Antibacterial polyester FDY (Fully Drawn Yarn) and manufacturing method thereof

Abstract

The invention discloses an antibacterial polyester FDY (Fully Drawn Yarn) and a manufacturing method thereof, and relates to the field of manufacturing of polyester fibers. According to the manufacturing method, polyester melt is extruded through a spinning assembly, cooled, oiled, drafted and shaped, subjected to a main network and wound, FDY is prepared, 1.2-2.5 wt% of zinc oxide coated nano-silver is added into the polyester melt through an online adding system, and the content of zinc oxide in the zinc oxide coated nano-silver is 10-20 wt%. According to the preparation method disclosed by the invention, the polyester FDY with efficient and long-acting antibacterial performance and anti-yellowing performance can be obtained.

Description

Technical Field

[0001] The present application relates to the field of polyester fiber manufacturing, and in particular to an antibacterial polyester FDY yarn and a manufacturing method thereof. Background Art

[0002] Polyester fiber occupies an important position in the fields of clothing, home textiles, medical protection, etc. due to its excellent mechanical properties, chemical corrosion resistance and easy processing characteristics. However, the hydrophobicity of the surface of polyester fabrics and the pore structure between fibers easily absorb organic residues such as human sweat and sebum, forming a breeding ground for microorganisms. Long-term use can easily cause problems such as odor, allergies and even cross-infection. At present, the industry generally uses post-finishing processes such as dipping and spraying to apply antibacterial agents such as quaternary ammonium salts and nanosilver to finished fabrics. Although it can inhibit the reproduction of bacterial flora in the short term, the antibacterial agent is only bonded to the fiber through physical adsorption or weak chemical bonds. In actual use, it is easy to fall off and become ineffective after repeated washing and friction. The antibacterial durability is difficult to meet the needs of high-frequency use scenarios such as medical protection and sportswear.

[0003] In order to improve the long-term antibacterial effect, some studies have tried to add inorganic antibacterial agents such as nano zinc oxide directly to polyester melts for co-spinning, and use the internal coating of the fiber to achieve sustained release of antibacterial ingredients. However, this method has obvious limitations. Zinc oxide relies on photocatalysis to achieve antibacterial effects, but its active sites are easily wrapped by polyester macromolecular chains, making it difficult to fully contact microorganisms and play a catalytic killing role. How to break through the technical bottleneck of antibacterial properties within the fiber and develop functional polyester fibers with both high-efficiency and long-term antibacterial properties has become a key breakthrough for industrial upgrading and product innovation. Summary of the invention

[0004] In order to solve the contradiction between the current antibacterial efficiency and durability of polyester fibers, the present application provides an antibacterial polyester FDY yarn and a manufacturing method thereof, which can produce polyester FDY yarn with both high efficiency and long-lasting antibacterial properties.

[0005] In a first aspect, the present application provides a method for manufacturing antibacterial polyester FDY yarn, wherein a polyester melt is extruded through a spinning assembly, cooled, oiled, stretched and shaped, main networked, and wound to obtain FDY yarn, and 1.2 to 2.5 wt % of zinc oxide-coated nanosilver is added to the polyester melt through an online adding system, wherein the zinc oxide content of the zinc oxide-coated nanosilver is 10 to 20 wt %.

[0006] In this application, by introducing zinc oxide-coated silver nanoparticles (ZnO@Ag) composite antibacterial agent into the polyester melt, the performance bottleneck of traditional antibacterial agents is broken through by the synergistic effect of the core-shell structure. The zinc oxide shell forms a physical isolation and chemical protection for the silver nanoparticle core. During the high-temperature melt spinning process (260 - 290 °C), the dense lattice structure of zinc oxide effectively blocks the direct contact between oxygen and silver nanoparticles, inhibits the oxidation inactivation of silver atoms, and ensures that the silver nanoparticles still maintain high antibacterial activity after processing. Silver nanoparticles quickly inactivate microorganisms through contact sterilization and silver ion slow-release mechanisms, while the photocatalytic properties of zinc oxide generate reactive oxygen species (ROS) under light conditions, forming a dual antibacterial path with silver ions, significantly improving the antibacterial efficiency.

[0007] The content of the zinc oxide shell layer is controlled at 10 - 20 wt%, which can not only maintain the efficient release of silver nanoparticles but also prevent the degradation of polyester molecules caused by the excessive release of zinc oxide, reducing processing defects such as increased spinning breakage rate and yellowing of polyester filaments, and achieving a balance between antibacterial performance and processing stability. 2+催化 It should be noted that the above 1.2 - 2.5 wt% zinc oxide-coated silver nanoparticles means that the total mass of zinc oxide-coated silver nanoparticles and the polyester melt is 100%, and the mass ratio of zinc oxide-coated silver nanoparticles is 1.2 - 2.5 wt%.

[0008] In any of the above technical solutions, the particle size of the zinc oxide-coated silver nanoparticles is 30 - 100 nm.

[0009] In any of the above technical solutions, a pre-networking process is provided between the oiling and drawing and setting processes, and the air pressure of the pre-networking is 0.03 - 0.06 MPa.

[0010] In any of the above technical solutions, the drawing and setting use a five-roll hot roll box, where the temperatures of the first, second, and third rolls are 82 - 87 °C, the temperatures of the fourth and fifth rolls are 120 - 135 °C, and the total draw ratio is 1.8 - 2.2.

[0011] In any of the above technical solutions, the tension of the tow at the outlet of the hot roll box is 14 - 18 cN.

[0012]

[0013] ​During the spinning process, a pre-networking process is added. Turbulent disturbance of the tow is carried out by high-pressure air flow, which promotes the formation of uniformly distributed air nodes between single filaments, breaks the fiber bundle state, and enables the oil agent to form a continuous lubricating film on the surface of the single filaments. The uniform coverage of the oil film can reduce the friction coefficient between the single filaments and the guide rollers and network nozzles, reduce friction heating, thereby inhibiting the thermal migration and surface oxidation of zinc oxide-coated silver nanoparticles, and avoiding the loss of antibacterial active ingredients. At the same time, the lubricating effect of the oil agent compensates for the increased frictional resistance caused by the addition of inorganic particles to the wear of spinning, and reduces the broken ends of the hairiness. It should be noted that this pre-networking process should be controlled under low-pressure conditions (the conventional network mixed fiber air pressure is greater than 0.1 MPa) to prevent the formation of unexpected network points.

[0014] Furthermore, the tension at the outlet of the hot roller box is controlled at 14 - 18 cN. By reducing the contact pressure between the tow and the hot roller, the orientation stress of the polymer chains inside the fiber is reduced, and microcracks at the antibacterial agent-polyester interface caused by excessive drawing are avoided. It should be noted that the tension at the outlet of the hot roller box can be controlled by adjusting the speed difference between the guide roller and the hot roller at the outlet of the hot roller box. When the speed difference increases, the tension increases.

[0015] In any of the above technical solutions, 60 g of 40 - 60 mesh metal sand and 40 g of 20 - 40 mesh metal sand are selected for the sand cup sand matching of the spinning component.

[0016] In any of the above technical solutions, the zinc oxide-coated silver nanoparticles are surface-modified: zinc oxide-coated silver nanoparticles with a mass ratio of 100:0.1 - 0.3 and mercaptopropionic acid are mixed in a solution, and a self-assembly reaction is carried out for 2 - 4 h.

[0017] In any of the above technical solutions, the mass ratio of the surface-modified zinc oxide-coated silver nanoparticles to dihydroxybenzophenone is 100:5 - 8.

[0018] During the preparation of zinc oxide-coated silver nanoparticles, due to incomplete coating or processing stress, local silver nanoparticles are easily exposed. Mercaptopropionic acid forms strong coordination bonds and covalent bonds with the silver surface through thiol groups, forming a self-assembled monolayer on the exposed area, blocking the oxidation erosion of silver nanoparticles by oxygen in the high-temperature melt, preventing the interface damage of the core-shell structure, and reducing the loss of silver nanoparticles. It is beneficial to extend the antibacterial aging time of polyester filaments. At the same time, the remaining coordination groups of mercaptopropionic acid can complex with Zn 2+ (Lewis acid) released from zinc oxide to form a stable coordination complex, reducing the catalytic degradation effect of free zinc ions on the polyester molecular chain and ensuring good breaking strength of the fiber. To further inhibit the thermal oxidative yellowing of polyester caused by zinc oxide, dihydroxybenzophenone is introduced in the surface modification stage. Its ortho-phenolic hydroxyl group reacts with Zn² +Chelating bonds are formed, and at the same time, as a free radical scavenger, it can effectively quench the alkoxy free radicals and peroxy free radicals generated during the processing of polyester, blocking the thermal oxidation chain reaction. After this dual modification, the yellowness index (YI) of the fiber decreases after melt extrusion, and the interfacial bonding strength between the antibacterial agent and the polyester matrix is improved, and the antibacterial rate is still >95% after 50 standard washes.

[0019] In any of the above technical solutions, the surface-modified zinc oxide-coated silver nanoparticles are placed in a solution environment with a pH of 4-5, and ultrasonically dispersed for 0.5-1 h; the pH is adjusted to 6-7, dihydroxybenzophenone is added, and the temperature is raised to 80-90 °C, and reflux reaction is carried out under nitrogen protection to obtain yellowing-resistant zinc oxide-coated silver nanoparticles.

[0020] In any of the above technical solutions, the oil content of the FDY yarn is 0.7-0.9%.

[0021] The oil content of this application refers to the mass percentage of the oil agent in the tow in the mass of the yarn. When measuring, it is carried out in accordance with the provisions of FZ / T 54118-2019 "High-shrinkage polyester drawn yarn / polyester pre-oriented yarn blended yarn".

[0022] In a second aspect, this application provides an antibacterial polyester FDY yarn, which is prepared by any of the above manufacturing methods.

[0023] In summary, this application has the following beneficial effects: Through the core-shell structure design of zinc oxide-coated silver nanoparticles, the synergistic modification of mercaptopropionic acid and dihydroxybenzophenone, combined with the optimization of the pre-network dispersion and low-temperature drawing process, this application realizes the unity of high-efficiency antibacterial and processing stability of polyester FDY yarn. The zinc oxide shell in the composite antibacterial agent protects the silver nanoparticles from high-temperature oxidation, and its photocatalytic activity and zinc ion release synergistically enhance the antibacterial efficacy, making the antibacterial rate of polyester FDY yarn against Escherichia coli and Staphylococcus aureus exceed 99.5%, and the antibacterial rate ≥95% after 50 standard washes. Mercaptopropionic acid complexes free zinc ions and covers the bare silver particles, inhibiting the thermal degradation of polyester, and the fiber breaking strength ≥4.0 cN / dtex; the grafting of dihydroxybenzophenone significantly reduces the yellowness index of polyester FDY yarn. The synergistic effect of the pre-network treatment and the low-tension setting of the hot roller ensures the uniform distribution of the oil agent and reduces the frictional heat damage, reducing the spinning breakage rate, and is suitable for high-value-added fields such as medical protection and sportswear, and has both the feasibility of large-scale production and environmental safety. Specific Embodiments Preparation Examples

[0024] Preparation Example 1, zinc oxide-coated silver nanoparticles, was prepared according to the following steps: Step 1: Dissolve 5.0 g of AgNO in 200 mL of deionized water, add 3.0 g of polyvinylpyrrolidone, and stir until transparent. Slowly add the NaBH4 solution (1.2 g dissolved in 50 mL of water) dropwise under an ice bath, and stir vigorously for 30 min to obtain silver nanocolloid.

[0025] Step 2: Dissolve 8.5 g of Zn(NO3)2 and 4.0 g of hexamethylenetetramine in 200 mL of water, add the silver nanocolloid, and perform a hydrothermal reaction at 80 °C for 3 h. Centrifuge, wash, and dry to obtain ZnO@Ag (particle size 50 - 80 nm, ZnO content 15 wt%).

[0026] Step 3: Disperse ZnO@Ag (100 g) in a mixed solution of ethanol / water (volume ratio 1:1), add 0.15 g of mercaptopropionic acid (mass ratio 100:0.15), stir at room temperature for 3 h, centrifuge and dry to obtain mercaptopropionic acid coordinated ZnO@Ag.

[0027] Step 4: Disperse mercaptopropionic acid coordinated ZnO@Ag in a buffer solution with a pH of 5, sonicate for 1 h, adjust the pH to 6.5, add 7.5 g of 2,4 - dihydroxybenzophenone (mass ratio 100:7.5), reflux under nitrogen protection at 85 °C for 4 h, centrifuge, wash, and dry to obtain 2,4 - dihydroxybenzophenone grafted ZnO@Ag.

[0028] Preparation Example 2, zinc oxide coated silver nanoparticles, different from Preparation Example 1 in that the amount of Zn(NO3)2 used is adjusted to 5.6 g, and the hydrothermal reaction time is shortened to 2 h. The obtained ZnO@Ag has a particle size of 40 - 60 nm and a ZnO content of 15 wt%. In addition, the amount of 2,4 - dihydroxybenzophenone used is 5.0 g (mass ratio 100:5).

[0029] Preparation Example 3, zinc oxide coated silver nanoparticles, different from Preparation Example 1 in that the amount of Zn(NO3)2 used is adjusted to 11.2 g, and the hydrothermal reaction time is extended to 4 h. The obtained ZnO@Ag has a particle size of 70 - 100 nm and a ZnO content of 20 wt%. In addition, the amount of 2,4 - dihydroxybenzophenone used is 8.0 g (mass ratio 100:8).

[0030] Preparation Example 4, zinc oxide coated silver nanoparticles, different from Preparation Example 1 in that the amount of mercaptopropionic acid used is 0.05 g (mass ratio 100:0.05), and the mercaptopropionic acid modification time (stirring time) is shortened to 1.5 h.

[0031] Preparation Example 5, zinc oxide coated silver nanoparticles, different from Preparation Example 1 in that the amount of mercaptopropionic acid used is 0.5 g (mass ratio 100:0.5), and the mercaptopropionic acid modification time (stirring time) is extended to 4 h.

[0032] Preparation Example 6, zinc oxide-coated silver nanoparticles. The difference from Preparation Example 1 is that after completing Step 3, Step 4 is not carried out, that is, the graft modification of dihydroxybenzophenone is not carried out.

[0033] Preparation Example 7, zinc oxide-coated silver nanoparticles. The difference from Preparation Example 1 is that after completing Step 2, Step 4 is directly carried out, that is, the modification with mercaptopropionic acid is not carried out. The specific operation of Step 4 is as follows: Disperse ZnO@Ag (100 g) in a buffer solution with a pH of 5, sonicate for 1 h, adjust the pH to 6.5, add 7.5 g of 2,4-dihydroxybenzophenone (mass ratio 100:7.5), reflux under ammonia protection at 85 °C for 4 h, centrifuge, wash, and dry to obtain ZnO@Ag grafted with dihydroxybenzophenone.

[0034] Preparation Example 8, zinc oxide-coated silver nanoparticles. The difference from Preparation Example 1 is that after completing Step 2, the modification with an amino silane coupling agent is carried out. The operation is as follows: Step 3: Disperse ZnO@Ag (100 g) in ethanol, add 2 g of aminopropyltriethoxysilane, reflux at 80 °C for 2 h, centrifuge, wash twice with ethanol, and dry to obtain silane-modified ZnO@Ag.

[0035] Preparation Example 9, zinc oxide-coated silver nanoparticles, is prepared according to the following steps: Step 1: Dissolve 5.0 g of AgNO in 200 mL of deionized water, add 3.0 g of polyvinylpyrrolidone, and stir until transparent. Slowly dropwise add a NaBH4 solution (1.2 g dissolved in 50 mL of water) under ice bath, and stir vigorously for 30 min to obtain a silver nanoparticle colloid.

[0036] Step 2: Dissolve 4 g of Zn(NO3)2·6H2O and 3.0 g of sodium hydroxide in 200 mL of water, add the silver nanoparticle colloid, carry out a hydrothermal reaction at 80 °C for 3 h, centrifuge, wash, and dry to obtain ZnO@Ag (particle size 40 - 60 nm, ZnO content 8 wt%).

[0037] Step 3: Disperse ZnO@Ag (100 g) in ethanol, add 2 g of aminopropyltriethoxysilane, reflux at 80 °C for 2 h, centrifuge, wash twice with ethanol, and dry to obtain silane-modified ZnO@Ag.

[0038] Preparation Example 10, zinc oxide-coated silver nanoparticles, is prepared according to the following steps: Step 1: Dissolve 5.0 g of AgNO in 200 mL of deionized water, add 3.0 g of polyvinylpyrrolidone, and stir until transparent. Slowly dropwise add a NaBH4 solution (1.2 g dissolved in 50 mL of water) under ice bath, and stir vigorously for 30 min to obtain a silver nanoparticle colloid.

[0039] Step 2: Dissolve 13 g of Zn(NO3)2 and 3.0 g of hexamethylenetetramine in 200 mL of water. Add nano-silver colloid, and conduct hydrothermal reaction at 80 °C for 3 h. Centrifuge, wash, and dry to obtain ZnO@Ag (particle size 70 - 90 nm, ZnO content 23 wt%).

[0040] Step 3: Disperse ZnO@Ag (100 g) in ethanol, add 2 g of aminopropyltriethoxysilane, reflux at 80 °C for 2 h, centrifuge, wash twice with ethanol, and dry to obtain silane-modified ZnO@Ag. Example

[0041] Raw material selection in the example: The intrinsic viscosity of the polyester melt is 0.632 ± 0.006 dL / g, and the end carboxyl value is 46 ± 3 mol / t.

[0042] Example 1, an antibacterial polyester FDY yarn, the preparation method is as follows: Through an online addition system, add 0.18 kg of zinc oxide-coated nano-silver prepared in Preparation Example 1 to 9.82 kg of polyester melt. The polyester melt is filtered through the sand cup of the spinning pack and extruded from the spinneret to obtain nascent fibers. The nascent fibers are cooled by ring blowing, pre-networked, oiled and bundled, drawn and shaped in a hot roll box, main-networked, and wound to obtain an FDY yarn with a specification of 83 dtex / 72F and an oil content of 0.83%.

[0043] Among them, the spinning box temperature is 283 - 288 °C, and the sand cup sand is selected as 60 mesh 60 g of metal sand and 40 mesh 40 g of metal sand. The ring blowing pressure is 20 ± 2 Pa, and the ring blowing temperature is 20.5 ± 1 °C; the oiling uses a dilution oil with an oil agent concentration of 90 wt%. The pre-network air pressure is 0.04 MPa, and the main-network air pressure is 0.3 MPa. The hot roll drawing and shaping uses a five-roll hot roll box. The temperatures of the first roll, the second roll, and the third roll are 82 - 85 °C, and the temperatures of the fourth roll and the fifth roll are 126 ± 1 °C. The total draw ratio is 2.1; the tension of the yarn bundle at the outlet of the hot roll box is 16 cN; the winding speed is 4620 m / min.

[0044] Example 2, an antibacterial polyester FDY yarn, the preparation method is as follows: Through an online addition system, add 0.12 kg of zinc oxide-coated nano-silver prepared in Preparation Example 2 to 9.88 kg of polyester melt. The polyester melt is filtered through the sand cup of the spinning pack and extruded from the spinneret to obtain nascent fibers. The nascent fibers are cooled by ring blowing, pre-networked, oiled and bundled, drawn and shaped in a hot roll box, main-networked, and wound to obtain an FDY yarn with a specification of 83 dtex / 72F and an oil content of 0.72%.

[0045] Among them, the spinneret box temperature is 283 - 288 °C, and the sand cup sand mixture selects 40-mesh 60 g metal sand and 20-mesh 40 g metal sand. The ring blowing pressure is 20 ± 2 Pa, and the ring blowing temperature is 20.5 ± 1 °C; the oiling uses diluted oil with an oil agent concentration of 90 wt%. The pre-network air pressure is 0.03 MPa, and the main network air pressure is 0.5 MPa. The hot roll drawing and setting uses a five-roll hot roll box. The temperatures of the first roll, the second roll, and the third roll are 84 - 86 °C, and the temperatures of the fourth roll and the fifth roll are 133 ± 1 °C. The total draw ratio is 2.2; the tension of the tow at the outlet of the hot roll box is 18 cN; the winding speed is 4600 m / min.

[0046] Example 3. An antibacterial polyester FDY yarn, and the preparation method is as follows: Through an on-line addition system, 0.25 kg of the zinc oxide-coated nano silver of Preparation Example 3 is added to 9.75 kg of polyester melt. After the polyester melt is filtered by the sand cup of the spinning pack, it is extruded from the spinneret to obtain a nascent fiber. The nascent fiber is cooled by ring blowing, pre-networked, oiled and bundled, drawn and set by a hot roll box, main-networked, and wound to obtain an FDY yarn with a specification of 83 dtex / 72F and an oil content of 0.88%.

[0047] Among them, the spinneret box temperature is 283 - 288 °C, and the sand cup sand mixture selects 60-mesh 60 g metal sand and 40-mesh 40 g metal sand. The ring blowing pressure is 25 ± 2 Pa, and the ring blowing temperature is 20.5 ± 1 °C; the oiling uses diluted oil with an oil agent concentration of 85 wt%. The pre-network air pressure is 0.06 MPa, and the main network air pressure is 0.4 MPa. The hot roll drawing and setting uses a five-roll hot roll box. The temperatures of the first roll, the second roll, and the third roll are 82 - 85 °C, and the temperatures of the fourth roll and the fifth roll are 126 ± 1 °C. The total draw ratio is 1.8; the tension of the tow at the outlet of the hot roll box is 14 cN; the winding speed is 4560 m / min.

[0048] Example 4. An antibacterial polyester FDY yarn, which is different from Example 1 in that the zinc oxide-coated nano silver of Preparation Example 4 is replaced with an equal amount of the zinc oxide-coated nano silver of Preparation Example 1.

[0049] Example 5. An antibacterial polyester FDY yarn, which is different from Example 1 in that the zinc oxide-coated nano silver of Preparation Example 5 is replaced with an equal amount of the zinc oxide-coated nano silver of Preparation Example 1.

[0050] Example 6. An antibacterial polyester FDY yarn, which is different from Example 1 in that the zinc oxide-coated nano silver of Preparation Example 6 is replaced with an equal amount of the zinc oxide-coated nano silver of Preparation Example 1.

[0051] Example 7. An antibacterial polyester FDY yarn, which is different from Example 1 in that the zinc oxide-coated nano silver of Preparation Example 7 is replaced with an equal amount of the zinc oxide-coated nano silver of Preparation Example 1.

[0052] Example 8. An antibacterial polyester FDY filament, which is different from that of Example 1 in that the zinc oxide-coated silver nanoparticles of Preparation Example 8 are used to replace the zinc oxide-coated silver nanoparticles of Preparation Example 1 in equal amounts.

[0053] Example 9. An antibacterial polyester FDY filament, which is different from that of Example 1 in that the pre-networking process is not carried out between the oiling and drawing and setting processes.

[0054] Example 10. An antibacterial polyester FDY filament, which is different from that of Example 1 in that the tension of the filament bundle at the outlet of the hot roller box is set to 20 cN. Comparative Example

[0055] Comparative Example 1. An antibacterial polyester FDY filament, which is different from that of Example 1 in that the zinc oxide-coated silver nanoparticles of Preparation Example 9 are used to replace the zinc oxide-coated silver nanoparticles of Preparation Example 1 in equal amounts.

[0056] Comparative Example 2. An antibacterial polyester FDY filament, which is different from that of Example 1 in that the zinc oxide-coated silver nanoparticles of Preparation Example 10 are used to replace the zinc oxide-coated silver nanoparticles of Preparation Example 1 in equal amounts.

[0057] Comparative Example 3. An antibacterial polyester FDY filament, which is different from that of Example 1 in that zinc oxide (average particle size 60 nm) in equal amounts is used to replace the zinc oxide-coated silver nanoparticles of Preparation Example 1. Performance Detection Test

[0058] Test 1: Antibacterial Performance Test (1) The test was carried out in accordance with the provisions of ISO 20743:2021 Determination of Antibacterial Activity of Textiles. Take the FDY filament samples (1 g) of each example and comparative example, and cut them into pieces with a length of 5 mm. Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 6538) were selected as the test bacteria. 0.1 mL of the bacterial suspension (1×10 6 CFU / mL) was dropped onto the surface of the sample, and cultured at 37 °C and 90% humidity for 24 h. After eluting the bacterial liquid, it was diluted and spread on an agar plate, and the surviving colonies were counted. The antibacterial rate was calculated according to the following formula: Antibacterial rate (%) = (number of colonies in the blank sample - number of colonies in the sample) / number of colonies in the blank sample × 100 (2) After washing 50 times according to the standard of GB / T 8629-2017, the above test was repeated to characterize the long-term antibacterial performance of the FDY filament.

[0059] Test 2: Tensile Strength Test of FDY Filament The test was carried out in accordance with the provisions of GB / T 14344-2022 Test Method for Tensile Properties of Chemical Fiber Filaments. The sampling length was 500 mm, the pre-tension was 0.05 cN / dtex, and the drawing speed was 500 mm / min.

[0060] Experiment 3: Statistics of spinning breakage rate of FDY yarn Record the number of spinning breakages during the 24-hour production process (times / 24h • 72 positions).

[0061] Experiment 4: Determination of yellowing index of FDY yarn Referring to GB / T 8427-2019, use a color difference meter to measure the L * , a * , b * values, and calculate the yellowing index (YI).

[0062] Table 1. Test results of FDY yarn properties

[0063] Data analysis: 1. Antibacterial performance For Examples 1-3, the initial antibacterial rate > 99.5%, and > 95% after 50 washes. Because the ZnO shell effectively protects the nano-silver, and the dual modification of mercaptopropionic acid / dihydroxybenzophenone reduces silver oxidation and zinc ion-catalyzed degradation.

[0064] In Example 4, the coating amount of mercaptopropionic acid is insufficient, and the antibacterial rate drops significantly (initial 98%, after washing 92.4%), verifying the necessity of mercaptopropionic acid coating for antibacterial performance, especially for long-term antibacterial performance. In Example 5, the coating amount of mercaptopropionic acid is too high, and the initial antibacterial rate drops significantly (98.3%), verifying that too high a concentration and too long a soaking time of mercaptopropionic acid will affect the initial antibacterial performance. In Example 7, mercaptopropionic acid coating is not carried out, and both its initial antibacterial performance and antibacterial performance after washing decrease (97.2%, 90.9%), further verifying the important influence of mercaptopropionic acid coating on antibacterial performance. In Comparative Examples 1-2, the ZnO contents are 8% and 23% respectively, resulting in too thin or too thick a shell, which leads to silver oxidation or release hindrance, and the antibacterial rate is lower than that of the examples.

[0065] 2. Spinning breakage, breaking strength and yellowing index For Examples 1-3, the spinning breakage rate < 5 times, the breaking strength ≥ 4.0 cN / dtex, and the yellowing index YI < 4.0. Due to the coordination effect of mercaptopropionic acid and dihydroxybenzophenone on the zinc ion catalyst, the catalytic degradation of free zinc on polyester macromolecules is inhibited. In Comparative Examples 1-2, the breakage rate > 2 times / ton due to particle agglomeration. In Example 6 (without grafting dihydroxybenzophenone), Example 7 (without coating mercaptopropionic acid), and Example 8 (without coating mercaptopropionic acid and without grafting dihydroxybenzophenone), the performance of all three in terms of spinning breakage rate, breaking strength and yellowing index shows obvious deterioration, because the radical quenching effect obtained by lacking mercaptopropionic acid or dihydroxybenzophenone.

[0066] This specific embodiment is only an interpretation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment that do not contribute creatively as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A method for producing antibacterial polyester FDY yarn, characterized in that: The polyester melt is extruded through a spinning assembly, cooled, oiled, drawn and shaped, main networked and wound to obtain FDY yarn. 1.2-2.5 wt% of zinc oxide-coated nanosilver is added to the polyester melt through an online adding system, and the zinc oxide content of the zinc oxide-coated nanosilver is 10-20 wt%.

2. The manufacturing method according to claim 1, characterized in that: A pre-networking process is provided between the oiling and the drawing and shaping processes, and the air pressure of the pre-networking process is 0.03-0.06 MPa.

3. The manufacturing method according to claim 1, characterized in that: The stretching and shaping adopts a five-roller hot roller box, wherein the temperature of the first roller, the second roller and the third roller is 82-87° C., the temperature of the fourth roller and the fifth roller is 120-135° C., and the total stretching multiple is 1.8-2.

2.

4. The manufacturing method according to claim 3, characterized in that: The tension of the filament bundle at the outlet of the hot roller box is 14-18 cN.

5. The manufacturing method according to claim 1, characterized in that: The sand cup of the spinning assembly is prepared by selecting 60g of 40-60 mesh metal sand and 40g of 20-40 mesh metal sand.

6. The manufacturing method according to claim 1, characterized in that: The zinc oxide coated nano-silver is surface modified by mixing the zinc oxide coated nano-silver and mercaptopropionic acid in a mass ratio of 100:0.1-0.3 in a solution, and performing a self-assembly reaction for 2-4 hours.

7. The manufacturing method according to claim 6, characterized in that: The surface-modified zinc oxide-coated nano-silver is placed in a solution environment with a pH value of 4 to 5, and ultrasonically dispersed for 0.5 to 1 hour; the pH value is adjusted to 6 to 7, dihydroxybenzophenone is added, the temperature is raised to 80 to 90° C., and refluxed under nitrogen protection to obtain anti-yellowing zinc oxide-coated nano-silver.

8. The manufacturing method according to claim 7, characterized in that: The mass ratio of the surface-modified zinc oxide-coated nano-silver to dihydroxybenzophenone is 100:5-8.

9. The manufacturing method according to claim 1, characterized in that: The oil content of the FDY yarn is 0.7-0.9%.

10. An antibacterial polyester FDY yarn, characterized in that: The invention is prepared by the method according to any one of claims 1 to 9.

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