Antibacterial antistatic regenerated polyester staple fiber and preparation method thereof

Abstract

The invention relates to the technical field of regenerated fibers, in particular to a bacteriostatic antistatic regenerated polyester staple fiber and a preparation method thereof. The invention aims to solve the technical problems that the regenerated polyester raw material contains many impurities, functional aids are easy to lose, antibacterial and antistatic functions are difficult to take into account and the durability is poor. Residual impurity ions in a crude monomer obtained by alcoholysis of waste polyester are used as a bridging agent, antibacterial metal ions and graphene oxide are induced to form a coordination complex structure, and a functional compound is prepared; then, dispersing the functional compound into ethylene glycol, and carrying out in-situ polymerization with terephthalic acid, so that the functional body is connected into a polyester molecular chain through a covalent bond to obtain a modified slice; and finally, carrying out sheath-core composite spinning by taking the modified slices as a sheath layer and taking common recycled polyester as a core layer, and finally carrying out two-stage thermal traction and heat setting. Through double locking of chemical bonding and physical coating, molecular-level fixation and long-acting durability of antibacterial and antistatic functions are realized.

Description

Technical Field

[0001] This invention relates to the field of regenerated fiber technology, specifically to an antibacterial and antistatic regenerated polyester staple fiber and its preparation method. Background Technology

[0002] With the widespread application of polyester materials in packaging, textiles, and other fields, the stock of waste polyester products continues to grow. Polyester typically degrades in the natural environment over 50 years, causing serious resource waste and solid waste pollution. Efficient recycling of polyester solid waste is essential for reducing greenhouse gas emissions, alleviating resource shortages, and promoting the development of a circular economy. Polyester fiber, as an important synthetic fiber, has advantages such as high strength and good abrasion resistance, and is widely used in the textile industry. However, conventional polyester fibers suffer from poor moisture absorption, are prone to static electricity, and are susceptible to bacterial growth. Especially in sportswear, workwear, and medical textiles, the need for antistatic and antibacterial functions is particularly urgent. In existing technologies, imparting antibacterial and antistatic functions to polyester fibers mainly involves the following approaches: first, adding functional auxiliaries during the spinning process, such as antibacterial metal ions, conductive carbon black, and graphene; second, post-processing the fiber surface by coating it with a functional coating. For example, existing patent CN118127663A discloses a method for preparing flame-retardant DTY polyester yarn by regenerating polyester fibers, but it pays insufficient attention to antistatic and antibacterial properties. Despite the existence of various technical solutions, existing technologies still suffer from the following core shortcomings: (1) Poor functional durability. Existing technologies are mostly simple physical blending or skin coating, and the functional factors lack chemical bonding with the polyester matrix. They are easily lost during use and washing, resulting in "effective at first, but ineffective after washing".

[0003] (2) Interference from impurities in recycled raw materials. The purity of recycled polyester raw materials is far lower than that of virgin chips. The ash, metal ions and other impurities contained therein can not only cause spinning breakage and pore blockage, but also preferentially adsorb or decompose functional additives, which greatly reduces the effective components actually added to the fiber.

[0004] (3) Poor functional synergy. Antibacterial agents and antistatic agents are prone to react with each other and become ineffective during high-temperature spinning, making it difficult to achieve both effects.

[0005] (4) Insufficient structural design and processing adaptability. In short fiber processing, multi-layer composite structures are easily damaged during drafting, cutting and subsequent spinning and twisting, resulting in the loss of functional layers.

[0006] To address the aforementioned problems, this invention proposes a novel technical solution that achieves molecular-level fixation and long-lasting durability of antibacterial and antistatic functions. Summary of the Invention

[0007] This invention aims to solve the following technical problems existing in the application of antibacterial and antistatic functions to recycled polyester fibers: poor functional durability, interference of impurities in recycled raw materials with functional performance, and difficulty in synergistic effects between antibacterial and antistatic functions. The invention provides a method for preparing antibacterial and antistatic recycled polyester staple fiber. The recycled polyester staple fiber has a core-sheath composite structure, with the sheath being a modified polyester containing antibacterial and antistatic functional groups linked by covalent bonds, and the core being ordinary recycled polyester.

[0008] An antibacterial and antistatic recycled polyester staple fiber and its preparation method are disclosed below: S1: Take 40-50 parts by weight of waste polyester textiles as a reference, crush them, add 80-90 parts of ethylene glycol for alcoholysis, transfer to a hydrothermal reactor, add 1-2 parts of antibacterial metal precursor and 2-3 parts of graphene oxide, stir and react at 150°C for 6 hours, cool and filter after the reaction, wash the filter cake with anhydrous ethanol and dry to obtain the functional compound. S2: Disperse 4-6 parts of the above functional compound in ethylene glycol with a solid content of 4% and treat at 15000 rpm for 30 minutes. Add 40-50 parts of terephthalic acid and 0.03-0.05 parts of antimony glycol. Then carry out esterification and polycondensation reaction. After the reaction is completed, discharge and pelletize to obtain in-situ polymerized modified polyester chips. S3: Using the modified polyester chips obtained in step S2 as the sheath material and the recycled polyester as the core material, the fibers are melt-extruded by a screw and spun through a sheath-core composite spinning assembly with a sheath-core mass ratio of 3:7 to obtain sheath-core nascent fibers. S4: The nascent fibers are cooled and cured by ring blowing at 20°C and 65% humidity, subjected to two-stage hot stretching, then fed into a packing box crimping machine for heat setting, and finally cut to obtain the short fibers of the present invention.

[0009] Furthermore, the alcoholysis described in step S1 specifically involves alcoholysis at 180°C for 6 hours.

[0010] Furthermore, the antibacterial metal precursor mentioned in step S1 is selected from silver nitrate or zinc acetate.

[0011] Furthermore, the drying described in step S1 specifically involves vacuum drying at 60°C for 12 hours.

[0012] Further, the esterification and polycondensation reactions described in step S2 are specifically carried out by esterification at 230°C to 240°C for 2 to 3 hours under nitrogen protection; then the temperature is raised to 270°C to 280°C, and the vacuum is drawn to less than 100 Pa to carry out polycondensation for 3 hours.

[0013] Furthermore, the spinning described in step S3 specifically involves a spinning temperature of 275°C to 285°C, a cooling air temperature of 22°C, and a winding speed of 1200 m / min.

[0014] Furthermore, the two-stage thermal stretching described in step S4 specifically consists of a first-stage 90°C hot water bath with a stretching ratio of 2.0 times; and a second-stage 130°C hot plate with a stretching ratio of 1.5 times, for a total stretching ratio of 3.0 times.

[0015] Furthermore, the heat setting described in step S4 specifically involves heat setting in hot air at 120°C to 130°C for 10 to 15 minutes.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses in-situ polymerization to attach functional components to polyester molecular chains via covalent bonds. Combined with the physical coating of the core-sheath structure and thermal traction and thermal setting crosslinking locking, the antibacterial and antistatic functions are fixed at the molecular level, achieving true long-lasting durability.

[0017] (2) This invention creatively utilizes impurity ions in recycled raw materials as bridging agents for complexation reactions, which not only solves the problem of impurities interfering with the function, but also transforms them into favorable factors for functional construction, reduces the demanding requirements on the purity of recycled raw materials, and improves the economy of the process.

[0018] (3) The present invention uses waste polyester as raw material, which is in line with the concept of circular economy; the amount of functional additives used is small and they are firmly fixed, which reduces the amount of functional additives used and the risk of environmental release. Attached Figure Description

[0019] Figure 1 This is a flow chart of a process for preparing antibacterial and antistatic recycled polyester staple fiber according to the present invention.

[0020] Figure 2 The infrared spectrum was measured for Experiment Example 1.

[0021] Figure 3 The image shows the esports scan from Experiment Example 2.

[0022] Figure 4 This is a comparison chart of the antibacterial performance results tested in Experiment Example 3.

[0023] Figure 5 This is a comparison chart of the electrostatic half-life results tested in Experiment Example 3. Detailed Implementation

[0024] The following embodiments further explain and illustrate the technical solutions of the present invention. It is particularly noted that each specific embodiment is a specific interpretation of the technical solution and should not be considered as a limitation on the scope of protection of the present invention. Those skilled in the art still have the right to modify the technical solutions of these embodiments and make equivalent substitutions for some or all of the technical features, and these modifications or substitutions do not change the essence of the corresponding technical solutions, nor do they cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions described in the present invention. (See attached...) Figure 1 The diagram shows a preparation process for antibacterial and antistatic recycled polyester staple fiber. The detailed preparation steps are as follows: 1. Pretreatment and alcoholysis of waste polyester Waste polyester textiles were crushed and alcoholyzed to obtain crude ethylene terephthalate monomer. The crude monomer contained residual impurity ions from the waste raw materials, mainly calcium and magnesium ions. These were then dissolved in ethylene glycol, and an antibacterial metal precursor and graphene oxide were added. After being mixed evenly, the mixture was transferred to a hydrothermal reactor for a complexation reaction. During the reaction, the residual calcium and magnesium ions and terminal carboxyl groups in the crude monomer were used as bridging agents to induce the antibacterial metal ions to form a stable carbon-metal ion complex structure with the oxygen-containing functional groups on the surface of graphene oxide through coordination bonds. After the reaction, the mixture was separated, washed, and dried to obtain the functional complex.

[0025] This invention utilizes these impurity ions as coordination centers, which simultaneously form coordination bonds with antibacterial metal ions and the carboxyl and hydroxyl groups on graphene oxide, acting as a bridge to chemically bind the antibacterial and antistatic components into a large molecular aggregate. This pre-complexed structure changes the traditional physical mixing model, fundamentally solving the problem of subsequent phase separation of the two components in the polyester matrix.

[0026] 2. In-situ polymerization and functional grafting The obtained functional composite was ultrasonically dispersed in ethylene glycol, terephthalic acid and catalyst were added, and esterification reaction was carried out, followed by polycondensation reaction. During the polymerization process, the active functional groups on the surface of the functional composite participated in the transesterification or polycondensation reaction and were covalently attached to the macromolecular chain of PET to obtain in-situ polymerized modified polyester chips. This step fixes the functional components onto the polyester molecular chain through chemical bonds, achieving molecular-level fixation of the functional factors. In subsequent high-temperature spinning, the functional groups of the modified chips will not migrate or agglomerate, nor will they precipitate during repeated washing, fundamentally solving the problem of functional durability. At the same time, since the functional components have been connected to the polyester molecular chain, their dispersibility in the matrix is ​​greatly improved.

[0027] 3. Core-Sheath Composite Spinning A twin-screw composite spinning machine is used, equipped with a core-sheath composite spinning assembly, and the spinneret orifice has a concentric circle structure of core and sheath. In-situ polymerized modified polyester chips are used as the sheath material and recycled polyester is used as the core material. They are melt-extruded separately by the screw and then merged into the core-sheath composite spinning assembly. The extrusion through the spinneret orifice forms a molten stream, which is cooled and solidified by side blowing to obtain core-sheath nascent fiber. Employing a core-sheath structure, the functional modified materials are concentrated in the sheath layer, allowing the functional components to directly contact the skin and exert their effects. The core layer uses low-cost ordinary recycled chips to ensure the physical strength of the fiber. This design ensures both functional effectiveness and cost control. Simultaneously, the functional components in the sheath layer are connected to the polyester molecular chains via chemical bonds, while the core layer is made of ordinary polyester. Due to molecular chain diffusion and partial co-crystallization at the interface, the two are firmly bonded and will not delaminate during subsequent processing.

[0028] 4. Post-processing The nascent fibers are cooled and cured by ring blowing at 20°C and 65% humidity. After the filaments are oiled, they undergo two-stage hot stretching. They are then fed into a crimping box crimping machine, where they are relaxed and heat-set under hot air. Finally, they are cut to obtain the short fibers of this invention.

[0029] Example 1 Table 1 Raw Material Information Table An antibacterial and antistatic recycled polyester staple fiber and its preparation method are disclosed, the preparation steps of which are as follows: S1: Take 45 parts by weight of waste polyester textiles as a reference, crush them, add 85 parts of ethylene glycol, and alcoholyze at 180℃ for 6 hours. Transfer to a hydrothermal reactor, add 1.5 parts of antibacterial metal precursor silver nitrate and 2.5 parts of graphene oxide, and stir at 150℃ for 6 hours. After the reaction is completed, cool and filter. Wash the filter cake three times with anhydrous ethanol and vacuum dry at 60℃ for 12 hours to obtain the functional complex. S2: Disperse 5 parts of the above functional compound in ethylene glycol with a solid content of 4% by ultrasonication at 15000 rpm for 30 minutes. Add 45 parts of terephthalic acid and 0.04 parts of antimony glycol. Perform esterification reaction at 235°C for 2.5 hours under nitrogen protection. Then raise the temperature to 275°C, evacuate to less than 100 Pa, and perform polycondensation reaction for 3 hours. After the reaction is completed, discharge and pelletize to obtain in-situ polymerized modified polyester chips. S3: Using the modified polyester chips obtained in step S2 as the sheath material and the recycled polyester as the core material, the fibers are melt-extruded by a screw and spun through a sheath-core composite spinning assembly with a sheath-core mass ratio of 3:7. The spinning temperature is 280℃, the cooling air temperature is 22℃, and the winding speed is 1200m / min to obtain sheath-core nascent fibers. S4: The nascent fibers are cooled and cured by ring blowing at 20°C and 65% humidity. After the filaments are oiled, they undergo two-stage hot stretching: the first stage is a 90°C hot water bath with a stretching ratio of 2.0 times; the second stage is a 130°C hot plate with a stretching ratio of 1.5 times, for a total stretching ratio of 3.0 times. Then, the fibers are placed in a crimping box crimping machine and then relaxed and heat-set in hot air at 125°C for 12 minutes. Finally, the fibers are cut to obtain the short fibers of this invention.

[0030] Example 2 The preparation method is the same as in Example 1, but with the following differences: In step S1: 40 parts by weight of waste polyester textiles, 80 parts by weight of ethylene glycol, 1 part by weight of antibacterial metal precursor zinc acetate, and 2 parts by weight of graphene oxide; In step S2: 4 parts of functional complex, 40 parts of terephthalic acid, and 0.03 parts of antimony glycolate are esterified at 230°C for 3 hours under nitrogen protection, and then the temperature is raised to 270°C. In step S3: the spinning temperature is 275℃; In step S4: Relax and heat set in hot air at 130°C for 10 minutes.

[0031] Example 3 The preparation method is the same as in Example 1, but with the following differences: In step S1: 50 parts by weight of waste polyester textiles, 90 parts by weight of ethylene glycol, 2 parts by weight of antibacterial metal precursor silver nitrate, and 3 parts by weight of graphene oxide; In step S2: 6 parts of functional complex, 50 parts of terephthalic acid, and 0.05 parts of antimony glycolate are esterified at 240°C for 2 hours under nitrogen protection, and then the temperature is raised to 280°C. In step S3: the spinning temperature is 285℃; In step S4: Relax and heat set in hot air at 120°C for 15 minutes.

[0032] Comparative Example 1 The preparation method of Example 1 is followed, but without using residual impurity ions from the crude monomer obtained from the alcoholysis of waste polyester as a bridging agent. An equal amount of purified polyethylene terephthalate monomer is mixed with silver nitrate and graphene oxide to form a functional composite. All other steps are the same.

[0033] Comparative Example 2 The preparation method of Example 1 was followed, but without in-situ polymerization modification, an equal amount of functional compound was directly blended with ordinary regenerated chips as the skin layer raw material. All other steps were the same.

[0034] Comparative Example 3 The preparation method of Example 1 was followed, but instead of using a core-sheath structure, the in-situ polymerized modified chips were directly subjected to conventional melt spinning. All other steps were the same.

[0035] Experimental Example 1 The recycled polyester staple fiber prepared in Example 1 was completely dried, ground, and pressed into sheets. It was then placed in an infrared spectrometer for transmission mode testing, with a scanning range of 4000-400 cm⁻¹. -1 Scanning range: 4000-400cm -1 Number of scans: 64; test results as follows: Figure 2 As shown; In the original graphene oxide spectrum, 1730 cm⁻¹ -1 The strong absorption peak nearby is attributed to the C=O stretching vibration of the carboxyl group; in the complex spectrum, this peak is significantly weakened, indicating that a large number of terminal carboxyl groups on the GO surface have participated in the reaction as ligands. Accompanying the weakening of the C=O peak, the spectrum is located at 1550-1650 cm⁻¹. -1 and 1380-1450cm -1 A pair of new characteristic peaks appeared in the region, which were attributed to the asymmetric stretching vibration peaks of the carboxylate group (V). as） The presence of symmetric stretching vibration peaks (Vs) indicates that this is due to the coordination of the carboxylate group; the 1550-1650 cm⁻¹ peaks in the spectrum... -1 The νas peak in the region exhibits a distinct bimodal split structure, which is due to the large ionic radius and variable coordination number of 6-8 of the residual calcium ions in the crude ethylene terephthalate monomer. When these ions interact with the GO edge and basal functional groups, it leads to the V... as The peak splits, which demonstrates the use of impurity ions to induce complex complexes. Frequency difference ΔV=V as -Vs is closely related to the coordination geometry. By extracting the accurate wavenumbers of these two peaks from the spectrum and calculating ΔV, if the difference is similar to the difference in the ionic form of the free carboxylate, it proves the existence of a "multidentate coordination bridging structure" in the system; V in the figure... as The value is approximately 1590cm -1 The Vs value is approximately 1410 cm. -1 The calculated ΔV is approximately 180cm. -1 This value is similar to that of typical free carboxylates (such as sodium acetate), which are in the range of 150–180 cm⁻¹. -1 The difference between the left and right sides is very close; The aforementioned infrared characteristics confirm that the calcium and magnesium impurity ions in the crude monomer in the technical solution successfully acted as bridging agents, tightly binding the silver ions in the antibacterial metal precursor with the oxygen-containing functional groups on the surface of graphene oxide through coordination bonds, forming a stable macromolecular aggregate complex structure.

[0036] Experimental Example 2 The cross-section of the recycled polyester staple fiber prepared in Example 1 was cut and subjected to scanning electron microscopy (SEM). The imaging mode was backscattered electron mode, the accelerating voltage was set between 10 kV and 15 kV, and the working distance was set to 10 mm. The test results are as follows: Figure 3 As shown, Figure a cross section clearly shows the concentric circle structure of the skin and core. Due to the presence of GO-metal complexes with high electron density in the skin polyester, the skin exhibits higher brightness than the core in backscattered electron mode, thus forming a distinct light-dark boundary. In Figures b and c: carbon and oxygen, as the basic constituent elements of polyester, are distributed throughout the entire cross-section; however, in the cortex region of the fiber, obvious abnormal enrichment of oxygen and carbon can be observed, which confirms that graphene oxide rich in oxygen-containing functional groups has been successfully introduced and stably exists in the cortex matrix. In Figure d: the core element silver in the antibacterial metal precursor has its signal strictly limited to the annular region at the fiber edge; if a significant metal signal is detected in the core layer, it indicates a defect in the design of the core-sheath distribution valve or spinneret. The core layer in the figure shows a dark field, indicating that the antibacterial component is precisely controlled in the sheath layer, achieving the expected structural design. In Figures e and f, the calcium and magnesium impurity ions, which are derived from crude ethylene terephthalate monomers, are also strictly confined to the annular region at the fiber edge. Their distribution is highly consistent with that of Ag and the abnormally enriched C and O, which directly proves that they act as coordination centers and combine antibacterial metal ions with graphene oxide into a stable macromolecular aggregate through coordination bonds and bridging effects.

[0037] Experimental Example 3 The short fibers prepared in both Examples 1-3 and Comparative Examples 1-3 were used to determine their overall properties. Antibacterial performance test: The test was conducted in accordance with standard GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method". The pathogenic bacteria selected for the test were Staphylococcus aureus and Escherichia coli. After testing the initial antibacterial rate, the textiles underwent 50 standard water washing cycles according to standard GB / T 8629-2017 "Household washing and drying procedures for textile testing", with the washing water temperature set at 60℃. The antibacterial rate was then tested after 50 standard water washing cycles. The antibacterial rate was calculated using the formula: Antibacterial rate = (Total number of viable colonies in the control sample shake flask - Total number of residual viable colonies in the test fiber shake flask) / Total number of viable colonies in the control sample shake flask × 100%. Antistatic dissipation performance test: The test was conducted in accordance with the standard GB / T 12703.1-2021 "Textiles - Test Methods for Electrostatic Properties - Part 1: Corona Charging Method". The test environment was a high-precision electrostatic test chamber with a constant temperature of 20℃ and a relative humidity as low as 30%. After applying a 10kV high-voltage corona discharge, the initial electrostatic half-life and the half-life decay data after 50 water washes were measured. The specific test comparison results are shown in Table 2. Figure 4 , Figure 5 As shown: Table 2. Comparison of overall performance between Examples 1-3 and Comparative Examples 1-3 As can be seen from the above comparison results, in Comparative Example 1, after 50 washes, the antibacterial rate dropped sharply, the electrostatic half-life deteriorated, and the function was basically lost. This is mainly because there are no impurity ions as bridging agents. The antibacterial metal ions and graphene oxide are only physically mixed. They are prone to agglomeration under the high temperature of subsequent polymerization and spinning. Due to the lack of the stabilizing effect of the complex structure, the antibacterial agent and antistatic agent are simply filled in the fiber matrix and do not form a stable macromolecular structure. During the 50 washes, a large amount of hydrophilic functional additives are released, resulting in a sharp drop in function. In Comparative Example 2, the initial antibacterial rate and antistatic properties are lower than those of the Example. This is because although the functional compound has a stable structure, it is not connected to the polyester molecular chain through chemical bonds. Instead, it is embedded in the polyester matrix. Under the mechanical shear force of washing and the swelling effect of hot water, gaps are generated at the interface between the functional compound and the polyester matrix, which eventually leads to the detachment of functional particles. This shows that without the lock of covalent bonds, physical encapsulation alone cannot resist the harsh washing environment. In Comparative Example 3, core-sheath spinning was not used. In homogeneous fibers, a large number of functional factors are distributed inside the fibers and cannot come into contact with bacteria or conduct static electricity. This is an ineffective distribution. Only the functional groups on the fiber surface are effective. After repeated washing, the fiber surface is worn down. After the effective functional layer on the surface is consumed, the internal replenishment efficiency is low, resulting in functional decay.

Claims

1. An antibacterial and antistatic recycled polyester staple fiber, having a core-sheath composite structure, characterized in that, It consists of a skin layer and a core layer, with a skin-to-core mass ratio of 3:

7. The skin layer is composed of chemically grafted polyethylene terephthalate, and its macromolecular chain is linked to graphene oxide-metal complex macromolecules by covalent ester bonds. In the complex, the metal ions and the oxygen-containing functional groups of the graphene oxide are connected by a multidentate coordination bridging structure through at least one divalent metal ion selected from calcium or magnesium. The core layer is ordinary recycled polyester.

2. The antibacterial and antistatic recycled polyester staple fiber according to claim 1, characterized in that, The skin layer comprises the following components and amounts: 4-6 parts of functional compound, 40-50 parts of terephthalic acid, and 0.03-0.05 parts of antimony glycolate; the functional compound comprises the following components and amounts: 40-50 parts by weight of waste polyester textiles, 1-2 parts of antibacterial metal precursor, and 2-3 parts of graphene oxide.

3. The antibacterial and antistatic recycled polyester staple fiber according to claim 1, characterized in that, The antibacterial metal precursor is selected from silver nitrate or zinc acetate.

4. A method for preparing an antibacterial and antistatic recycled polyester staple fiber according to any one of claims 1-3, characterized in that, Includes the following steps: S1: Take 40-50 parts by weight of waste polyester textiles as a reference, crush them, add 80-90 parts of ethylene glycol for alcoholysis, transfer to a hydrothermal reactor, add 1-2 parts of antibacterial metal precursor and 2-3 parts of graphene oxide, stir and react at 150°C for 6 hours, cool and filter after the reaction, wash the filter cake with anhydrous ethanol and dry to obtain the functional compound. S2: Disperse 4-6 parts of the above functional compound in ethylene glycol with a solid content of 4% and treat at 15000 rpm for 30 minutes. Add 40-50 parts of terephthalic acid and 0.03-0.05 parts of antimony glycol. Then carry out esterification and polycondensation reaction. After the reaction is completed, discharge and pelletize to obtain in-situ polymerized modified polyester chips. S3: Using the modified polyester chips obtained in step S2 as the sheath material and the recycled polyester as the core material, the fibers are melt-extruded by a screw and spun through a sheath-core composite spinning assembly with a sheath-core mass ratio of 3:7 to obtain sheath-core nascent fibers. S4: The nascent fibers are cooled and cured by ring blowing at 20°C and 65% humidity, subjected to two-stage hot stretching, then fed into a packing box crimping machine for heat setting, and finally cut to obtain the short fibers of the present invention.

5. The method for preparing antibacterial and antistatic recycled polyester staple fiber according to claim 4, characterized in that, The alcoholysis described in step S1 specifically involves alcoholysis at 180°C for 6 hours.

6. The method for preparing antibacterial and antistatic recycled polyester staple fiber according to claim 4, characterized in that, The drying process described in step S1 specifically involves vacuum drying at 60°C for 12 hours.

7. The method for preparing antibacterial and antistatic recycled polyester staple fiber according to claim 4, characterized in that, The esterification and polycondensation reactions described in step S2 are specifically carried out by esterification at 230°C to 240°C for 2 to 3 hours under nitrogen protection; then the temperature is raised to 270°C to 280°C, and the vacuum is drawn to less than 100 Pa for polycondensation for 3 hours.

8. The method for preparing antibacterial and antistatic recycled polyester staple fiber according to claim 4, characterized in that, The spinning described in step S3 specifically involves a spinning temperature of 275℃~285℃, a cooling air temperature of 22℃, and a winding speed of 1200m / min.

9. The method for preparing antibacterial and antistatic recycled polyester staple fiber according to claim 4, characterized in that, The two-stage thermal stretching described in step S4 specifically consists of a first-stage 90°C hot water bath with a stretching ratio of 2.0 times; and a second-stage 130°C hot plate with a stretching ratio of 1.5 times, for a total stretching ratio of 3.0 times.

10. The method for preparing antibacterial and antistatic recycled polyester staple fiber according to claim 4, characterized in that, The heat setting described in step S4 specifically involves relaxing the heat setting process in hot air at 120°C to 130°C for 10 to 15 minutes.

Images