WO2022111040A1

WO2022111040A1 - Functional polyamide 56 filament and manufacturing method therefor

Info

Publication number: WO2022111040A1
Application number: PCT/CN2021/121258
Authority: WO
Inventors: 郝新敏; 郭亚飞; 闫金龙; 乔荣荣; 董梦杰
Original assignee: 军事科学院系统工程研究院军需工程技术研究所
Priority date: 2020-11-27
Filing date: 2021-09-28
Publication date: 2022-06-02
Also published as: CN112501702B; CN112501702A

Abstract

Disclosed are a functional polyamide 56 filament and a manufacturing method therefor. The manufacturing method comprises the following steps: 1) chip drying: segmented vacuum drying treatment is performed on a selected functional polyamide 56 chip; 2) melt spinning: the dried chip is ejected from a screw extruder and a spinneret of a spinning box to obtain a thin stream of melt, the thin stream of melt is cooled by blowing air and solidified into strands; after being bundled and oiled, the strands are cooled and drafted to obtain a polyamide 56 tow; and 3) filament post-processing: the tow is subjected to heat drafting, heat setting, and winding of different processes to obtain a functional polyamide 56 filament. 1) The segmented vacuum drying process can reduce chip damage and achieve uniform spinning; 2) the cooling and drafting process is beneficial to high-power drafting to obtain a filament having stable performance; 3) by screening indicators such as a viscosity index and a terminated amino group of the chip and adjusting the drafting process, the polyamide 56 filament and textured yarn having excellent performance can be manufactured, thereby satisfying use requirements in a special environment, and being widely applied to various industries.

Description

A kind of functional polyamide 56 filament and preparation method thereof

technical field

The invention relates to a functional polyamide 56 filament and a preparation method thereof, belonging to the field of textiles.

Background technique

The repeating units (monomers) of polyamide (PA) have amide groups as a characteristic feature. Polyamide fiber is nylon, also known as polyamide in our country. Polyamide is the second largest synthetic fiber after polyester fiber. Due to its high breaking strength, wear resistance, fatigue resistance, light weight and softness, breathability and moisture absorption, and good elasticity, it is widely used in textiles, engineering plastics, military products, Rubber frame materials, ropes, nets, ropes, tarpaulins, industrial filter cloths and silk for high-grade sewing threads have good market prospects.

Polyamides are prepared by condensation reactions between diamines and diacids. At present, polyamide fibers are basically prepared from petroleum derivatives, such as polyamide 6 and polyamide 66, which have the largest market share. Their raw materials, caprolactam and adipic acid, are hydrogenated by benzene homologues. It is prepared by a series of reactions such as oxidation, and hexamethylene diamine is prepared by first synthesizing adiponitrile from butadiene or acrylonitrile and then by catalytic hydrogenation. Currently, it is prepared by petrochemical methods.

The subsequent fiber product development of thermoplastic polymers is an important task. Melt spinning is the most commonly used spinning method, which is divided into melt direct spinning and chip spinning. Melt spinning does not require solvent, it can be directly spun, the process is simple, the cost is low, and there is no solvent recovery problem.

SUMMARY OF THE INVENTION

The invention relates to a functional polyamide 56 filament, which belongs to a novel bio-based polymer product. The raw material, pentamethylene diamine, is mainly prepared by a biological fermentation method, and then synthesized with adipic acid to obtain a bio-based polyamide 56 polymer.

The preparation method of a functional polyamide 56 filament provided by the invention comprises the following technological process:

1) Functional slice drying: segmented vacuum drying is performed on functional polyamide 56 slices;

2) Melt spinning: the dried functional polyamide 56 slices are sprayed out through the screw extruder and the spinneret of the spinning box to obtain a melt stream, which is cooled and solidified by air blowing. thread;

3) cold drafting: after the strands are bundled and oiled, they are cooled and drafted by cooling drafting rollers to obtain polyamide 56 tow;

4) Filament post-processing: the polyamide 56 tow is subjected to thermal drawing, heat setting and winding, or a texturing process to obtain functional polyamide 56 filaments.

In above-mentioned preparation technique 1), the index of described functional polyamide 56 slices is as follows:

In particular, when the prepared functional polyamide 56 filament is a high-strength polyamide 56 filament, the slice viscosity index is 145-180 ml/g;

In particular, when the prepared functional polyamide 56 filament is a flame-retardant polyamide 56 filament, the slice viscosity index is 135-160 ml/g;

In particular, when the prepared functional polyamide 56 filament is an easy-dyeing polyamide 56 filament, the amino group content index at the end of the slice is 40-70 mmol/kg;

In particular, when the prepared functional polyamide 56 filament is a mildew-proof polyamide 56 filament, the amino group content index at the end of the slice is 30-55 mmol/kg.

In above-mentioned preparation technique 1), the condition of described subsection vacuum drying is as follows:

First dry at 40-60°C for 10-12h, then heat up to 80-95°C for 7-10h, then heat up to 105-115°C and dry for 5-7h, continue at 130-140°C Heat preservation for 3 to 6 hours.

The index of the described functional polyamide 56 slices after the segmental vacuum drying described in step 1) is as follows:

The water content of the slices is ≤600ppm; the melting point is 245～260℃.

In the above-mentioned preparation process 2), the temperature of each zone of the screw of the spinning box: the temperature of each zone of the screw: 260-290 ℃ in the first zone, 260-290 ℃ in the second zone, 260-290 ℃ in the third zone, 260-290 ℃ in the fourth zone, and 5. Zone 260～290℃, box temperature 260～290℃, metering pump temperature 260～290℃, metering pump speed 12rpm～16rpm, spinning speed 800m/min～4500m/min;

In particular, when the prepared functional polyamide 56 filament is a high-strength polyamide 56 filament, the spinning speed is specifically 3000m/min～4500m/min;

In the above-mentioned preparation process 2), the cooling mode of air blowing by ring blowing or side blowing is adopted, and the conditions are as follows: wind speed: 30～60m/min; wind temperature: 18～26 ℃; wind pressure: 350Pa～600Pa;

The mass concentration of the oiling agent is 3% to 5%.

The temperature of the cooling drafting roll is 0-20°C, and the drafting ratio is 1.05-1.45.

In the above-mentioned preparation process 3), the hot drawing process can be one-stage drafting, two-stage drafting or multi-stage drafting, and the process conditions: the drafting ratio is 1.01～5.50, and the drafting temperature is 80～200 ℃ ;

In particular, high-strength polyamide 56 filaments are prepared with a draw ratio of 3.00 to 5.50.

In the above preparation process 4), the texturing process includes a process for preparing functionalized polyamide 56 drawn textured yarn and a process for preparing functionalized polyamide 56 air-textured yarn.

The process for preparing the functionalized polyamide 56 stretched textured yarn includes the steps of hot drawing, twisting, networking, heat setting and winding, and the conditions are as follows:

The hot drafting temperature is 100～200℃, the drafting ratio is 1.10～2.50, the speed of the drafting roller is 300～1000m/min; the twisting is divided into S twist or Z twist, the twisting tension is 20～60cN, and the untwisting tension is 25～65cN, D/Y is the ratio of the surface speed of the friction disc and the speed of the thread leaving the false twister, specifically 1.5～2.0; in the network step, the wind pressure is 1.0～1.6bar; the diameter of the nozzle is 1.2～1.6mm, The heat setting temperature is 180～220℃, and the winding speed is 600～1200m/min.

The process for preparing the functionalized polyamide 56 air-textured yarn includes the steps of thermal drawing, thermal jet texturing, cooling stabilization and winding. The conditions are as follows:

The hot drawing temperature is 100～190℃, the drawing ratio is 1.05～3.50, the speed of the drafting roller is 1500～2500m/min; The rate is 15-30%, the cooling air temperature is 15-30°C, and the winding speed is 1500-2800 m/min.

Detailed ways

The experimental methods used in the following examples are conventional methods unless otherwise specified.

The materials, reagents, etc. used in the following examples can be obtained from commercial sources unless otherwise specified.

The functional polyamide 56 filament samples in the following examples were tested for performance according to the following methods:

1. Breaking strength and breaking elongation: GB/T 14344-2008 Test method for tensile properties of chemical fiber filaments;

2. Moisture regain: GB/T 6503-2017 Chemical fiber moisture regain test method;

3. Limiting oxygen index: GB/T 5454-1997 Textile combustion performance test oxygen index method;

4. Anti-mildew properties: GB/T 24346-2009 Evaluation of anti-mildew properties of textiles;

5. Network measurement: R2071 network degree meter is used, according to FZ/T 50001 synthetic fiber filament network degree test method;

6. Dyeing rate test: use a spectrophotometer to measure the absorbance of the dye solution before and after dyeing at the maximum absorption wavelength, and calculate the dyeing percentage according to the following formula: Ct=(1-A ₁ /A ₀ )×100% (wherein : A ₀ is the absorbance of the original dye solution; A ₁ is the absorbance of the residual solution after dyeing, choose 10g/L acid red 2B dye test.)

Example 1, high-strength polyamide 56 filament

The viscosity index of functional slices is 163ml/g, and the amino group content is 36.4mmol/kg. The vacuum drying process of slices is as follows: first dry at 50°C for 12h, then heat up to 85°C for 8h, and then heat up to 110°C It was dried for 6h under the condition of 130°C and kept at 130°C for 5h. After drying, the functional chips contained 427 ppm of water and a melting point of 256°C.

Set the spinning speed: 4250m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The fourth zone is 288°C, the fifth zone is 288°C, the temperature of the box is 288°C, the temperature of the metering pump is 288°C, and the speed of the metering pump is 14rpm. It solidifies into strands, the cooling wind speed is 40m/min, the wind temperature is 21°C, and the wind pressure is 430Pa, and then the strands are oiled with a concentration of 3% oil, and then cold-drawn at 5°C for 1.23 times to obtain polyamide 56 strands bundle.

The polyamide 56 tow is subjected to two-stage drawing, the first-drawing multiple is 4.53, the second-drawing multiple is 1.12, the first-drawing temperature is 110 °C, the second-drawing temperature is 175 °C, and then heat-set at 185 °C, 3800m/min winding, High-strength polyamide 56 filaments were obtained.

The breaking strength of the high-strength polyamide filament is 8.45cN/dtex, the elongation at break is 33.7%, the moisture regain is 4.36%, and the limiting oxygen index is 35.5%.

Example 2, high-strength polyamide 56 filament

The viscosity index of the functional chips is 148ml/g, and the amino group content is 36.4mmol/kg. The vacuum drying process is as follows: first dry at 60°C for 10h, then heat up to 95°C for 8h, and then heat up to 115°C. Condition drying for 5h, continue to keep at 140 ℃ for 3h. After drying, the slices have a water content of 302 ppm and a melting point of 254 °C.

Set the spinning speed: 3650m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The four zones are 290°C, the fifth zone is 290°C, the box temperature is 290°C, the metering pump temperature is 290°C, and the metering pump speed is 16rpm. It solidifies into strands, the cooling wind speed is 60m/min, the wind temperature is 18°C, and the wind pressure is 360Pa, and then the strands are oiled with an oil concentration of 3%, and then cold-drawn at 15°C for 1.35 times to obtain a polyamide 56 tows.

The polyamide 56 tow is subjected to two-stage drawing, the first-draw multiple is 4.13, the second-draw multiple is 1.25, the first-draw temperature is 130°C, and the second-draw temperature is 180°C, and then heat-set at 190°C and wound at 3500m/min, High-strength polyamide 56 filaments were obtained.

The breaking strength of the high-strength polyamide filament is 7.83cN/dtex, the elongation at break is 37.7%, the moisture regain is 4.28%, and the limiting oxygen index is 34.7%.

Example 3, flame retardant polyamide 56 filament

The viscosity index of functional slices is 142ml/g. The vacuum drying process is as follows: first dry at 60°C for 12h, then heat up to 90°C for 8h, then heat up to 105°C for 5h, and continue to dry at 105°C for 5 hours. Incubate at 135°C for 4h. After drying, the sliced slices have a water content of 447 ppm and a melting point of 255°C.

Set the spinning speed: 3100m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The four zone is 286°C, the fifth zone is 286°C, the temperature of the box is 286°C, the temperature of the metering pump is 286°C, and the speed of the metering pump is 14rpm. It solidifies into strands, the cooling wind speed is 45m/min, the wind temperature is 23°C, and the wind pressure is 450Pa, then the strands are oiled with an oil concentration of 3%, and then cold drawn at 10°C for 1.18 times to obtain a polyamide 56 tows.

The polyamide 56 tow is subjected to two-stage drafting, the first-drawing multiple is 3.68, the second-drawing multiple is 1.02, the first-drawing temperature is 80 °C, the second-drawing temperature is 165 °C, and then heat-set at 175 °C, 2400m/min winding, A flame retardant polyamide 56 filament was obtained.

The breaking strength of the flame-retardant polyamide filament is 5.18cN/dtex, the elongation at break is 34.2%, the moisture regain is 4.48%, and the limiting oxygen index is 37.3%.

Example 4, flame retardant polyamide 56 filament

The viscosity index of functional slices is 137.7ml/g. The vacuum drying process is as follows: first dry at 40°C for 12h, then heat up to 80°C for 8h, then heat up to 105°C for 6h, and continue Incubate at 135°C for 5h. The sliced slices have a water content of 579 ppm and a melting point of 253°C.

Set the spinning speed: 2000m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The four zone is 287°C, the fifth zone is 287°C, the temperature of the box is 287°C, the temperature of the metering pump is 287°C, and the speed of the metering pump is 13rpm. It solidifies into strands, the cooling wind speed is 40m/min, the wind temperature is 21°C, and the wind pressure is 480Pa, then the strands are oiled with an oil concentration of 5%, and then cold-drawn at 0°C for 1.30 times to obtain a polyamide 56 tows.

The polyamide 56 tow is subjected to two-stage drawing, the first-drawing multiple is 3.30, the second-drawing multiple is 1.15, the first-drawing temperature is 100 °C, the second-drawing temperature is 170 °C, and then heat-set at 180 °C, 1800m/min winding, A flame retardant polyamide 56 filament was obtained.

The breaking strength of the flame-retardant polyamide filament is 4.99cN/dtex, the elongation at break is 40.4%, the moisture regain is 4.37%, and the limiting oxygen index is 36.4%.

Example 5. Easy-dyeing polyamide 56 filament

The content of terminal amino group of functional slices is 68.8mmol/kg. The vacuum drying process is as follows: first drying at 55℃ for 10h, then heating to 90℃ for 10h, and then heating to 110℃ for 6h , and continue to incubate at 130 °C for 5 h. After drying, the slices have a water content of 363 ppm and a melting point of 249°C.

Set the spinning speed: 1550m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The temperature of the four zone is 283°C, the zone five is 283°C, the temperature of the box is 283°C, the temperature of the metering pump is 283°C, and the speed of the metering pump is 15rpm. It solidifies into strands, the cooling wind speed is 48m/min, the wind temperature is 20°C, and the wind pressure is 460Pa, and then the strands are oiled with an oil concentration of 3%, and then cold-drawn at 10°C for 1.28 times to obtain a polyamide 56 tows.

The polyamide 56 tow is subjected to two-stage drawing, the first-drawing ratio is 3.11, the second-drawing ratio is 1.10, the first-drawing temperature is 100 °C, the second-drawing temperature is 185 °C, and then heat-set at 200 °C, 1300m/min winding, Easy-dyeing polyamide 56 filaments were obtained.

The breaking strength of the easily dyed polyamide filament is 4.63cN/dtex, the elongation at break is 51.1%, the moisture regain is 4.51%, the limiting oxygen index is 32.1%, and the dyeing rate is 99.2%.

Example 6, easy-dyeing polyamide 56 filament

The amino-terminal content of functional slices is 68.8 mmol/kg. The vacuum drying process is as follows: first drying at 55°C for 12h, then heating to 95°C for 10h, and then heating to 115°C for 6h , and kept at 140°C for 4h. After drying, the slices have a water content of 398 ppm and a melting point of 253°C.

Set the spinning speed: 1200m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The four zones are 270°C, the fifth zone is 270°C, the box temperature is 270°C, the metering pump temperature is 270°C, and the metering pump speed is 15rpm. Solidify into strands, the cooling wind speed is 40m/min, the wind temperature is 25°C, and the wind pressure is 400Pa, then the strands are oiled with an oil concentration of 3%, and then cold drawn at 5°C for 1.20 times to obtain a polyamide 56 tows.

The polyamide 56 tow is subjected to two-stage drawing, the first-drawing multiple is 3.00, the second-drawing multiple is 1.10, the first-drawing temperature is 100 °C, the second-drawing temperature is 160 °C, and then heat-setting at 180 °C, 1000m/min winding, Easy-dyeing polyamide 56 filaments were obtained.

The breaking strength of the easily dyeable polyamide filament is 4.60cN/dtex, the elongation at break is 51.4%, the moisture regain is 4.44%, the limiting oxygen index is 32.2%, and the dyeing rate is 99.5%.

Example 7, mildew-proof polyamide 56 filament

The amino content of functional slices is 32.4mmol/kg. The vacuum drying process is as follows: first dry at 55°C for 10h, then heat up to 90°C for 10h, then heat up to 110°C for 6h, and continue Incubate at 130°C for 5h. After drying, the slices had a water content of 412 ppm and a melting point of 251°C.

Set the spinning speed: 1000m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The temperature of the four zone is 283°C, the zone five is 283°C, the temperature of the box is 283°C, the temperature of the metering pump is 283°C, and the speed of the metering pump is 15rpm. Solidify into strands, the cooling wind speed is 45m/min, the wind temperature is 20°C, and the wind pressure is 440Pa, and then the strands are oiled with an oil concentration of 3%, and then cold-drawn at 10°C for 1.25 times to obtain a polyamide 56 tows.

The polyamide 56 tow is subjected to two-stage drawing, the first-draw multiple is 2.30, the second-draw multiple is 1.15, the first-draw temperature is 80 °C, and the second-draw temperature is 155 °C, and then heat-set at 165 °C, 900m/min winding, Mildew-resistant polyamide 56 filaments were obtained.

The anti-fungal properties of the filament were evaluated, wherein the concentration of mixed spore solution: 1.2 × 106 CFU/mL, and the molds used for detection were Aspergillus niger AS 3.4463, Penicillium funiculosum AS 3.3875, globosa ( chaetoomium globsum) AS 3.4254, Trichoderma viride AS 3.2942.

The breaking strength of the mildew-resistant polyamide filament is 4.34 cN/dtex, the elongation at break is 58.2%, the moisture regain is 4.53%, the limiting oxygen index is 32.3%, and the mildew resistance is grade 0.

Example 8, mildew-proof polyamide 56 filament

The amino content of functional slices is 42.4 mmol/kg. The vacuum drying process is as follows: first dry at 50 °C for 10 hours, then heat up to 90 °C for 8 hours, then heat up to 110 °C for 5 hours, and continue Incubate at 130°C for 3h. After drying, the slices have a water content of 362 ppm and a melting point of 251°C.

Set the spinning speed: 1000m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The four zones are 280°C, the fifth zone is 280°C, the box temperature is 280°C, the metering pump temperature is 280°C, and the metering pump speed is 15rpm. It solidifies into strands, the cooling wind speed is 40m/min, the wind temperature is 23°C, and the wind pressure is 420Pa, then the strands are oiled with an oil concentration of 4%, and then cold drawn at 0°C for 1.08 times to obtain polyamide 56 tows.

The polyamide 56 tow is subjected to two-stage drafting, the first-drawing multiple is 3.03, the second-drawing multiple is 1.10, the first-drawing temperature is 110 °C, the second-drawing temperature is 180 °C, and then heat-set at 200 °C, 900m/min winding, Mildew-resistant polyamide 56 filaments were obtained.

The anti-mildew performance of the filament was evaluated, wherein the concentration of mixed spore solution: 1.2*106 CFU/mL, and the molds used for the detection were Aspergillus niger AS 3.4463, Penicillium funiculosum AS 3.3875, globosa ( chaetoomium globsum) AS 3.4254, Trichoderma viride AS 3.2942.

The breaking strength of the mildew-resistant polyamide filament is 4.41 cN/dtex, the elongation at break is 50.7%, the moisture regain is 4.33%, the limiting oxygen index is 33.8%, and the mildew resistance is grade 0.

Example 9, flame retardant polyamide 56 stretched textured yarn

The viscosity index of the functional slices was 144.1 ml/g, and the vacuum drying process was the same as that in Example 3. After drying, the slices had a water content of 584 ppm and a melting point of 251°C.

The parameter settings of spinning, cold drawing, and hot drawing are the same as those in Example 3, and the drawn polyamide 56 tow is obtained.

The obtained polyamide 56 tow was drawn 2.00 times under the condition of 180 ° C, the speed of the drawing roller was 800 m/min, and the filament was S-twisted after drawing, the twisting tension was 45cN, and the untwisting tension was 48cN; the D /Y is 1.8, network air pressure is 1.2 bar; nozzle diameter is 1.3 mm, heat setting temperature is 190° C., and the winding speed is 900 m/min.

The breaking strength of the flame retardant polyamide stretched textured yarn is 5.38cN/dtex, the elongation at break is 34.2%, the moisture regain is 4.26%, the limiting oxygen index is 37.8%, and the degree of network (the number of nodes) is 101.

Example 10. Easy-dyeing polyamide 56 air textured yarn

The terminal amino group value of the functional slice is 63.1 mmol/kg, and the vacuum drying process is the same as that in Example 5. After drying, the slice contains 412 ppm of water and has a melting point of 251°C.

The process parameters of spinning, cold drawing and hot drawing are the same as those in Example 5, and the drawn polyamide 56 tow is obtained. After drawing, the tow was thermally drawn at 160°C by 1.10 times, the thermal jet deformation temperature was 230°C, the air jet pressure was 300kPa, the overfeed rate was 25%, the cooling air temperature was 15°C, and the winding speed was 1400m/min. An easily dyeable polyamide 56 air textured yarn was obtained.

The breaking strength of the easily dyeable polyamide air-textured yarn is 5.13cN/dtex, the elongation at break is 46.1%, the moisture regain is 4.32%, the limiting oxygen index is 33.4%, and the dyeing rate is 99.4%.

Comparative example, polyamide 56 filament preparation

The vacuum drying process of the slices is as follows: firstly, dry at 120°C for 24h. The slices were slightly yellowed, the viscosity index was 118.6 ml/g, the amino group content was 19.1 mmol/kg, the water content of the slices was 372 ppm, and the melting point was 251°C.

Set the spinning speed: 500m/min, cut the dried polyamide 56 into slices, and enter the spinning box through the screw extruder. The four zones are 285°C, the fifth zone is 285°C, the box temperature is 285°C, the metering pump temperature is 285°C, and the metering pump speed is 15rpm. It solidifies into strands, the cooling wind speed is 45m/min, the wind temperature is 20°C, and the wind pressure is 440Pa, then the strands are oiled with an oil concentration of 3%, and the polyamide 56 tow is obtained by winding.

The polyamide 56 tow is subjected to two-stage drawing, the first-draw multiple is 2.0, the second-draw multiple is 1.10, the first-draw temperature is 80°C, and the second-draw temperature is 150°C, and then heat-set at 165°C, 600m/min winding, Polyamide 56 filaments were obtained.

The properties of the comparative example filaments: breaking strength 2.87cN/dtex, breaking elongation breaking elongation 86.8%, moisture regain 4.21%, limiting oxygen index 22.3%.

It can be seen from the performance data of the PA56 filaments prepared in Examples 1-10 and Comparative Examples that under different process parameters, the performance of the filaments is quite different. , the filament has high breaking strength; when the viscosity index and the terminal amino value are within a certain range, the limiting oxygen index of the filament is high, and the flame retardant performance is good; when the amino value of the slice end is high, the low-temperature dyeing performance of the filament is significantly better than other Filament prepared under conditions; when the amino value of slices is within a certain range, the filament has anti-mildew properties. In the comparative example, the high-temperature vacuum drying process was used, and the chips with low viscosity index and terminal amino value were selected. Under the condition of low-speed spinning, polyamide 56 filament and textured yarn were prepared by low-drawing. The results showed that the breaking strength and limit of the product were Oxygen index and dye uptake are not as good as the filament products of the examples.

Industrial application

The present invention has the following beneficial technical effects:

(1) The moisture in the polyamide 56 slices is removed by a segmented vacuum drying process, which reduces the defects such as thermal degradation of the slices, decreased viscosity, and deepened color, and at the same time improves the crystallinity of the slices, which is helpful for uniform and stable spinning; (2) Spinning The cooling and drawing process is added to the silk process. This is because the cooling crystallization rate of polyamide 56 is found to be slow in the research, and the incompletely cooled tow not only affects the winding and oiling process, but also directly draws and shapes the product. The mechanical properties are unstable. Therefore, adding a cooling drafting process to rapidly cool the tow formed by the spinneret is beneficial to the subsequent high-stretching to obtain polyamide filaments with stable performance and excellent performance. (3) Polyamide 56 filaments and textured yarns with excellent mechanical properties, flame retardant properties, dyeing properties, and mildew resistance can be prepared according to different viscosity, terminal amino group, draft ratio and other indicators to meet the use in special environments. requirements, widely used in all walks of life.

Claims

A preparation method of functional polyamide 56 filament, characterized in that: comprising the steps:

1) Functional slice drying: segmented vacuum drying is performed on functional polyamide 56 slices;

2) Melt spinning: the dried functional polyamide 56 slices are sprayed out through the screw extruder and the spinneret of the spinning box to obtain a melt stream, which is cooled and solidified by air blowing. thread;

3) cold drafting: after the strands are bundled and oiled, they are cooled and drafted by cooling drafting rollers to obtain polyamide 56 tow;

4) Filament post-processing: the polyamide 56 tow is subjected to thermal drawing, heat setting and winding, or a texturing process to obtain functional polyamide 56 filaments.
preparation method according to claim 1, is characterized in that: in step 1), the index of described functional polyamide 56 slices is as follows:

a) When the prepared functional polyamide 56 filament is a high-strength polyamide 56 filament, the slice index: the viscosity is 145-180ml/g;

b) When the prepared functional polyamide 56 filament is a flame retardant polyamide 56 filament, the slice index: the viscosity is 135-160ml/g;

c) When the prepared functional polyamide 56 filament is easily dyed polyamide 56 filament, the slice index: the content of terminal amino groups is 40-70 mmol/kg;

d) When the prepared functional polyamide 56 filament is a mildew-proof polyamide 56 filament, the slice index: the content of terminal amino groups is 30-50 mmol/kg.
preparation method according to claim 1 and 2, is characterized in that: in step 1), the condition of described segmental vacuum drying treatment is as follows:

First dry at 40-60°C for 10-12h, then heat up to 80-95°C for 7-10h, then heat up to 105-115°C and dry for 5-7h, continue at 130-140°C Heat preservation for 3 to 6 hours.
The preparation method according to any one of claims 1-3, wherein the index of the functional polyamide 56 slices after the segmental vacuum drying treatment described in step 1) is as follows:

The water content of the slices is ≤600ppm; the melting point is 245～260℃.
The preparation method according to any one of claims 1-4, characterized in that: in step 2), the conditions of the melt spinning are as follows:

The temperature of each zone of the screw: the temperature of the first zone is 260～290℃, the temperature of the second zone is 260～290℃, the temperature of the third zone is 260～290℃, the temperature of the fourth zone is 260～290℃, and the temperature of the fifth zone is 260～290℃. The temperature of the body is 260～290℃, the temperature of the metering pump is 260～290℃, the rotating speed of the metering pump is 12rpm～16rpm, and the spinning speed is 800m/min～4500m/min.
The preparation method according to claim 5, wherein: when the prepared functional polyamide 56 filament is a high-strength polyamide 56 filament, the spinning speed is 3000m/min～4500m/min;

The air cooling method of ring air blowing or side air blowing is adopted, and the conditions are as follows:

The wind speed is 30～60m/min; the wind temperature is 18～26℃; the wind pressure is 350Pa～600Pa.
The preparation method according to any one of claims 1-4, characterized in that: in step 3), the mass concentration of the oil used in the oiling is 3% to 5%.

The temperature of the cooling drafting roll is 0-20°C, and the drafting ratio is 1.05-1.45;

In particular, high-strength polyamide 56 filaments are prepared with a draw ratio of 3.00 to 5.50.
The preparation method according to any one of claims 1-4, characterized in that: in step 4), the thermal drafting is one-level drafting, two-level drafting or multi-level drafting, and process conditions: drawing The stretching temperature is 80-200° C., and the drafting ratio is 1.01-5.50. In particular, the high-strength polyamide 56 filament is prepared, and the drafting ratio is 3.00-5.50.
The preparation method according to any one of claims 1-4, characterized in that: in step 4), the texturing process comprises a process for preparing functionalized polyamide 56 stretched textured yarn and preparing functionalized polyamide 56 Process of air textured yarn.
The preparation method according to claim 9, wherein the process for preparing the functionalized polyamide 56 stretched textured yarn comprises the steps of thermal drawing, twisting, networking, heat setting and winding, and each condition is as follows:

The hot drafting temperature is 100～200℃, the drafting ratio is 1.10～2.50, the speed of the drafting roller is 300～1000m/min; the twisting is divided into S twist or Z twist, the twisting tension is 20～60cN, and the untwisting tension is 25～65cN, D/Y is the ratio of the surface speed of the friction disc and the speed of the thread leaving the false twister, specifically 1.5～2.0; in the network step, the wind pressure is 1.0～1.6bar; the diameter of the nozzle is 1.2～1.6mm, The heat setting temperature is 180～220℃, and the winding speed is 600～1200m/min.
The preparation method according to claim 9, wherein the process for preparing the functionalized polyamide 56 air-textured yarn comprises the steps of thermal drawing, thermal jet deformation, cooling stabilization and winding. The conditions are as follows:

The hot drawing temperature is 100～190℃, the drawing ratio is 1.05～3.50, the speed of the drafting roller is 1500～2500m/min; The rate is 15-30%, the cooling air temperature is 15-30°C, and the winding speed is 1500-2800 m/min.
The functional polyamide 56 filament prepared by the method according to any one of claims 1-11; characterized in that: the monofilament linear density of the functional polyamide 56 filament is 1-7 dtex, and the breaking strength is 3.5-12.0 cN /dtex, the performance is any of the following 1)-4):

1) When the functional polyamide 56 filament is a high-strength polyamide 56 filament, the breaking strength is 6.0-12.0 cN/dtex;

2) When the functional polyamide 56 filament is a flame-retardant polyamide 56 filament, the limiting oxygen index is 33-38%;

3) When the functional polyamide 56 filament is an easy-dyeing polyamide 56 filament, the dyeing rate of the filament is over 96.0%;

4) When the functional polyamide 56 filament is a mildew-proof polyamide 56 filament, the mildew-proof grade of the filament is ≤ grade 1.