阅读说明：本技术 一种聚酯工业丝短流程纺丝方法 (Short-process spinning method for polyester industrial yarn ) 是由 张玉梅 陈康 黄瑶 王彤 郁秀峰 邵义伟 陈瑞 于 2021-06-25 设计创作，主要内容包括：本发明涉及一种聚酯工业丝短流程纺丝方法,向聚酯熔体中引入改性聚四氟乙烯后,按聚酯工业丝的加工工艺进行纺丝；聚酯为聚对苯二甲酸乙二醇酯,聚酯熔体的特性粘度为0.95～1.05dL/g；改性聚四氟乙烯为表面含有酯基的聚四氟乙烯纳米粒子；表面含有酯基的聚四氟乙烯纳米粒子的平均粒径不超过600nm,酯基的质量百分数为10～100ppm；聚酯工业丝的加工工艺参数包括：一辊速度2000～3000m/min,后拉伸级数2,后拉伸倍率1.2～2.5,喷头拉伸比300～500；最终制得的聚酯工业丝中改性聚四氟乙烯的含量不超过0.5wt％,聚酯工业丝的断裂强度≥7.8cN/dtex,初始模量≥90cN/dtex。本方法利用改性聚四氟乙烯纳米粉体极低的摩擦系数,减小聚酯熔体分子链之间的摩擦力,在喷头拉伸比和速度大大增加的情况下,减少微观的缠结。(The invention relates to a short-process spinning method of polyester industrial yarn, which comprises the steps of introducing modified polytetrafluoroethylene into a polyester melt, and spinning according to the processing technology of the polyester industrial yarn; the polyester is polyethylene glycol terephthalate, and the intrinsic viscosity of the polyester melt is 0.95-1.05 dL/g; the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the average particle size of the polytetrafluoroethylene nanoparticles with ester groups on the surfaces is not more than 600nm, and the mass percentage of the ester groups is 10-100 ppm; the processing parameters of the polyester industrial yarn comprise: the first roller speed is 2000-3000 m/min, the rear stretching stage number is 2, the rear stretching multiplying power is 1.2-2.5, and the spray head stretching ratio is 300-500; the content of the modified polytetrafluoroethylene in the finally prepared polyester industrial yarn is not more than 0.5 wt%, the breaking strength of the polyester industrial yarn is not less than 7.8cN/dtex, and the initial modulus is not less than 90 cN/dtex. The method utilizes the extremely low friction coefficient of the modified polytetrafluoroethylene nano powder to reduce the friction force between the molecular chains of the polyester melt, and reduces the microscopic entanglement under the condition that the stretching ratio and the speed of the spray head are greatly increased.)

1. A polyester industrial yarn short-process spinning method is characterized in that modified polytetrafluoroethylene is introduced into a polyester melt, and then spinning is carried out according to the processing technology of the polyester industrial yarn;

the polyester is polyethylene glycol terephthalate, and the intrinsic viscosity of the polyester melt is 0.95-1.05 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the average particle size of the polytetrafluoroethylene nanoparticles with ester groups on the surfaces is not more than 600nm, and the mass percentage of the ester groups is 10-100 ppm;

the processing parameters of the polyester industrial yarn comprise: the first roller speed is 2000-3000 m/min, the rear stretching stage number is 2, the rear stretching multiplying power is 1.2-2.5, and the spray head stretching ratio is 300-500;

the content of the modified polytetrafluoroethylene in the finally prepared polyester industrial yarn is not more than 0.5 wt%, the breaking strength of the polyester industrial yarn is not less than 7.8cN/dtex, and the initial modulus is not less than 90 cN/dtex.

2. The polyester industrial yarn short-process spinning method according to claim 1, characterized in that the introduction process is as follows: and respectively metering the dried polyester chips and the dried modified polytetrafluoroethylene, mixing the polyester chips and the dried modified polytetrafluoroethylene according to the proportion required by the finally prepared polyester industrial yarn, and feeding the polyester industrial yarn into a screw for melting.

3. The polyester industrial yarn short-process spinning method according to claim 1, characterized in that the introduction process is as follows: respectively metering the dried polyester chips and the dried modified polytetrafluoroethylene to prepare modified polytetrafluoroethylene/polyester master batches, respectively metering the dried modified polytetrafluoroethylene/polyester master batches and the dried polyester chips, mixing the metered modified polytetrafluoroethylene/polyester master batches and the dried polyester master batches according to the proportion required by the finally prepared polyester industrial yarns, and feeding the mixture into a screw to be melted.

4. The polyester industrial yarn short-process spinning method according to claim 1, characterized in that the introduction process is as follows: and respectively metering the dried polyester chips and the dried modified polytetrafluoroethylene to prepare modified polytetrafluoroethylene/polyester master batches, melting the dried modified polytetrafluoroethylene/polyester master batches, and mixing the melted modified polytetrafluoroethylene/polyester master batches with the polyester melt according to the proportion required by the finally prepared polyester industrial yarn.

5. The polyester industrial yarn short-process spinning method according to claim 3 or 4, wherein the content of the modified polytetrafluoroethylene in the modified polytetrafluoroethylene/polyester master batch is 10-20 wt%.

6. The polyester industrial yarn short-process spinning method according to claim 1, wherein the average particle diameter of the ester group-containing polytetrafluoroethylene nanoparticles is 300-500 nm.

7. The polyester industrial yarn short-process spinning method according to claim 1, wherein the polyester industrial yarn processing process comprises the following steps: melting → conveying → metering → extruding → solidifying → stretching → shaping → winding.

8. The polyester industrial yarn short-process spinning method according to claim 7, wherein the processing parameters of the polyester industrial yarn further comprise: the melting temperature is 290-310 ℃, the conveying temperature is 290-300 ℃, the conveying pressure is 90-300 bar, the conveying speed is 0.5-1.5 m/min, the extrusion temperature is 280-300 ℃, the cooling temperature is 18-24 ℃, the temperature of a first roller is 125-140 ℃, the temperature of a second roller is 200-240 ℃, the winding speed is 3600-5000 m/min, the pressure of the component is 16-25 MPa, and the service cycle of the component is 40-45 days.

9. The polyester industrial yarn short-process spinning method according to claim 1, wherein the content of the modified polytetrafluoroethylene in the finally prepared polyester industrial yarn is 0.01-0.05 wt%.

10. The short-process spinning method of the polyester industrial yarn as claimed in claim 1, wherein the filament number of the finally prepared polyester industrial yarn is 3-10 dtex, and the elongation at break is 10.0% -20.0%.

Technical Field

The invention belongs to the technical field of polyester industrial yarns, and relates to a short-process spinning method of polyester industrial yarns.

Background

The polyester industrial yarn has the advantages of mature processing technology, environmental protection, flexibility and strength, is praised as a high-performance fiber with the highest cost performance, and is widely applied to various fields such as engineering construction, transportation, aerospace, military protection and the like.

The preparation of the polyester industrial yarn adopts high molecular weight polyester to perform lower-speed extrusion and lower-multiple nozzle drawing (relative to the high-speed spinning of civil yarn), and then the multi-stage multi-time hot drawing is performed to generate the structural characteristics of high crystallization and high orientation, thereby obtaining the performances of high strength, high modulus and high dimensional stability. The existing polyester industrial yarn technology has long routes, the yarn is cooled and then heated, and the energy consumption is greatly increased. The reason why the high-speed spinning process route of the civil yarn is not suitable for preparing the high-strength industrial yarn is that the polyester melt is cooled after being extruded and stretched at a high speed, and meanwhile, local entanglement points are not opened in time to generate orientation unevenness, high stress under the high-speed condition induces crystallization, and a micro heterogeneous structure of the fiber is increased, so that the characteristics that the crystallization size is small, the thickness of a lamellar crystal is small, the size of an amorphous area is increased although the crystallinity is high, the strength and the modulus are not improved, and the dimensional stability is poor are shown on the final fiber.

Therefore, the research on a method for reducing the microstructure defects in the high-speed polyester spinning process and further preparing the industrial yarn is of great significance.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provide a short-process spinning method for polyester industrial yarns.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a polyester industrial yarn short-process spinning method, after introducing the modified polytetrafluoroethylene into polyester melt, carry on the spinning according to the processing technology of the polyester industrial yarn;

the polyester is polyethylene glycol terephthalate, and the intrinsic viscosity of the polyester melt is 0.95-1.05 dL/g; the polyester melt is free of micromolecular flow promoters;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the average particle size of the polytetrafluoroethylene nanoparticles with ester groups on the surfaces is not more than 600nm (the average particle size of the polytetrafluoroethylene nanoparticles with ester groups on the surfaces is not more than 600nm, so that defects in fibers can be avoided, and further, the fiber strength unevenness is avoided to be large), the mass percentage of the ester groups is 10-100 ppm (when the content of the ester groups is less than 10ppm, the compatibility of the added ester groups with a polyester system is poor, when the content of the ester groups is more than 100ppm, the compatibility of the nanoparticles and the polyester is improved, but the requirement on the modification process of the polytetrafluoroethylene nanoparticles is strict, and batch production cannot be realized);

the processing parameters of the polyester industrial yarn comprise: the speed of one roller is 2000-3000 m/min (generally 440-650 m/min in the prior art), the post-stretching stage number is 2 (generally 4-5 in the prior art) (the spinning flow is shortened by reducing the post-stretching stage number, which can be called short-flow spinning), the post-stretching multiplying power is 1.2-2.5 (generally 5.5-6.5 in the prior art), and the nozzle stretching ratio is 300-500 (generally 30-300 in the prior art);

the content of the modified polytetrafluoroethylene in the finally prepared polyester industrial yarn is not more than 0.5 wt% so as to ensure that the modified polytetrafluoroethylene is distributed in an amorphous region of polyester, the crystallization of the polyester is not influenced, the industrial yarn has enough mechanical properties, and the breaking strength of the polyester industrial yarn is not less than 7.8cN/dtex and the initial modulus is not less than 90cN/dtex measured according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

In the prior art, the polyester industrial yarn cannot be spun at high speed, because orientation of a high molecular chain segment is generated in the cooling and high-speed stretching processes after the polyester melt is extruded, local kinks are not opened in time to generate uneven orientation, in addition, high stress under the high-speed condition induces crystallization to generate, and the microscopic heterogeneous structure of the fiber is increased, so that the characteristics that the crystallization size is small, the thickness of a lamellar crystal is small, the size of an amorphous area is increased although the crystallinity is high on the final fiber are shown, the improvement of the strength and the modulus is not facilitated, and the dimensional stability is poor. The invention solves the problem by introducing the modified polytetrafluoroethylene into the polyester melt, the friction coefficient of the modified polytetrafluoroethylene is extremely low, the entanglement and the friction force among molecular chains of the high molecular weight polyester can be reduced, the microstructure defect in the high-speed spinning process is reduced, the high-speed spinning process goal of reducing the thermal stretching series and multiplying power is achieved, finally, the one-roller speed of the invention is increased, the post-stretching series and multiplying power are reduced, the energy consumption is reduced, the short-process spinning of the polyester industrial yarn is realized, and the strength and the modulus of the finally prepared product are higher.

As a preferred technical scheme:

the polyester industrial yarn short-process spinning method comprises the following steps: and (3) respectively metering the dried polyester chips (with the water content of 20-100 ppm) and the dried modified polytetrafluoroethylene (with the water content of 20-100 ppm), mixing the polyester chips and the dried modified polytetrafluoroethylene according to the proportion required by the finally prepared polyester industrial yarn, and feeding the polyester industrial yarn into a screw for melting.

The polyester industrial yarn short-process spinning method can also be introduced in the following steps: and (2) respectively metering the dried polyester chips (with the water content of 20-100 ppm) and the dried modified polytetrafluoroethylene (with the water content of 20-100 ppm), preparing modified polytetrafluoroethylene/polyester master batches, respectively metering the dried modified polytetrafluoroethylene/polyester master batches (with the water content of 20-100 ppm) and the dried polyester chips (with the water content of 20-100 ppm), mixing according to the proportion required by the finally prepared polyester industrial yarn, and feeding the mixture into a screw for melting.

The polyester industrial yarn short-process spinning method can also be introduced in the following steps: and (2) respectively metering the dried polyester chips (with the water content of 20-100 ppm) and the dried modified polytetrafluoroethylene (with the water content of 20-100 ppm), preparing modified polytetrafluoroethylene/polyester master batches, melting the dried modified polytetrafluoroethylene/polyester master batches (with the water content of 20-100 ppm), and mixing the melted polyester with the polyester melt according to the proportion required by the finally prepared polyester industrial yarn.

According to the polyester industrial yarn short-process spinning method, the content of the modified polytetrafluoroethylene in the modified polytetrafluoroethylene/polyester master batch is 10-20 wt%.

According to the polyester industrial yarn short-process spinning method, the average particle diameter of the ester-group-containing polytetrafluoroethylene nanoparticles is 300-500 nm.

The polyester industrial yarn short-process spinning method comprises the following processing technological processes: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding; the spinning adopts a conventional spinning assembly; the surfaces of the melt conveying pipeline and the spinning assembly are not coated.

The polyester industrial yarn short-process spinning method further comprises the following processing technological parameters: the melting temperature is 290-310 ℃ (generally 290-310 ℃ in the prior art), the conveying temperature is 290-300 ℃ (generally 290-300 ℃ in the prior art), the conveying pressure is 90-300 bar (generally 90-300 bar in the prior art), the conveying speed is 0.5-1.5 m/min (generally 0.5-1.5 m/min in the prior art), the extrusion temperature is 280-300 ℃ (generally 280-300 ℃ in the prior art), the cooling temperature is 18-24 ℃ (generally 18-24 ℃ in the prior art), the one-roller temperature is 125-140 ℃ (generally 75-85 ℃ in the prior art), the two-roller temperature is 200-240 ℃ (generally 90-100 ℃ in the prior art), the winding speed is 0-5000 m/min (generally 2600-3600 m/min in the prior art), the assembly pressure is 16-25 MPa (generally 16-25 MPa in the prior art), and the assembly service cycle is 40-45 days (generally 40-45 days in the prior art); according to the invention, because the modified polytetrafluoroethylene nano particles with low friction coefficient are added into the melt, the mutual entanglement acting force of molecular chains in the melt is reduced, so that the spinning speed of one roller can be increased in spinning, and the spinning process flow is shortened.

According to the polyester industrial yarn short-process spinning method, the content of the modified polytetrafluoroethylene in the finally prepared polyester industrial yarn is 0.01-0.05 wt%.

According to the polyester industrial yarn short-process spinning method, the filament number of the finally prepared polyester industrial yarn is 3-10 dtex, and the elongation at break is 10.0-20.0% measured according to a standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

The principle of the invention is as follows:

in the prior art, in the cooling and high-speed stretching processes after extrusion of a high-viscosity polyester melt, except for the orientation of a high-molecular chain segment, local entanglement points are always not opened in time to generate uneven orientation, in addition, high stress under a high-speed condition induces crystallization, and the microscopic heterogeneous structure of the fiber is increased, so that the characteristics that the final fiber has high crystallinity, but small crystal size, small lamella thickness, increased size of an amorphous area, unfavorable improvement of strength and modulus and poor size stability are realized, and therefore, the polyester industrial yarn cannot be directly spun at high speed and must be subjected to multiple times of drafting. The modified polytetrafluoroethylene with the average particle size not more than 600nm is introduced into the high-viscosity polyester melt with the particle size of 0.95-1.05 dL/g, the friction coefficient of the modified polytetrafluoroethylene is extremely low, entanglement and friction among molecular chains of high-molecular-weight polyester can be reduced, microstructure defects in the high-speed spinning process are reduced, and the high-speed spinning process goal of reducing the thermal stretching grade and the multiplying power is achieved.

Has the advantages that:

(1) according to the short-process spinning method for the polyester industrial yarn, the nano modified polytetrafluoroethylene is added into the high-molecular-weight polyester, and the characteristics that the friction coefficient of the polytetrafluoroethylene is extremely low are utilized, so that the entanglement and the friction force among molecular chains of the high-molecular-weight polyester are reduced, the defect of a microstructure in the high-speed spinning process is reduced, the high-speed spinning process goal of reducing the thermal stretching grade and the multiplying power is achieved, the energy consumption is reduced, the short-process spinning of the polyester industrial yarn is realized, and the strength and the modulus of a finally prepared product are high;

(2) according to the short-flow spinning method for the polyester industrial yarn, the speed of one roller is increased, the number of post-stretching stages and the multiplying power are reduced, and the energy consumption is reduced.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

The intrinsic viscosity of the polyester melt in the following examples was measured by: adopting phenol/1, 1,2, 2-tetrachloroethane (mass ratio is 50:50) as a solvent, fully dissolving a fully dried and weighed experimental sample at 90-100 ℃ to prepare a 0.5g/dL solution, naturally cooling the solution to room temperature, measuring by using an Ubbelohde viscometer with the diameter of 0.8mm, keeping the constant temperature water bath temperature at (25 +/-0.05) DEG C, recording the flowing time of the pure solvent and the solution, and calculating the intrinsic viscosity by a one-point method, wherein the intrinsic viscosity is calculated according to the following formula:

in the formula: eta_spTo increase specific viscosity (. eta.)_sp＝t₁/t₀-1，t₁Time of solution flow, t₀Time to pure solvent run-off); [ eta ]]Is intrinsic viscosity, dL/g; c is the solution concentration, g/dL.

Example 1

The preparation method of the polytetrafluoroethylene nano-particles with ester groups on the surfaces comprises the following specific steps:

preparing chlorobenzene solution with methacrylate volume content of 37.5%, and mixing with polytetrafluoroethylene nano-powder (polymerization degree of 5 × 10)³Average particle size of 300nm) was placed in the solution (mass ratio of polytetrafluoroethylene nano-powder to the solution was 1:2), and plasma treatment was performed in an argon atmosphere for 100 seconds to cause chemical graft polymerization of methacrylate on the surface of the polytetrafluoroethylene nano-powder to form a layer of graft polymer on the surface, thereby obtaining polytetrafluoroethylene nanoparticles having an average particle size of 300nm and an ester group content of 20ppm and containing ester groups on the surface.

The structural formula of the polytetrafluoroethylene nano particles containing ester groups on the surface is shown as a formula (I), wherein,

example 2

The preparation method of the polytetrafluoroethylene nano-particles with ester groups on the surfaces comprises the following specific steps:

preparing chlorobenzene solution with ethyl methacrylate volume content of 37.5%, mixing with polytetrafluoroethylene nano powder (polymerization degree of 5 × 10)³Average particle size of 350nm) was placed in the solution (mass ratio of polytetrafluoroethylene nano-powder to the solution was 1:2), and treated with plasma in an argon atmosphere for 150 seconds to cause ethyl methacrylate to undergo chemical graft polymerization on the surface of the polytetrafluoroethylene nano-powder to form a layer of graft polymer on the surface, thereby obtaining polytetrafluoroethylene nanoparticles having an average particle size of 350nm and an ester group content of 30ppm and containing ester groups on the surface.

The structural formula of the polytetrafluoroethylene nano particles containing ester groups on the surface is shown as a formula (I), wherein,

example 3

The preparation method of the polytetrafluoroethylene nano-particles with ester groups on the surfaces comprises the following specific steps:

preparing chlorobenzene solution with propyl methacrylate volume content of 37.5%, mixing with polytetrafluoroethylene nano powder (polymerization degree of 5 × 10)³And the average particle diameter is 400nm) is placed in the solution (the mass ratio of the polytetrafluoroethylene nano powder to the solution is 1:2), plasma treatment is carried out in an argon atmosphere for 200s, propyl methacrylate is subjected to chemical graft polymerization on the surface of the polytetrafluoroethylene nano powder, a layer of graft polymer is formed on the surface, and the polytetrafluoroethylene nano particles with the average particle diameter of 400nm and the ester group content of 40ppm and containing the ester groups on the surface are obtained.

The structural formula of the polytetrafluoroethylene nano particles containing ester groups on the surface is shown as a formula (I), wherein,

example 4

The preparation method of the polytetrafluoroethylene nano-particles with ester groups on the surfaces comprises the following specific steps:

preparing chlorobenzene solution with butyl methacrylate volume content of 37.5%, and mixing with polytetrafluoroethylene nano-powder (polymerization degree of 5 × 10)³Average particle size of 450nm) was placed in the solution (mass ratio of polytetrafluoroethylene nano-powder to the solution was 1:2), and treated with plasma in an argon atmosphere for 300 seconds to cause butyl methacrylate to undergo chemical graft polymerization on the surface of the polytetrafluoroethylene nano-powder to form a layer of graft polymer on the surface, thereby obtaining polytetrafluoroethylene nanoparticles having an average particle size of 450nm and an ester group content of 60ppm and containing ester groups on the surface.

The structural formula of the polytetrafluoroethylene nano particles containing ester groups on the surface is shown as a formula (I), wherein,

example 5

The preparation method of the polytetrafluoroethylene nano-particles with ester groups on the surfaces comprises the following specific steps:

preparing chlorobenzene solution with volume content of amyl methacrylate of 37.5%, and mixing with polytetrafluoroethylene nano-powder (polymerization degree of 5 × 10)³Average particle size of 450nm) was placed in the solution (mass ratio of polytetrafluoroethylene nano-powder to the solution was 1:2), and treated with plasma in an argon atmosphere for 500 seconds to cause chemical graft polymerization of amyl methacrylate on the surface of the polytetrafluoroethylene nano-powder to form a layer of graft polymer on the surface, thereby obtaining polytetrafluoroethylene nanoparticles having an average particle size of 450nm and an ester group content of 80ppm and containing ester groups on the surface.

The structural formula of the polytetrafluoroethylene nano particles containing ester groups on the surface is shown as a formula (I), wherein,

example 6

The preparation method of the polytetrafluoroethylene nano-particles with ester groups on the surfaces comprises the following specific steps:

preparing chlorobenzene solution with hexyl methacrylate volume content of 37.5%, and mixing with polytetrafluoroethylene nano powder (polymerization degree of 5 × 10)³Average particle size of 400nm) was placed in the solution (mass ratio of polytetrafluoroethylene nano-powder to the solution was 1:2), and treated with plasma in an argon atmosphere for 600 seconds to cause chemical graft polymerization of hexyl methacrylate on the surface of the polytetrafluoroethylene nano-powder to form a layer of graft polymer on the surface, thereby obtaining polytetrafluoroethylene nanoparticles having an average particle size of 400nm and an ester group content of 100ppm and containing ester groups on the surface.

The structural formula of the polytetrafluoroethylene nano particles containing ester groups on the surface is shown as a formula (I), wherein,

example 7

A short-process spinning method of polyester industrial yarns comprises the following specific steps:

(1) preparing raw materials;

the polyester is polyethylene terephthalate, and the intrinsic viscosity of the polyester melt is 1.05 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the polytetrafluoroethylene nanoparticles with ester groups on the surfaces are prepared by the method of example 1;

(2) after introducing modified polytetrafluoroethylene into the polyester melt, spinning according to the processing technology of polyester industrial yarns;

the introduction process is as follows: respectively metering the dried polyester chips (the water content is 50ppm after drying) and the dried modified polytetrafluoroethylene (the water content is 30ppm after drying), mixing according to the proportion required by the finally prepared polyester industrial yarn, and feeding the mixture into a screw for melting.

The processing process flow of the polyester industrial yarn is as follows: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding;

the processing parameters of the polyester industrial yarn are as follows: the melting temperature is 290 ℃, the conveying pressure is 90bar, the conveying speed is 0.5m/min, the extrusion temperature is 280 ℃, the cooling temperature is 18 ℃, the first roller temperature is 125 ℃, the two roller temperature is 200 ℃, the first roller speed is 2000m/min, the post-stretching stage number is 2, the post-stretching multiplying power is 2.5, the nozzle stretching ratio is 300, the winding speed is 5000m/min, the assembly pressure is 16MPa, and the assembly service cycle is 45 days.

The filament number of the finally prepared polyester industrial yarn is 10dtex, the content of the modified polytetrafluoroethylene in the polyester industrial yarn is 0.01 wt%, and the polyester industrial yarn has the breaking strength of 8.8cN/dtex, the elongation at break of 10% and the initial modulus of 110cN/dtex, which are measured according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

Comparative example 1

A process for spinning polyester industrial yarn substantially as in example 7 except that no modified polytetrafluoroethylene was introduced into the polyester melt, the speed of one roll was 650m/min (no further increase in filament tension, filament bundle instability, etc. was found in the test), the post-draw stage was 5 (no further decrease in filament strength and modulus, too low dimensional stability, etc. was found in the test), the post-draw ratio was 5.5 (no further decrease in filament strength and modulus, too low dimensional stability, etc. was found in the test), and the jet draw ratio was 250 (no further increase in filament tension, filament bundle instability, etc. was found in the test).

The filament number of the finally prepared polyester industrial yarn is 10dtex, and the breaking strength is 7.6cN/dtex, the elongation at break is 12% and the initial modulus is 88cN/dtex according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

Compared with example 7, the elongation at break of comparative example 1 is larger than that of example 7, but the breaking strength is smaller because modified polytetrafluoroethylene powder is not added in comparative example 1, entanglement among molecular chains cannot be reduced, local entanglement points cannot be opened in time to generate orientation nonuniformity in the processes of cooling and high-speed stretching after extrusion of polyester melt, high stress under high-speed conditions induces crystallization, and a micro heterogeneous structure of fiber is increased, so that the molecular chains cannot be pulled apart to form a highly oriented structure in the process of subsequent stretching, therefore, the breaking strength is far lower than that of example 7.

Example 8

A short-process spinning method of polyester industrial yarns comprises the following specific steps:

(1) preparing raw materials;

the polyester is polyethylene terephthalate, and the intrinsic viscosity of the polyester melt is 0.95 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the polytetrafluoroethylene nanoparticles with ester groups on the surfaces are prepared by the method of example 2;

(2) after introducing modified polytetrafluoroethylene into the polyester melt, spinning according to the processing technology of polyester industrial yarns;

the introduction process is as follows: respectively metering the dried polyester chips (the water content is 50ppm after drying) and the dried modified polytetrafluoroethylene (the water content is 30ppm after drying), mixing according to the proportion required by the finally prepared polyester industrial yarn, and feeding the mixture into a screw for melting.

The processing process flow of the polyester industrial yarn is as follows: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding;

the processing parameters of the polyester industrial yarn are as follows: the melting temperature is 294 ℃, the conveying temperature is 292 ℃, the conveying pressure is 120bar, the conveying speed is 0.7m/min, the extrusion temperature is 284 ℃, the cooling temperature is 19 ℃, the first roller temperature is 127 ℃, the second roller temperature is 205 ℃, the first roller speed is 2200m/min, the post-stretching stage number is 2, the post-stretching ratio is 2.2, the nozzle stretching ratio is 330, the winding speed is 4840m/min, the assembly pressure is 17MPa, and the assembly service cycle is 44 days.

The filament number of the finally prepared polyester industrial yarn is 8dtex, the content of the modified polytetrafluoroethylene in the polyester industrial yarn is 0.02 wt%, and the polyester industrial yarn has the breaking strength of 8.6cN/dtex, the elongation at break of 12% and the initial modulus of 108cN/dtex according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

Example 9

A short-process spinning method of polyester industrial yarns comprises the following specific steps:

(1) preparing raw materials;

the polyester is polyethylene terephthalate, and the intrinsic viscosity of the polyester melt is 0.97 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the polytetrafluoroethylene nanoparticles with ester groups on the surfaces are prepared by the method of example 3;

(2) after introducing modified polytetrafluoroethylene into the polyester melt, spinning according to the processing technology of polyester industrial yarns;

the introduction process is as follows: respectively metering dried polyester chips (with the water content of 50ppm after drying) and dried modified polytetrafluoroethylene (with the water content of 30ppm after drying), preparing modified polytetrafluoroethylene/polyester master batches, respectively metering the dried modified polytetrafluoroethylene/polyester master batches and the dried polyester chips, mixing according to the proportion required by the finally prepared polyester industrial yarns, and feeding the polyester industrial yarns into a screw for melting; the content of the modified polytetrafluoroethylene in the modified polytetrafluoroethylene/polyester master batch is 10 wt%;

the processing process flow of the polyester industrial yarn is as follows: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding;

the processing parameters of the polyester industrial yarn are as follows: the melting temperature is 298 ℃, the conveying temperature is 294 ℃, the conveying pressure is 150bar, the conveying speed is 0.9m/min, the extrusion temperature is 288 ℃, the cooling temperature is 20 ℃, the first roller temperature is 130 ℃, the two roller temperature is 210 ℃, the first roller speed is 2400m/min, the post-stretching stage number is 2, the post-stretching ratio is 2, the nozzle stretching ratio is 360, the winding speed is 4800m/min, the assembly pressure is 18MPa, and the assembly service cycle is 44 days.

The filament number of the finally prepared polyester industrial yarn is 7dtex, the content of the modified polytetrafluoroethylene in the polyester industrial yarn is 0.02 wt%, and the polyester industrial yarn has the breaking strength of 8.4cN/dtex, the elongation at break of 14% and the initial modulus of 105cN/dtex according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

Example 10

A short-process spinning method of polyester industrial yarns comprises the following specific steps:

(1) preparing raw materials;

the polyester is polyethylene terephthalate, and the intrinsic viscosity of the polyester melt is 0.99 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the polytetrafluoroethylene nanoparticles with ester groups on the surfaces are prepared by the method of example 4;

(2) after introducing modified polytetrafluoroethylene into the polyester melt, spinning according to the processing technology of polyester industrial yarns;

the introduction process is as follows: respectively metering dried polyester chips (with the water content of 50ppm after drying) and dried modified polytetrafluoroethylene (with the water content of 30ppm after drying), preparing modified polytetrafluoroethylene/polyester master batches, respectively metering the dried modified polytetrafluoroethylene/polyester master batches and the dried polyester chips, mixing according to the proportion required by the finally prepared polyester industrial yarns, and feeding the polyester industrial yarns into a screw for melting; the content of the modified polytetrafluoroethylene in the modified polytetrafluoroethylene/polyester master batch is 15 wt%;

the processing process flow of the polyester industrial yarn is as follows: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding;

the processing parameters of the polyester industrial yarn are as follows: the melting temperature is 302 ℃, the conveying temperature is 296 ℃, the conveying pressure is 190bar, the conveying speed is 1.1m/min, the extrusion temperature is 292 ℃, the cooling temperature is 21 ℃, the one-roller temperature is 133 ℃, the two-roller temperature is 220 ℃, the one-roller speed is 2500m/min, the post-stretching stage number is 2, the post-stretching ratio is 1.8, the nozzle stretching ratio is 390, the winding speed is 4500m/min, the assembly pressure is 19MPa, and the assembly service cycle is 43 days.

The filament number of the finally prepared polyester industrial yarn is 6dtex, the content of the modified polytetrafluoroethylene in the polyester industrial yarn is 0.03 wt%, and the polyester industrial yarn has the breaking strength of 8.2cN/dtex, the elongation at break of 16% and the initial modulus of 102cN/dtex according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

Example 11

A short-process spinning method of polyester industrial yarns comprises the following specific steps:

(1) preparing raw materials;

the polyester is polyethylene terephthalate, and the intrinsic viscosity of the polyester melt is 1.01 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the polytetrafluoroethylene nanoparticles with ester groups on the surfaces are prepared by the method of example 5;

(2) after introducing modified polytetrafluoroethylene into the polyester melt, spinning according to the processing technology of polyester industrial yarns;

the introduction process is as follows: respectively measuring the dried polyester slices (the water content is 50ppm after drying) and the dried modified polytetrafluoroethylene (the water content is 30ppm after drying), preparing modified polytetrafluoroethylene/polyester master batches, melting the dried modified polytetrafluoroethylene/polyester master batches, and mixing the melted modified polytetrafluoroethylene/polyester master batches with polyester melt according to the proportion required by the finally prepared polyester industrial yarn; the content of the modified polytetrafluoroethylene in the modified polytetrafluoroethylene/polyester master batch is 10 wt%;

the processing process flow of the polyester industrial yarn is as follows: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding;

the processing parameters of the polyester industrial yarn are as follows: the melting temperature is 305 ℃, the conveying temperature is 298 ℃, the conveying pressure is 220bar, the conveying speed is 1.3m/min, the extrusion temperature is 294 ℃, the cooling temperature is 22 ℃, the one-roller temperature is 135 ℃, the two-roller temperature is 230 ℃, the one-roller speed is 2600m/min, the post-stretching stage number is 2, the post-stretching ratio is 1.6, the nozzle stretching ratio is 420, the winding speed is 4160m/min, the assembly pressure is 22MPa, and the assembly service cycle is 42 days.

The filament number of the finally prepared polyester industrial yarn is 5dtex, the content of the modified polytetrafluoroethylene in the polyester industrial yarn is 0.04 wt%, and the polyester industrial yarn has the breaking strength of 8cN/dtex, the elongation at break of 17% and the initial modulus of 98cN/dtex, which are measured according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

Example 12

A short-process spinning method of polyester industrial yarns comprises the following specific steps:

(1) preparing raw materials;

the polyester is polyethylene terephthalate, and the intrinsic viscosity of the polyester melt is 1.03 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the polytetrafluoroethylene nanoparticles with ester groups on the surfaces are prepared by the method of example 5;

(2) after introducing modified polytetrafluoroethylene into the polyester melt, spinning according to the processing technology of polyester industrial yarns;

the introduction process is as follows: respectively measuring the dried polyester slices (the water content is 50ppm after drying) and the dried modified polytetrafluoroethylene (the water content is 30ppm after drying), preparing modified polytetrafluoroethylene/polyester master batches, melting the dried modified polytetrafluoroethylene/polyester master batches, and mixing the melted modified polytetrafluoroethylene/polyester master batches with polyester melt according to the proportion required by the finally prepared polyester industrial yarn; the content of the modified polytetrafluoroethylene in the modified polytetrafluoroethylene/polyester master batch is 17 wt%;

the processing process flow of the polyester industrial yarn is as follows: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding;

the processing parameters of the polyester industrial yarn are as follows: the melting temperature is 307 ℃, the conveying temperature is 299 ℃, the conveying pressure is 260bar, the conveying speed is 1.4m/min, the extrusion temperature is 298 ℃, the cooling temperature is 23 ℃, the first roller temperature is 137 ℃, the second roller temperature is 235 ℃, the first roller speed is 2700m/min, the post-stretching stage number is 2, the post-stretching multiplying power is 1.4, the nozzle stretching ratio is 470, the winding speed is 3780m/min, the assembly pressure is 24MPa, and the assembly service cycle is 41 days.

The filament number of the finally prepared polyester industrial yarn is 4dtex, the content of the modified polytetrafluoroethylene in the polyester industrial yarn is 0.05 wt%, and the polyester industrial yarn has the breaking strength of 7.9cN/dtex, the elongation at break of 19% and the initial modulus of 95cN/dtex according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.

Example 13

A short-process spinning method of polyester industrial yarns comprises the following specific steps:

(1) preparing raw materials;

the polyester is polyethylene terephthalate, and the intrinsic viscosity of the polyester melt is 1.04 dL/g;

the modified polytetrafluoroethylene is polytetrafluoroethylene nano-particles with ester groups on the surface; the polytetrafluoroethylene nanoparticles with ester groups on the surfaces are prepared by the method of example 6;

(2) after introducing modified polytetrafluoroethylene into the polyester melt, spinning according to the processing technology of polyester industrial yarns;

the introduction process is as follows: respectively measuring the dried polyester slices (the water content is 50ppm after drying) and the dried modified polytetrafluoroethylene (the water content is 30ppm after drying), preparing modified polytetrafluoroethylene/polyester master batches, melting the dried modified polytetrafluoroethylene/polyester master batches, and mixing the melted modified polytetrafluoroethylene/polyester master batches with polyester melt according to the proportion required by the finally prepared polyester industrial yarn; the content of the modified polytetrafluoroethylene in the modified polytetrafluoroethylene/polyester master batch is 20 wt%;

the processing process flow of the polyester industrial yarn is as follows: melting → conveying → metering → extruding → solidifying → stretching → sizing → winding;

the processing parameters of the polyester industrial yarn are as follows: the melting temperature is 310 ℃, the conveying temperature is 300 ℃, the conveying pressure is 300bar, the conveying speed is 1.5m/min, the extrusion temperature is 300 ℃, the cooling temperature is 24 ℃, the first roller temperature is 140 ℃, the second roller temperature is 240 ℃, the first roller speed is 3000m/min, the post-stretching stage number is 2, the post-stretching ratio is 1.2, the nozzle stretching ratio is 500, the winding speed is 3600m/min, the assembly pressure is 25MPa, and the assembly service cycle is 40 days.

The filament number of the finally prepared polyester industrial yarn is 3dtex, the content of the modified polytetrafluoroethylene in the polyester industrial yarn is 0.05 wt%, and the polyester industrial yarn has the breaking strength of 7.8cN/dtex, the elongation at break of 20% and the initial modulus of 90cN/dtex according to the standard test method of GB/T14344-2008 chemical fiber filament tensile property experimental method.