CN116180250A - A kind of full-dull fine-denier polyamide 56 full-drawn yarn and its melt direct spinning method - Google Patents

Abstract

The invention provides a full-dull fine denier bio-based polyamide 56 fully drawn yarn and a melt direct spinning method thereof. The full-dull fine denier polyamide 56 fully drawn yarn has stable production, less floating filaments and head-injecting filaments, high fiber yield and excellent mechanical property and dyeing property.

Description

A full-dull fine-denier polyamide 56 full-drawn yarn and its melt direct spinning method

technical field

The invention belongs to the technical field of polyamide materials, and in particular relates to full-dull polyamide 56 melt direct-spun fine-denier full-drawn yarn and a preparation method thereof.

Background technique

Melt spinning is one of the main forming methods of synthetic fibers, referred to as melt spinning. Melt spinning is divided into direct spinning method and chip spinning method. Direct spinning is to send the polymer melt directly to spinning; slice spinning requires the polymer melt to be sent to spinning after casting, pelletizing, drying and other pre-spinning preparation processes.

Polyamide 6 has a relatively high monomer content (about 10wt%), and the slices need to be extracted before melt spinning can be realized. At present, industrial melt direct spinning cannot be realized. In the spinning process of polyamide 66, problems such as gelation and dyeing difficulties are prone to occur, and it faces great difficulties in the melt direct spinning technology of civilian yarns. Although direct melt spinning has been partially realized in the field of industrial yarns, the melt transportation Pipes and spinning boxes need to be disassembled, calcined and cleaned regularly, which increases the cost of spinning.

Patent No. CN105669969 B discloses a nylon 6 polymerization method and its melt direct spinning method, by first preparing polyamide 6 prepolymer at low temperature, pre-controlling the content of oligomers in the melt, and then strengthening the kinetics through polycondensation reaction , completing the polymerization before a large amount of cyclic oligomers are generated to obtain a nylon 6 polymer melt with a certain molecular weight. In the resulting product, the extractable content is ≤ 1.5wt%, and the cyclic dimer content is ≤ 0.2wt%; then , after the polycondensation reaction kinetics is strengthened, it is directly melt-spun into shape, but there is still no technological breakthrough and industrialization case.

Patent No. CN103668510 A discloses a device and method for producing fine denier or ultra-fine denier nylon 66 filaments. The device includes an evaporator, a preheater, a reactor, a flash evaporator and a finisher system, and the nylon 66 salt After the aqueous solution undergoes a polycondensation reaction, nylon 66 melt is obtained, and then the nylon 66 melt is directly spun to prepare fine denier or ultrafine denier nylon 66 POY filaments. The spinning speed is 4200-4300m/min, and the spinning speed is low. Yield is low and fiber strength is low.

Bio-based polyamide 56 uses bio-based pentamethylenediamine as a monomer raw material, and the carbon emission per unit weight of bio-based polyamide 56 is more than 50% lower than that of nylon 66 and nylon 6 with the same weight. The application and promotion of bio-based polyamide 56 will play a positive role in improving my country's dependence on foreign imports of key materials, and is of great significance for solving the dependence on fossil resources and the sustainable development of low-carbon emission reduction. Bio-based polyamide 56 material has excellent mechanical properties, moisture absorption and quick-drying, skin-friendly, wear-resistant, good softness and low-temperature easy-to-dye characteristics, etc. It has broad application prospects in the fields of body filament and monofilament. However, at present, there is no relevant research and report on the preparation of fine denier fully drawn yarn by one-step direct spinning of fully dull polyamide 56 melt.

Contents of the invention

In order to realize the industrial production requirements of bio-based polyamide 56 melt direct spinning, the present invention prepares large-capacity and high-performance full-dull bio-based polyamide 56 full-drawn yarns by optimizing the melt direct spinning process, and the production is stable and smooth. Fewer monofilaments and injection filaments, high fiber production rate, excellent mechanical properties and dyeing properties.

The first object of the present invention is to provide a full-dull fine-denier polyamide 56 fully-drawn yarn, which is prepared by one-step melt direct spinning, and the fineness of the fully-dull fine-denier polyamide 56 fully-drawn yarn is ≤ 95dtex, or ≤78dtex, or ≤66dtex, or ≤55dtex, eg 15-78dtex.

In some specific embodiments, the breaking strength of the full-dull fine-denier polyamide 56 full-drawn yarn is 4.0-6.5 cN/dtex, or 4.3-6.0 cN/dtex, or 4.5-5.8 cN/dtex, Or it is 4.7-5.5cN/dtex; the coefficient of variation (CV)% of breaking strength is ≤ 4%, preferably ≤ 3.5%, more preferably ≤ 3.0%, even more preferably ≤ 2.5%.

In some specific embodiments, the elongation at break of the full-dull fine denier polyamide 56 fully drawn yarn is ≤55%, or ≤52%, or ≤48%, or ≤45%, for example It is 40-45%; the coefficient of variation (CV)% of elongation at break is ≤4.5%, preferably ≤4.0%, more preferably ≤3.5%, and even more preferably ≤3.0%. In some specific embodiments, the boiling water shrinkage of the full-dull fine denier polyamide 56 full-drawn yarn is ≤12%, preferably ≤11.5%, more preferably ≤11%, even more preferably ≤10.5%, For example 9-12%.

In some specific embodiments, the evenness unevenness of the full-dull fine-denier polyamide 56 fully drawn yarn is ≤1.0%, preferably ≤0.9%, more preferably ≤0.8%, even more preferably ≤0.7% %, for example 0.75-0.95%.

In some specific embodiments, the dyeing uniformity (gray scale) of the fully dull fine-denier polyamide 56 fully drawn yarn is ≥3.5 grades, preferably ≥4.0 grades, more preferably ≥4.5 grades, and even more preferably ≥4.5 grades. ≥ grade 4.7.

In some specific embodiments, the dyed double A ratio of the full-dull fine-denier polyamide 56 fully drawn yarn is ≥95%, preferably ≥96%, more preferably ≥97%, even more preferably ≥98% %; and/or, the appearance double A ratio of the silk cake is ≥96%, preferably ≥97%, more preferably ≥97.5%, even more preferably ≥98%.

The second object of the present invention is to provide the melt direct spinning method of the full-dull fine denier polyamide 56 full-drawn yarn, the melt direct spinning at least includes the following steps: the polyamide 56 melt is melt-enhanced Pressure pump, melt filter, melt conveying pipeline to the spinning box to form as-spun yarn, and the as-spun yarn is cooled, oiled, drawn, heat-set, and wound to obtain full-dull fine-denier polyamide 56 drawn wire;

The titanium dioxide content in the polyamide 56 melt is 1.2-1.8wt%, preferably 1.3-1.7wt%, more preferably 1.4-1.65wt%, even more preferably 1.45-1.63wt%.

In some specific embodiments, the titanium dioxide is added during flash evaporation.

In some specific embodiments, the relative viscosity of the polyamide 56 melt is 2.38-2.9, preferably 2.4-2.88, more preferably 2.42-2.86, more preferably 2.45-2.84.

In some specific embodiments, the polyamide 56 melt terminal amino group content is 35-90mmol/kg, preferably 38-80mmol/kg, more preferably 40-70mmol/kg, further preferably 42-60mmol/kg .

In some specific embodiments, the polyamide 56 melt has an equilibrium moisture content of 300-900 ppm, preferably 350-850 ppm, more preferably 400-800 ppm, and even more preferably 450-750 ppm.

In some specific embodiments, the preparation method of the polyamide 56 melt includes the following steps: preparing a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtaining a polyamide 56 salt solution through prepolymerization, flash evaporation, and polycondensation. Amide 56 melt.

In some specific embodiments, the molar ratio of pentamethylenediamine to adipic acid is (1-1.09):1.

In some specific embodiments, the concentration of the polyamide 56 salt solution is 40-80 wt%.

In some specific embodiments, the pH value of the polyamide 56 salt solution is 6.5-8.8, preferably 6.7-8.7, more preferably 6.8-8.6, even more preferably 6.9-8.5.

In some specific embodiments, the pressure of the prepolymerization is 1.4-2.4Mpa, preferably 1.5-2.3Mpa, more preferably 1.6-2.2Mpa, even more preferably 1.7-2.1Mpa; the temperature of the prepolymerization 180-260°C, preferably 200-258°C, more preferably 210-256°C, still more preferably 220-254°C.

In some specific embodiments, the polycondensation pressure is -(0-0.09) Mpa, preferably -(0.01-0.08) Mpa, more preferably -(0.02-0.07) Mpa, even more preferably -(0.03 -0.06) Mpa; the polycondensation temperature is 266-288°C, preferably 267-287°C, more preferably 268-286°C, even more preferably 269-285°C.

In some specific embodiments, the melt filter is provided with a filter net, and the specification of the filter net is 3-15 μm, preferably 5-13 μm, and more preferably 8-10 μm. The material of the filter screen is selected from metal or non-woven fabric, preferably stainless steel.

In some specific embodiments, the spinning assembly of the spinning beam is provided with a filter, and the specification of the filter is 8-18 μm, preferably 10-15 μm. The material of the filter screen is selected from metal or non-woven fabric, preferably non-woven fabric.

The preparation method of the present invention obtains the matting effect by adding titanium dioxide, the method is simple and easy to operate, and the production cost is low, and the inventors have found that by setting filter screens in both the melt filter and the spinning pack, the combination of two filters can effectively reduce The agglomerated particles of titanium dioxide with larger particle size make the distribution of titanium dioxide in the melt more uniform, and improve the overall uniformity of the polyamide 56 melt. Not only can a better matting effect be obtained, but also the spinning process has less interrupted single filaments and the component replacement cycle is long. , suitable for industrial production.

In some specific embodiments, the dispersed particle size of the titanium dioxide in the polyamide 56 melt is 0.1-0.6 μm, and preferably, the particle distribution ratio of the titanium dioxide dispersed particle size is 0.2-0.4 μm is above 98%; more Preferably, the distribution ratio of titanium dioxide particles with a dispersed particle diameter of 0.2-0.3 μm is above 95%.

In some specific embodiments, the temperature of the melt delivery pipeline is controlled to be 265-290°C, preferably 268-288°C, more preferably 270-286°C, even more preferably 272-284°C.

In some specific embodiments, from the melt booster pump to the spinning box, the dynamic viscosity of the polyamide 56 melt is controlled to be ≥200pa*s, preferably ≥210pa*s, more preferably ≥220pa*s, for example It is 230-350pa*s.

In some specific embodiments, the temperature of the spinning box is 270-292°C, more preferably 273-290°C, further preferably 275-288°C, even more preferably 277-285°C.

In some specific embodiments, the spinning assembly pressure of the spinning beam is 10-25 MPa, preferably 12-22 MPa, more preferably 14-18 MPa.

In some specific embodiments, the melt pressure at the inlet of the spinning beam is ≥9.0 MPa, preferably ≥10.0 MPa, more preferably ≥11.0 MPa, for example 12.0-16.0 MPa.

In some specific embodiments, the polyamide 56 melt is transported to the spinning box through the melt pipeline, and after being accurately metered by the metering pump, it is injected into the spinning assembly, and is ejected from the spinneret to form a spun filament .

In some preferred specific embodiments, a saturated superheated steam device and a monomer suction device are arranged below the spinning beam. The inventor sprays the saturated superheated steam from around the bottom of the spinneret, and the polyamide oligomer overflowing from the spinneret hole and its fiber surface is dissolved in the saturated superheated steam, and then taken away by the monomer suction device, Keep the spinneret and its lower part clean, prolong the shoveling cycle of the spinning assembly, reduce the phenomenon of injecting filaments and broken monofilaments caused by oligomers during the spinning process, and effectively improve the stability and yield of spinning production.

In some specific embodiments, the temperature of the saturated superheated steam device is controlled to be 100-250°C, further 110-240°C, and further 120-230°C.

In some specific embodiments, the pressure of the saturated superheated steam device is controlled to be 0.8-2.8 bar, further 1.0-2.5 bar, and further 1.2-2.3 bar.

In some specific embodiments, the pressure of the monomer suction device is controlled to be ≥ 0.6 MPa, further ≥ 0.65 MPa, and further 0.7-1.0 MPa.

In some specific embodiments, the oil used for oiling can be commercially available polyamide silk oil, such as DAKO oil, bamboo oil, Kekai oil, Sima oil, etc.

In some specific embodiments, the drafting adopts 2 pairs of drafting rolls or more, preferably 2 pairs of drafting rolls, that is, the as-spun yarn after oiling is first fed into G1 drafting rolls, and then drawn in G2 The drafting heat setting is carried out between the roll and the G1 drafting roll.

In some specific embodiments, the speed of the G1 drafting roll is 2200-3800 m/min, preferably 2500-3700 m/min, more preferably 2800-3500 m/min.

In some specific embodiments, the speed of the G2 drafting roll is 4500-5500 m/min, preferably 4600-5400 m/min, more preferably 4700-5200 m/min.

In some specific embodiments, the draw ratio is 1.25-2.5, preferably 1.3-2.0, more preferably 1.4-1.8.

In some specific embodiments, the heat setting temperature is 140-175°C, preferably 145-170°C, more preferably 150-165°C.

In some specific embodiments, the winding speed is ≥4500m/min, preferably ≥4700m/min, more preferably 4700-5500m/min.

In some specific embodiments, the number of broken filaments of the full-dull fine-denier polyamide 56 fully drawn yarn is ≤ 2/1 spinning position 24h, preferably ≤ 1/1 spinning position 24h, more preferably ≤0/1 spinning position for 24h.

In some specific embodiments, the production rate of the full-dull fine-denier polyamide 56 full-drawn yarn is ≥ 96%, preferably ≥ 96.5%, more preferably ≥ 97%, and even more preferably ≥ 97.5% .

The full-dull fine-denier polyamide 56 full-drawn yarn provided by the present invention is used in knitted and woven fabrics without limitation, including underwear, shirts, suits, yoga clothes, down jackets, jackets, socks, bags, curtains, shoe materials , Embroidery thread, trademark, sofa release, tooling, sportswear, elastic band and other fields.

On the basis of conforming to common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred examples of the present invention. The reagents and raw materials used in the present invention are all commercially available.

The positive progress effect of the present invention is:

First, 1,5-pentamethylenediamine, the raw material for the production of polyamide 56 full-drawn yarn provided by the present invention, is made by biological method, is a green material, does not depend on petroleum resources and does not cause serious pollution to the environment, and can reduce carbon dioxide emissions, reduce the greenhouse effect, and adapt to the development trend of carbon neutrality.

Second, adopt the melt direct spinning method of full-dull fine-denier polyamide 56 full-drawn yarn of the present invention to control the melt delivery temperature, the dynamic viscosity of the melt, the temperature of the spinning box, the pressure of the components and the melting temperature at the entrance. The parameters such as body pressure can not only realize the stable production of full-dull fine-denier polyamide 56 full-drawn yarns of various specifications, but also effectively reduce the gel content of the melt booster pump into the spinning box.

Specifically, the annual output of the full-dull fine-denier polyamide 56 full-drawn yarn can reach 0.8-20,000 tons/line; position/line and below; the number of spinning heads can be 8-24 heads/position, preferably 12-24 heads/position. This method saves links such as melt pelletizing, chip drying, and screw melting in the chip spinning process, and greatly reduces the production cost of polyamide 56 full-drawn yarn. The gel content can be controlled below 1.1wt%/6 months, preferably ≤1.0wt%/6 months, more preferably ≤0.9wt%/6 months, more preferably ≤0.8wt%/6 months 1, the reduction of the gel content greatly reduces the disassembly, calcination and cleaning times of the melt pipe and the spinning box, and reduces the production cost.

Third, the production of the full-dull fine-denier polyamide 56 full-drawn yarn of the present invention is stable, with few floating monofilaments and injection filaments, high fiber production rate, and excellent mechanical properties and dyeing properties.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the implementation of the present invention. example, not all examples. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention. For the experimental methods that do not specify specific conditions in the following examples, select according to conventional methods and conditions, or according to the product instructions.

Test Methods:

(1) Relative viscosity: Ubbelohde viscometer concentrated sulfuric acid method: take a polyamide melt sample online and dry it, accurately weigh 0.25±0.0002g, add 50mL concentrated sulfuric acid (96wt%) to dissolve; measure in a constant temperature water bath at 25°C And record the concentrated sulfuric acid flow time t ₀ and the polyamide sample solution flow time t. Viscosity calculation formula: relative viscosity = t/t ₀ ; t—solution flow time; t ₀ —solvent flow time.

(2) Terminal amino group: determined by an automatic titrator.

(3) Moisture content: measured by Karl Fischer moisture titrator.

(4) Denier: measured according to GB/T 14343.

(5) Breaking strength, coefficient of variation (CV)% of breaking strength, elongation at break, coefficient of variation (CV)% of elongation at break: according to GB/T 14344-2008 test method for tensile properties of chemical fibers; apply 0.05± 0.005cN/dtex pretension, holding distance 250mm, stretching speed 1000mm/min.

(6) Evenness unevenness: Evenness unevenness refers to the degree of thickness variation of the yarn along its own length direction, including uneven yarn appearance diameter and linear density. The testing equipment is Uster evenness instrument.

(7) Boiling water shrinkage: determined according to GB/6505-2008.

(8) Dyeing uniformity (gray card)/level: According to FZ/T 50008 test method for dyeing uniformity of nylon filament.

(9) Dyeing double-A rate: dyeing double-A rate=((weight of fibers with dyeing uniformity ≥ 4.5)/total weight of all dyed fibers)×100%; double-A rate of silk cake appearance: manual discrimination.

(10) Number of broken single wires: manual statistics.

(11) Production rate: production rate=(prepared finished fiber mass/total input polyamide melt mass)×100%.

(12) Gel content: Randomly select melt samples in 6 melt delivery pipelines after the production line has been in operation for 6 months, measure and average according to the following method, weigh the quality of the melt samples after cooling and drying as A1, After using the Soxhlet extraction method for reflux extraction, take out the sample and dry it, weigh the sample mass in the filter paper bag as A2, and calculate the gel content with the formula: gel content wt%=A2/A1*100%.

Embodiment 1 Full-dull fine-denier polyamide 56 full-drawn silk 15dtex/7f

(1) Prepare a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtain a polyamide 56 melt through prepolymerization, flash evaporation, and polycondensation;

Wherein, the molar ratio of pentamethylenediamine to adipic acid is 1.09:1; the concentration of polyamide 56 salt solution is 52wt%, and the pH value is 7.9;

The pressure of the prepolymerization is 1.7Mpa and the temperature is 248°C; the pressure of the polycondensation is -0.03Mpa and the temperature is 272°C;

The relative viscosity of the polyamide 56 melt is 2.48, the terminal amino group content is 43mmol/kg, and the equilibrium water content is 300ppm;

The titanium dioxide content of the polyamide 56 melt was 1.53 wt%, which was added during flash evaporation.

(2) The polyamide 56 melt obtained in step (1) passes through a melt booster pump, a melt filter, and a melt delivery pipeline to a spinning box to form a spun silk, and the spun silk is cooled, oiled, and drawn. Stretching, heat setting, and winding to obtain full-dull fine-denier polyamide 56 full-drawn yarn;

The melt filter is provided with a 10 μm stainless steel filter screen; the spinning assembly of the spinning box is provided with a 15 μm non-woven filter screen;

The dispersed particle size of titanium dioxide in polyamide 56 melt is 0.1-0.6 μm, the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.4 μm is 98.5%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 96.4% %;

Control the temperature of the melt delivery pipeline to be 272°C; from the melt booster pump to the spinning box, control the dynamic viscosity of the polyamide 56 melt to be 220pa*s; the temperature of the spinning box is 274°C; The pressure of the spinning assembly of the spinning box is 14 MPa; the melt pressure at the inlet of the spinning box is 11.0 MPa.

A saturated superheated steam device and a monomer suction device are arranged below the spinning beam, wherein the temperature of the saturated superheated steam device is controlled to be 140°C, the pressure of the saturated superheated steam device is controlled to be 1.5 bar, and the unit is controlled to The pressure of the body suction device is 0.6MPa.

The drafting adopts 2 pairs of drafting rollers. The as-spun yarn after oiling is firstly fed into the G1 drafting roller, and then the drafting heat setting is carried out between the G2 drafting roller and the G1 drafting roller, wherein the speed of the G1 drafting roller is The speed of the G2 drafting roller is 4800 m/min; the draw ratio is 1.5; the heat setting temperature is 160° C.; the winding speed is 4770 m/min.

The annual output of full-dull fine-denier polyamide 56 full-drawn yarn described in this embodiment can reach 4,000 tons/line, the spinning position is 48 positions/line, and the number of spinning heads is 24 heads/position.

Embodiment 2 Full-dull fine-denier polyamide 56 full-drawn silk 17dtex/5f

(1) Prepare a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtain a polyamide 56 melt through prepolymerization, flash evaporation, and polycondensation;

Wherein, the molar ratio of pentamethylenediamine to adipic acid is 1.08:1; the concentration of polyamide 56 salt solution is 53wt%, and the pH value is 7.8;

The pressure of the prepolymerization is 1.6Mpa and the temperature is 250°C; the pressure of the polycondensation is -0.05Mpa and the temperature is 275°C;

The relative viscosity of the polyamide 56 melt is 2.55, the terminal amino group content is 47mmol/kg, and the equilibrium water content is 400ppm;

The titanium dioxide content of the polyamide 56 melt was 1.6 wt%, which was added during flash evaporation.

(2) The polyamide 56 melt obtained in step (1) passes through a melt booster pump, a melt filter, and a melt delivery pipeline to a spinning box to form a spun silk, and the spun silk is cooled, oiled, and drawn. Stretching, heat setting, and winding to obtain full-dull fine-denier polyamide 56 full-drawn yarn;

The melt filter is provided with a 10 μm stainless steel filter screen; the spinning assembly of the spinning box is provided with a 15 μm non-woven filter screen;

The dispersed particle size of titanium dioxide in the polyamide 56 melt is 0.1-0.6 μm, the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.4 μm is 98.2%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 96.0 %;

Control the temperature of the melt delivery pipeline to be 274°C; from the melt booster pump to the spinning box, control the dynamic viscosity of the polyamide 56 melt to be 230pa*s; the temperature of the spinning box is 274°C; The pressure of the spinning assembly of the spinning beam is 15 MPa; the melt pressure at the inlet of the spinning beam is 12.0 MPa.

A saturated superheated steam device and a monomer suction device are arranged below the spinning beam, wherein the temperature of the saturated superheated steam device is controlled to be 150° C., the pressure of the saturated superheated steam device is controlled to be 1.2 bar, and the unit is controlled to The pressure of the body suction device is 0.6MPa.

The drafting adopts 2 pairs of drafting rollers. The as-spun yarn after oiling is firstly fed into the G1 drafting roller, and then the drafting heat setting is carried out between the G2 drafting roller and the G1 drafting roller, wherein the speed of the G1 drafting roller is The speed of the G2 drafting roller is 4600 m/min; the draw ratio is 1.53; the heat setting temperature is 160° C.; the winding speed is 4580 m/min.

The annual output of full-dull fine-denier polyamide 56 full-drawn yarn described in this embodiment can reach 5,000 tons/line, the spinning position is 48 positions/line, and the number of spinning heads is 24 heads/position.

Embodiment 3 Full-dull fine-denier polyamide 56 full-drawn yarn 22dtex/10f

(1) Prepare a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtain a polyamide 56 melt through prepolymerization, flash evaporation, and polycondensation;

Wherein, the molar ratio of pentamethylenediamine to adipic acid is 1.05:1; the concentration of the polyamide 56 salt solution is 55 wt%, and the pH value is 8.0;

The pressure of the prepolymerization is 1.7Mpa and the temperature is 252°C; the pressure of the polycondensation is -0.05Mpa and the temperature is 278°C;

The relative viscosity of the polyamide 56 melt is 2.64, the terminal amino group content is 52mmol/kg, and the equilibrium water content is 500ppm;

The titanium dioxide content of the polyamide 56 melt was 1.62 wt%, which was added during flash evaporation.

(2) The polyamide 56 melt obtained in step (1) passes through a melt booster pump, a melt filter, and a melt delivery pipeline to a spinning box to form a spun silk, and the spun silk is cooled, oiled, and drawn. Stretching, heat setting, and winding to obtain full-dull fine-denier polyamide 56 full-drawn yarn;

The melt filter is provided with a 10 μm stainless steel filter screen; the spinning assembly of the spinning box is provided with a 15 μm non-woven filter screen;

The dispersed particle size of titanium dioxide in the polyamide 56 melt is 0.1-0.6 μm, the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.4 μm is 98.6%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 96.4% %;

Control the temperature of the melt delivery pipeline to be 278°C; from the melt booster pump to the spinning box, control the dynamic viscosity of the polyamide 56 melt to be 240pa*s; the temperature of the spinning box is 276°C; The pressure of the spinning assembly of the spinning beam is 16MPa; the melt pressure at the inlet of the spinning beam is 13.0MPa.

A saturated superheated steam device and a monomer suction device are arranged below the spinning beam, wherein the temperature of the saturated superheated steam device is controlled to be 140° C., the pressure of the saturated superheated steam device is controlled to be 1.2 bar, and the unit is controlled to The pressure of the body suction device is 0.7MPa.

The drafting adopts 2 pairs of drafting rollers. The as-spun yarn after oiling is firstly fed into the G1 drafting roller, and then the drafting heat setting is carried out between the G2 drafting roller and the G1 drafting roller, wherein the speed of the G1 drafting roller is The speed of the G2 drafting roller is 4900 m/min; the draw ratio is 1.53; the heat setting temperature is 160° C.; the winding speed is 4870 m/min.

The annual output of full-dull fine-denier polyamide 56 full-drawn yarn described in this embodiment can reach 6,000 tons/line, the spinning position is 48 positions/line, and the number of spinning heads is 24 heads/position.

Example 4 Full-dull fine-denier polyamide 56 full-drawn yarn 22dtex/24f

(1) Prepare a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtain a polyamide 56 melt through prepolymerization, flash evaporation, and polycondensation;

Wherein, the molar ratio of pentamethylenediamine to adipic acid is 1.04:1; the concentration of polyamide 56 salt solution is 53wt%, and the pH value is 8.2;

The pressure of the prepolymerization is 1.68Mpa and the temperature is 254°C; the pressure of the polycondensation is -0.06Mpa and the temperature is 280°C;

The relative viscosity of the polyamide 56 melt is 2.75, the terminal amino group content is 53mmol/kg, and the equilibrium water content is 440ppm;

The titanium dioxide content of the polyamide 56 melt was 1.52 wt%, which was added during flash evaporation.

(2) The polyamide 56 melt obtained in step (1) passes through a melt booster pump, a melt filter, and a melt delivery pipeline to a spinning box to form a spun silk, and the spun silk is cooled, oiled, and drawn. Stretching, heat setting, and winding to obtain full-dull fine-denier polyamide 56 full-drawn yarn;

The melt filter is provided with a 10 μm stainless steel filter screen; the spinning assembly of the spinning box is provided with a 15 μm non-woven filter screen;

The dispersed particle size of titanium dioxide in polyamide 56 melt is 0.1-0.6 μm, the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.4 μm is 98.8%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 97.2% %;

Control the temperature of the melt delivery pipeline to be 280°C; from the melt booster pump to the spinning box, control the dynamic viscosity of the polyamide 56 melt to be 250pa*s; the temperature of the spinning box is 280°C; The pressure of the spinning assembly of the spinning beam is 15 MPa; the melt pressure at the inlet of the spinning beam is 12.0 MPa.

A saturated superheated steam device and a monomer suction device are arranged below the spinning beam, wherein the temperature of the saturated superheated steam device is controlled to be 160° C., the pressure of the saturated superheated steam device is controlled to be 1.2 bar, and the unit is controlled to The pressure of the body suction device is 0.8MPa.

The drafting adopts 2 pairs of drafting rollers. The as-spun yarn after oiling is firstly fed into the G1 drafting roller, and then the drafting heat setting is carried out between the G2 drafting roller and the G1 drafting roller, wherein the speed of the G1 drafting roller is The speed of the G2 drafting roller is 5000 m/min; the draw ratio is 1.43; the heat setting temperature is 155° C.; the winding speed is 4960 m/min.

The annual output of full-dull fine-denier polyamide 56 full-drawn yarn in this embodiment can reach 6,000 tons/line, the spinning position is 96 positions/line, and the number of spinning heads is 12 heads/position.

Example 5 Full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

(1) Prepare a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtain a polyamide 56 melt through prepolymerization, flash evaporation, and polycondensation;

Wherein, the molar ratio of pentamethylenediamine to adipic acid is 1.06:1; the concentration of polyamide 56 salt solution is 50wt%, and the pH value is 8.3;

The pressure of the prepolymerization is 1.78Mpa and the temperature is 255°C; the pressure of the polycondensation is -0.07Mpa and the temperature is 283°C;

The relative viscosity of the polyamide 56 melt is 2.80, the terminal amino group content is 50mmol/kg, and the equilibrium water content is 400ppm;

The titanium dioxide content of the polyamide 56 melt was 1.5% by weight, which was added during flash evaporation.

(2) The polyamide 56 melt obtained in step (1) passes through a melt booster pump, a melt filter, and a melt delivery pipeline to a spinning box to form a spun silk, and the spun silk is cooled, oiled, and drawn. Stretching, heat setting, and winding to obtain full-dull fine-denier polyamide 56 full-drawn yarn;

The melt filter is provided with a 10 μm stainless steel filter screen; the spinning assembly of the spinning box is provided with a 15 μm non-woven filter screen;

The dispersed particle size of titanium dioxide in polyamide 56 melt is 0.1-0.6 μm, the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.4 μm is 98.5%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 97.8% %;

Control the temperature of the melt delivery pipeline to be 282°C; from the melt booster pump to the spinning box, control the dynamic viscosity of the polyamide 56 melt to be 255pa*s; the temperature of the spinning box is 282°C; The pressure of the spinning assembly of the spinning box is 17 MPa; the melt pressure at the inlet of the spinning box is 12.0 MPa.

A saturated superheated steam device and a monomer suction device are arranged below the spinning beam, wherein the temperature of the saturated superheated steam device is controlled to be 180° C., the pressure of the saturated superheated steam device is controlled to be 1.2 bar, and the unit is controlled to The pressure of the body suction device is 0.7MPa.

The drafting adopts 2 pairs of drafting rollers. The as-spun yarn after oiling is firstly fed into the G1 drafting roller, and then the drafting heat setting is carried out between the G2 drafting roller and the G1 drafting roller, wherein the speed of the G1 drafting roller is The speed of the G2 drafting roller is 4800 m/min; the draw ratio is 1.43; the heat setting temperature is 180° C.; the winding speed is 4770 m/min.

The annual output of full-dull fine-denier polyamide 56 full-drawn yarn described in this embodiment can reach 9,000 tons/line, the spinning position is 48 positions/line, and the number of spinning heads is 12 heads/position.

Example 6 Full-dull fine-denier polyamide 56 full-drawn yarn 44dtex/48f

(1) Prepare a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtain a polyamide 56 melt through prepolymerization, flash evaporation, and polycondensation;

Wherein, the molar ratio of pentamethylenediamine to adipic acid is 1.05:1; the concentration of polyamide 56 salt solution is 52wt%, and the pH value is 8.0;

The pressure of the prepolymerization is 1.72Mpa and the temperature is 250°C; the pressure of the polycondensation is -0.06Mpa and the temperature is 280°C;

The relative viscosity of the polyamide 56 melt is 2.75, the terminal amino group content is 48mmol/kg, and the equilibrium water content is 500ppm;

The titanium dioxide content of the polyamide 56 melt was 1.52 wt%, which was added during flash evaporation.

(2) The polyamide 56 melt obtained in step (1) passes through a melt booster pump, a melt filter, and a melt delivery pipeline to a spinning box to form a spun silk, and the spun silk is cooled, oiled, and drawn. Stretching, heat setting, and winding to obtain full-dull fine-denier polyamide 56 full-drawn yarn;

The melt filter is provided with a 15 μm stainless steel filter screen; the spinning assembly of the spinning box is provided with a 15 μm non-woven filter screen;

The dispersed particle size of titanium dioxide in the polyamide 56 melt is 0.1-0.6 μm, the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.4 μm is 98.8%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 97.3 %;

Control the temperature of the melt delivery pipeline to be 280°C; from the melt booster pump to the spinning box, control the dynamic viscosity of the polyamide 56 melt to be 245pa*s; the temperature of the spinning box is 280°C; The pressure of the spinning assembly of the spinning beam is 18MPa; the melt pressure at the inlet of the spinning beam is 11.0MPa.

A saturated superheated steam device and a monomer suction device are arranged below the spinning beam, wherein the temperature of the saturated superheated steam device is controlled to be 170° C., the pressure of the saturated superheated steam device is controlled to be 1.3 bar, and the unit is controlled to The pressure of the body suction device is 0.7MPa.

The drafting adopts 2 pairs of drafting rollers. The as-spun yarn after oiling is firstly fed into the G1 drafting roller, and then the drafting heat setting is carried out between the G2 drafting roller and the G1 drafting roller, wherein the speed of the G1 drafting roller is The speed of the G2 drafting roller is 4800 m/min; the draw ratio is 1.43; the heat setting temperature is 170° C.; the winding speed is 4760 m/min.

The annual output of full-dull fine-denier polyamide 56 full-drawn yarn in this embodiment can reach 12,000 tons/line, the spinning position is 48 positions/line, and the number of spinning heads is 24 heads/position.

Example 7 Full-dull fine-denier polyamide 56 full-drawn yarn 78dtex/68f

(1) Prepare a polyamide 56 salt solution with pentamethylenediamine, adipic acid and water, and then obtain a polyamide 56 melt through prepolymerization, flash evaporation, and polycondensation;

Wherein, the molar ratio of pentamethylenediamine to adipic acid is 1.04:1; the concentration of polyamide 56 salt solution is 54wt%, and the pH value is 8.1;

The pressure of the prepolymerization is 1.74Mpa and the temperature is 253°C; the pressure of the polycondensation is -0.05Mpa and the temperature is 282°C;

The relative viscosity of the polyamide 56 melt is 2.78, the terminal amino group content is 53mmol/kg, and the equilibrium water content is 600ppm;

The titanium dioxide content of the polyamide 56 melt was 1.53 wt%, which was added during flash evaporation.

(2) The polyamide 56 melt obtained in step (1) passes through a melt booster pump, a melt filter, and a melt delivery pipeline to a spinning box to form a spun silk, and the spun silk is cooled, oiled, and drawn. Stretching, heat setting, and winding to obtain full-dull fine-denier polyamide 56 full-drawn yarn;

The melt filter is provided with a 15 μm stainless steel filter screen; the spinning assembly of the spinning box is provided with a 15 μm non-woven filter screen;

The dispersed particle size of titanium dioxide in the polyamide 56 melt is 0.1-0.6 μm, the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.4 μm is 98.9%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 97.8% %;

Control the temperature of the melt delivery pipeline to be 282°C; from the melt booster pump to the spinning box, control the dynamic viscosity of the polyamide 56 melt to be 250pa*s; the temperature of the spinning box is 282°C; The pressure of the spinning assembly of the spinning beam is 178MPa; the melt pressure at the inlet of the spinning beam is 10.0MPa.

A saturated superheated steam device and a monomer suction device are arranged below the spinning beam, wherein the temperature of the saturated superheated steam device is controlled to be 130° C., the pressure of the saturated superheated steam device is controlled to be 1.4 bar, and the unit is controlled to The pressure of the body suction device is 0.75MPa.

The drafting adopts 2 pairs of drafting rollers. The as-spun yarn after oiling is firstly fed into the G1 drafting roller, and then the drafting heat setting is carried out between the G2 drafting roller and the G1 drafting roller, wherein the speed of the G1 drafting roller is The speed of the G2 drafting roller is 4900 m/min; the draw ratio is 1.48; the heat setting temperature is 175° C.; the winding speed is 4880 m/min.

The annual output of full-dull fine-denier polyamide 56 full-drawn yarn described in this embodiment can reach 20,000 tons/line, the spinning position is 48 positions/line, and the number of spinning heads is 24 heads/position.

Comparative Example 1 Full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

The preparation method is the same as that of Example 5, the difference is that the polyamide 56 melt obtained in step (1) is first granulated and dried to obtain slices, melted by a single screw, and then transported to the spinning box through a melt conveying pipeline, and the slices are spun. Yarn preparation Full-dull fine-denier polyamide 56 full-drawn yarn.

Comparative Example 2 Full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

The preparation method is the same as that of Example 5, except that the polyamide 56 melt has an equilibrium water content of 1300 ppm.

Comparative example 3 full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

The preparation method is the same as in Example 5, the difference is that: the melt filter is provided with a 20 μm stainless steel filter screen; the dispersed particle size of titanium dioxide in the polyamide 56 melt is 0.1-0.6 μm, and the dispersed particle size of titanium dioxide is 0.2- The particle distribution ratio of 0.4 μm is 93.7%; the particle distribution ratio of titanium dioxide dispersed particle size is 0.2-0.3 μm is 93.4%.

Comparative example 4 Full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

The preparation method is the same as that of Example 5, the difference is that: the spinning assembly of the spinning box is provided with a 25 μm non-woven filter screen; the dispersed particle size of titanium dioxide in the polyamide 56 melt is 0.1-0.6 μm, and the titanium dioxide is dispersed The distribution ratio of particles with a particle size of 0.2-0.4 μm is 91.8%; the distribution ratio of particles with a dispersed particle size of titanium dioxide of 0.2-0.3 μm is 91.2%.

Comparative Example 5 Full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

The preparation method is the same as that of Example 5, except that the temperature of the melt delivery pipeline is controlled to be 293°C.

Comparative example 6 full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

The preparation method is the same as that of Example 5, except that the kinematic viscosity of polyamide 56 melt is controlled to 170pa*s.

Comparative Example 7 Full-dull fine-denier polyamide 56 full-drawn yarn 33dtex/48f

The preparation method is the same as that of Example 5, except that the melt pressure at the inlet of the spinning box is 6.0 MPa.

The polyamide 56 fully drawn silk parameters prepared by the embodiment and comparative example of table 1

As can be seen from Table 1, the melt direct spinning method adopting the full-dull fine-denier polyamide 56 full-drawn yarn of the present invention controls the melt delivery temperature, the dynamic viscosity of the melt, the spinning box temperature, the assembly pressure and The parameters such as the melt pressure at the entrance can not only realize the stable production of various specifications of full-dull fine-denier polyamide 56 full-drawn yarns, obtain high-performance full-drawn yarns, but also effectively reduce the melt pressure from the booster pump to the spinning box. Gel content in the body. Moreover, the combination of two filtrations effectively reduces the agglomerated particles of titanium dioxide with larger particle sizes, makes the distribution of titanium dioxide in the melt more uniform, improves the overall uniformity of the polyamide 56 melt, and has a long replacement cycle for spinning components, which is suitable for industrial production.

The above description of the embodiments is for those of ordinary skill in the art to understand and use the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative effort. Therefore, the present invention is not limited to the above-mentioned embodiments. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (11)

1. The full-dull fine denier polyamide 56 fully drawn yarn is prepared by a melt direct spinning one-step method, and is characterized in that the fineness of the full-dull fine denier polyamide 56 fully drawn yarn is less than or equal to 95dtex;

the breaking strength of the full-dull fine denier polyamide 56 fully drawn yarn is 4.0-6.5cN/dtex; the Coefficient of Variation (CV) in breaking strength is not more than 4%, preferably not more than 3.5%, more preferably not more than 3.0%, still more preferably not more than 2.5%; and/or the number of the groups of groups,

the breaking elongation of the full-dull fine denier polyamide 56 fully drawn yarn is less than or equal to 55%; the Coefficient of Variation (CV) in elongation at break is not more than 4.5%, preferably not more than 4.0%, more preferably not more than 3.5%, still more preferably not more than 3.0%; and/or the number of the groups of groups,

the boiling water shrinkage of the full-dull fine denier polyamide 56 fully drawn yarn is less than or equal to 12%, preferably less than or equal to 11.5%, more preferably less than or equal to 11%, and even more preferably less than or equal to 10.5%; and/or the number of the groups of groups,

the full-dull fine denier polyamide 56 fully drawn yarn has a sliver unevenness of 1.0% or less, preferably 0.9% or less, more preferably 0.8% or less, and even more preferably 0.7% or less; and/or the number of the groups of groups,

the dyeing uniformity (gray card) of the full-dull fine denier polyamide 56 fully drawn yarn is more than or equal to 3.5, preferably more than or equal to 4.0, more preferably more than or equal to 4.5, and even more preferably more than or equal to 4.7; and/or the number of the groups of groups,

the dyeing double A rate of the full-dull fine denier polyamide 56 fully drawn yarn is more than or equal to 95%, preferably more than or equal to 96%, more preferably more than or equal to 97%, still more preferably more than or equal to 98%; and/or the number of the groups of groups,

the cake appearance double A rate of the full-dull fine denier polyamide 56 fully drawn yarn is more than or equal to 96%, preferably more than or equal to 97%, more preferably more than or equal to 97.5%, and even more preferably more than or equal to 98%.

2. The full-matted fine denier polyamide 56 fully drawn yarn as claimed in claim 1, characterized in that said melt direct spinning comprises at least the steps of: the melt of the polyamide 56 is conveyed to a spinning box body through a melt booster pump, a melt filter and a melt conveying pipeline to form primary filaments, and the primary filaments are cooled, oiled, drawn, heat-set and wound to obtain full-dull fine denier polyamide 56 fully drawn filaments;

the titanium dioxide content of the polyamide 56 melt is 1.2 to 1.8 wt.%, preferably 1.3 to 1.7 wt.%, more preferably 1.4 to 1.65 wt.%, still more preferably 1.45 to 1.63 wt.%.

3. The full-matted fine denier polyamide 56 fully drawn yarn according to claim 2, characterized in that the relative viscosity of the polyamide 56 melt is 2.38-2.9; and/or the number of the groups of groups,

the amino content of the melt end of the polyamide 56 is 35-90mmol/kg; and/or the number of the groups of groups,

the polyamide 56 melt has an equilibrium moisture content of 300 to 900ppm.

4. A full-dull fine denier polyamide 56 fully drawn yarn according to claim 2, characterized in that said melt filter has a filter mesh disposed therein, said filter mesh having a gauge of 3-15 μm, preferably 5-13 μm, still more preferably 8-10 μm; and/or the number of the groups of groups,

the spinning component of the spinning box is provided with a filter screen, and the specification of the filter screen is 8-18 mu m, preferably 10-15 mu m.

5. The full-drawn yarn of full-dull fine denier polyamide 56 according to claim 2, wherein the dispersed particle size of the titanium dioxide in the melt of polyamide 56 is 0.1 to 0.6 μm, and preferably the particle distribution ratio of the titanium dioxide dispersed particle size of 0.2 to 0.4 μm is 98% or more; more preferably, the proportion of particles having a titanium dioxide dispersed particle diameter of 0.2 to 0.3 μm is 95% or more.

6. Full-matted fine denier polyamide 56 fully drawn yarn according to claim 2, characterized in that the temperature of the melt conveying conduit is controlled in the range of 265-290 ℃, preferably in the range of 268-288 ℃, further preferably in the range of 270-286 ℃, still further preferably in the range of 272-284 ℃.

7. The full-matted fine denier polyamide 56 fully drawn yarn according to claim 2, characterized in that the dynamic viscosity of the polyamide 56 melt is controlled from the melt booster pump to the spinning beam to be equal to or greater than 200pa, preferably equal to or greater than 210pa, further preferably equal to or greater than 220 pa.

8. Full-matted fine denier polyamide 56 fully drawn yarn according to claim 2 characterized in that the temperature of the spinning beam is 270-292 ℃, more preferably 273-290 ℃, still more preferably 275-288 ℃, still more preferably 277-285 ℃.

9. Full-matted fine denier polyamide 56 fully drawn yarn according to claim 2 characterized in that the spin pack pressure of the spin beam is 10-25MPa, preferably 12-22MPa, further preferably 14-18MPa.

10. Full-dull fine denier polyamide 56 fully drawn yarn according to claim 2 characterized in that the melt pressure at the inlet of the spinning beam is not less than 9.0MPa, preferably not less than 10.0MPa, further preferably not less than 11.0MPa.

11. The full-dull fine denier polyamide 56 fully drawn yarn according to claim 2, wherein 2 pairs or more of drawing rolls, preferably 2 pairs of drawing rolls, are adopted for the drawing, i.e. the finished primary yarn is fed into a G1 drawing roll first, and then is subjected to drawing heat setting between a G2 drawing roll and a G1 drawing roll; and/or the number of the groups of groups,

the G1 draft roller speed is 2200-3800m/min, preferably 2500-3700m/min, more preferably 2800-3500m/min; and/or the number of the groups of groups,

the G2 draft roller speed is 4500-5500m/min, preferably 4600-5400m/min, more preferably 4700-5200m/min; and/or the number of the groups of groups,

the draft multiple is 1.25-2.5; and/or the number of the groups of groups,

the heat setting temperature is 140-175 ℃; and/or the number of the groups of groups,

the winding speed is more than or equal to 4500m/min.