polyester fibers. When processing a melt, two-stage filtration is used to improve the purity of the melt, and a modified filler is prepared to improve the efficiency of the two-stage filtration. The modified filler with a small particle size can play a dual role as a stabilizer and a dispersant in the polyester melt, and can effectively react with impurity particles in the melt to form these impurities into smaller and more uniform particles at the microscopic level, thereby reducing the filtration burden; in the two-stage filtration process, the primary filtration can efficiently remove smaller particles, and the pressure load in the fine filtration stage can also be significantly reduced, thereby extending the service life of the filter and reducing the frequency of cleaning and replacement. The small particle size of the modified filler promotes its ability to form a stable distribution in the melt, which not only further improves the efficiency of the two-stage filtration, but also improves the stability of the entire filtration system and reduces unnecessary downtime for maintenance.

[0045] 3. The polyester segments in the melt obtained by filtration in the present invention can be cross-linked with the active functional groups on the surface of the modified filler. This cross-linked structure can more effectively isolate and remove impurities in the molten polyester, and enhance the complexity of the spatial structure of the polyester segments. While improving its mechanical properties, nano-titanium dioxide has photocatalytic properties, which can help decompose harmful chemicals during the filtration process, significantly improve the filtration efficiency, and is more environmentally friendly, bringing additional environmental cleaning benefits; and in the process of preparing high-temperature wear-resistant oil, firstly, a modified polyetheretherketone is prepared by selecting a monomer, and the ketone group thereof cross-links with the amino group grafted on the modified titanium filler at high temperature to form a stable structure. After being coated on the polyester surface, the epoxy group grafted on the modified titanium filler continues to form a cross-link with the polyester surface, and the modified carbon filler acts as a bridge to form a stable cross-linked structure between the high-temperature wear-resistant oil and the polyester fiber. The main component polyetheretherketone in the high-temperature wear-resistant oil significantly improves the wear resistance and high temperature resistance of the fiber, reduces the loss of the polyester fiber in the subsequent winding process, and gives the polyester fiber excellent wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 The present invention is a process flow chart for preparing polyester yarn cakes. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] This embodiment provides a method for regenerating waste polyester textiles to prepare polyester fibers, comprising the following steps:

[0051] S1. Preparation of modified titanium filler

[0052] Weigh: 18.0g of tetraisopropyl titanate and 70.0mL of ethanol are added to a reactor, the stirring rate of the reactor is 60rpm, and the reaction is stirred at room temperature for 10min. 50.0mL of deionized water and 12.0mL of 0.2M hydrochloric acid solution are added to the reactor, and the stirring is continued for 2h, and then it is left to stand for 12h to obtain an aged gel. The aged sol is added to a drying oven at a temperature of 60°C and vacuum dried for 2h. The material is placed in a tubular furnace, nitrogen is introduced for protection, and the temperature is increased to 400°C at a heating rate of 5°C / min, and the temperature is kept for 1h. The crystalline titanium dioxide particles are naturally cooled, and the titanium dioxide particles are obtained after grinding and passing through a 10000 mesh sieve;

[0053] Weigh: 8.0 g of titanium dioxide particles and 32.0 mL of deionized water are dispersed in a hydrothermal reactor, the temperature of the hydrothermal reactor is controlled to be 120° C., the pressure is 2 MPa, and the reaction is kept warm for 1 hour. After the reactor is cooled to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is placed in a drying oven at a temperature of 80° C. for vacuum drying until the filter cake has a constant weight, thereby obtaining a hydroxylated filler;

[0054] Weigh: 20.0g of hydroxylated filler, 6.0g of N-aminoethyl-3-aminopropyltriethoxysilane, 5.0g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 0.8g of triethylamine and 80.0mL of deionized water, add into the reactor, keep warm for 1h, after the reactor is lowered to room temperature, filter the reaction liquid to collect the filter cake, place the filter cake in a drying oven at 80°C for vacuum drying until the filter cake has constant weight, to obtain a modified titanium filler.

[0055] S2. Preparation of molten polyester

[0056] The waste polyester textiles are put into a rotary drum and preheated with 150°C steam, the water evaporates and the water vapor is extracted with the help of a vacuum system, the water is removed by vacuuming for 8 hours, and the drying is completed to obtain the pre-treated waste polyester;

[0057] Weigh: 84.0 g of pre-treated waste polyester, 24.0 g of modified titanium filler, 12.0 g of triphenyl phosphate, 8.0 g of zinc stearate and 12.0 g of dilauryl sulfide and add them into a twin-screw extruder, the temperatures of the eight temperature sections of the twin-screw extruder from the feed port to the discharge port are 280° C., 280, 285° C., 295° C., 295° C., 300° C., 300° C., the main engine speed of the twin-screw extruder is 80 rpm, the pressure is 100 bar, and a melt is extruded;

[0058] The melt was first filtered through a primary filter with a particle size of 20 μm at a pressure of 1 MPa, and then filtered again through a secondary filter with a particle size of 8 μm at a pressure of 2 MPa to obtain molten polyester.

[0059] S3. Preparation of spinning fibers

[0060] The molten polyester is added into the spinning box, and the melt is kept warm by using a gas phase heat medium, wherein biphenyl-biphenyl ether is selected as the gas phase heat medium, and the melt temperature is controlled at 285°C, and the heat medium system circulation is set at 100°C to maintain uniform heat transfer to obtain a uniformly heated melt;

[0061] The homogenized melt was introduced into a spiral static mixer at a flow rate of 500 kg / h using a metering pump for homogenization. The homogenization time was 30 s, and a homogenized polyester with a temperature of 285° C., a dynamic viscosity of 250 Pa·s, a dispersion uniformity of 98.3%, and an impurity content of 0.004% was obtained.

[0062] The homogenized molten polyester is extruded through a spinneret, the holes of the spinneret are circular, the mesh number is 32, the pore size is 0.1 mm and the spinning pressure is 80 bar. After extrusion, it is transferred to a side-blown air chamber, the cold wind is air, the relative humidity is 30%, the temperature is 20°C and the flow rate is maintained at 5 m / s, and the spun fiber is obtained after air cooling and curing.

[0063] S4. Preparation of high temperature wear-resistant oil

[0064] Weigh: 20.0 g of dihydroxydibenzocyclohexanone, 8.4 g of 1,3-dichlorobenzene, 2.0 g of potassium carbonate and 100.0 mL of diphenyl sulfone are added to a reactor, the temperature of the reactor is raised to 300° C., and the reaction is kept warm for 2 hours. After the reaction is completed, the temperature of the reactor is lowered to room temperature, and the material is washed three times with deionized water at a temperature of 50° C., and then placed in a rotary evaporator with a salt bath temperature of 150° C., and decompressed and distilled until no liquid is produced to obtain modified polyetheretherketone;

[0065] Weigh: 18.0 g of modified polyetheretherketone and 8.0 g of modified titanium filler are added to a reactor and stirred. The temperature of the reactor is raised to 350° C. and stirred for 1 hour. After the reactor is cooled to room temperature, the material is ground through a 300-mesh sieve to obtain modified polyetheretherketone powder;

[0066] Weigh: 18.0 g of modified polyetheretherketone powder, 5.0 g of polyvinylpyrrolidone and 100.0 mL of N-methylpyrrolidone, add into a reactor and stir, raise the temperature of the reactor to 150° C., keep stirring for 2 h at a stirring rate of 80 rpm, and obtain high-temperature wear-resistant oil after natural cooling.

[0067] S5. Preparation of polyester yarn cake

[0068] The high-temperature wear-resistant oil is evenly applied to the spinning fiber using a roller oiler, wherein the roller diameter of the roller oiler is 50 mm, the rotation speed is 200 rpm, the spinning fiber contact pressure is 0.5 N, the high-temperature wear-resistant oil flow rate is 10 ml / min and the temperature is maintained at 20° C., and the polyester fiber is solidified;

[0069] The polyester fiber is wound to obtain a silk cake. The winding operation is carried out by stretching with double drafting rollers and then winding. The temperature of the first drafting roller is 80°C, the temperature of the second drafting roller is 100°C, the draft ratio is 4, the speed of the first drafting roller is 300m / min, the speed of the second drafting roller is 1200m / min, and the speed of the winding head is 1500m / min. A wire detector is arranged in front of the winder to detect the broken ends of the tow, activate the cutter, the tow collection device and the waste wire suction system. The detection sensitivity is 0.3mm, the signal response time is 30ms, the delay time of the activation cutter is 50ms, the pressure of the waste wire suction system is maintained at 0.3MPa, and the capacity of the tow collection device is 1m 3 , the yarn cakes are graded and packaged to obtain polyester yarn cakes.

[0070] Example 2

[0071] This embodiment provides a method for regenerating waste polyester textiles to prepare polyester fibers, comprising the following steps:

[0072] S1. Preparation of modified titanium filler

[0073] Weigh: 20.0g of tetraisopropyl titanate and 40.0mL of ethanol are added to a reactor, the stirring rate of the reactor is 80rpm, and the reaction is stirred at room temperature for 15min. 50.0mL of deionized water and 10.0mL of 0.2M hydrochloric acid solution are added to the reactor, and the stirring is continued for 3h, and then it is left to stand for 16h to obtain an aged gel. The aged sol is added to a drying oven at a temperature of 60°C and vacuum dried for 3h. The material is placed in a tubular furnace, nitrogen is introduced for protection, and the temperature is increased to 500°C at a heating rate of 5°C / min, and the temperature is kept for 1h. The crystalline titanium dioxide particles are naturally cooled, and the titanium dioxide particles are obtained after grinding and passing through a 10000 mesh sieve;

[0074] Weigh: 8.0 g of titanium dioxide particles and 32.0 mL of deionized water are dispersed in a hydrothermal reactor, the temperature of the hydrothermal reactor is controlled to be 150° C., the pressure is 3 MPa, and the reaction is kept warm for 1 hour. After the reactor is cooled to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is placed in a drying oven at a temperature of 80° C. for vacuum drying until the filter cake has a constant weight, thereby obtaining a hydroxylated filler;

[0075] Weigh: 18.0 g of hydroxylated filler, 6.0 g of N-aminoethyl-3-aminopropyltriethoxysilane, 5.0 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 0.8 g of triethylamine and 100.0 mL of deionized water, add into the reactor, keep warm for 1 hour, after the reactor is lowered to room temperature, filter the reaction liquid to collect the filter cake, place the filter cake in a drying oven at 80°C for vacuum drying until the filter cake has constant weight, to obtain a modified titanium filler.

[0076] S2. Preparation of molten polyester

[0077] The waste polyester textiles are put into a drum and preheated with 150°C steam, the water evaporates and the water vapor is extracted with the help of a vacuum system, the water is removed by vacuuming for 10 hours, and the drying is completed to obtain the pre-treated waste polyester;

[0078] Weigh: 96.0 g of pre-treated waste polyester, 24.0 g of modified titanium filler, 7.2 g of triphenyl phosphate, 4.8 g of zinc stearate and 7.2 g of dilauryl sulfide and add them into a twin-screw extruder, the temperatures of the eight temperature sections of the twin-screw extruder from the feed port to the discharge port are 280° C., 280, 285° C., 295° C., 295° C., 300° C., 300° C., the main engine speed of the twin-screw extruder is 120 rpm, the pressure is 150 bar, and a melt is extruded;

[0079] The melt was first filtered through a primary filter with a particle size of 30 μm at a pressure of 2 MPa, and then filtered again through a secondary filter with a particle size of 5 μm at a pressure of 4 MPa to obtain molten polyester.

[0080] S3. Preparation of spinning fibers

[0081] The molten polyester is added into the spinning box, and the melt is kept warm by using a gas phase heat medium, wherein biphenyl-biphenyl ether is selected as the gas phase heat medium, and the melt temperature is controlled at 290°C, and the heat medium system circulation is set at 120°C to maintain uniform heat transfer to obtain a uniformly heated melt;

[0082] The homogenized melt was introduced into a spiral static mixer at a flow rate of 1000 kg / h using a metering pump for homogenization. The homogenization time was 50 s, and a homogenized polyester with a temperature of 285° C., a dynamic viscosity of 280 Pa·s, a dispersion uniformity of 98.5%, and an impurity content of 0.004% was obtained.

[0083] The homogenized molten polyester is extruded through a spinneret, the holes of the spinneret are circular, the mesh number is 64, the aperture is 0.5 mm and the spinning pressure is 150 bar. After extrusion, it is transferred to a side-blown air chamber, the cold wind is air, the relative humidity is 50%, the temperature is 30°C and the flow rate is maintained at 10 m / s, and the spun fiber is obtained after air cooling and curing.

[0084] S4. Preparation of high temperature wear-resistant oil

[0085] Weigh: 18.0 g of dihydroxydibenzocyclohexanone, 8.0 g of 1,3-dichlorobenzene, 2.0 g of potassium carbonate and 100.0 mL of diphenyl sulfone are added to a reactor, the temperature of the reactor is raised to 340° C., and the reaction is kept warm for 3 hours. After the reaction is completed, the temperature of the reactor is lowered to room temperature, and the material is washed 5 times with deionized water at a temperature of 60° C., and then placed in a rotary evaporator with a salt bath temperature of 160° C., and decompressed and distilled until no liquid is produced to obtain modified polyetheretherketone;

[0086] Weigh: 20.0 g of modified polyetheretherketone and 8.0 g of modified titanium filler are added to a reactor and stirred. The temperature of the reactor is raised to 360° C. and stirred for 2 h. After the reactor is cooled to room temperature, the material is ground through a 600-mesh sieve to obtain modified polyetheretherketone powder;

[0087] Weigh: 18.0 g of modified polyetheretherketone powder, 5.0 g of polyvinylpyrrolidone and 100.0 mL of N-methylpyrrolidone, add into the reactor and stir, raise the temperature of the reactor to 170°C, keep stirring for 2 h, the stirring rate is 120 rpm, and obtain high-temperature wear-resistant oil after natural cooling.

[0088] S5. Preparation of polyester yarn cake

[0089] The high-temperature wear-resistant oil is evenly applied to the spinning fiber using a roller oiler, wherein the roller diameter of the roller oiler is 100 mm, the rotation speed is 300 rpm, the spinning fiber contact pressure is 1.0 N, the high-temperature wear-resistant oil flow rate is 30 ml / min and the temperature is maintained at 25° C., and the polyester fiber is solidified;

[0090] The polyester fiber is wound to obtain a silk cake. The winding operation is carried out by stretching with double drafting rollers and then winding. The temperature of the first drafting roller is 90°C, the temperature of the second drafting roller is 120°C, the draft ratio is 4, the speed of the first drafting roller is 400m / min, the speed of the second drafting roller is 1600m / min, and the speed of the winding head is 200m / min. A wire detector is arranged in front of the winder to detect the broken ends of the tow, activate the cutter, the tow collection device and the waste wire suction system. The detection sensitivity is 0.5mm, the signal response time is 25ms, the delay time of the activation cutter is 150ms, the pressure of the waste wire suction system is maintained at 0.5MPa, and the capacity of the tow collection device is 3m 3, the yarn cakes are graded and packaged to obtain polyester yarn cakes.

[0091] Example 3

[0092] This embodiment provides a method for regenerating waste polyester textiles to prepare polyester fibers, comprising the following steps:

[0093] S1. Preparation of modified titanium filler

[0094] Weigh: 18.0g of tetraisopropyl titanate and 80.0mL of ethanol are added to a reactor, the stirring rate of the reactor is 80rpm, and the reaction is stirred at room temperature for 15min. 50.0mL of deionized water and 10.0mL of 0.3M hydrochloric acid solution are added to the reactor, and the stirring is continued for 3h, and then it is left to stand for 14h to obtain an aged gel. The aged sol is added to a drying oven at a temperature of 60°C and vacuum dried for 3h. The material is placed in a tubular furnace, nitrogen is introduced for protection, and the temperature is increased to 500°C at a heating rate of 5°C / min, and the temperature is kept for 2h. The crystalline titanium dioxide particles are naturally cooled, and the titanium dioxide particles are obtained after grinding and passing through a 10000 mesh sieve;

[0095] Weigh: 10.0 g of titanium dioxide particles and 30.0 mL of deionized water are dispersed in a hydrothermal reactor, the temperature of the hydrothermal reactor is controlled to be 150° C., the pressure is 3 MPa, and the reaction is kept warm for 2 hours. After the reactor is cooled to room temperature, the reaction liquid is filtered to collect the filter cake, and the filter cake is placed in a drying oven at a temperature of 80° C. for vacuum drying until the filter cake has a constant weight, thereby obtaining a hydroxylated filler;

[0096] Weigh: 20.0g of hydroxylated filler, 5.4g of N-aminoethyl-3-aminopropyltriethoxysilane, 6.0g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 0.8g of triethylamine and 100.0mL of deionized water, add into the reactor, keep warm for 2h, after the reactor is lowered to room temperature, filter the reaction liquid to collect the filter cake, place the filter cake in a drying oven at 80°C for vacuum drying until the filter cake has constant weight, to obtain a modified titanium filler.

[0097] S2. Preparation of molten polyester

[0098] The waste polyester textiles are put into a rotary drum and preheated with 150°C steam, the water evaporates and the water vapor is extracted with the help of a vacuum system, the water is removed by vacuuming for 9 hours, and the drying is completed to obtain the pre-treated waste polyester;

[0099] Weigh: 96.0 g of pre-treated waste polyester, 24.0 g of modified titanium filler, 7.2 g of triphenyl phosphate, 4.8 g of zinc stearate and 6.4 g of dilauryl sulfide and add them into a twin-screw extruder, the temperatures of the eight temperature sections of the twin-screw extruder from the feed port to the discharge port are 280° C., 280, 285° C., 295° C., 295° C., 300° C., 300° C., the main engine speed of the twin-screw extruder is 100 rpm, the pressure is 125 bar, and a melt is extruded;

[0100] The melt was first filtered through a primary filter with a particle size of 20 μm at a pressure of 2 MPa, and then filtered again through a secondary filter with a particle size of 6 μm at a pressure of 3 MPa to obtain molten polyester.

[0101] S3. Preparation of spinning fibers

[0102] The molten polyester is added into the spinning box, and the melt is kept warm by using a gas phase heat medium, wherein biphenyl-biphenyl ether is selected as the gas phase heat medium, and the melt temperature is controlled at 290°C, and the heat medium system circulation is set at 110°C to maintain uniform heat transfer to obtain a uniformly heated melt;

[0103] The homogenized melt was introduced into a spiral static mixer at a flow rate of 750 kg / h using a metering pump for homogenization. The homogenization time was 45 s, and a homogenized polyester with a temperature of 290° C., a dynamic viscosity of 270 Pa·s, a dispersion uniformity of 98.6%, and an impurity content of 0.003% was obtained.

[0104] The homogenized molten polyester is extruded through a spinneret, the holes of the spinneret are circular, the mesh number is 48, the aperture is 0.3 mm and the spinning pressure is 125 bar. After extrusion, it is transferred to a side-blown air chamber, the cold wind is air, the relative humidity is 40%, the temperature is 25°C and the flow rate is maintained at 8 m / s, and the spun fiber is obtained after air cooling and curing.

[0105] S4. Preparation of high temperature wear-resistant oil

[0106] Weigh: 20.0g of dihydroxydibenzocyclohexanone, 9.6g of 1,3-dichlorobenzene, 2.1g of potassium carbonate and 100.0mL of diphenyl sulfone are added to a reactor, the temperature of the reactor is raised to 320°C, and the reaction is kept warm for 3h. After the reaction is completed, the temperature of the reactor is lowered to room temperature, and the material is washed 3-5 times with deionized water at a temperature of 60°C, and then the material is placed in a rotary evaporator with a salt bath temperature of 160°C, and decompressed and distilled until no liquid is produced to obtain modified polyetheretherketone;

[0107] Weigh: 18.0 g of modified polyetheretherketone and 8.0 g of modified titanium filler are added to a reactor and stirred. The temperature of the reactor is raised to 360° C. and stirred for 2 h. After the reactor is cooled to room temperature, the material is ground through a 450-mesh sieve to obtain modified polyetheretherketone powder;

[0108] Weigh: 18.0 g of modified polyetheretherketone powder, 5.4 g of polyvinylpyrrolidone and 100.0 mL of N-methylpyrrolidone, add into a reactor and stir, raise the temperature of the reactor to 160° C., keep stirring for 2 h at a stirring rate of 100 rpm, and obtain high-temperature wear-resistant oil after natural cooling.

[0109] S5. Preparation of polyester yarn cake

[0110] The high-temperature wear-resistant oil is evenly applied to the spinning fiber using a roller oiler, wherein the roller diameter of the roller oiler is 75 mm, the rotation speed is 250 rpm, the spinning fiber contact pressure is 0.75 N, the high-temperature wear-resistant oil flow rate is 20 ml / min and the temperature is maintained at 25° C., and the polyester fiber is solidified;

[0111] The polyester fiber is wound to obtain a silk cake. The winding operation is performed by drawing with double drafting rollers and then winding. The temperature of the first drafting roller is 85°C, the temperature of the second drafting roller is 110°C, the draft ratio is 4, the speed of the first drafting roller is 350m / min, the speed of the second drafting roller is 1400m / min, and the speed of the winding head is 1800m / min. A wire detector is arranged in front of the winder to detect the broken ends of the tow, activate the cutter, the tow collection device and the waste wire suction system. The detection sensitivity is 0.5mm, the signal response time is 25ms, the delay time of the activation cutter is 100ms, the pressure of the waste wire suction system is maintained at 0.4MPa, and the capacity of the tow collection device is 2m 3 , the yarn cakes are graded and packaged to obtain polyester yarn cakes.

[0112] Comparative Example 1

[0113] The difference between this comparative example and Example 3 is that in step S2, the use of modified titanium filler is cancelled, and the same amount of modified titanium filler continues to be used in step S2.

[0114] Comparative Example 2

[0115] The difference between this comparative example and Example 3 is that the step of preparing the modified titanium filler in step S1 is eliminated, and in steps S2 and S4, an equal amount of nano titanium dioxide particles are used to replace the modified titanium filler.

[0116] Comparative Example 3

[0117] The difference between this comparative example and Example 3 is that the step of preparing the wear-resistant high-temperature oil in step S4 is eliminated, and in step S4, an equal amount of epoxy resin is used to replace the wear-resistant high-temperature oil.

[0118] Performance Test:

[0119] The breaking strength and breaking elongation of the polyester fibers prepared in Examples 1-3 and Comparative Examples 1-3 were tested in accordance with the standard GB / T 14337-2008 “Test Method for Tensile Properties of Chemical Staple Fibers”;

[0120] The breaking strength of the polyester fiber prepared in Example 1-3 and Comparative Example 1-3 was recorded as Q1, and the sample was placed in an environment of 180° C. The breaking strength of the sample was tested again, and the breaking strength was recorded as Q2. Referring to the formula (Q1-Q2) / Q1×100%, the breaking strength loss rate of the polyester sample at high temperature was calculated to verify the high temperature resistance of the polyester fiber prepared in Example 1-3 and Comparative Example 1-3;

[0121] Referring to the standard GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles Part 3: Oscillation method", the antibacterial rate of the polyester fibers prepared in Examples 1-3 and Comparative Examples 1-3 was tested, wherein the selected bacterial species were Gram-positive bacteria Staphylococcus aureus and fungus Candida albicans;

[0122] The volume abrasion loss of the polyester fibers prepared in Examples 1-3 and Comparative Examples 1-3 was tested with reference to the standard GB / T 9867-2008 “Determination of the wear resistance of vulcanized rubber or thermoplastic rubber (rotating roller abrader method)”. The specific data are shown in Table 1.

[0123] Table 1-Performance test data of each sample

[0124]

[0125] Data Analysis:

[0126] Comparing and analyzing the data in Table 1 above, the polyester fiber prepared by the present invention has a breaking strength of 7.4 MPa, a breaking strength loss rate of 2.0%, a breaking elongation of 150.5%, a Staphylococcus aureus antibacterial rate of 96.5%, a Candida albicans antibacterial rate of 97.3%, and a volume wear of only 37 mm 3 , the performance data of each embodiment are better than those of the comparative example;

[0127] The present invention prepares a modified titanium filler and high-temperature wear-resistant oil, wherein the modified titanium filler improves the efficiency of double-stage filtration while hybridizing the polyester chain segment, and serves as the skeleton of the wear-resistant high-temperature oil and the bridge connecting the wear-resistant high-temperature oil and the polyester fiber to stabilize the properties of the polyester fiber and reduce the loss of the polyester fiber during the winding process. A large amount of titanium dioxide particles inside the polyester fiber and in the high-temperature wear-resistant oil can excite electrons under ultraviolet light to generate strong oxidants, destroying bacterial cell membranes and genetic material, thereby achieving effective sterilization, and finally preparing a wear-resistant and antibacterial polyester fiber.

[0128] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for regenerating polyester fibers from waste polyester textiles, characterized in that: The following steps are involved: S1, adding the pre-treated waste polyester, modified titanium filler and auxiliary materials into a twin-screw extruder for melt extrusion to obtain a molten body, and then filtering the molten body in two stages to obtain a molten polyester; S2, adding molten polyester into a spinning manifold, and obtaining homogenized molten polyester after homogenization and distribution; S3, extruding the homogenized molten polyester through a spinneret and transferring it to a side-blowing chamber, and obtaining spun fibers after air cooling and solidification; S4, using a roller oiler to evenly coat the spun fiber with high temperature wear-resistant oil, and solidifying it to obtain polyester fiber; The preparation method of the modified titanium filler comprises the following steps: A1. Add tetraisopropyl titanate and ethanol to a reactor, stir at room temperature for 10-15 min, add deionized water and a 0.1-0.3 M hydrochloric acid solution to the reactor, continue stirring for 2-4 h, and let stand for 12-16 h to obtain an aged gel, which is then post-treated to obtain titanium dioxide particles; A2, dispersing titanium dioxide particles and deionized water in a hydrothermal reactor, controlling the temperature of the hydrothermal reactor to 120-150° C., the pressure to 2-3 MPa, keeping the reaction temperature for 1-2 hours, and post-treating to obtain a hydroxylated filler; A3. Add hydroxylated filler, N-aminoethyl-3-aminopropyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, triethylamine and deionized water into a reactor, keep the reaction warm for 1-2 hours, and post-treat to obtain modified titanium filler.

2. The method for regenerating polyester fibers from waste polyester textiles according to claim 1, characterized in that: In step S1, the amount ratio of pre-treated waste polyester, modified titanium filler and auxiliary materials is 80-100g:20-30g:13-21g, wherein the auxiliary materials include: heat stabilizer, lubricant and antioxidant, and the pre-treatment step is: putting the waste polyester textile into a drum and preheating it with 150°C steam, evaporating the water and extracting the water vapor with the help of a vacuum system, vacuuming for 8-10 hours to remove the water, completing drying, and obtaining the pre-treated waste polyester.

3. The method for regenerating polyester fibers from waste polyester textiles according to claim 1, characterized in that: In step A1, the stirring rate of the reactor is 60-80rpm, and the dosage ratio of tetraisopropyl titanate, ethanol, deionized water and 0.1-0.3M hydrochloric acid solution is 8-10g:30-40mL:20-30mL:5-6mL; in step A2, the dosage ratio of titanium dioxide particles and deionized water is 3-5g:15-20mL; in step A3, the dosage ratio of hydroxylated filler, N-aminoethyl-3-aminopropyltriethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, triethylamine and deionized water is 8-10g:2-3g:2-3g:0.3-0.5g:40-60mL.

4. The method for regenerating polyester fibers from waste polyester textiles according to claim 1, characterized in that: In step S2, the operation of averaging and distributing includes the following steps: B1. Use gas phase heat medium to keep the melt warm, control the melt temperature at 285-290°C, and set the heat medium system circulation at 100-120°C to maintain uniform heat transfer to obtain a uniformly heated melt; B2. Use a metering pump to introduce the homogenized melt into a static mixer for homogenization to obtain a homogenized polyester.

5. The method for regenerating polyester fibers from waste polyester textiles according to claim 4, characterized in that: In step B1, the gas phase heat medium is biphenyl-biphenyl ether; in step B2, the flow rate of the homogenized melt is 500-1000 kg / h, the static mixer is one of a spiral static mixer and a honeycomb static mixer, the homogenization time is 30-60 s, and the homogenized polyester should meet the temperature of 285-290 ° C, the dynamic viscosity of 250-280 Pa·s, the dispersion uniformity of 95-99% and the impurity content of 0.001-0.005%.

6. The method for regenerating polyester fibers from waste polyester textiles according to claim 1, characterized in that: In step S4, the preparation method of high temperature wear-resistant oil is: C1. Add dihydroxydibenzocyclohexanone, 1,3-dichlorobenzene, potassium carbonate and diphenyl sulfone into a reactor, raise the temperature of the reactor to 300-340° C., keep the temperature for 2-3 hours, and perform post-treatment to obtain modified polyetheretherketone; C2, adding modified polyetheretherketone and modified titanium filler into a reactor and stirring, raising the temperature of the reactor to 350-360° C., keeping the temperature and stirring for 1-2 hours, and post-treating to obtain modified polyetheretherketone powder; C3. Add modified polyetheretherketone powder, polyvinyl pyrrolidone and N-methylpyrrolidone into a reactor and stir. The temperature of the reactor is increased to 150-170°C. The reactor is stirred for 1-2 hours at this temperature. After natural cooling, high-temperature wear-resistant oil is obtained.

7. The method for regenerating polyester fibers from waste polyester textiles according to claim 6, characterized in that: In step C1, the dosage ratio of dihydroxydibenzocyclohexanone, 1,3-dichlorobenzene, potassium carbonate and diphenyl sulfone is 8-10g:3-5g:0.8-1.2g:45-60mL; in step C2, the dosage ratio of modified polyetheretherketone and modified titanium filler is 8-10g:3-4g; in step C3, the stirring rate of the reactor is 80-120rpm, and the dosage ratio of modified polyetheretherketone powder, polyvinylpyrrolidone and N-methylpyrrolidone is 8-10g:2-3g:40-60mL.

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