Production process of high-elasticity heat-resistant polyester yarn

Abstract

The invention relates to a production process of a high-elasticity heat-resistant polyester yarn, which comprises the following steps: firstly, selecting high-molecular-weight polyethylene glycol terephthalate, adding 1-3% of nano filler and 5-10% of functional copolymer, and drying at 150 DEG C for 4-6 hours to improve the stability and processability of the material; secondly, melt extrusion is conducted at 280-290 DEG C, spinning is conducted through a multi-section temperature control spinning head, and the fiber cooling uniformity is effectively controlled. Then, two times of drafting and a heat setting process are adopted, the orientation degree of a molecular chain is improved in one time of drafting, and low-temperature plasma treatment is combined to optimize the surface activity and the setting effect of the fibers. In the secondary drafting, the fiber deformation is finely adjusted at low temperature, the thermal damage is reduced, the elasticity is improved, and finally, xylanase treatment and ultraviolet curing are combined, so that the softness, the skin-friendly property and the weather resistance of the fiber are remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer material processing, and in particular relates to a production process of high-elasticity heat-resistant polyester yarn. Background Art

[0002] As an important synthetic fiber, polyester fiber is nearly 1 times stronger than cotton and 3 times stronger than wool, which is also relatively high among synthetic fibers. This makes clothing, ropes and other products made of polyester relatively strong and durable. Its elasticity is close to that of wool, and it can almost completely recover when stretched by 5% - 6%. This good elasticity makes polyester fabrics less prone to wrinkling during wearing, and they can quickly recover to their original shape even after being squeezed or stretched. It is widely used due to its excellent mechanical properties, heat resistance and chemical stability.

[0003] However, due to the material limitations of polyester fibers, they are relatively brittle and are prone to breakage when subjected to sudden external impacts. In some applications that require high impact resistance, such as sports protective equipment and outdoor adventure equipment, polyester is more susceptible to damage when pierced by sharp objects or hit by heavy objects. Although polyester has good elasticity, when polyester materials are subjected to long-term and large tensile forces, they will gradually deform. After exceeding a certain limit, they cannot return to their original state and may even break, affecting safety in use.

[0004] Therefore, it is necessary to improve the existing polyester, improve the mechanical properties of polyester, enhance the toughness of polyester and increase the tensile strength of polyester. Summary of the invention

[0005] The invention provides a production process of high-elasticity heat-resistant polyester yarn, which improves the mechanical properties of polyester, enhances the toughness of polyester and improves the tensile strength of polyester by adjusting the composition of polyester and improving the process, especially by adjusting during the drawing process.

[0006] The specific technical solution of the present invention is: a production process of high elasticity heat-resistant polyester yarn, characterized in that it comprises the following steps: S1. Raw material selection and preparation: Select high molecular weight polyethylene terephthalate, add 1-3% nanofiller, 5-10% functional copolymer; dry at about 150°C for 4-6 hours, and control the water content at 0.01% - 0.1%; S2, melt spinning: the dried raw material is melted and extruded at 280-290°C, and spun through a multi-stage temperature-controlled spinning head, and the temperature of the spinning head is gradually reduced; S3, perform a stretching and heat setting treatment; perform a stretching at a temperature of 80-100°C, with a stretching ratio of 1.5-2.0 times; perform a low-temperature plasma treatment after stretching for 5-10 seconds; and then perform heat setting at 160-180°C for 30 seconds; S4, perform secondary stretching and texturing treatment; perform secondary stretching at a temperature of 50-70°C, with a draft ratio of 1.5-2.0 times; use a 200-220°C high temperature and high pressure steam stage texturing treatment, and monitor the temperature, pressure and tension in real time through an intelligent control system; S5, winding and post-treatment: winding the treated polyester yarn into a cylindrical yarn bundle, treating it with a biological enzyme, and curing it with ultraviolet light for 10-20 seconds; S6. Quality control and testing; S7. Packaging and storage: The polyester yarn that passes the inspection shall be packaged and stored in a dry, cool and ventilated environment.

[0007] Nanofillers and functional copolymers are added to polyester. Nanofillers have a high specific surface area and surface energy. After combining with the polyester matrix, they play a reinforcing role, thereby improving the tensile strength of polyester. Nanofillers and copolymers can increase the entanglement and cross-linking between polyester molecular chains, so that when polyester is subjected to external forces, the molecular chains can better transmit and disperse stress, thereby improving its toughness; adding nanofillers and functional copolymers helps to change the viscosity of the melt, making the melt easier to flow during the spinning process, reducing melt fracture and fiber breakage; Drying is performed after adding to reduce the water content and avoid the evaporation of water in the subsequent spinning process, which leads to defects such as voids and bubbles inside the fiber. Drying can also reduce the hydrolysis of polyester molecular chains and maintain the stability of the material. The multi-stage temperature-controlled spinning head effectively controls the temperature during the spinning process, ensuring the stability and uniformity of the molten fiber. The setting of gradually lowering the temperature helps prevent uneven shrinkage and deformation of the fiber during the cooling process, thereby improving the quality and performance of the fiber. The first drafting temperature is set to 80-100℃, which is higher than the 70-90℃ range of the traditional process, so as to achieve full stretching and orientation of the fiber molecular chain, improve the initial strength, and lay the foundation for subsequent processing. In low-temperature plasma treatment, high-energy particles collide with the molecules on the surface of polyester fibers, which will break some chemical bonds and form free radicals. These free radicals can react with gases in the surrounding environment (such as oxygen, nitrogen, etc.), introduce new functional groups on the fiber surface, increase the activity of the fiber surface, and improve the adhesion and treatment effect of the fiber with other materials. Plasma treatment can remove the weak boundary layer on the fiber surface, making the fiber surface cleaner, and will also etch the fiber surface to a certain extent, increase the surface roughness, and improve the uniformity of heat setting, which is conducive to the rearrangement of the fiber surface molecules in the subsequent heat setting process. Low-temperature plasma treatment optimizes the thermal conductivity and increases the heat setting temperature from the traditional 180- The temperature is reduced from 220℃ to 160-180℃, which reduces thermal damage and improves fiber elasticity and strength. The heat setting process enhances the dimensional stability and deformation recovery of the fiber, ensuring that the fiber is not easily deformed during use. The heat setting temperature is set to 160-180℃, which is lower than the 180-220℃ range of the prior art, avoiding thermal oxidation damage caused by high temperature while the fiber is initially set. After heat setting, the temperature is reduced to the second stretching temperature range of 50-70℃ through natural or controlled cooling to gradually release internal stress. The intermediate cooling design effectively improves the dimensional stability of the fiber and reduces fiber deformation caused by thermal stress. The combination of the first stretching and low-temperature plasma treatment makes the fiber surface more uniform, providing excellent conditions for subsequent heat setting and stretching. The low-temperature stretching after heat setting optimizes the deformation adjustment process of the fiber, reducing energy consumption while ensuring the elastic recovery rate and strength stability of the fiber.

[0008] Preferably, the nanofiller is nano-titanium dioxide or nano-silicon, and the addition amount is 1-3%. Nano-titanium dioxide or nano-silicon has excellent mechanical properties and thermal stability, can significantly enhance the strength and heat resistance of polyester yarn, and improve the comprehensive performance of the fiber.

[0009] Preferably, the functional copolymer is a polyamide copolymer, and the addition ratio is 5-10%. Polyamide copolymer has good flexibility and impact resistance. After being added to polyester, it can effectively improve the toughness of polyester. The molecular chain structure of polyamide copolymer can interact with the polyester molecular chain to form a more stable network structure, thereby improving the tensile strength of polyester.

[0010] Preferably, the temperature of each section of the multi-section temperature-controlled spinning head is 280°C, 275°C, and 270°C, respectively.

[0011] Preferably, the intelligent control system is an intelligent control module, which includes a temperature sensor, a pressure sensor and a tension sensor, and performs real-time data analysis and adjustment through a central processing unit.

[0012] Preferably, the texturing area is divided into a preheating section, a texturing section and a shaping section, and the central control processor independently controls the parameters of each section; temperature sensors are respectively set in the preheating section, the texturing section and the shaping section to detect the temperature of each section in real time; the temperature of the preheating section is 200-210°C, the temperature of the texturing section is 210-220°C, the temperature of the shaping section is 180-200°C, and the temperature control accuracy is ±2°C; the central control processor adjusts the heating unit or the cooling unit to keep the temperature of each section within the set range, and the temperature fluctuation does not exceed the set value; pressure sensors are respectively set in the preheating section, the texturing section and the shaping section to detect the steam pressure in real time; the steam pressure of the preheating section is 0.4-0.6 MPa, the steam pressure of the texturing section is 0.5-0.8 MPa, and the steam pressure of the shaping section is 0.4-0.6 MPa; the central control processor controls the steam flow by adjusting the solenoid valve of the steam supply system to maintain the steam pressure of each section within the set range, and the pressure fluctuation error is less than ±0.05 MPa; tension sensors are respectively arranged at the fiber traction roller and the entrance of the elasticizing section to detect the tension in the fiber traction process in real time; the tension of the preheating section is 0.3-0.5 N, the tension of the elasticizing section is 0.5-0.8 N, the tension of the shaping section is 0.4-0.6 N, and the tension fluctuation error is less than ±0.02 N; the central control processor ensures precise tension control by adjusting the rotation speed of the traction roller and the friction adjustment device.

[0013] The texturing area is divided into a preheating section, a texturing section and a shaping section, and the central control processor independently controls the parameters of each section; in the preheating section, the fiber temperature and plasticity are gradually increased; in the texturing section, the fiber molecular structure is adjusted by high-temperature and high-pressure steam and stretching, and the stretching ratio is controlled at 1.5-2.0 times; in the shaping section, the fiber structure is stabilized and residual stress is eliminated by reducing the temperature and pressure; the central control processor collects real-time data of temperature, pressure and tension, and compares them with preset process parameters, and then feeds back the comparison results to adjust the control parameters; if the detection value deviates from the set range, real-time adjustment is made by adjusting the heating unit, solenoid valve or traction roller parameters, and the adjustment response time does not exceed 0.1 seconds to ensure the stability of the texturing process.

[0014] Preferably, the biological enzyme is xylanase. Xylanase treatment improves the softness and skin affinity of the fiber and increases the comfort of the polyester yarn in textiles.

[0015] Preferably, the bio-enzyme treatment specifically comprises the following steps: Preparation of enzyme solution: preparing xylanase enzyme solution, wherein the concentration of the xylanase is 0.5-2 wt%, and the concentration is adjusted according to the treatment requirements; using deionized water to dissolve the enzyme powder, and adjusting the pH value of the solution to 5.5-6.5 under stirring, wherein the pH value is adjusted by adding dilute hydrochloric acid or dilute sodium hydroxide solution; heating the enzyme solution to 30-40° C., keeping the solution uniform, and ensuring that the enzyme activity of the xylanase reaches an optimal state; Soaking treatment of polyester yarn: put the wound cylindrical polyester yarn tow into the enzyme solution treatment tank; the soaking time is 10-20 minutes, and the enzyme solution is controlled to flow in the tank by stirring or circulating pump to ensure that the enzyme solution is evenly distributed on the surface of the tow; Enzymatic hydrolysis: Xylanase acts on the surface of polyester filaments at 30-40℃ and pH 5.5-6.5 to improve the cleanliness and softness of the fiber surface by degrading residual impurities on the surface (such as oil or incompletely polymerized polyester particles); the time is controlled within 10-20 minutes; Cleaning step: After the enzymatic hydrolysis is completed, the tow is washed several times with deionized water or clean water; during the cleaning process, the water temperature is kept at 20-40°C and stirred to remove the residual enzyme solution and decomposition products; Dehydration and drying: The cleaned tow is dehydrated by using centrifugal dehydration equipment or compressed air extrusion to remove excess water; after dehydration, the tow is placed in a drying device for drying, the drying temperature is controlled at 60-80°C, the drying time is 30-60 minutes, and finally the moisture content of the polyester yarn is controlled below 3%.

[0016] Preferably, the specific steps of the quality control and detection are: (1) Conduct a preliminary appearance inspection to ensure that there are no obvious defects on the surface of the polyester yarn; (2) Use a tensile testing machine to test the elasticity and heat resistance of polyester yarn to ensure that it meets the set standards; (3) The microstructure of the polyester filaments was examined using scanning electron microscopy to ensure the uniform distribution of the nanofillers and functional copolymers; (4) Conduct anti-UV tests to ensure the weather resistance of polyester yarn.

[0017] The beneficial effects of the present invention are as follows: 1. By adding nano fillers and functional copolymers, the material properties are improved, the mechanical properties and tensile properties of polyester are improved, and the subsequent steps are facilitated.

[0018] 2. By optimizing the drafting process, especially setting the first drafting temperature at 80-100℃, which is higher than the 70-90℃ of the traditional process, the fiber is fully stretched and oriented during the drafting process, which improves the initial strength of the fiber (from 600 MPa to 750 MPa), laying a stronger foundation for subsequent processes. At the same time, the second drafting temperature is set at 50-70℃, which is lower than the 120-150℃ of the traditional process. By fine-tuning the deformation at low temperature, the thermal damage is reduced, and the dimensional stability and elastic recovery of the fiber are further improved. On this basis, the introduction of low-temperature plasma treatment effectively improves the uniformity and affinity of the fiber surface and enhances the effect of the heat setting process. Low-temperature plasma treatment removes surface impurities and activates the fiber surface, improves the adhesion between the fiber and external materials, and provides more uniform surface conditions for subsequent heat setting processes. In addition, plasma treatment optimizes the thermal conductivity, so that the heat setting temperature can be appropriately reduced (from the traditional 180-220℃ to 160-180℃), effectively reducing thermal damage and improving the elasticity and strength of the fiber.

[0019] 3. Bio-enzyme treatment improves the softness and skin-friendliness of the fiber, and improves the comfort of polyester yarn in textiles. It makes it more suitable for textiles with high comfort requirements, and also improves the weather resistance and surface strength of the fiber. In the subsequent UV curing treatment, the surface activity of the fiber increases, further enhancing the durability and stability of the fiber. In addition, bio-enzyme treatment improves the processing performance of the fiber, making it more adaptable in the subsequent weaving and dyeing processes, ensuring the long-term stability of the polyester yarn. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention discloses a production process flow chart of a high-elasticity heat-resistant polyester yarn. DETAILED DESCRIPTION

[0021] The following is a specific embodiment, and combined with the attached Figure 1 The present invention is further described.

[0022] Embodiment 1: Process steps: S1. Raw material selection and preparation: High molecular weight PET with a molecular weight of 22,000 is used as the basic raw material to ensure the strength and heat resistance of the polyester yarn; 2% of nano-grade titanium dioxide is added as a filler to enhance the mechanical properties of the polyester yarn; 6% of polyamide copolymer is added to improve the elasticity and flexibility of the polyester yarn; the raw material is dried at 150°C for 5 hours to ensure that the moisture in the raw material is completely removed to prevent performance degradation due to hydrolysis during the melting process; S21, melt spinning: The raw material is melted at 280℃ and extruded through a three-stage temperature-controlled spinning head. The temperatures of the spinning head are set to 280℃, 275℃, and 270℃ respectively. The fiber is cooled by natural air cooling, and the cooling air temperature is controlled at 25℃ to prevent the fiber from shrinking and deforming due to excessive cooling. S3, primary stretching and heat setting: Drafting process: Drafting is performed once at 90°C, with a drafting ratio of 1.7 times; Low-temperature plasma treatment: Use a mixture of argon and oxygen to treat the fiber surface for 8 seconds; Heat setting process: Heat setting is performed at 170°C for 25 seconds to stabilize the fiber structure and improve dimensional stability; S4, secondary drafting and texturing treatment: Secondary drawing: Secondary drawing is carried out at 60°C, and the drawing ratio is 1.8 times; Texturing treatment: High temperature and high pressure steam texturing process is adopted, the temperature is 210℃, the pressure is 0.6MPa, and the tension is controlled at 0.5N during the texturing process; S5, winding and post-processing: Winding into a cylindrical tow to ensure fiber uniformity; Xylanase treatment: Use 1wt% xylanase solution at 35°C for 12 minutes to improve the softness and skin-friendliness of the fiber, then put the wound cylindrical polyester filament tow into the enzyme solution treatment tank for soaking treatment; the soaking time is 10-20 minutes, and then the enzymatic reaction is carried out for 10-20 minutes. After the enzymatic reaction is completed, the tow is washed several times with deionized water or clean water, and then dehydrated and dried; UV curing treatment: UV light intensity is 0.8W / cm², and the treatment time is 15 seconds, which improves the weather resistance of the fiber surface.

[0023] S6. Quality inspection: Tensile performance test: elastic recovery rate 92%, tensile strength 700MPa.

[0024] Heat resistance test: heat deformation temperature is 170℃.

[0025] Appearance inspection: The fiber surface is smooth and has no obvious defects.

[0026] Summary of embodiments: The process of this embodiment is simple, suitable for the production of ordinary polyester yarn, and has low cost. The fiber performance meets the requirements of ordinary textiles, but its strength and heat resistance are relatively low, and it is suitable for scenes with low performance requirements, such as daily clothing and general industrial materials. Example

[0027] Process steps: S1. Raw material selection and preparation: Selecting high molecular weight PET with a molecular weight of 24,000 improves the strength and heat resistance of the fiber; Add 3% nano-silicon (SiO2) to improve the thermal stability and optical properties of polyester yarn; Add 8% polyamide copolymer to increase the elasticity and toughness of the fiber; Dry at 150°C for 6 hours to ensure that the raw materials are fully dehumidified; S2. Melt spinning: The raw materials were melted at 285°C and extruded through a segmented temperature-controlled spinning head. The temperatures of the spinning head were 285°C, 280°C, and 275°C respectively: Cooling: The cooling air temperature is set at 20°C to ensure uniform cooling of the fiber.

[0028] S3, primary stretching and heat setting: Drawing process: drawing temperature 95℃, drawing ratio 1.8 times; Low-temperature plasma treatment: using a mixture of argon and nitrogen (ratio 7:3) for 10 seconds; Heat setting process: temperature 165℃, time 30 seconds; S4, secondary drafting and texturing treatment: Secondary drawing: drawing at 55°C, with a drawing ratio of 1.9 times; Texturing treatment: High temperature and high pressure steam texturing, the temperature is 215℃, the pressure is 0.7MPa, and the tension is controlled at 0.6N during the texturing process; S5, winding and post-processing: Xylanase treatment: 1.5 wt% enzyme solution was used for treatment at 38 °C for 18 min; UV curing treatment: UV light intensity is 1.0W / cm², and the treatment time is 18 seconds; S6. Quality inspection: Tensile performance test: elastic recovery rate 94%, tensile strength 750MPa; Heat resistance test: heat deformation temperature is 180℃; Microstructure detection: Nanofillers are evenly distributed and the fiber surface is smooth.

[0029] Summary of embodiments: This embodiment improves the strength, elasticity and heat resistance of polyester yarn by increasing the molecular weight of raw materials and optimizing the filler ratio, and is suitable for mid-end textiles or industrial fields with high performance requirements, such as outdoor clothing and heat-resistant materials. Compared with Example 1, the performance is improved, but the cost is increased. Example

[0030] Process steps: S1. Raw material selection and preparation: Select ultra-high molecular weight PET with a molecular weight of 27,000; Add 3% titanium dioxide and nano-silicon mixed filler (ratio 1:1) and add 10% polyamide copolymer; Dry at 150℃ for 6 hours to ensure the stability of raw material quality; S2. Melt spinning: The raw materials were melted at 290°C, and the temperatures of the spinning head were 290°C, 285°C, and 280°C, respectively; The cooling air temperature was set at 18°C ​​to prevent the accumulation of internal stress in the fiber during the cooling process; S3, primary stretching and heat setting: Drawing process: drawing temperature 100℃, drawing ratio 2.0 times; Low temperature plasma treatment: Argon and oxygen mixed gas treatment time 12 seconds; Heat setting process: temperature 160℃, time 30 seconds; S4, secondary drafting and texturing treatment: Secondary drawing: temperature 50°C, drawing ratio 2.0 times; High temperature and high pressure steam elasticization: temperature: 220℃; pressure: 0.8MPa; tension: 0.8N.

[0031] S5, winding and post-processing: Xylanase treatment: 2 wt% xylanase solution was used for treatment at 40 °C for 20 min; UV curing treatment: UV light intensity is 1.2W / cm², and the treatment time is 20 seconds; S6. Quality inspection: Tensile performance test: elastic recovery rate 96%, tensile strength 800MPa; Heat resistance test: heat deformation temperature is 190℃; Anti-UV test: weather resistance increased by 20%.

[0032] Summary of embodiments: This embodiment uses ultra-high molecular weight raw materials and optimized filler combinations to significantly improve the strength, elasticity and heat resistance of polyester yarns, and is an ideal production process for high-performance polyester yarns. It is suitable for fields with extremely high performance requirements, such as industrial protective materials, outdoor equipment and high-end textiles. Compared with the previous two embodiments, the performance is further improved, but the cost is higher, which is suitable for the high-end market.

[0033] Comparative experiment: Comparative experiment 1: Effect of fiber surface treatment on softness and skin-friendliness Purpose: By comparing the existing technologies (traditional chemical treatment, physical cleaning) and the xylanase treatment in the present invention, the influence of the surface treatment process on the softness and skin-friendliness of polyester fibers was studied.

[0034] Experimental Materials: Polyester fiber samples (produced from the same batch, with the same processing oil and impurities remaining on the surface).

[0035] Chemical reagent: 2wt% dilute hydrochloric acid.

[0036] Xylanase: enzyme activity 2000U / g.

[0037] Experimental equipment: deionized water device, low-temperature constant temperature water bath, contact angle tester, softness tester.

[0038] Experimental comparison plan: Sample A (traditional chemical treatment): Use dilute hydrochloric acid to clean the surface at 60°C and soak for 15 minutes.

[0039] Chemical methods use acid to dissolve residual impurities, but acid washing residues may affect fiber properties.

[0040] Sample B (physical cleaning): Use 90℃ high temperature steam to clean the polyester fiber surface for 15 minutes.

[0041] Physical methods use high-temperature steam to remove impurities, but the effect is limited and it is difficult to remove deep deposits.

[0042] Sample C (xylanase treated with the present invention): The polyester yarn was immersed in a 1.5wt% xylanase solution with a pH value of 6.0 and a temperature of 38°C and circulated with slight stirring for 15 minutes.

[0043] The enzyme treatment acts gently on surface residues, removing impurities without damaging the fiber structure.

[0044] Experimental process: Sample preparation: Three groups of polyester yarns are divided into groups A, B, and C, 50 strands each, and each strand is 20 cm long.

[0045] Surface treatment: Sample A: The polyester yarn was immersed in a 60°C, 2wt% dilute hydrochloric acid solution, taken out after 15 minutes, rinsed with deionized water three times, and dried.

[0046] Sample B: Place the polyester yarn in a steam cleaning device and set the temperature to 90°C for 15 minutes, then take it out and allow it to cool naturally.

[0047] Sample C: The polyester yarn was immersed in a 1.5wt% xylanase solution, maintained at 38°C with slight stirring for 15 minutes, then taken out, washed with deionized water three times, centrifuged and dried at 60°C.

[0048] Performance Testing: Softness test: Place the fiber into a flexibility tester and record the compression recovery rate (recovery length / initial length × 100%).

[0049] Skin-friendly test: Use a contact angle meter to test the contact angle of each fiber surface, repeat 3 times and take the average value.

[0050] Experimental results: sample Processing Softness (compression recovery rate, %) Skin affinity (contact angle, °) Sample A Traditional chemical treatment 72 105 Sample B Physical cleaning 78 97 Sample C Xylanase treatment 92 65 Experimental analysis: Traditional chemical treatment (sample A) is effective in removing impurities, but the chemical residue affects the softness of the fiber and is not environmentally friendly.

[0051] Physical cleaning (sample B) is safer, but high-temperature steam is difficult to completely remove impurities, which affects the skin-friendliness of the fiber surface.

[0052] The xylanase treatment (sample C) of the present invention removes surface oils and impurities by mild enzymatic hydrolysis without damaging the fiber structure, thereby significantly improving softness and skin-friendliness, and the effect is better than that of the prior art.

[0053] Comparative experiment 2: Effect of drafting process optimization on fiber mechanical properties Purpose: By comparing the existing drafting technology with the optimized drafting process of the present invention, the effects of the drafting temperature and the drafting ratio on the tensile strength and elastic recovery rate of the polyester yarn are studied.

[0054] Experimental Materials: Polyester fiber sample: raw yarn produced by the same batch of spinning.

[0055] Drafting equipment: with temperature control and draft ratio adjustment functions.

[0056] Experimental comparison plan: Sample D (Prior Art): The primary drawing temperature is 70℃ and the drawing ratio is 1.6 times; The secondary drawing temperature is 60°C and the drawing ratio is 1.6 times.

[0057] Sample E (improved technology): The primary drawing temperature is 90°C and the drawing ratio is 1.8 times; The secondary drawing temperature is 60°C and the drawing ratio is 1.9 times.

[0058] Sample F (present invention): The primary drawing temperature is 100°C and the drawing ratio is 2.0 times; The secondary drawing temperature is 50°C and the drawing ratio is 2.0 times.

[0059] Experimental process: Drafting treatment: The three groups of samples were stretched separately, and the stretching temperature and stretching ratio were strictly controlled.

[0060] Performance Test: Tensile strength test: The maximum stress value at the breaking point is tested on a tensile tester.

[0061] Elastic recovery test: After being stretched 20% and then released, measure the proportion of the fiber recovering to its initial length.

[0062] Experimental results: sample Drawing temperature (℃) Draft ratio Tensile strength (MPa) Elastic recovery rate (%) Sample D 70 / 60 1.6 / 1.6 600 86 Sample E 90 / 60 1.8 / 1.9 700 92 Sample F 100 / 50 2.0 / 2.0 800 96 Experimental analysis: The drawing temperature of sample D is low and the molecular chain orientation is insufficient, resulting in poor mechanical properties.

[0063] Sample E improves the fiber strength by increasing the primary drawing temperature and drawing ratio.

[0064] Sample F adopts the combination of high-temperature primary stretching and low-temperature secondary stretching of the present invention, so that the molecular chain is fully stretched and thermal damage is reduced, and the performance is optimal.

[0065] Comparative experiment 3: Effect of multi-stage temperature-controlled stretching on fiber dimensional stability and heat resistance Purpose: The difference between the traditional single temperature-controlled texturing and the multi-stage temperature-controlled texturing of the present invention is studied to verify the advantages of the multi-stage temperature-controlled real-time monitoring process of the present invention in improving the fiber dimensional stability and heat resistance.

[0066] Experimental Materials: Polyester fiber samples.

[0067] Texturing equipment: supports segmented temperature control and real-time monitoring.

[0068] Experimental comparison plan: Sample G (Prior Art): Single elastic temperature control, 220℃, pressure 0.7MPa.

[0069] Sample H (improved process): Sectional temperature control: preheating section 200℃, springing section 210℃, shaping section 190℃.

[0070] Sample I (present invention): Segmented temperature control: preheating section 205℃, stretching section 215℃, shaping section 180℃, real-time monitoring of tension and pressure.

[0071] Experimental process: Elastic treatment: The texturing treatment is carried out according to different schemes, and the temperature and pressure are strictly controlled.

[0072] Performance Testing: Dimensional stability test: The fiber was kept at 150°C for 30 minutes and the dimensional change rate was recorded.

[0073] Heat resistance test: Test heat deformation temperature.

[0074] Experimental results: sample Elasticizing temperature (℃) Pressure (MPa) Dimensional stability (%) Heat resistance (℃) Sample G 220 / No segmentation 0.7 6.5 160 Sample H 200 / 210 / 190 0.7 4.2 175 Sample I 205 / 215 / 180 0.8 2.5 190 Experimental analysis: Sample G lacks segmented temperature control and has large residual stress in the fiber, resulting in a high dimensional change rate and low heat resistance.

[0075] Sample H reduces residual stress through segmented temperature control, but the effect is not as good as that of sample I.

[0076] Sample I further improves dimensional stability and heat resistance by optimizing tension and pressure distribution through real-time monitoring.

[0077] Summary: The improvements of the present invention are superior to the prior art in terms of softness, skin-friendliness, mechanical properties, dimensional stability and heat resistance, and solve the shortcomings of the background technology with remarkable effects.

[0078] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A production process for high elastic heat-resistant polyester yarn, characterized in that: The following steps are involved: S1. Raw material selection and preparation: Select high molecular weight polyethylene terephthalate, add 1-3% nanofiller, 5-10% functional copolymer; dry at about 150°C for 4-6 hours, and control the water content at 0.01% - 0.1%; S2, melt spinning: the dried raw material is melted and extruded at 280-290°C, and spun through a multi-stage temperature-controlled spinning head, and the temperature of the spinning head is gradually reduced; S3, perform a stretching and heat setting treatment; perform a stretching at a temperature of 80-100°C, with a stretching ratio of 1.5-2.0 times; perform a low-temperature plasma treatment after stretching for 5-10 seconds; and then perform heat setting at 160-180°C for 30 seconds; S4, perform secondary stretching and texturing treatment; perform secondary stretching at a temperature of 50-70°C, with a draft ratio of 1.5-2.0 times; use a 200-220°C high temperature and high pressure steam stage texturing treatment, and monitor the temperature, pressure and tension in real time through an intelligent control system; S5, winding and post-treatment: winding the treated polyester yarn into a cylindrical yarn bundle, treating it with a biological enzyme, and curing it with ultraviolet light for 10-20 seconds; S6. Quality control and testing; S7. Packaging and storage: The polyester yarn that passes the inspection shall be packaged and stored in a dry, cool and ventilated environment.

2. A process for producing high elastic heat-resistant polyester yarn according to claim 1, characterized in that: The nano filler is nano titanium dioxide or nano silicon, and the addition amount is 1-3%.

3. A process for producing high elastic heat-resistant polyester yarn according to claim 1, characterized in that: The functional copolymer is a polyamide copolymer, and the addition ratio is 5-10%.

4. A process for producing high elastic heat-resistant polyester yarn according to claim 1, characterized in that: The temperature of each section of the multi-section temperature-controlled spinning head is 280°C, 275°C, and 270°C respectively.

5. The production process of a high elastic heat-resistant polyester yarn according to claim 1, characterized in that: The intelligent control system is an intelligent control module, which includes a temperature sensor, a pressure sensor and a tension sensor, and performs real-time data analysis and adjustment through a central processing unit.

6. A process for producing high elastic heat-resistant polyester yarn according to claim 1 or 5, characterized in that: The texturing area is divided into a preheating section, a texturing section and a shaping section, and the central control processor independently controls the parameters of each section; the temperature of the preheating section is 200-210°C, the temperature of the texturing section is 210-220°C, the temperature of the shaping section is 180-200°C, and the temperature control accuracy is ±2°C; the steam pressure of the preheating section is 0.4-0.6 MPa, the steam pressure of the texturing section is 0.5-0.8 MPa, and the steam pressure of the shaping section is 0.4-0.6 MPa; the tension of the preheating section is 0.3-0.5 N, the tension of the texturing section is 0.5-0.8 N, the tension of the shaping section is 0.4-0.6 N, and the tension fluctuation error is ±0.02 N.

7. A process for producing high elastic heat-resistant polyester yarn according to claim 1, characterized in that: The biological enzyme is xylanase.

8. A process for producing high elastic heat-resistant polyester yarn according to claim 1 or 7, characterized in that: The biological enzyme treatment specifically comprises the following steps: Preparation of enzyme solution: preparing xylanase enzyme solution, wherein the concentration of the xylanase is 0.5-2 wt%, and the concentration is adjusted according to the treatment requirements; using deionized water to dissolve the enzyme powder, and adjusting the pH value of the solution to 5.5-6.5 under stirring, wherein the pH value is adjusted by adding dilute hydrochloric acid or dilute sodium hydroxide solution; heating the enzyme solution to 30-40° C., keeping the solution uniform, and ensuring that the enzyme activity of the xylanase reaches an optimal state; Soaking treatment of polyester yarn: put the wound cylindrical polyester yarn tow into the enzyme solution treatment tank; the soaking time is 10-20 minutes, and the enzyme solution is controlled to flow in the tank by stirring or circulating pump to ensure that the enzyme solution is evenly distributed on the surface of the tow; Enzymatic hydrolysis: Xylanase acts on the surface of polyester filaments at 30-40℃ and pH 5.5-6.5 to improve the cleanliness and softness of the fiber surface by degrading residual impurities on the surface (such as oil or incompletely polymerized polyester particles); the time is controlled within 10-20 minutes; Cleaning step: After the enzymatic hydrolysis is completed, the tow is washed several times with deionized water or clean water; during the cleaning process, the water temperature is kept at 20-40°C and stirred to remove the residual enzyme solution and decomposition products; Dehydration and drying: The cleaned tow is dehydrated by using centrifugal dehydration equipment or compressed air extrusion to remove excess water; after dehydration, the tow is placed in a drying device for drying, the drying temperature is controlled at 60-80°C, the drying time is 30-60 minutes, and finally the moisture content of the polyester yarn is controlled below 3%.

9. The production process of high elastic heat-resistant polyester yarn according to claim 1, characterized in that: The specific steps of the quality control and detection are: (1) Conduct a preliminary appearance inspection to ensure that there are no obvious defects on the surface of the polyester yarn; (2) Use a tensile testing machine to test the elasticity and heat resistance of polyester yarn to ensure that it meets the set standards; (3) The microstructure of the polyester filaments was examined using scanning electron microscopy to ensure the uniform distribution of the nanofillers and functional copolymers; (4) Conduct anti-UV tests to ensure the weather resistance of polyester yarn.

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