Preparation process of molecular sieve-polypropylene blended spinning high-strength fiber

Abstract

The invention relates to the technical field of high-strength fibers, in particular to a preparation process of molecular sieve-polypropylene blended spinning high-strength fibers, which comprises the following steps: S1, uniformly mixing polypropylene, a modified molecular sieve and a modified master batch, granulating by using a twin-screw extruder, extruding a strip-shaped material, and water-cooling and pelletizing; and S2, adding the mixed material into a hopper of a spinning machine, adopting a two-stage hot drafting process, and collecting at a winding speed of 2500-3000m / min to finally obtain the molecular sieve-polypropylene blended spinning high-strength fiber. The crystallinity and orientation degree of the fiber are remarkably improved by optimizing the adding amount of the molecular sieves, the spinning temperature, the draw ratio and the like, so that high breaking strength and proper elongation at break are obtained, industrial production is easy to realize, and the prepared fiber can be used in the field of clothing and also can be used in the field of clothing. And the yarn can also be widely applied to the industrial yarn fields of ropes, Christmas tree materials, tire cords, rubber product framework materials and the like, and has a wide market prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high-strength fibers, in particular to a preparation process of molecular sieve-polypropylene blended high-strength fibers. BACKGROUND

[0002] Polypropylene fibers have become one of the rapidly developing varieties of synthetic fibers due to their abundant raw material sources, simple production process, and low energy consumption. However, the polypropylene molecular structure is tight, the crystallinity is high, the hydrophobicity is strong, and there is a lack of polar groups or reactive groups, which leads to poor moisture absorption and dyeing, limiting its application in the field of textiles and clothing.

[0003] To improve the moisture absorption and dyeing of polypropylene fibers, chemical modification methods such as blending, copolymerization, and grafting are commonly used in the prior art, but these methods generally have the problems of complex process, high cost, and high equipment requirements. In recent years, methods for constructing a microporous structure inside the fiber through physical methods to improve moisture absorption and moisture conductivity through capillary effect have gradually attracted attention. At the same time, inorganic particle filling modification has become an effective way to realize low-cost and high-performance of polymers, and molecular sieves show unique advantages in composite materials due to their uniform pore size, large specific surface area, and good adsorption performance.

[0004] At present, there are still few studies on blending molecular sieves with polypropylene for spinning and systematically optimizing the spinning process to simultaneously improve the mechanical properties and functionality (such as moisture absorption and dyeing) of the fibers. The effects of process parameters on the structure of the fibers are not clear, and there is a lack of a complete and industrialized preparation scheme for high-strength functional polypropylene fibers. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a preparation process of molecular sieve-polypropylene blended high-strength fibers.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: The preparation process of molecular sieve-polypropylene blended high-strength fibers comprises the following preparation steps: S1. 80-100 parts by mass of polypropylene, 4-8 parts by mass of modified molecular sieve, and 1-2 parts by mass of modified masterbatch are uniformly mixed, granulated by using a twin-screw extruder, and extruded into strip-shaped materials, which are then water-cooled and cut into particles; S2. The mixture obtained in step S1 is added to the hopper of a spinning machine, a two-stage hot drawing process is adopted, and the final molecular sieve-polypropylene blended high-strength fibers are collected at a winding speed of 2500-3000 m / min; The preparation of the modified molecular sieve comprises the following steps: S11. 80-100 parts of molecular sieve were dried in an oven at 110-120℃ for 3-4h to obtain pretreated molecular sieve; S12. 1.5-2.5 parts of silane coupling agent, 0.5-1 part of titanate coupling agent and 0.5-1 part of polyethylene glycol 400 were added into 150-200 parts of anhydrous ethanol, stirred uniformly, then adjusted pH to 8-9 with ammonia water, and hydrolyzed for 18-20min to obtain coupling modifier; S13. The pretreated molecular sieve obtained in step S11 and the coupling modifier obtained in step S12 were mixed, and 1-3 parts of nano-silicon dioxide was added, and stirred at a speed of 150-200r / min in a water bath at 55-60℃ for 1-2h; S14. The solution after reaction obtained in step S13 was filtered, washed with anhydrous ethanol for 3-4 times, and dried in an oven at 75-80℃ for 4-6h, and then sieved through a 300 mesh sieve to obtain modified molecular sieve.

[0007] Preferably, the preparation of the modified master batch comprises the following steps: S21. 80-100 parts of cooling master batch, 5-10 parts of color master batch, 1-3 parts of zinc stearate, 0.5-1 part of antioxidant 1010, 0.5-1 part of erucamide and 20-30 parts of polypropylene carrier resin were mixed uniformly, and dried at 60℃ for 1-2h to obtain pretreated mixture; S22. The pretreated mixture obtained in step S21 was extruded into strips using a twin-screw extruder at 170-190℃ and a speed of 200-250rpm, and then the strips were water-cooled and pelletized to obtain modified master batch.

[0008] Preferably, the polypropylene in step S1 is selected from drawn polypropylene chips.

[0009] Preferably, in step S2, the screw temperature of the spinning machine hopper is 200-225℃, the spinning box temperature is 225-230℃, the spinneret hole diameter is 0.25-0.35mm, the spinning speed is 800-1200m / min, the side blowing air speed is 0.3-0.5m / s, and the side blowing air temperature is 20-25℃.

[0010] Preferably, in step S2, the two-stage hot drawing process comprises: in the first stage, the temperature is 85-95℃, and the drawing ratio is 3-3.5; in the second stage, the temperature is 120-130℃, and the drawing ratio is 1.2-1.5; the heat setting temperature is 110-120℃, and the time is 10-20s.

[0011] Preferably, the molecular sieve in step S11 is selected from ZSM-5 type.

[0012] Preferably, the silane coupling agent in step S12 is selected from KH-550.

[0013] Preferably, the titanate coupling agent in step S12 is selected from NDZ-201.

[0014] Preferably, the temperature-reducing master batch in step S21 is selected from HY-F30.

[0015] Preferably, the color master batch in step S21 is selected from Holcopearl 2287.

[0016] Compared with the prior art, the present application has the following beneficial effects: 1. The present application significantly improves the crystallinity and orientation of the fiber by optimizing the addition amount of molecular sieve, spinning temperature, draw ratio, etc., thereby obtaining high breaking strength, suitable breaking elongation, and dry heat shrinkage rate controlled in 3-6%, and the fiber has excellent comprehensive mechanical properties. At the same time, physical blending and conventional spinning process are combined without complex chemical steps, and the process has strong adaptability and is easy to realize industrial production. A small amount of temperature-reducing master batch is added to control the melt flowability, ensuring good spinnability, and the prepared fiber can be used not only in the clothing field but also widely used in the industrial silk field such as rope, Christmas tree material, tire cord, rubber product framework material, etc., and has broad market prospects.

[0017] 2. The present application enhances the moisture absorption and moisture conductivity of the fiber through the synergistic effect of modified molecular sieve and modified master batch, so that the fiber has excellent dyeing property and color fastness while maintaining high strength, delays aging while reducing fiber heat shrinkage rate, maintains long-term performance stability of the fiber, and realizes the triple effect of structure enhancement, process optimization and function integration in the physical blending spinning system. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 The preparation process flow chart of the molecular sieve-polypropylene blended spinning high-strength fiber of the present application is shown in the figure; Fig. 2 The preparation process flow chart of the modified molecular sieve of the present application is shown in the figure; Fig. 3 The preparation process flow chart of the modified master batch of the present application is shown in the figure. DETAILED DESCRIPTION

[0019] The present application will be described in detail below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0020] Please refer to Figs. 1-3 The present application provides a technical solution: Example 1 Preparation process of molecular sieve-polypropylene blended spinning high-strength fiber Before preparing the molecular sieve-polypropylene blended spinning high-strength fiber, the preparation of modified molecular sieve and modified master batch is carried out: The preparation of the modified molecular sieve comprises the following steps: S11. Dry 80-100 g of molecular sieve (ZSM-5 type) in an oven at 110-120°C for 3-4 h to obtain pretreated molecular sieve; S12. Add 1.5-2.5 g of silane coupling agent (KH-550), 0.5-1 g of titanate coupling agent (NDZ-201), and 0.5-1 g of polyethylene glycol 400 to 150-200 g of anhydrous ethanol, stir uniformly, adjust the pH to 8-9 with ammonia water, and hydrolyze for 18-20 min to obtain a coupling modifier; S13. Mix the pretreated molecular sieve obtained in step S11 and the coupling modifier obtained in step S12, and add 1-3 g of nano-silicon dioxide, stir at a speed of 150-200 r / min in a water bath at 55-60°C for 1-2 h; S14. Perform suction filtration on the solution after the reaction in step S13, wash with anhydrous ethanol for 3-4 times, dry in an oven at 75-80°C for 4-6 h, and pass through a 300-mesh sieve to obtain modified molecular sieve.

[0021] The preparation of the modified master batch comprises the following steps: S21. Mix 80-100 g of cooling master batch (HY-F30), 5-10 g of color master batch (Holcopearl 2287), 1-3 g of zinc stearate, 0.5-1 g of antioxidant 1010, 0.5-1 g of erucamide, and 20-30 g of polypropylene carrier resin uniformly, dry at 60°C for 1-2 h to obtain pretreated mixture; S22. Use a double-screw extruder to extrude the pretreated mixture obtained in step S21 at a speed of 200-250 rpm at 170-190°C, and water-cool and granulate to obtain modified master batch.

[0022] S1. Mix 80-100 g of polypropylene (drawn polypropylene chips), 4-8 g of modified molecular sieve, and 1-2 g of modified master batch uniformly, use a double-screw extruder to granulate and extrude the material into a strip, and water-cool and granulate; S2. The mixture obtained in step S1 is added to a spinning machine hopper (screw temperature is 200-225℃, spinning box temperature is 225-230℃, spinneret hole diameter is 0.25-0.35mm, spinning speed is 800-1200m / min, side blowing air speed is 0.3-0.5m / s, side blowing air temperature is 20-25℃), a two-stage hot drawing process is used (temperature in the first stage is 85-95℃, drawing ratio is 3-3.5; temperature in the second stage is 120-130℃, drawing ratio is 1.2-1.5; heat setting temperature is 110-120℃, time is 10-20s), and then collected at a winding speed of 2500-3000m / min, to obtain a molecular sieve-polypropylene blended spun high-strength fiber.

[0023] Example 2 Preparation process of the molecular sieve-polypropylene blended spun high-strength fiber: Before preparing the molecular sieve-polypropylene blended spun high-strength fiber, the modified molecular sieve and the modified master batch are prepared: The preparation of the modified molecular sieve includes the following steps: S11. 80-100g of molecular sieve (ZSM-5 type) is dried in an oven at 110-120℃ for 3-4h to obtain pretreated molecular sieve; S12. 1.5-2.5g of silane coupling agent (KH-550), 0.5-1g of titanate coupling agent (NDZ-201) and 0.5-1g of polyethylene glycol 400 are added to 150-200g of anhydrous ethanol, stirred uniformly, then adjusted to pH 8-9 with ammonia water, and hydrolyzed for 18-20min to obtain a coupling modifier; S13. The pretreated molecular sieve obtained in step S11 and the coupling modifier obtained in step S12 are mixed, and 1-3g of nano-silicon dioxide is added, and stirred at a speed of 150-200r / min in a water bath at 55-60℃ for 1-2h; S14. The reacted solution obtained in step S13 is suction filtered, washed with anhydrous ethanol for 3-4 times, and then dried in an oven at 75-80℃ for 4-6h, and sieved through a 300 mesh sieve to obtain modified molecular sieve.

[0024] The preparation of the modified master batch includes the following steps: S21. 80-100g of cooling master batch (HY-F30), 5-10g of color master batch (Holcopearl 2287), 1-3g of zinc stearate, 0.5-1g of antioxidant 1010, 0.5-1g of erucamide and 20-30g of polypropylene carrier resin are mixed uniformly, and dried at 60℃ for 1-2h to obtain pretreated mixture; S22. The pretreated mixture obtained in step S21 is extruded into strips using a twin-screw extruder at 170-190°C at a speed of 200-250 rpm, and the extruded strips are water-cooled and cut into particles to obtain the modified masterbatch.

[0025] S1. 80-100 g of polypropylene (drawn polypropylene chips), 4-8 g of modified molecular sieve, and 1-2 g of modified masterbatch are uniformly mixed, and granulation is performed using a twin-screw extruder to obtain strip-shaped material, which is water-cooled and cut into particles; S2. The mixture obtained in step S1 is added to a spinning machine hopper (screw temperature: 200-225°C, spinning box temperature: 225-230°C, spinneret hole diameter: 0.25-0.35 mm, spinning speed: 800-1200 m / min, side-blowing air speed: 0.3-0.5 m / s, side-blowing air temperature: 20-25°C), and a two-stage hot-drawing process is used (temperature in the first stage: 85-95°C, draw ratio: 3-3.5; temperature in the second stage: 120-130°C, draw ratio: 1.2-1.5; heat setting temperature: 110-120°C, time: 10-20 s), and the resulting product is collected at a winding speed of 2500-3000 m / min to obtain a molecular sieve-polypropylene blended spun high-strength fiber.

[0026] Example 3 Preparation process of the molecular sieve-polypropylene blended spun high-strength fiber: Before preparing the molecular sieve-polypropylene blended spun high-strength fiber, the modified molecular sieve and the modified masterbatch are prepared: The preparation of the modified molecular sieve includes the following steps: S11. 80-100 g of molecular sieve (ZSM-5 type) is dried in an oven at 110-120°C for 3-4 h to obtain pretreated molecular sieve; S12. 1.5-2.5 g of silane coupling agent (KH-550), 0.5-1 g of titanate coupling agent (NDZ-201), and 0.5-1 g of polyethylene glycol 400 are added to 150-200 g of anhydrous ethanol, stirred uniformly, and then adjusted to a pH of 8-9 with ammonia water, and hydrolyzed for 18-20 min to obtain a coupling modifier; S13. The pretreated molecular sieve obtained in step S11 and the coupling modifier obtained in step S12 are mixed, and 1-3 g of nano-silicon dioxide is added, and the mixture is stirred at a speed of 150-200 r / min in a water bath at 55-60°C for 1-2 h; S14. The reaction solution obtained in step S13 is filtered under suction, washed with anhydrous ethanol for 3-4 times, and then dried in an oven at 75-80°C for 4-6 h, and then sieved through a 300-mesh sieve to obtain the modified molecular sieve.

[0027] The preparation of the modified masterbatch includes the following steps: S21. 80-100 g of the temperature-reducing masterbatch (HY-F30), 5-10 g of the color masterbatch (Holcopearl 2287), 1-3 g of zinc stearate, 0.5-1 g of antioxidant 1010, 0.5-1 g of erucamide, and 20-30 g of a polypropylene carrier resin are uniformly mixed and dried at 60°C for 1-2 h to obtain a pretreated mixture; S22. The pretreated mixture obtained in step S21 is extruded into a strip using a twin-screw extruder at 170-190°C at a speed of 200-250 rpm, and the extruded strip is water-cooled and cut into particles to obtain a modified masterbatch.

[0028] S1. 80-100 g of polypropylene (drawn polypropylene chips), 4-8 g of modified molecular sieve, and 1-2 g of modified masterbatch are uniformly mixed and granulated using a twin-screw extruder to obtain a strip-shaped material, which is water-cooled and cut into particles. S2. The mixture obtained in step S1 is added to a spinning machine hopper (the screw temperature is 200-225°C, the spinning box temperature is 225-230°C, the spinneret hole diameter is 0.25-0.35 mm, the spinning speed is 800-1200 m / min, the side-blowing air speed is 0.3-0.5 m / s, and the side-blowing air temperature is 20-25°C), a two-stage hot-drawing process is adopted (the temperature in the first stage is 85-95°C, the drawing ratio is 3-3.5; the temperature in the second stage is 120-130°C, the drawing ratio is 1.2-1.5; the heat-setting temperature is 110-120°C, and the time is 10-20 s), and finally the molecular sieve-polypropylene blended spun high-strength fiber is collected at a winding speed of 2500-3000 m / min.

[0029] Comparative Example 1 Comparative Example 1 differs from Example 1 in that the modified molecular sieve is replaced by ZSM-5 molecular sieve, and the other steps are the same as in Comparative Example 1 and Example 1.

[0030] Comparative Example 2 Comparative Example 2 differs from Example 1 in that the modified masterbatch is replaced by the temperature-reducing masterbatch HY-F30, and the other steps are the same as in Comparative Example 2 and Example 1.

[0031] Performance Test: The molecular sieve-polypropylene blended spun high-strength fiber obtained in Examples 1-3 and Comparative Examples 1-2 is tested for breaking strength, breaking strength CV value, breaking elongation, breaking elongation CV value, and dry shrinkage according to GB / T 3916-2013 “Textiles – Package yarn – Determination of breaking force and elongation of single yarns” and GB / T 6505-2017 “Chemical fibres – Filament heat-shrinkage test method”, and the obtained data are shown in Table 1. Table 1 performance test results

[0032] According to the data in Table 1, the molecular sieve-polypropylene blended high-strength fiber obtained by the embodiments 1-3 is superior to the comparative examples in the breaking strength, breaking elongation and dry shrinkage, indicating that the synergistic effect of the modified molecular sieve and the modified master batch effectively enhances the crystallinity and orientation degree of the fiber, improves the bearing capacity, improves the uniformity of the fiber structure, reduces the performance fluctuation, realizes the functionalization and stabilization of the polypropylene fiber, and has significant industrialization advantages.

[0033] Although the embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for preparing high-strength fibers by molecular sieve-polypropylene blend spinning, characterized in that, The preparation steps include the following: S1. By weight, mix 80-100 parts of polypropylene, 4-8 parts of modified molecular sieve and 1-2 parts of modified masterbatch evenly, granulate using a twin-screw extruder, extrude strip material, and cut into pellets by water cooling. S2. Add the mixture obtained in step S1 to the hopper of the spinning machine, use a two-stage hot drawing process, and collect it at a winding speed of 2500-3000 m / min to finally obtain molecular sieve-polypropylene blended high-strength fiber. The preparation of the modified molecular sieve includes the following steps: S11. By weight, 80-100 parts of molecular sieve are dried in an oven at 110-120℃ for 3-4 hours to obtain pretreated molecular sieve; S12. Add 1.5-2.5 parts of silane coupling agent, 0.5-1 part of titanate coupling agent and 0.5-1 part of polyethylene glycol 400 to 150-200 parts of anhydrous ethanol, stir evenly, adjust the pH to 8-9 with ammonia water, and hydrolyze for 18-20 minutes to obtain the coupling modifier. S13. Mix the pretreated molecular sieve obtained in step S11 and the coupling modifier obtained in step S12, and add 1-3 parts of nano silica. Stir the mixture at 150-200 r / min for 1-2 h in a water bath at 55-60℃. S14. Filter the reaction solution obtained in step S13, wash it 3-4 times with anhydrous ethanol, dry it in an oven at 75-80℃ for 4-6 hours, and pass it through a 300-mesh sieve to obtain the modified molecular sieve.

2. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 1, characterized in that, The preparation of the modified masterbatch includes the following steps: S21. By weight, mix 80-100 parts of cooling masterbatch, 5-10 parts of color masterbatch, 1-3 parts of zinc stearate, 0.5-1 parts of antioxidant 1010, 0.5-1 parts of erucamide and 20-30 parts of polypropylene carrier resin evenly, and dry at 60℃ for 1-2 hours to obtain pretreated mixture. S22. The pretreated mixture obtained in step S21 is extruded into strips at 170-190℃ and 200-250rpm using a twin-screw extruder, and then water-cooled and pelletized to obtain modified masterbatch.

3. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 1, characterized in that, In step S1, the polypropylene is selected from fiber-grade polypropylene chips.

4. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 1, characterized in that, In step S2, the screw temperature of the spinning machine hopper is 200-225℃, the spinning box temperature is 225-230℃, the spinneret orifice diameter is 0.25-0.35mm, the spinning speed is 800-1200m / min, the side blowing air speed is 0.3-0.5m / s, and the side blowing air temperature is 20-25℃.

5. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 1, characterized in that, The two-stage hot drawing process in step S2 includes: the temperature in the first stage of drawing is 85-95℃ and the drawing ratio is 3-3.5; the temperature in the second stage of drawing is 120-130℃ and the drawing ratio is 1.2-1.5; the heat setting temperature is 110-120℃ and the time is 10-20s.

6. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 1, characterized in that, In step S11, molecules were screened from ZSM-5 type.

7. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 1, characterized in that, In step S12, the silane coupling agent is selected from KH-550.

8. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 1, characterized in that, In step S12, the titanate coupling agent is selected from NDZ-201.

9. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 2, characterized in that, The cooling masterbatch in step S21 is selected from HY-F30.

10. The preparation process of high-strength fibers by molecular sieve-polypropylene blend spinning according to claim 2, characterized in that, In step S21, the masterbatch is selected from Holcopearl 2287.

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