阅读说明：本技术 一种废旧聚酯再生熔体直纺高强涤纶工业丝生产方法 (Production method of waste polyester regenerated melt direct-spinning high-strength polyester industrial yarn ) 是由 马建平 陈文兴 金亮 陈世昌 戴锁洪 张先明 王海波 王金香 孔令训 于 2021-08-31 设计创作，主要内容包括：本发明涉及一种废旧聚酯再生熔体直纺高强涤纶工业丝生产方法,它包括(1)将废旧聚酯进行分拣破断,(2)将处理后的物料进行螺杆熔融,(3)将熔融后的物料粗滤后,进入立式、无动力、竖管外降膜液相增黏反应器,(4)将经过步骤(3)处理后的物料精滤后,经水下切粒机造粒形成高黏度再生聚酯切片或通过熔体管道输送直接进行熔体直接纺丝,制得再生涤纶工业长丝。本发明能够实现再生聚酯脱挥、聚合增黏一体化,特性黏度可高效提升达到工业丝级,填补了熔体直纺高强度再生聚酯工业丝制备的行业空白,采用多点柔性在线添加,可以形成原位有色再生聚酯工业丝和阻燃、抗菌等多功能复合差别化再生聚酯工业丝,进一步提高废旧聚酯再生制品附加值。(The invention relates to a production method of waste polyester regenerated melt direct spinning high-strength polyester industrial filaments, which comprises the steps of (1) sorting and breaking waste polyester, (2) carrying out screw rod melting on the treated material, (3) carrying out rough filtration on the melted material, then feeding the coarse filtration into a vertical, unpowered and vertical pipe outer falling film liquid phase tackifying reactor, and (4) carrying out fine filtration on the material treated in the step (3), and then carrying out granulation by an underwater granulator to form high-viscosity regenerated polyester chips or directly carrying out melt direct spinning through melt pipeline conveying to obtain the regenerated polyester industrial filaments. The invention can realize the integration of devolatilization, polymerization and viscosity increasing of the regenerated polyester, the intrinsic viscosity can be efficiently improved to reach the industrial yarn level, the blank of the industry for preparing the melt direct spinning high-strength regenerated polyester industrial yarn is filled, the multi-point flexible online addition is adopted, the in-situ colored regenerated polyester industrial yarn and the multifunctional composite differential regenerated polyester industrial yarn with flame retardance, antibacterial property and the like can be formed, and the added value of the waste polyester regenerated product is further improved.)

1. A production method of waste polyester regenerated melt direct-spinning high-strength polyester industrial yarns is characterized by comprising the following steps: which comprises the following steps of,

(1) the waste polyester is treated by a sorting and breaking device (1) to obtain a broken waste polyester raw material with consistent appearance and shape and the length of not more than 80 cm;

(2) performing screw rod melting on the material treated in the step (1), and performing multi-stage vacuum pumping treatment through a vacuum system (2) when the screw rod is melted to remove moisture and low-molecular volatile matters;

(3) after the material treated in the step (2) is subjected to coarse filtration, the material enters a vertical unpowered vertical-pipe external falling film liquid phase tackifying reactor (3) to increase the intrinsic viscosity value of the melt to 0.9-1.2 dl/g;

(4) and (4) after the material processed in the step (3) is subjected to precise filtration, granulating by an underwater granulator to obtain high-viscosity regenerated polyester chips or carrying out direct melt spinning by melt pipeline conveying to obtain the regenerated polyester industrial filament with the breaking strength of more than 8.0 cN/dtex.

2. The production method of the waste polyester regenerated melt direct-spun high-strength polyester industrial yarn according to claim 1, which is characterized by comprising the following steps of: performing densification treatment on the waste polyester after the step (1), and then performing vacuum screw melting in the step (2), wherein the densification treatment temperature is 230-255 ℃, and the bulk density of the densified broken polyester waste reaches 400kg/m³The above.

3. The production method of the waste polyester regenerated melt direct-spun high-strength polyester industrial yarn according to claim 1, which is characterized by comprising the following steps of: the screw melting comprises two stages of vacuum screws, wherein the first stage is a conveying screw (4) which is a single screw with vacuum degassing, a densification device is arranged above a feeding hole, after most of moisture of the materials is removed by softening and vacuum at the temperature of 260-280 ℃, the materials in a solid-melt mixed state enter a second stage of vacuum single screw or double screw (5) at stable feeding pressure, are extruded, melted, compressed and metered at the temperature of 280-320 ℃, and are further subjected to moisture removal and small molecular volatile matters through two arranged vacuum degassing holes; the two-stage vacuum screw vacuum degassing is connected with a vacuum system (2), the vacuum system (2) is a mechanical vacuum pump group, and the ultimate vacuum degree is less than 1000 Pa.

4. The production method of the waste polyester regenerated melt direct-spun high-strength polyester industrial yarn according to claim 1, which is characterized by comprising the following steps of: in the step (3), the falling film liquid phase tackifying reactor (3) adopts a vertical structure and does not have a mechanical stirring device, and materials in the reactor are completely transferred from a feeding end to a discharging end under the action of gravity; the regenerated polyester melt flows in a falling film mode outside the vertical pipe, the temperature of materials in the reactor is controlled to be 275-282 ℃, the pressure in the reactor is 0.01-0.04 MPa, and the residence time of the melt in the reactor is 30-60 min.

5. The production method of the waste polyester regenerated melt direct-spun high-strength polyester industrial yarn according to claim 1, which is characterized by comprising the following steps of: in the step (4), the melt direct spinning comprises the steps that the high-viscosity regenerated polyester melt output by a discharge booster pump is conveyed to a metering pump in a spinning box body through a melt pipeline, the metering pump accurately meters the high-viscosity regenerated polyester melt and then enters a spinning assembly (6), the high-viscosity regenerated polyester melt is extruded through a spinneret orifice of a spinneret plate in the spinning assembly (6) to form fibers, and the fibers are slowly cooled, air-cooled, oiled, pre-meshed, multi-stage stretch-formed and finally-meshed to be knotted and then are wound into the high-strength regenerated polyester industrial yarns at a high speed;

the booster pump and the melt pipeline are insulated by adopting a liquid phase heating medium, the temperature is 280-290 ℃, and the pressure of the booster pump is 12-24 MPa; the spinning manifold is insulated by gas phase heat medium at 290-310 ℃; the multistage stretching and shaping are carried out, wherein the stretching multiplying power is 4.0-6.2, the relaxation ratio is 3-12%, and the stretching and shaping temperature is 80-250 ℃.

6. The production method of the waste polyester regenerated melt direct-spun high-strength polyester industrial yarn according to claim 5, characterized by comprising the following steps: adding one or more functional additives such as a coloring agent, a flame retardant or an antibacterial agent into the screw rod melting step (2), the falling film liquid phase tackifying reactor (3) step (3) and the melt pipeline step (4), and preparing the regenerated high-strength industrial polyester filament with multiple composite functions in situ by using stock solution coloring as a basic function;

adding a colorant in the step (2), wherein the colorant comprises a toner, the toner comprises one or more of carbon black, iron oxide red, azo yellow and phthalocyanine blue, and the mass ratio of the toner to the polyester melt is 0.1-1%;

adding one or more functional additives such as a flame retardant and an antibacterial agent in the steps (3) and (4), wherein the flame retardant comprises one or more compounds such as diethyl aluminum hypophosphite, magnesium hydroxide, aluminum hydroxide and silicon, and the mass ratio of the flame retardant to the polyester melt is 0.5-5.0%; the antibacterial agent comprises one or more alloys of nano silver, nano copper and nano zinc, and the mass ratio of the antibacterial agent to the polyester melt is 0.1-0.5%.

7. The production method of the waste polyester regenerated melt direct-spun high-strength polyester industrial yarn according to claim 1, which is characterized by comprising the following steps of: in the step (1), the waste polyester comprises waste silk of polyester civil silk, polyester industrial silk spinning and waste silk, waste blocks, waste leftover materials and the like in the production process of the industrial mesh belt by taking the polyester industrial silk as a raw material, and waste industrial mesh belts and the like recovered after consumption.

Technical Field

The invention relates to a production method of polyester industrial yarns, in particular to a production method of waste polyester regenerated melt direct spinning polyester industrial yarns.

Background

China is a world large country for textile production and consumption, Polyester (PET) is used as one of main raw materials of chemical fiber textiles, the total output of polyester chemical fibers reaches 4100 ten thousand tons in 2020, accounts for 69.4 percent of the total output of the global chemical fibers, and occupies an absolutely dominant position. However, with the rapid development of the polyester chemical fiber industry, the problem of disposing waste polyester products is more and more urgent. The waste polyester (textile) mainly refers to various leftovers and wastes produced in the processing production process by using the polyester chemical fiber as a raw material, including waste silk waste blocks produced in the preparation process of the chemical fiber and various waste textiles produced after consumption. According to statistics, the production amount of waste polyester (textiles) reaches more than 3200 million tons every year.

Although the recycled polyester capacity in China reaches the first world at present, the recycled polyester has low intrinsic viscosity and generally low product quality, the recycled product can only be degraded and recycled to be used in the low-end fields of filling, coating and the like, and a great gap exists from the real recycling. For example, chinese published patent CN 102605454A: a method for producing industrial polyester filament yarn in large scale by recovered PET bottle flakes comprises the steps of crushing the recovered PET bottles into flakes, cleaning, drying, feeding the flakes into a crystallization bed body, crystallizing under the action of hot air entering the crystallization bed body to form a crystallization layer on the surfaces of the flakes, feeding the crystallized flakes into a drying tower, feeding the dried flakes into a screw extruder for melt extrusion, feeding the obtained melt into a two-stage filtering device consisting of a coarse filter, a fine filter and a pressure pump between the coarse filter and the fine filter for filtering to remove impurities and coagulates harmful to spinning, feeding the melt subjected to the two-stage filtering into a liquid phase viscosity increasing kettle, carrying out polycondensation reaction in the liquid phase viscosity increasing kettle under the conditions of vacuum degree of 40-71Pa and temperature of 279-281 ℃ and stirring to increase the viscosity of the melt to 0.820 +/-0.001 dl/g, and (3) enabling the melt after liquid phase tackifying to enter a spinning box, and spinning by adopting a high-speed spinning process to prepare the industrial polyester filament. In the key liquid phase tackifying step in the method, a squirrel cage horizontal reaction kettle with stirring is adopted, and due to the structural defects, the problems of overlarge stirring current, poor film forming effect, excessive dead zones and the like can be caused when the melt with high viscosity of more than 0.820 dl/g is prepared, so that the polyester industrial yarns with high strength and uniform quality cannot be produced, the production cost is high, and the varieties are single.

Disclosure of Invention

The purpose of the invention is as follows: the invention aims to overcome the defects in the prior art, and provides a waste polyester physical-chemical method regeneration technology, wherein a vertical falling film melting polycondensation reactor is adopted, devolatilization, polymerization and tackifying integration can be realized, the intrinsic viscosity can be improved to reach the industrial yarn level, and the industrial blank of melt direct spinning high-strength regenerated polyester industrial yarn preparation is filled, so that high-efficiency, high-quality and high-valued recycling of waste polyester is realized.

The technical scheme is as follows: in order to solve the technical problem, the invention discloses a production method of waste polyester regenerated melt direct-spun high-strength polyester industrial yarn, which comprises the following steps,

(1) processing the waste polyester by a sorting and breaking device to obtain a broken waste polyester raw material with consistent appearance and shape and the length of not more than 80 cm;

(2) performing screw rod melting on the material treated in the step (1), and performing multi-stage vacuum pumping treatment through a vacuum system during screw rod melting to remove moisture and low-molecular volatile matters;

(3) after the material treated in the step (2) is subjected to coarse filtration, the material enters a vertical unpowered vertical-pipe external falling film liquid phase tackifying reactor, so that the intrinsic viscosity value of the melt is increased to be more than 0.9-1.2 dl/g;

(4) and (4) after the material processed in the step (3) is subjected to precise filtration, granulating by an underwater granulator to obtain high-viscosity regenerated polyester chips or carrying out direct melt spinning by melt pipeline conveying to obtain the regenerated polyester industrial filament with the breaking strength of more than 8.0 cN/dtex.

Further, the waste polyester is subjected to densification treatment after the step (1), and then is subjected to vacuum screw melting in the step (2), wherein the densification treatment temperature is 230-255 ℃, and the bulk density of the densified broken polyester waste reaches 400kg/m³The above.

Further, screw melting consists of two stages of vacuum screws, the first stage is a conveying screw which is a single screw with vacuum degassing, a densification device is arranged above a feeding hole, after most of moisture of the materials is removed through softening and vacuum at the temperature of 260-280 ℃, the materials in a solid-melt mixed state enter a second stage of vacuum single screw or double screw at stable feeding pressure, extrusion melting, compression and metering are carried out at the temperature of 280-320 ℃, and moisture and small molecule volatile matters are further removed continuously through two vacuum degassing holes; the two-stage vacuum screw vacuum degassing is connected with a vacuum system, the vacuum system is a mechanical vacuum pump group, and the ultimate vacuum degree is less than 1000 Pa.

Further, in the step (3), the falling film liquid phase tackifying reactor adopts a vertical structure and no mechanical stirring device, preferably the structure of patent ZL201610302101.3 which is issued by the invention, and the materials are completely transferred from the feeding end to the discharging end by gravity; the regenerated polyester melt flows in a falling film mode outside the vertical pipe, the temperature of materials in the reactor is controlled to be 275-282 ℃, the pressure in the reactor is 0.01-0.04 MPa, and the residence time of the melt in the reactor is 30-60 min.

Further, in the step (4), the melt direct spinning comprises the steps that the high-viscosity regenerated polyester melt output by a discharge booster pump is conveyed to a metering pump in a spinning box body through a melt pipeline, the metering pump accurately meters the high-viscosity regenerated polyester melt and then enters a spinning assembly, the high-viscosity regenerated polyester melt is extruded through a spinneret orifice of a spinneret plate in the spinning assembly to form fibers, and the fibers are slowly cooled, air-cooled, oiled, pre-meshed, multi-stage stretch-formed and finally meshed and then are wound into the high-strength regenerated polyester industrial yarns at a high speed;

the booster pump and the melt pipeline are insulated by adopting a liquid phase heating medium, the temperature is 280-290 ℃, and the pressure of the booster pump is 12-24 MPa; the spinning manifold is insulated by gas phase heat medium at 290-310 ℃; the multistage stretching and shaping are carried out, wherein the stretching multiplying power is 4.0-6.2, the relaxation ratio is 3-12%, and the stretching and shaping temperature is 80-250 ℃.

Further, a multi-point flexible online adding device is arranged at the positions of the screw rod melting in the step (2), the falling film liquid phase tackifying reactor (3) in the step (3) and the melt pipeline in the step (4), one or more functional additives such as a coloring agent, a flame retardant or an antibacterial agent are added, and the regenerated high-strength industrial polyester filament with multiple composite functions is prepared in situ by taking stock solution coloring as a basic function;

adding a colorant in the step (2), wherein the colorant comprises a toner, the toner comprises one or more of carbon black, iron oxide red, azo yellow and phthalocyanine blue, and the mass ratio of the toner to the polyester melt is 0.1-1%;

adding one or more functional additives such as a flame retardant and an antibacterial agent in the steps (3) and (4), wherein the flame retardant comprises one or more compounds such as diethyl aluminum hypophosphite, magnesium hydroxide, aluminum hydroxide and silicon, and the mass ratio of the flame retardant to the polyester melt is 0.5-5.0%; the antibacterial agent comprises one or more alloys of nano silver, nano copper and nano zinc, and the mass ratio of the antibacterial agent to the polyester melt is 0.1-0.5%.

Further, in the step (1), the waste polyester comprises polyester domestic yarns, polyester industrial yarn spinning yarns, waste blocks, waste leftover materials and other waste materials in the production process of the industrial woven belts by using the polyester industrial yarns as raw materials, waste industrial woven belts recycled after consumption and the like.

Has the advantages that: compared with the prior art, the invention has the following remarkable advantages: the invention adopts a physical and chemical regeneration technology and a vertical falling film melt polycondensation reactor to integrally complete devolatilization and tackifying of a regenerated polyester melt, the intrinsic viscosity can be improved to reach an industrial yarn level, the liquid phase tackifying of the regenerated polyester can reach higher viscosity of 0.9-1.2 dl/g, the reaction efficiency is high, the direct spinning production of the regenerated polyester industrial yarn melt with the high strength of more than 8.0cN/dtex can be realized within about 40min, the industrial blank of the preparation of the melt direct spinning high-strength regenerated polyester industrial yarn is filled, the high-efficiency, high-quality and high-valued reutilization of waste polyester is realized, the high-performance regenerated polyester industrial yarn is prepared by creatively applying a multi-point online addition technology, and compared with the prior art, the invention adopts the multi-point flexible online addition technology for preparing in-situ colored and flame-retardant industrial yarns, such as screw extrusion, falling film liquid phase tackifying, melt conveying pipelines and the like, The multifunctional composite regenerated polyester industrial yarn with antibacterial property and the like has obvious technical advantages, the preparation process of functional master batches is omitted, the influence of low viscosity and master batch carrier on the strength of the polyester industrial yarn is avoided, the dispersibility of low-content toner in a polyester melt is good, the color uniformity is ensured by multi-link mixing of screw extrusion, liquid-phase adhesion and melt conveying, the technology for preparing colored regenerated polyester industrial yarn by in-situ color matching and the multifunctional composite differentiated regenerated polyester industrial yarn with flame retardance, antibacterial property and the like can be formed, the added value of a waste polyester regenerated product is further improved, the polyester civil yarn, the polyester industrial yarn spinning, waste yarn, waste blocks, leftover materials and other waste materials in the production process of the industrial braid by taking the polyester industrial yarn as a raw material and the waste industrial braid recovered after consumption are adopted to circularly regenerate and prepare high-performance chemical fibers, and the real method for preparing the high-performance chemical fibers from the polyester spinning (waste) -industrial braid (leftover materials) -market waste (recovered) -polyester (differentiated high-performance spinning) (differentiated high-spinning from the waste materials) -industrial braid (leftover materials) -waste materials-waste industrial braid-spinning-market-spinning-polyester The method has the advantages that polyester B2B (woven) is brought to (woven) Belt (Belt) in the process of chemical fiber) -regenerated industrial weaving Belt (GRS authentication) "for recycling a production system, waste products generated in the whole life cycle of polyester products are efficiently regenerated, high-value utilization of waste polyester resources is realized, and the method can be popularized and applied to resource recycling of waste polyester such as PC, PBT, PTT and the like.

Drawings

FIG. 1 is a schematic flow diagram of the present invention.

Detailed Description

The invention is further described below with reference to the figures and examples.

Example 1

As shown in figure 1, a production method of waste polyester regenerated melt direct-spun high-strength polyester industrial yarn comprises the following steps,

(1) processing the waste polyester by a sorting and breaking device 1 to obtain a broken waste polyester raw material with consistent appearance and shape and the length of not more than 80 cm;

(2) performing screw rod melting on the material treated in the step (1), and performing multi-stage vacuum pumping treatment through a vacuum system 2 when the screw rod is melted to remove moisture and low-molecular volatile matters;

(3) after being roughly filtered, the material treated in the step (2) enters a vertical unpowered vertical-pipe external falling film liquid phase tackifying reactor 3, so that the intrinsic viscosity value of the melt is increased to 1.06 dl/g;

(4) and (4) after the material processed in the step (3) is subjected to precise filtration, granulating by an underwater granulator to obtain high-viscosity regenerated polyester chips or carrying out direct melt spinning by melt pipeline conveying to obtain the industrial polyester filament with the breaking strength of more than 8.0 cN/dtex.

Performing densification treatment on the waste polyester after the step (1), and then performing vacuum screw melting in the step (2), wherein the densification treatment temperature is 235 ℃, and the bulk density of the densified broken polyester waste reaches 400kg/m³The above.

The screw melting consists of two stages of vacuum screws, wherein the first stage is a conveying screw 4 which is a single screw with vacuum degassing, a densification device is arranged above a feeding hole, after most of moisture of the materials is removed by softening and vacuum at 275 ℃, the materials in a solid-melt mixed state enter a second stage of vacuum single screw or double screw 5 at stable feeding pressure, and are subjected to extrusion melting, compression and metering at 310 ℃, and further moisture and small molecule volatile matters are removed continuously through two arranged vacuum degassing holes; the two-stage vacuum screw vacuum degassing is connected with a vacuum system 2, the vacuum system 2 is a mechanical vacuum pump group, and the ultimate vacuum degree is less than 1000 Pa.

In the step (3), the falling film liquid phase tackifying reactor 3 adopts a vertical structure and does not have a mechanical stirring device, and materials in the reactor are completely transferred from a feeding end to a discharging end under the action of gravity; the regenerated polyester melt flows in a falling film mode outside the vertical pipe, the material temperature in the reactor is controlled to be 278 ℃, the pressure in the reactor is 0.03 MPa, and the melt retention time in the reactor is 40min, so that the regenerated polyester melt with the intrinsic viscosity of 1.06dl/g is obtained.

In the step (4), the melt direct spinning comprises the steps that the high-viscosity regenerated polyester melt output by a discharge booster pump is conveyed to a metering pump in a spinning box body through a melt pipeline, the metering pump accurately meters the high-viscosity regenerated polyester melt and then enters a spinning assembly 6, the high-viscosity regenerated polyester melt is extruded through a spinneret orifice of a spinneret plate in the spinning assembly 6 to form fibers, and the fibers are slowly cooled, air-cooled, oiled, pre-screened, multi-stage stretch-formed and finally screened and knotted and then are wound into the high-strength regenerated polyester industrial yarn at high speed;

the booster pump and the melt pipeline are insulated by adopting a liquid phase heating medium, the temperature is 285 ℃, and the pressure of the booster pump is 18 MPa; the spinning manifold is insulated by a gas phase heating medium at the temperature of 295 ℃; the multistage stretching and setting are carried out, the pre-stretching multiplying power is 1.003, the primary stretching multiplying power is 1.4, the stretching temperature is 95 ℃, the secondary stretching multiplying power is 4.2, the stretching and setting temperature is 180 ℃, the relaxation ratio is 5%, the fineness is 1110dtex, the breaking strength is 8.1cN/dtex, and the breaking elongation is 11%, so that the regenerated high-strength low-elongation polyester industrial yarn is suitable for being applied to geotextile materials.

Example 2

As shown in figure 1, a production method of waste polyester regenerated melt direct-spun high-strength polyester industrial yarn comprises the following steps,

(1) processing the waste polyester by a sorting and breaking device 1 to obtain a broken waste polyester raw material with consistent appearance and shape and the length of not more than 80 cm;

(2) performing screw rod melting on the material treated in the step (1), and performing multi-stage vacuum pumping treatment through a vacuum system 2 when the screw rod is melted to remove moisture and low-molecular volatile matters;

(3) after being roughly filtered, the material treated in the step (2) enters a vertical unpowered vertical-pipe external falling film liquid phase tackifying reactor 3, so that the intrinsic viscosity value of the melt is increased to 1.12 dl/g;

(4) and (4) after the material processed in the step (3) is subjected to precise filtration, granulating by an underwater granulator to obtain high-viscosity regenerated polyester chips or carrying out direct melt spinning by melt pipeline conveying to obtain the industrial polyester filament with the breaking strength of more than 8.0 cN/dtex.

Performing densification treatment on the waste polyester after the step (1), and then performing vacuum screw melting in the step (2), wherein the densification treatment temperature is 245 ℃, and the bulk density of the densified broken polyester waste reaches 500kg/m³The above.

The screw melting consists of two stages of vacuum screws, wherein the first stage is a conveying screw 4 which is a single screw with vacuum degassing, a densification device is arranged above a feeding hole, after most of moisture of the materials is removed by softening and vacuum at 265 ℃, the materials in a solid-melt mixed state enter a second stage of vacuum single screw or double screw 5 at stable feeding pressure, and are subjected to extrusion melting, compression and metering at 290 ℃, and the moisture and small molecule volatile matters are further removed continuously through two arranged vacuum degassing holes; the two-stage vacuum screw vacuum degassing is connected with a vacuum system 2, the vacuum system 2 is a mechanical vacuum pump group, and the ultimate vacuum degree is less than 1000 Pa.

In the step (3), the falling film liquid phase tackifying reactor 3 adopts a vertical structure and does not have a mechanical stirring device, and materials in the reactor are completely transferred from a feeding end to a discharging end under the action of gravity; the regenerated polyester melt flows in a falling film mode outside the vertical pipe, the material temperature in the reactor is controlled at 280 ℃, the pressure in the reactor is 0.02 MPa, and the melt retention time in the reactor is 50min, so that the regenerated polyester melt with the intrinsic viscosity of 1.12dl/g is obtained.

In the step (4), the melt direct spinning comprises the steps that the high-viscosity regenerated polyester melt output by a discharge booster pump is conveyed to a metering pump in a spinning box body through a melt pipeline, the metering pump accurately meters the high-viscosity regenerated polyester melt and then enters a spinning assembly 6, the high-viscosity regenerated polyester melt is extruded through a spinneret orifice of a spinneret plate in the spinning assembly 6 to form fibers, and the fibers are slowly cooled, air-cooled, oiled, pre-screened, multi-stage stretch-formed and finally screened and knotted and then are wound into the high-strength regenerated polyester industrial yarn at high speed;

the booster pump and the melt pipeline are insulated by liquid phase heating medium, the temperature is 289 ℃, and the pressure of the booster pump is 22 MPa; the spinning manifold is insulated by adopting a gas phase heating medium at the temperature of 305 ℃; the multistage stretching and setting are carried out, the pre-stretching multiplying power is 1.003, the primary stretching multiplying power is 1.43, the stretching temperature is 110 ℃, the secondary stretching multiplying power is 4.25, the stretching and setting temperature is 220 ℃, and the relaxation ratio is 3%.

And (3) adding a colorant at the stage of the step (2), wherein the colorant comprises a toner which comprises one or more of carbon black, iron oxide red, azo yellow and phthalocyanine blue, and the mass ratio of the toner to the polyester melt is 0.3%.

In the step (1), the waste polyester comprises waste silk of polyester civil silk, polyester industrial silk spinning and waste silk, waste blocks, waste leftover materials and the like in the production process of the industrial mesh belt by taking the polyester industrial silk as a raw material, and waste industrial mesh belts and the like recovered after consumption.

Example 3

As shown in figure 1, a production method of waste polyester regenerated melt direct-spun high-strength polyester industrial yarn comprises the following steps,

(1) processing the waste polyester by a sorting and breaking device 1 to obtain a broken waste polyester raw material with consistent appearance and shape and the length of not more than 80 cm;

(2) performing screw rod melting on the material treated in the step (1), and performing multi-stage vacuum pumping treatment through a vacuum system 2 when the screw rod is melted to remove moisture and low-molecular volatile matters;

(3) after being roughly filtered, the material treated in the step (2) enters a vertical unpowered vertical-pipe external falling film liquid phase tackifying reactor 3, so that the intrinsic viscosity value of the melt is increased to 1.15 dl/g;

(4) and (4) after the material processed in the step (3) is subjected to precise filtration, granulating by an underwater granulator to obtain high-viscosity regenerated polyester chips or carrying out direct melt spinning by melt pipeline conveying to obtain the industrial polyester filament with the breaking strength of more than 8.0 cN/dtex.

Performing densification treatment on the waste polyester after the step (1), and then performing vacuum screw melting in the step (2), wherein the densification treatment temperature is 250 ℃, and the bulk density of the densified broken polyester waste reaches 500kg/m³The above.

The screw melting consists of two stages of vacuum screws, wherein the first stage is a conveying screw 4 which is a single screw with vacuum degassing, a densification device is arranged above a feeding hole, after most of moisture of the materials is removed by softening and vacuum at 270 ℃, the materials in a solid-melt mixed state enter a second stage of vacuum single screw or double screw 5 at stable feeding pressure, and are subjected to extrusion melting, compression and metering at the temperature of 300 ℃, and the moisture and small molecule volatile matters are further removed continuously through two arranged vacuum degassing holes; the two-stage vacuum screw vacuum degassing is connected with a vacuum system 2, the vacuum system 2 is a mechanical vacuum pump group, and the ultimate vacuum degree is less than 1000 Pa.

In the step (3), the falling film liquid phase tackifying reactor 3 adopts a vertical structure and does not have a mechanical stirring device, and materials in the reactor are completely transferred from a feeding end to a discharging end under the action of gravity; the regenerated polyester melt flows in a falling film mode outside the vertical pipe, the material temperature in the reactor is controlled to be 279 ℃, the pressure in the reactor is 0.02 MPa, and the melt retention time in the reactor is 45min, so that the regenerated polyester melt with the intrinsic viscosity of 1.15dl/g is obtained.

In the step (4), the melt direct spinning comprises the steps that the high-viscosity regenerated polyester melt output by a discharge booster pump is conveyed to a metering pump in a spinning box body through a melt pipeline, the metering pump accurately meters the high-viscosity regenerated polyester melt and then enters a spinning assembly 6, the high-viscosity regenerated polyester melt is extruded through a spinneret orifice of a spinneret plate in the spinning assembly 6 to form fibers, and the fibers are slowly cooled, air-cooled, oiled, pre-screened, multi-stage stretch-formed and finally screened and knotted and then are wound into the high-strength regenerated polyester industrial yarn at high speed;

the booster pump and the melt pipeline are insulated by adopting a liquid phase heating medium, the temperature is 288 ℃, and the pressure of the booster pump is 20 MPa; the spinning manifold is insulated by adopting a gas phase heating medium at the temperature of 300 ℃; the multistage stretching and setting are carried out, the pre-stretching multiplying power is 1.004, the primary stretching multiplying power is 1.44, the stretching temperature is 120 ℃, the secondary stretching multiplying power is 4.24, the stretching and setting temperature is 230 ℃, and the relaxation ratio is 6%.

Adding a colorant at the stage of the step (2), wherein the colorant comprises a toner which comprises one or more of carbon black, iron oxide red, azo yellow and phthalocyanine blue, and the mass ratio of the toner to the polyester melt is 0.5%;

adding one or more functional additives such as a flame retardant and an antibacterial agent in the steps (3) and (4), wherein the flame retardant comprises one or more compounds such as diethyl aluminum hypophosphite, magnesium hydroxide, aluminum hydroxide and silicon series, and the mass ratio of the flame retardant to the polyester melt is 2.0%; the antibacterial agent comprises one or more alloys of nano silver, nano copper and nano zinc, and the mass ratio of the antibacterial agent to the polyester melt is 0.3%.

In the step (1), the waste polyester comprises waste silk of polyester civil silk, polyester industrial silk spinning and waste silk, waste blocks, waste leftover materials and the like in the production process of the industrial mesh belt by taking the polyester industrial silk as a raw material, and waste industrial mesh belts and the like recovered after consumption.

The invention adopts a physical and chemical regeneration technology and a vertical falling film melt polycondensation reactor to integrally complete devolatilization and tackifying of a regenerated polyester melt, the intrinsic viscosity can be improved to reach an industrial yarn level, the liquid phase tackifying of the regenerated polyester can reach higher viscosity of 0.9-1.2 dl/g, the reaction efficiency is high, the direct spinning production of the regenerated polyester industrial yarn melt with the high strength of more than 8.0cN/dtex can be realized within about 40min, the industrial blank of the preparation of the melt direct spinning high-strength regenerated polyester industrial yarn is filled, the high-efficiency, high-quality and high-valued reutilization of waste polyester is realized, the high-performance regenerated polyester industrial yarn is prepared by creatively applying a multi-point online addition technology, and compared with the prior art, the invention adopts the multi-point flexible online addition technology for preparing in-situ colored and flame-retardant industrial yarns, such as screw extrusion, falling film liquid phase tackifying, melt conveying pipelines and the like, The multifunctional composite regenerated polyester industrial yarn with antibacterial property and the like has obvious technical advantages, the preparation process of functional master batches is omitted, the influence of low viscosity and master batch carrier on the strength of the polyester industrial yarn is avoided, the dispersibility of low-content toner in a polyester melt is good, the color uniformity is ensured by multi-link mixing of screw extrusion, liquid-phase adhesion and melt conveying, the technology for preparing colored regenerated polyester industrial yarn by in-situ color matching and the multifunctional composite differentiated regenerated polyester industrial yarn with flame retardance, antibacterial property and the like can be formed, the added value of a waste polyester regenerated product is further improved, the polyester civil yarn, the polyester industrial yarn spinning, waste yarn, waste blocks, leftover materials and other waste materials in the production process of the industrial braid by taking the polyester industrial yarn as a raw material and the waste industrial braid recovered after consumption are adopted to circularly regenerate and prepare high-performance chemical fibers, and the real method for preparing the high-performance chemical fibers from the polyester spinning (waste) -industrial braid (leftover materials) -market waste (recovered) -polyester (differentiated high-performance spinning) (differentiated high-spinning from the waste materials) -industrial braid (leftover materials) -waste materials-waste industrial braid-spinning-market-spinning-polyester The method has the advantages that polyester B2B (woven) is brought to (woven) Belt (Belt) in the process of chemical fiber) -regenerated industrial weaving Belt (GRS authentication) "for recycling a production system, waste products generated in the whole life cycle of polyester products are efficiently regenerated, high-value utilization of waste polyester resources is realized, and the method can be popularized and applied to resource recycling of waste polyester such as PC, PBT, PTT and the like.

The present invention provides a thought and a method, and a method and a way for implementing the technical scheme are many, the above is only a preferred embodiment of the present invention, it should be noted that, for a person skilled in the art, a plurality of improvements and modifications can be made without departing from the principle of the present invention, and the improvements and modifications should be regarded as the protection scope of the present invention, and each component not explicitly described in the embodiment can be implemented by the prior art.