A method for producing polyester chips using ethylene glycol produced from industrial flue gas and manufacturing industrial polyester filaments, and industrial polyester filaments manufactured therefrom

Abstract

The present invention relates to a method for producing polyester chips and manufacturing industrial polyester long fibers using ethylene glycol produced from industrial flue gas, and to industrial polyester long fibers manufactured therefrom. Specifically, using ethylene glycol produced from industrial flue gas having an ethylene glycol content of 99.9% or more as a raw material, a slurry is prepared having an EG:PTA molar ratio of 1.0 to 1.3, and a coal-based PET chip having an intrinsic viscosity of 0.6 to 0.8 dl / g and a terminal carboxyl group content of 25 to 30 mol / t is synthesized using a catalyst containing antimony and an acetic acid-based inhibitor of 1 to 5 ppm, and after increasing the viscosity, a coal-based high-viscosity chip with a viscosity of 1.00 to 1.2 dl / g is obtained, and then spun in an industrial filament production line; By controlling the screw temperature and adjusting the lengths of the material input and metering sections, the chips are sufficiently melted, while ensuring that no additional chain breakage occurs due to pyrolysis by including a small amount of flexible chains in the molten material, and the safety of the screw outlet pressure is guaranteed; the spinning assembly applies a multi-layer filter mesh structure to mitigate adverse effects caused by the high presence of impurities in the coal-based chips; and the stretching and fixing conditions are adjusted to optimize physical properties, fluffiness, and spinnability, thereby ensuring that all requirements are met.

Description

Technology Field

[0001] The present application belongs to the field of chemical fibers, and specifically relates to a method for producing polyester chips using ethylene glycol produced from industrial flue gas and manufacturing polyester industrial long fibers, and polyester industrial long fibers manufactured therefrom. Background Technology

[0002] Approximately 94% of commercially available ethylene glycol is used as a raw material for polyester. While traditional ethylene glycol production utilizes the petroleum ethylene process, this method faces significant constraints in terms of both resource utilization and production costs due to China's scarcity of petroleum resources. Conversely, given China's abundant coal resources, the process of synthesizing ethylene glycol from coal-based synthesis gas offers a wide range of material sources, low costs, and high technical economic feasibility.

[0003] The excessive reliance of chemical fiber production on petroleum-based chemical products leads to the consumption of large amounts of non-renewable resources such as oil, resulting in resource depletion and environmental pollution. According to the introduction, global oil resources can be extracted for about 40 years, while the extractable lifespan of China's oil resources does not exceed 30 years.

[0004] Using industrial flue gas as a raw material for ethylene glycol production not only realizes the resource utilization of flue gas compared to petroleum-based ethylene glycol, but also offers relatively high market competitiveness due to its eco-friendliness and low cost. However, in conventional technology, ethylene glycol produced using industrial flue gas as a raw material contains residual oxalic acid, a reaction byproduct. Consequently, when it enters the polyester production process, it cannot be completely removed from the top of the process tower. Furthermore, when it subsequently enters the condensation process, thermal decomposition occurs as the degree of polymerization increases, which is directly reflected in the increase in the terminal carboxyl group content among the final analysis indicators of the polyester. The terminal carboxyl group content of a polyester product can reflect the regularity of the polymer material chain and is generally controlled to be 30 mol / t or less. However, if the terminal carboxyl group content rises above 35 mol / t, it causes changes in the post-spinning processing performance of the polyester product, resulting in an increase in the number of broken filaments during spinning and a decrease in the strength indicators of the fiber product to some extent. In addition, a small amount of oxalic acid undergoes an esterification reaction with ethylene glycol, and during the condensation reaction, a small amount of flexible chains are formed and may be introduced into the finished polyester product. Additionally, as thermal decomposition occurs, chain breakage may occur, which manifests as a sudden single-filament phenomenon during spinning, but the surface of the spinning plate remains very clean.

[0005] In the process of manufacturing industrial polyester long fibers using petroleum-based chips, the spinning assembly uses a three-layer filter structure, with the middle layer being a felt net and the upper and lower layers supported by screen plates. In the process of manufacturing industrial polyester long fibers using coal-based chips, the relatively high impurity content and the significant impact of the molten material on the filter net cause the filter structure to clog and the pressure in the spinning assembly to rise rapidly; this leads to die swell easily occurring during the spinning process, resulting in a high number of defects such as adhesion to the spinning plate, fuzziness, and blobby filaments at the ends. The problem to be solved

[0006] Therefore, the technical problem that this application aims to solve is as follows:

[0007] 1) A method of performing a polyester process using industrial flue gas ethylene glycol as a raw material and obtaining polyester chips;

[0008] 2) A method for improving the intrinsic viscosity of polyester chips by performing a solid-phase thickening process;

[0009] 3) A method to ensure that the physical properties, fluff, and other indicators of the manufactured industrial polyester long fibers pass. means of solving the problem

[0010] A method for producing polyester chips using ethylene glycol produced from industrial flue gas and manufacturing industrial long fibers of polyester (dacron), wherein the method comprises:

[0011] Step 1, wherein terephthalic acid (p-phthalic acid, PTA), ethylene glycol (EG) produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry having an EG:PTA molar ratio of 1.0 to 1.3; the slurry is transferred to an esterification reaction vessel to obtain an initial esterification product; the initial esterification product is transferred into a pre-condensation reaction vessel to perform a pre-condensation reaction to obtain a polyester prepolymer; the polyester prepolymer is subjected to a final condensation reaction to obtain a polyester melt; and the polyester melt is cooled and pelletized to produce PET polyester chips with a viscosity of 0.6 to 0.8 dL / g.

[0012] Step 2, in which the manufactured 0.6~0.8 dL / g PET polyester chips are placed into the reaction vessel of a batch polymerization reactor to obtain 1.00~1.2 dL / g PET polyester chips;

[0013] Step 3, transferring PET polyester chips of 1.00~1.2 dL / g to a screw extruder and extruding the melt through the screw extruder;

[0014] Step 4, in which the molten material extruded from the screw extruder is distributed to a spinning box to form a spinning melt, and under conditions of 295–305°C, after filtration, the spinning melt is discharged from a spinneret plate to obtain a melt flow;

[0015] Step 5, after slow cooling the above molten flow, to cool the molten flow using an annular blowing or lateral blowing method to obtain a filament body; and

[0016] Step 6 includes passing the cooled filament body through a spinning channel, followed by performing stretching, fixing, and winding treatments to obtain industrial polyester long fibers made from coal-based polyester chips.

[0017] The present invention provides a polyester industrial long fiber manufactured based on the method described above. Brief explanation of the drawing

[0018] To more clearly explain the technical methods of the embodiments of the present disclosure, the accompanying drawings used in the embodiments are briefly introduced below. It should be understood that the following accompanying drawings merely illustrate specific embodiments of the present disclosure and should not be construed as a limitation on the scope of the present disclosure. FIG. 1 is a polyester process flowchart according to one embodiment of the present application. FIG. 2 is a schematic diagram of the cross-sectional structure of a single hole in a radiating plate according to one embodiment of the present application. FIG. 3 is a schematic diagram of a partial structure of a radiation assembly according to one embodiment of the present application. In the attached drawing, the components are a spinning assembly (1), a spinning box (2), a heating cover (3), a spinning plate (4), and an insulating tube (5); a is the direction of molten body flow; b is the direction of molten body microflow filament extrusion; and c is the direction of cooling air. Specific details for implementing the invention

[0019] Cross-reference of related applications

[0020] The present invention claims priority to a Chinese patent application filed with the Chinese Intellectual Property Office on September 23, 2024, with the invention title “Method for producing polyester chips and manufacturing polyester industrial filament fibers using ethylene glycol produced from industrial flue gas and polyester industrial filament fibers manufactured therefrom” and application number 202411326908.1, the entire contents of said application are incorporated into the present invention by reference.

[0021] The embodiments of the present application are described in detail below in conjunction with the examples. However, those skilled in the art will understand that the following examples are intended only to illustrate the present application and should not be construed as limiting the scope of the application. Where specific conditions are not specified in the examples, the application is performed under ordinary conditions or conditions recommended by the manufacturer. Where the manufacturer of the reagents or equipment used is not specified, they are all general products available on the market.

[0022] The endpoints and any values ​​of the ranges disclosed herein are not limited to the exact ranges or values, and should be understood that such ranges or values ​​include values ​​that approximate these ranges or values. In numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and individual point values, and the individual point values ​​may be combined with one another to obtain one or more new numerical ranges, and such numerical ranges should be considered as specifically disclosed herein. Here, the terms “optional” and “optionally selected” mean that they may or may not be included (or may exist or may not exist). As used herein, “and / or” is inclusive; for example, “A and / or B” means that A is present only, B is present only, or A and B are present simultaneously.

[0023] Where equivalents, concentrations, or other values ​​or parameters are expressed as a range, a preferred range, or a range limited by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing any range formed by any pairing of any upper range or preferred value and any lower range or preferred value, regardless of whether such range is disclosed separately. For example, if a range "1 to 5" is disclosed, the stated range should be interpreted as including ranges such as "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. Where numerical ranges are described in this specification, unless otherwise specified, such ranges are intended to include their endpoint values ​​and all integers and fractions within such ranges.

[0024] Regarding the disadvantages or shortcomings of the prior art, the technical problem to be solved in this application is to provide a method for producing polyester chips using ethylene glycol produced from industrial flue gas and manufacturing long polyester fibers for the polyester industry, and to provide long polyester fibers for the polyester industry manufactured therefrom.

[0025] To solve the aforementioned technical problem, the present application is implemented through the following technical solution:

[0026] The present application proposes a method for producing polyester chips and manufacturing industrial polyester long fibers using ethylene glycol produced from industrial flue gas. The method comprises:

[0027] Step 1, wherein terephthalic acid (PTA), ethylene glycol (EG) produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry having an EG:PTA molar ratio of 1.0 to 1.3; the slurry is transferred to an esterification reaction vessel to obtain an initial esterification product; the initial esterification product is transferred into a pre-condensation reaction vessel to perform a pre-condensation reaction to obtain a polyester prepolymer; the polyester prepolymer is subjected to a final condensation reaction to obtain a polyester melt; and the polyester melt is cooled and pelletized to produce PET polyester chips with a viscosity of 0.6 to 0.8 dL / g.

[0028] Step 2, in which the manufactured 0.6~0.8 dL / g PET polyester chips are placed into the reaction vessel of a batch polymerization reactor to obtain 1.00~1.2 dL / g PET polyester chips;

[0029] Step 3, transferring PET polyester chips of 1.00~1.2 dL / g to a screw extruder and extruding the melt through the screw extruder;

[0030] Step 4, in which the molten material extruded from the screw extruder is distributed to a spinning box to form a spinning melt, and under conditions of 295–305°C, after filtration, the spinning melt is discharged from a spinning plate to obtain a molten material flow;

[0031] Step 5, after slow cooling the above molten flow, to obtain a molten body by cooling the molten flow using an annular blowing or lateral blowing method; and

[0032] The method is characterized by including step 6, which involves passing a cooled filament body through a spinning channel, followed by performing stretching, fixing, and winding treatments to obtain a long polyester industrial fiber made from coal-based polyester chips.

[0033] In one or more embodiments, the catalyst preparation is a catalyst having an antimony content of 150 to 180 ppm;

[0034] and / or, the pressure of the esterification reaction vessel is set to 0.06~0.1 MPa and the temperature is set to 253~273℃;

[0035] and / or, the vacuum level of the pre-condensation polypolymerization reaction is 8 to 11 kPa and the temperature is 260 to 280°C;

[0036] and / or, the vacuum level of the final condensation reaction is 150 to 250 Pa, and the temperature is 272 to 293°C.

[0037] In one or more embodiments, the esterification reaction vessel comprises a first esterification reaction vessel and a second esterification reaction vessel, wherein the temperature of the first esterification reaction vessel is set to 258 to 262°C; and the temperature of the second esterification reaction vessel is set to 262 to 276°C.

[0038] In one or more embodiments, the temperature inside the reaction vessel of the batch polymerization reactor is stirred under conditions where the vacuum level inside the reaction vessel is 20 Pa or less, and the temperature inside the reaction vessel is uniformly raised to 90 to 120°C by heating the heat transfer oil pipes and heated for 2 to 10 hours, then the temperature is continued to be raised to 130 to 180°C and heated for 5 to 17 hours to obtain a preliminary crystal chip, and then the temperature is continued to be uniformly raised to 200 to 240°C and heated for 27 to 33 hours, so that after solid-state polymerization, the viscosity of the polyester chip is improved from 0.6 to 0.8 dl / g to 1.00 to 1.2 dL / g, and the moisture content of the final high-viscosity chip is 15 ppm or less.

[0039] In one or more embodiments, the screw outlet temperature of the screw extruder is ≥280°C; and / or, the length ratio of the material input section, melting section, and metering section of the screw extruder is 1:(1.0~3.0):(1.0~4.0). Preferably, the length ratio of the material input section, melting section, and metering section of the screw extruder is 1:(1.5~2.5):(2.5~4); more preferably, the length ratio of the material input section, melting section, and metering section of the screw extruder is 1:(1.8~2.2):(2.8~4).

[0040] In one or more embodiments, the screw diameter of the screw extruder is 75 to 170 mm, and the length-to-diameter ratio (L / D ratio) is 24 to 33.

[0041] In one or more embodiments, the filtration uses a multilayer metal filter mesh, and the filtration precision of the multilayer metal filter mesh decreases layer by layer along the direction of travel of the radiating melt, and the radiating melt is uniformly distributed to the radiating holes.

[0042] In one or more embodiments, the ratio of the micropore passage length of the radiator to the diameter of the radiator is 1.0 to 3.0; and / or, the filtration precision is 5 to 30 μm; preferably, the filtration precision is 20 to 30 μm.

[0043] In one or more embodiments, the slow cooling treatment is completed through a heating cover having a temperature of 300 to 330°C and an insulating tube having a height of 50 to 500 mm; the annular airflow temperature is 50 to 70°C, the dynamic pressure is 0.02 to 0.06 kPa, and the humidity is 50 to 70%; the side airflow temperature is 18 to 25°C, the wind speed is 0.4 to 0.6 m / s, and the humidity is 50 to 70%.

[0044] In one or more embodiments, the parameters of the stretch fixation include a traction speed of 300 to 4000 meters / min; a total stretch factor of 2.0 to 6.5; a fixation temperature of 230°C to 260°C; a total relaxation rate of 1.6 to 9%; and a winding speed of 2000 to 7000 meters / min.

[0045] In one or more embodiments, the terminal carboxyl group content of the polyester chip produced from the industrial flue gas is 25 to 30 mol / t;

[0046] and / or, the color value L of the polyester chip produced from the industrial flue gas is ≥79;

[0047] and / or, the color value b of the polyester chip produced from the industrial flue gas is 1.5±2.0;

[0048] and / or, the moisture content of the polyester chips produced from the industrial flue gas is ≤0.40%;

[0049] and / or, the diethylene glycol content of the polyester chips produced from the industrial flue gas is 0.80 to 1.00%.

[0050] In one or more embodiments, the fineness of the polyester industrial filament is 100 to 3300 dtex, and preferably, the fineness of the polyester industrial filament is 167 to 3300 dtex;

[0051] and / or, the breaking strength of the above-mentioned industrial polyester long fiber is ≥7.15 cN / dtex;

[0052] and / or, the coefficient of variation in breaking strength of the above-mentioned industrial polyester long fiber is ≤4.0%;

[0053] and / or, the elongation at break of the above-mentioned industrial polyester long fiber is 11.5–24%;

[0054] and / or, the intermediate elongation of the above polyester industrial long fiber is 5 to 10%.

[0055] In one or more embodiments, the ethylene glycol content in the ethylene glycol produced from the industrial flue gas is 99% or more.

[0056] In one or more embodiments, the ethylene glycol content in the ethylene glycol produced from the industrial flue gas is 99.9% or more.

[0057] The present application provides a polyester industrial long fiber manufactured based on the method described above.

[0058] In one or more embodiments, the polyester industrial long fiber is intended for manufacturing tire cord fabric, seat belts, airbags, or sewing thread.

[0059] Compared to the prior art, the present application has the following technical effects:

[0060] The present application selects and uses ethylene glycol produced from industrial flue gas as a raw material to prepare a slurry with an EG:PTA molar ratio of 1.0 to 1.3, synthesizes coal-based PET chips with an intrinsic viscosity of 0.6 to 0.8 dl / g and a terminal carboxyl group content of 25 to 30 mol / t using an antimony-containing catalyst and an acetic acid-based inhibitor, obtains coal-based high-viscosity chips with a viscosity of 1.00 to 1.2 dl / g after increasing the viscosity, and then spins them in an industrial filament production line; controls the screw temperature and adjusts the lengths of the material input section and the metering section to ensure that the chips are sufficiently melted, while ensuring that no additional chain breakage occurs due to pyrolysis by including a small amount of flexible chains in the molten material, and guarantees the safety of the screw outlet pressure; and installs a filter member in the spinning assembly to improve the problem of the pressure in the spinning assembly rising rapidly due to the high impurity content in the coal-based chips; Adjust the stretching fixation conditions to optimize them so that physical properties, fluffiness, and spinnability all meet the requirements.

[0061] Hereinafter, technical solutions within the embodiments of this application are described clearly and completely in conjunction with the drawings attached to the embodiments of this application. It is evident that the described embodiments are only a part of the embodiments of this application and not the whole. Based on the embodiments in this application, all other embodiments obtained by a person skilled in the art without creative labor fall within the scope of protection of this application.

[0062] The present application uses ethylene glycol produced from industrial flue gas having an ethylene glycol content of 99% or more, preferably 99.9% or more, as a raw material; specifically, recovers steel mill flue gas and produces ethylene glycol by the oxalic acid method; prepares a slurry with an EG:PTA molar ratio of 1.0 to 1.3; uses antimony ethylene glycolate with an antimony content of 150 to 180 ppm as a catalyst; uses an acetic acid-based inhibitor of 1 to 5 ppm; synthesizes coal-based PET chips having an intrinsic viscosity of 0.6 to 0.8 dl / g and a terminal carboxyl group content of 25 to 30 mol / t through a five-reactor process; increases the viscosity of the coal-based chips to 1.00 to 1.2 dl / g using a suitable thickening process; designs melting and cooling temperatures suitable for the coal-based chips produced from industrial flue gas to obtain a spinn melt that is stably extruded; and simultaneously By optimizing the stretching process parameters, industrial polyester long fibers are obtained from coal-based polyester chips produced from industrial flue gas, wherein the physical properties and fluffiness are acceptable.

[0063] A method for producing polyester chips and manufacturing industrial polyester long fibers using ethylene glycol produced from industrial flue gas comprises the following steps:

[0064] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with an EG:PTA molar ratio of 1.0 to 1.3; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.1 MPa and a temperature of 253 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred via a pressure difference to a pre-condensation reaction vessel with a vacuum of 8 to 11 kPa and a temperature of 260 to 280°C to perform a pre-condensation reaction, thereby obtaining a polyester prepolymer. Then, the prepolymer is transferred via a prepolymer transfer pump to perform a final condensation reaction under conditions of a vacuum of 150 to 250 Pa and a temperature of 272 to 293°C to obtain a polyester melt; Finally, the polyester melt undergoes cooling and pelletizing to produce PET polyester chips with a viscosity of 0.6 to 0.8 dL / g, as shown in Fig. 1.

[0065] When manufacturing polyester chips by reacting PTA with ethylene glycol produced from industrial flue gas, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump. The temperature of the first esterification reaction vessel is controlled to a range of 258–262°C, and the temperature of the second esterification reaction vessel is controlled to a range of 262–276°C. This is approximately 3°C higher than the temperature of typical petroleum-based ethylene glycol and 2°C higher than the normal control range, and the purpose is to promote the forward progress of the reaction. In the polyester process, since an increase in the esterification temperature increases the reaction rate, the esterification temperature is an important control parameter. The effect of temperature is that, under conditions where the EG / PTA molar ratio is constant, increasing the reaction temperature also increases the reaction rate, thereby accelerating the esterification reaction and shortening the time; however, at the same time, side reactions within the system are accelerated, the diethylene glycol (DEG) content increases, and ultimately, the DEG content in the chip product increases. This means that in the polyester production process, temperature must be precisely controlled to ensure product quality and production volume. Otherwise, the melting point of the product may decrease and the color may deteriorate.

[0066] In order to manufacture chips of the same index, if process conditions such as temperature, liquid level position, and catalyst are changed, the byproduct DEG content is correspondingly improved, and by selecting and using a suitable acetic acid-based inhibitor, the amount added is controlled within the range of 1 to 5 ppm, and the DEG content is controlled within the normal range.

[0067] Specifically, the reactor used for the final condensation reaction is a squirrel cage horizontal reactor. In the control method, the vacuum level is controlled by adjusting the amount of suction steam introduced by the ethylene glycol vapor injection pump. The reactor jacket is heated by a gaseous heat medium, and the gaseous heat medium is generated by a heat medium evaporator. The temperature of the entire polymerization section is 274°C to 293°C. Temperature is one of the important means of controlling the degree of polymerization; large temperature fluctuations during the entire process cause fluctuations in the degree of polymerization, and if the temperature is too high, the antioxidant capacity of the ester particles decreases, causing the B value to rise and affecting the quality of the final product. To simultaneously guarantee the degree of polymerization and the B value of the product, liquid level indicators are installed on the material supply side and the material discharge side of the reactor, respectively. The material supply amount of the prepolymer transfer pump is controlled using the two liquid level values, and the residence time of the material is controlled.

[0068] The antimony content in the above catalyst preparation is 150 to 180 ppm. Specifically, when antimony ethylene glycolate is used as a catalyst for a polycondensation reaction in the production process and chips are manufactured using ethylene glycol produced from industrial flue gas, the catalyst is controlled to a range of 150 to 180 ppm. On the other hand, the antimony content in the catalyst preparation used in petroleum-based products is 170 to 200 ppm, which is an average of 20 ppm lower than the antimony content in the catalyst preparation of the present application. When the amount of catalyst added is large and other conditions are the same, the rate of the polycondensation reaction increases and the viscosity increases; when the amount of catalyst added is small and other conditions are the same, the rate of the polycondensation reaction decreases and the viscosity decreases.

[0069] The intrinsic viscosity of the polyester chips produced from the above industrial flue gas is 0.6 to 0.8 dl / g.

[0070] The terminal carboxyl group content of the polyester chips produced from the above industrial flue gas is 25 to 30 mol / t.

[0071] The color value L of the polyester chip produced from the above industrial flue gas is ≥79.

[0072] The color value b of the polyester chip produced from the above industrial flue gas is 1.5±2.0.

[0073] The moisture content of the polyester chips produced from the above industrial flue gas is ≤0.40%.

[0074] The diethylene glycol content of the polyester chips produced from the above industrial flue gas is 0.80 to 1.00%.

[0075] Step 2. The manufactured PET polyester chips of 0.6~0.8 dL / g are placed into the reaction vessel of a batch polymerization reactor, stirred under conditions where the vacuum level is 20 Pa or less, and the temperature inside the reaction vessel is uniformly raised to 90~120°C by heating the heat transfer fluid piping and heated for 2~10 hours, then the temperature is continued to be raised to 130~180°C and heated for 5~17 hours to obtain pre-crystallized chips, then the temperature inside the reaction vessel is uniformly raised to 200~240°C by continuing to heat the heat transfer fluid piping and heated for 27~33 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.6~0.8 dL / g to 1.00~1.2 dL / g, and the moisture content of the final high-viscosity chips is 15 ppm or less.

[0076] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 75 to 170 mm, the screw length ratio is 24 to 33, and the screw exit temperature is ≥280℃.

[0077] Oxalic acid is present as a reaction byproduct of ethylene glycol produced from industrial flue gas. Since oxalic acid remains in the ethylene glycol and has a boiling point of 150°C, it cannot be removed in the process tower. Consequently, it is discharged along with the ethylene glycol product at the bottom of the process tower and enters the production system of the polymerization section. During the polymerization process, an increase in flexible chains occurs, which degrades the thermal stability of the polyester product. Therefore, when spinning with coal-based chips produced from industrial flue gas, the lengths of each functional section of the screw used must be distinguished from those when spinning with petroleum-based raw material chips. By optimizing each functional section (e.g., increasing the lengths of the melting and metering sections and decreasing the length of the material input section) according to the deposition density and melting time of the coal-based chips produced from industrial flue gas after drying, the stability of the screw extrusion volume and extrusion pressure can be ensured, and the normal performance of spinning production can be secured.

[0078] Since ethanedioic acid, another byproduct of oxalic acid, cannot be fully removed from the process tower during the polyester production process, coal-based chips produced from industrial flue gas have a complex composition, and there is a significant difference in melting rates between particles of different compositions and shapes. Therefore, compared to spinning with petroleum-based chips, the melting process using coal-based chips produced from industrial flue gas requires the application of relatively mild melting conditions; that is, the melting or metering section is appropriately extended to extend the residence time, viscosity is increased to improve the mechanical performance of coal-based polyester long fibers, and the temperature of the melting and metering sections is appropriately lowered to reduce the decomposition of the molten material. Depending on the aforementioned differences in characteristics between coal-based chips produced from industrial flue gas and petroleum-based chips, the length of the metering section can be appropriately extended to increase the residence time, effectively stabilize the extrusion pressure of the screw, and play an important role in stabilizing the spinning process.

[0079] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipe of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow, as shown in FIG. 3. The spinning box (2) includes the metering pump and the spinning assembly (1) described above, and the spinning assembly (1) includes a filter mesh and a spinning plate (4). Here, the number of spinning holes in the spinning plate (4) is 28 to 960; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 1.0 to 3.0, and as shown in FIG. 2, L1 is the micropore passage length and D1 is the diameter of the spinning holes; the precision of the filter mesh of the spinning assembly (1) is 5 to 30 μm, preferably 20 to 30 μm, and improves the uniformity of the spinning body. The spinning box (2) is heated to a biphenyl temperature of 295~305℃ to maintain good molten fluidity and pressure.

[0080] Thickening chips produced from industrial flue gas contain many impurities and are prone to decomposition. During the spinning process, outlet expansion occurs easily, leading to frequent defects such as sticking of the spinning plate, lint, and sealing of the head section. A suitable assembly filtration component was designed to address the specific characteristics of thickening chips produced from industrial flue gas. It features a multi-layer metal filter mesh structure that improves upon the problem of rapid pressure rise in the assembly caused by the high impurity content of coal-based chips, reduces the shear rate when the molten material passes through the spinning hole, significantly suppresses expansion, greatly reduces defects and sealing of the head section, and greatly improves spinnability. Currently, the maximum spinning speed reaches 5600 m / min, achieving a level equivalent to melt spinning using petroleum-based raw materials.

[0081] Step 5. After slow cooling the molten fine streams by group, the molten fine streams are cooled by annular or lateral airflow to obtain the main body of the molten body. Here, the annular airflow temperature is 50–70°C, the dynamic pressure is 0.02–0.06 kPa, and the humidity is 50–70%; the lateral airflow temperature is 18–25°C, the wind speed is 0.4–0.6 m / s, and the humidity is 50–70%. The slow cooling device includes a heating cover (3) and an insulating tube (5), and the molten fine streams ejected from the radiating plate (4) sequentially flow into the heating cover (3) and the insulating tube (5); the temperature control range of the heating cover (3) is 300–330°C, and a good thermal insulation effect is maintained. Operation of the heating cover (3): It heats the internal air to allow the molten material to remain in the heat for a certain period of time, thereby preventing rapid cooling. At the same time, it prevents the molten material from easily rupturing; On the other hand, the stress within the polymer is removed to improve fiber stretching performance; an insulating tube (5) with a height of 50 to 500 mm is used, that is, the distance the molten microflow travels within the insulating tube (5) is 50 to 500 mm in height, and this improves the high physical property CV value and the many single-filament fluffing phenomena caused by uneven cooling. The molten microflow flowing out from the insulating tube (5) is fed into an annular blower or a side blower. Here, the function of the insulating tube (5): by extending the length of the windless zone, on the one hand, the downward airflow reduces the impact on the spinning plate (4) and the unsolidified molten material; on the other hand, it also exerts the function of delaying cooling so that the spinning stretching is completed before the molten material solidifies, which is advantageous for the generation of polymer straight chains and homogenizes the orientation of each part; the length is variable and has a significant effect on the fiber breakage stretching.

[0082] Step 6. After passing the above-described cooled yarn body through a spinning channel, stretching and fixing and winding treatments are performed to obtain an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas, wherein the parameters of stretching and fixing are: a traction speed of 300 to 4000 meters / min; oiling of the surface of the yarn body; a total stretching factor of 2.0 to 6.5; a fixing temperature of 230°C to 260°C; a total relaxation rate of 1.6 to 9%; and winding molding is performed under the condition of a winding speed of 2000 to 7000 meters / min to obtain an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas.

[0083] The fineness of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 100 to 3300 dtex, and preferably 167 to 3300 dtex.

[0084] The breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 7.15 cN / dtex or higher.

[0085] The coefficient of variation in breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 4.0% or less.

[0086] The breaking elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 11.5 to 24%.

[0087] The intermediate elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 5 to 10%.

[0088] The present application manufactures ethylene glycol using industrial flue gas as a raw material, and oxalic acid, a reaction byproduct, remains in the ethylene glycol product and cannot be completely removed from the top of the process tower when fed into the polyester production process, and a small amount of oxalic acid undergoes an esterification reaction with ethylene glycol and generates a small amount of flexible chains during the condensation reaction, which can be introduced into the polyester product, and after increasing the viscosity, obtains a coal-based condensed chip of 1.00~1.2 dl / g and spins it in an existing industrial filament production line; by controlling the screw temperature to 280~310℃, the chip is sufficiently melted, and a small amount of flexible chains are contained in the molten body, thereby ensuring that no additional chain breakage phenomenon occurs due to thermal decomposition, and the safety of the screw outlet pressure is guaranteed; the spinning assembly (1) selects and uses a multilayer metal filter mesh structure of 20~30μm to improve the problem of the pressure of the spinning assembly (1) rising rapidly due to the high impurity content in the coal-based chip; By adjusting the draw and fixation conditions to optimize them, physical properties, fluffiness, and spinnability are all ensured to meet requirements. Production process parameters suitable for coal-based chips have been established, enabling the stable production of stabilized coal-based industrial polyester filaments; furthermore, the various indicators of these coal-based industrial polyester filaments are close to those of petroleum-based filaments of the same specifications.

[0089] The purity of the ethylene glycol is 99.92%, which is close to the lower limit of the indicator and significantly lower than the 99.99% of petroleum-based ethylene glycol; the moisture content is 3.4 times that of petroleum-based ethylene glycol, meaning it not only increases the burden on the process tower but also increases the burden on the vacuum, affecting the viscosity and color values ​​of the chips. Considering these effects, the esterification temperature is increased, the liquid level in the polymerization section is raised, and the residence time is increased during the test period to compensate for potential fluctuations. Increased ash content increases impurities within the entire system, affecting the color value of the product, which in turn reduces the L value. The UV transmittance of the ethylene glycol product manufactured from industrial flue gas is low, mainly because coking material generated during the rectification process of ethylene glycol enters the product; these impurities ultimately affect the L value of the product during the polyester synthesis process, and to address the potential impact, the reaction temperature in the polymerization section is lowered to compensate for changes in color values ​​caused by high temperatures.

[0090] Polyester industrial long fibers produced using coal-based polyester chips manufactured from industrial flue gas can be used to manufacture tire cord fabrics, sewing yarns, airbags, or seat belts.

[0091] When manufacturing industrial polyester long fibers for tire cord fabrics, the process steps are specifically as follows:

[0092] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with a molar ratio of EG to PTA of 1.0 to 1.3; wherein the antimony content in the catalyst preparation solution is 150 to 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.1 MPa and a temperature of 253 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 8 to 11 kPa and a temperature of 260 to 280°C to perform a pre-condensation reaction, thereby obtaining a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 150–250 Pa and a temperature of 272–293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a density of 0.6–0.8 dL / g.

[0093] Step 2. The manufactured PET polyester chips of 0.6~0.8 dL / g are placed into the reaction vessel of a batch polymerization reactor, stirred under conditions where the vacuum level is 20 Pa or less, and the temperature inside the reaction vessel is uniformly raised to 90~120°C by heating the heat transfer fluid piping and heated for 2~10 hours, then the temperature is continued to be raised to 130~180°C and heated for 5~17 hours to obtain pre-crystallized chips, then the temperature inside the reaction vessel is uniformly raised to 200~240°C by continuing to heat the heat transfer fluid piping and heated for 27~33 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.6~0.8 dL / g to 1.00~1.2 dL / g, and the moisture content of the final high-viscosity chips is 15 ppm or less.

[0094] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 75 to 170 mm, the screw length ratio is 24 to 33, the screw outlet temperature is ≥280°C, the length ratio of the material input section, melting section, and metering section in the screw extruder is 1:(1.0~3.0):(1.0~4.0), the temperature of the material input section is 290~310°C, the temperature of the melting section is 300~310°C, and the temperature of the metering section is 280~295°C.

[0095] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipe of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is 192 to 960; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 1.0 to 3.0; and the filter mesh of the spinning assembly (1) has a filter mesh precision of 5 to 30 μm, thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 295 to 305°C.

[0096] Step 5. After slow cooling the molten fine stream, the molten fine stream is cooled by an annular air blower to obtain a four-piece body. Here, the annular air blower temperature is 50~70℃, the dynamic pressure is 0.02~0.06kPa, the humidity is 50~70%, and when slow cooling, a heating cover (3) with a temperature of 300~330℃ and an insulating tube (5) with a height of 50~120mm are used.

[0097] Step 6. After passing the above-described cooled yarn body through a spinning channel, a stretching fixation and winding process is performed to obtain an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas, specifically, after oiling the surface of the yarn body, stretching fixation and winding are performed; wherein, the stretching fixation is completed through six pairs of rollers; the temperature of the first roller pair is 80–95°C and the speed is 2700–3200 meters / min, the temperature of the second roller pair is 90–100°C and the speed is 3700–4300 meters / min, the temperatures of the third, fourth, and fifth roller pairs are 240–260°C and the speed is 5600–6000 meters / min, the sixth roller pair is not heated and the speed is 5500–5900 meters / min; parameters of stretching fixation: the total stretching factor is 2.0–3.0; The total relaxation rate is 2.0~5.0%, and the winding speed is 5000~6000 meters / min. Under these conditions, industrial polyester long fibers are obtained from coal-based polyester chips produced from industrial flue gas.

[0098] The fineness of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 1100 to 3300 dtex.

[0099] The breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 7.15 cN / dtex or higher.

[0100] The coefficient of variation in breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 3.0% or less.

[0101] The breaking elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 11.5 to 15.5%.

[0102] The medium elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 5 to 7%.

[0103] When manufacturing industrial polyester filaments for sewing, the process steps are specifically as follows:

[0104] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with an EG:PTA molar ratio of 1.0 to 1.3, wherein the antimony content in the catalyst preparation solution is 150 to 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.1 MPa and a temperature of 253 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 8 to 11 kPa and a temperature of 260 to 280°C to perform a pre-condensation reaction, thereby obtaining a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 150–250 Pa and a temperature of 272–293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a density of 0.6–0.8 dL / g.

[0105] Step 2. The manufactured PET polyester chips of 0.6~0.8 dL / g are placed into the reaction vessel of a batch polymerization reactor, stirred under conditions where the vacuum level is 20 Pa or less, and the temperature inside the reaction vessel is uniformly raised to 90~120°C by heating the heat transfer fluid piping and heated for 2~10 hours, then the temperature is continued to be raised to 130~180°C and heated for 5~17 hours to obtain pre-crystallized chips, then the temperature inside the reaction vessel is uniformly raised to 200~240°C by continuing to heat the heat transfer fluid piping and heated for 27~33 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.6~0.8 dL / g to 1.00~1.2 dL / g, and the moisture content of the final high-viscosity chips is 15 ppm or less.

[0106] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 75 to 170 mm, the screw length ratio is 24 to 33, the screw outlet temperature is ≥280°C, the length ratio of the material input section, melting section, and metering section in the screw extruder is 1:(1.0~3.0):(1.0~4.0), the temperature of the material input section is 290~310°C, the temperature of the melting section is 300~310°C, and the temperature of the metering section is 280~295°C.

[0107] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipe of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is 28 to 144; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 1.0 to 3.0; and the filter mesh of the spinning assembly (1) has a filter mesh precision of 5 to 30 μm, thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 295 to 305°C.

[0108] Step 5. After slow cooling the molten fine stream, the molten fine stream is cooled by a side air blower to obtain a shard body. Here, the side air blower temperature is 18~25℃, the wind speed is 0.4~0.6 m / s, and the humidity is 50~70%. When slow cooling, a heating cover (3) with a temperature of 300~330℃ and an insulating tube (5) with a height of 100~300 mm are used.

[0109] Step 6. After passing the above-described cooled yarn body through a spinning channel, a stretching fixation and winding process is performed to obtain an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas, specifically, after oiling the surface of the yarn body, stretching fixation and winding are performed; wherein, the stretching fixation is completed through five pairs of rollers; the temperature of the first pair of rollers is 80–95°C and the speed is 350–550 meters / min, the temperature of the second pair of rollers is 100–125°C and the speed is 350–550 meters / min, the temperature of the third pair of rollers is 100–125°C and the speed is 1400–1550 meters / min, the temperature of the fourth pair of rollers is 230–255°C and the speed is 2400–2700 meters / min, and the fifth pair of rollers is not heated and the speed is 2300–2500 meters / min; Parameters of the elongation fixation: the total elongation factor is 5 to 6.2; the total relaxation rate is 3 to 8%; and the winding speed is 2000 to 4000 meters / min. Under these conditions, industrial polyester long fibers are obtained from coal-based polyester chips produced from industrial flue gas.

[0110] The fineness of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 100 to 1110 dtex.

[0111] The breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 7.5 cN / dtex or higher.

[0112] The coefficient of variation in breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 4.0% or less.

[0113] The breaking elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 13 to 19%.

[0114] When manufacturing industrial polyester filaments for airbags, the process steps are specifically as follows:

[0115] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with a molar ratio of EG to PTA of 1.0 to 1.3; wherein the antimony content in the catalyst preparation solution is 150 to 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.1 MPa and a temperature of 253 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 8 to 11 kPa and a temperature of 260 to 280°C to perform a pre-condensation reaction, thereby obtaining a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 150–250 Pa and a temperature of 272–293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a density of 0.6–0.8 dL / g.

[0116] Step 2. The manufactured PET polyester chips of 0.6~0.8 dL / g are placed into the reaction vessel of a batch polymerization reactor, stirred under conditions where the vacuum level is 20 Pa or less, and the temperature inside the reaction vessel is uniformly raised to 90~120°C by heating the heat transfer fluid piping and heated for 2~10 hours, then the temperature is continued to be raised to 130~180°C and heated for 5~17 hours to obtain pre-crystallized chips, then the temperature inside the reaction vessel is uniformly raised to 200~240°C by continuing to heat the heat transfer fluid piping and heated for 27~33 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.6~0.8 dL / g to 1.00~1.2 dL / g, and the moisture content of the final high-viscosity chips is 15 ppm or less.

[0117] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 75 to 170 mm, the screw length ratio is 24 to 33, the screw outlet temperature is ≥280°C, the length ratio of the material input section, melting section, and metering section in the screw extruder is 1:(1.0~3.0):(1.0~4.0), the temperature of the material input section is 290~310°C, the temperature of the melting section is 300~310°C, and the temperature of the metering section is 280~295°C.

[0118] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipe of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is 72 to 300; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 1.0 to 3.0; and the filter mesh of the spinning assembly (1) has a filter mesh precision of 5 to 30 μm, thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 295 to 305°C.

[0119] Step 5. After slow cooling the molten fine streams by group, the molten fine streams are cooled by a side air blower to obtain a four-piece body. Here, the side air blower temperature is 18~25℃, the wind speed is 0.4~0.6 m / s, and the humidity is 50~70%. When slow cooling, a heating cover (3) with a temperature of 300~330℃ and an insulating tube (5) with a height of 200~400 mm are used.

[0120] Step 6. After passing the above-described cooled yarn body through a spinning channel, a stretching fixation and winding process is performed to obtain an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas, specifically, the surface of the yarn body is oiled, followed by stretching fixation and winding; wherein, the stretching fixation is completed through six pairs of rollers; The temperature of the first roller pair is 80–95°C and the speed is 300–600 meters / min; the temperature of the second roller pair is 100–135°C and the speed is 300–600 meters / min; the temperature of the third roller pair is 100–135°C and the speed is 1400–1600 meters / min; the temperature of the fourth roller pair is 230–255°C and the speed is 2500–2700 meters / min; the temperature of the fifth roller pair is 230–255°C and the speed is 2400–2600 meters / min; the sixth roller pair is not heated and the speed is 2000–2600 meters / min; parameters of stretching fixation: the total stretching factor is 5–6.2; The total relaxation rate is 7~9%, and the winding speed is 2000~4000 meters / min. Under these conditions, industrial polyester long fibers are obtained from coal-based polyester chips produced from industrial flue gas.

[0121] The fineness of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 350 to 2220 dtex.

[0122] The breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 7.8 cN / dtex or higher.

[0123] The coefficient of variation in breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 3.0% or less.

[0124] The breaking elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 18–24%.

[0125] When manufacturing industrial polyester long fibers for safety belts, the process steps are specifically as follows:

[0126] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with an EG:PTA molar ratio of 1.0 to 1.3; wherein the antimony content in the catalyst preparation solution is 150 to 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.1 MPa and a temperature of 253 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 8 to 11 kPa and a temperature of 260 to 280°C to perform a pre-condensation reaction to obtain a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 150–250 Pa and a temperature of 272–293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a density of 0.6–0.8 dL / g.

[0127] Step 2. The manufactured PET polyester chips of 0.6~0.8 dL / g are placed into the reaction vessel of a batch polymerization reactor, stirred under conditions where the vacuum level is 20 Pa or less, and the temperature inside the reaction vessel is uniformly raised to 90~120°C by heating the heat transfer fluid piping and heated for 2~10 hours, then the temperature is continued to be raised to 130~180°C and heated for 5~17 hours to obtain pre-crystallized chips, then the temperature inside the reaction vessel is uniformly raised to 200~240°C by continuing to heat the heat transfer fluid piping and heated for 27~33 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.6~0.8 dL / g to 1.00~1.2 dL / g, and the moisture content of the final high-viscosity chips is 15 ppm or less.

[0128] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 75 to 170 mm, the screw length ratio is 24 to 33, the screw outlet temperature is ≥280°C, the length ratio of the material input section, melting section, and metering section in the screw extruder is 1:(1.0~3.0):(1.0~4.0), the temperature of the material input section is 290~310°C, the temperature of the melting section is 300~310°C, and the temperature of the metering section is 280~295°C.

[0129] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipe of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is 72 to 192; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 1.0 to 3.0; and the filter mesh of the spinning assembly (1) has a filter mesh precision of 5 to 30 μm, thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 295 to 305°C.

[0130] Step 5. After slow cooling the molten fine streams by group, the molten fine streams are cooled by a side air blower to obtain a four-piece body. Here, the side air blower temperature is 18~25℃, the wind speed is 0.4~0.6 m / s, the humidity is 50~70%, and when slow cooling, a heating cover (3) with a temperature of 300~330℃ and an insulating tube (5) with a height of 300~500 mm are used.

[0131] Step 6. After passing the above-described cooled yarn body through a spinning channel, a stretching fixation and winding process is performed to obtain an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas, specifically, after oiling the surface of the yarn body, stretching fixation and winding are performed; wherein, the stretching fixation is completed through five pairs of rollers; the temperature of the first pair of rollers is 85–100°C and the speed is 300–500 meters / min, the temperature of the second pair of rollers is 110–140°C and the speed is 300–500 meters / min, the temperature of the third pair of rollers is 100–140°C and the speed is 1200–1500 meters / min, the temperature of the fourth pair of rollers is 220–250°C and the speed is 2300–2600 meters / min, and the fifth pair of rollers is not heated and the speed is 2300–4000 meters / min; Parameters of the elongation fixation: the total elongation factor is 5 to 6.5; the total relaxation rate is 1 to 5%; and the winding speed is 2000 to 4000 meters / min. Under these conditions, industrial polyester long fibers are obtained from coal-based polyester chips produced from industrial flue gas.

[0132] The fineness of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 555 to 2220 dtex.

[0133] The breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 7.9 cN / dtex or higher.

[0134] The coefficient of variation in breaking strength of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 3.0% or less.

[0135] The breaking elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 11.5 to 16.5%.

[0136] The medium elongation of the industrial polyester long fibers produced from coal-based polyester chips produced from the above industrial flue gas is 5 to 7%.

[0137] Example 1

[0138] The industrial polyester filament for tire cord fabrics is a high-modulus, low-shrinkage filament, and the manufacturing steps for the industrial polyester filament used therein are as follows:

[0139] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 2.5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with an EG:PTA molar ratio of 1.06; wherein the antimony content in the catalyst is 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.08 MPa and a temperature of 258 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 9.5 kPa and a temperature of 269 to 277°C to perform a pre-condensation reaction, thereby obtaining a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 200 Pa and a temperature of 274 to 293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a viscosity of 0.67 dL / g.

[0140] Step 2. Coal-based polyester chips produced from industrial flue gas with a viscosity of 0.67 dl / g are placed in a batch rotary drum reaction vessel, that is, a batch solid-state polymerization reaction vessel, and rotated under conditions of a vacuum of 10 Pa. Then, the temperature inside the reaction vessel is uniformly raised to 100°C by heating the heat transfer fluid piping and heated for 3 hours, then the temperature is continued to be raised to 160°C and heated for 6 hours to obtain pre-crystallized chips, and then the temperature inside the reaction vessel is uniformly raised to 223°C by continuing to heat the heat transfer fluid piping and heated for 30 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.67 dl / g to 1.13 dL / g and high-viscosity chips are formed.

[0141] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 130 mm, and the length and temperature of the material input section, the length and temperature of the melting section, the length and temperature of the metering section, and the temperature of the screw outlet are as shown in Table 1.

[0142] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipes of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh within the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is as shown in Table 2; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 1.3; the micropore passage length refers to a length corresponding to the direction of molten material flow within the spinning holes; and the filter mesh of the spinning assembly (1) has a maximum filter mesh precision of 25 μm (i.e., the maximum precision among the 4-layer metal filter meshes), thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 298°C.

[0143] Step 5. After slow cooling the molten fine streams by group, the molten fine streams are cooled by an annular air blower to obtain a filament body. Here, the annular air blower temperature is 60°C, the dynamic pressure is 0.03 kPa, and the humidity is 60%. In the slow cooling device, the temperature of the heating cover (3) is 330°C, and the height of the insulation tube (5) is 80 mm, thereby improving the high physical property CV value and the phenomenon of many single thread fluff caused by uneven cooling.

[0144] Step 6. After passing the above-described cooled yarn body through a spinning channel and performing stretch fixation and winding processes, an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas is obtained, specifically, after oiling the surface of the yarn body, stretch fixation and winding is performed; wherein, the stretch fixation is completed through six pairs of rollers; the temperature of the first roller pair is 90°C and the speed is 2911 meters / min, the temperature of the second roller pair is 95°C and the speed is 4075 meters / min, the temperatures of the third, fourth, and fifth roller pairs are 247°C and the speed is 5821 meters / min, the sixth roller pair is not heated and the speed is 5600 meters / min; parameters of the stretch fixation: the total stretch factor is 2.0; The total relaxation rate is 3.95%, and industrial polyester long fibers are obtained by winding and molding under conditions of a winding speed of 5600 meters / min using coal-based polyester chips produced from industrial flue gas.

[0145] Example 2

[0146] The manufacturing steps for industrial polyester filaments for sewing are as follows:

[0147] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 2.5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with an EG:PTA molar ratio of 1.06; wherein the antimony content in the catalyst is 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.08 MPa and a temperature of 258 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 9.5 kPa and a temperature of 269 to 277°C to perform a pre-condensation reaction, thereby obtaining a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 200 Pa and a temperature of 274 to 293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a viscosity of 0.67 dL / g.

[0148] Step 2. Coal-based polyester chips produced from industrial flue gas with a viscosity of 0.67 dl / g are placed in a batch rotary drum reaction vessel, that is, a batch solid-state polymerization reaction vessel, and rotated under conditions of a vacuum of 10 Pa. Then, the temperature inside the reaction vessel is uniformly raised to 100°C by heating the heat transfer fluid piping and heated for 3 hours, then the temperature is continued to be raised to 160°C and heated for 6 hours to obtain pre-crystallized chips, and then the temperature inside the reaction vessel is uniformly raised to 220°C by continuing to heat the heat transfer fluid piping and heated for 29 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.67 dl / g to 1.12 dL / g and high-viscosity chips are formed.

[0149] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 125 mm, and the length and temperature of the material input section, the length and temperature of the melting section, the length and temperature of the metering section, and the temperature of the screw outlet are as shown in Table 1.

[0150] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipes of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is as shown in Table 2; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 2.0; the micropore passage length refers to a length corresponding to the direction of molten material flow within the spinning holes; and the filter mesh of the spinning assembly (1) has a maximum filter mesh precision of 20 μm, thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 296°C.

[0151] Step 5. After slow cooling the molten fine streams by group, the molten fine streams are cooled by a side air blower to obtain a filament body. Here, the side air blower temperature is 25℃, the wind speed is 0.5 m / s, and the humidity is 60%. In the slow cooling device, the temperature of the heating cover (3) is 330℃, and the height of the insulation tube (5) is 150 mm, thereby improving the high physical property CV value and the phenomenon of many single thread fluff caused by uneven cooling.

[0152] Step 6. After passing the above-described cooled yarn body through a spinning channel and performing stretch fixation and winding treatment, an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas is obtained, specifically, after oiling the surface of the yarn body, stretch fixation and winding is performed; wherein, the stretch fixation is completed through five pairs of rollers; the temperature of the first roller pair is 85°C and the speed is 449 meters / min, the temperature of the second roller pair is 115°C and the speed is 456 meters / min, the temperature of the third roller pair is 115°C and the speed is 1464 meters / min, the temperature of the fourth roller pair is 240°C and the speed is 2540 meters / min, and the fifth roller pair is not heated and the speed is 2410 meters / min; wherein, the parameters of the stretch fixation: the total stretch factor is 5.66; The total relaxation rate is 5.83%, and industrial polyester long fibers are obtained by winding and molding under conditions of a winding speed of 2400 meters / min using coal-based polyester chips produced from industrial flue gas.

[0153] Example 3

[0154] The manufacturing steps for industrial polyester long fibers for airbags are as follows:

[0155] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 2.5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with an EG:PTA molar ratio of 1.06; wherein the antimony content in the catalyst is 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.08 MPa and a temperature of 258 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 9.5 kPa and a temperature of 269 to 277°C to perform a pre-condensation reaction, thereby obtaining a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 200 Pa and a temperature of 274 to 293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a viscosity of 0.67 dL / g.

[0156] Step 2. Coal-based polyester chips produced from industrial flue gas with a viscosity of 0.67 dl / g are placed in a batch rotary drum reaction vessel, that is, a batch solid-state polymerization reaction vessel, and rotated under conditions of a vacuum of 10 Pa. Then, the temperature inside the reaction vessel is uniformly raised to 100°C by heating the heat transfer fluid piping and heated for 3 hours, then the temperature is continued to be raised to 160°C and heated for 6 hours to obtain pre-crystallized chips, and then the temperature inside the reaction vessel is uniformly raised to 220°C by continuing to heat the heat transfer fluid piping and heated for 29 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.67 dl / g to 1.12 dL / g and high-viscosity chips are formed.

[0157] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 130 mm, and the length and temperature of the material input section, the length and temperature of the melting section, the length and temperature of the metering section, and the temperature of the screw outlet are as shown in Table 1.

[0158] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipes of each spinning box (2) to form a spinning molten material, the spinning molten material is fed into the spinning assembly (1) via a metering pump, filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is as shown in Table 2; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 2.0; the micropore passage length refers to a length corresponding to the direction of molten material flow within the spinning holes; and the filter mesh of the spinning assembly (1) has a maximum filter mesh precision of 20 μm, thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 296°C.

[0159] Step 5. After slow cooling the molten fine streams by group, the molten fine streams are cooled by a side air blower to obtain a filament body. Here, the side air blower temperature is 25℃, the wind speed is 0.55 m / s, and the humidity is 60%. In the slow cooling device, the temperature of the heating cover (3) is 330℃, and the height of the insulation tube (5) is 250 mm, thereby improving the high physical property CV value and the phenomenon of many single thread fluff caused by uneven cooling.

[0160] Step 6. After passing the above-described cooled yarn body through a spinning channel, and then performing stretch fixation and winding treatment, an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas is obtained, specifically, after oiling the surface of the yarn body, stretch fixation and winding is performed; wherein, the stretch fixation is completed through six pairs of rollers; the temperature of the first roller pair is 85°C and the speed is 441 meters / min, the temperature of the second roller pair is 120°C and the speed is 542 meters / min, the temperature of the third roller pair is 120°C and the speed is 1764 meters / min, the temperature of the fourth roller pair is 237°C and the speed is 2603 meters / min, the temperature of the fifth roller pair is 237°C and the speed is 2500 meters / min, and the sixth roller pair is not heated and the speed is 2400 meters / min; Here, the parameters of the draw fixation are: the total draw factor is 5.9; the total relaxation rate is 8.46%; and the drawer is formed by winding at a winding speed of 2400 meters / min to obtain industrial polyester long fibers made from coal-based polyester chips produced from industrial flue gas.

[0161] Example 4

[0162] The manufacturing steps for industrial polyester long fibers for safety belts are as follows:

[0163] Step 1. PTA, EG produced from industrial flue gas, a catalyst preparation solution, and 2.5 ppm of an acetic acid-based inhibitor are added to a slurry preparation system and stirred to prepare a slurry with an EG:PTA molar ratio of 1.06; wherein the antimony content in the catalyst is 180 ppm; then, the prepared slurry is transferred to an esterification reaction vessel via a slurry transfer pump and stirred under a pressure of 0.06 to 0.08 MPa and a temperature of 258 to 273°C to obtain an initial esterification product. Then, the initial esterification product is transferred through a pressure difference to a pre-condensation reaction vessel with a vacuum of 9.5 kPa and a temperature of 269 to 277°C to perform a pre-condensation reaction, thereby obtaining a polyester-free polymer. Next, a polyester melt is obtained by performing a final condensation reaction of the prepolymer through a prepolymer transfer pump under conditions of a vacuum of 200 Pa and a temperature of 274 to 293°C; finally, the polyester melt undergoes cooling and pelletization to produce PET polyester chips with a viscosity of 0.67 dL / g.

[0164] Step 2. Coal-based polyester chips produced from industrial flue gas with a viscosity of 0.67 dl / g are placed in a batch rotary drum reaction vessel, that is, a batch solid-state polymerization reaction vessel, and rotated under conditions of a vacuum of 10 Pa. Then, the temperature inside the reaction vessel is uniformly raised to 100°C by heating the heat transfer fluid piping and heated for 3 hours, then the temperature is continued to be raised to 160°C and heated for 6 hours to obtain pre-crystallized chips, and then the temperature inside the reaction vessel is uniformly raised to 223°C by continuing to heat the heat transfer fluid piping and heated for 30 hours, so that after solid-state polymerization, the viscosity of the polyester chips is improved from 0.67 dl / g to 1.13 dL / g and high-viscosity chips are formed.

[0165] Step 3. After transferring the solid-state polymerized high-viscosity chips to a screw extruder, the molten material is extruded through the screw extruder, wherein the screw diameter of the screw extruder is 130 mm, and the length and temperature of the material input section, the length and temperature of the melting section, the length and temperature of the metering section, and the temperature of the screw outlet are as shown in Table 1.

[0166] Step 4. The extruded molten material is distributed through the molten material main pipe to the molten material pipes of each spinning box (2) to form a spinning molten material, and the spinning molten material flows into the spinning assembly (1) through a metering pump, is filtered through a filter mesh in the spinning assembly (1), and the molten material is ejected from the spinning plate (4) to obtain a molten material microflow. Here, the number of spinning holes in the spinning plate (4) is as shown in Table 2; the ratio of the micropore passage length of the spinning holes to the diameter of the spinning holes is 2.0; the micropore passage length refers to a length corresponding to the direction of molten material flow within the spinning holes; and the filter mesh of the spinning assembly (1) has a maximum filter mesh precision of 25 μm, thereby improving the uniformity of the spinning body. Good fluidity and pressure of the molten material are maintained using a biphenyl temperature of 296°C.

[0167] Step 5. After slow cooling the molten fine streams by group, the molten fine streams are cooled by a side air blower to obtain a filament body. Here, the side air blower temperature is 25℃, the wind speed is 0.55 m / s, and the humidity is 60%. In the slow cooling device, the temperature of the heating cover (3) is 310℃, and the height of the insulation tube (5) is 450 mm, thereby improving the high physical property CV value and the phenomenon of many single thread fluff caused by uneven cooling.

[0168] Step 6. After passing the above-described cooled yarn body through a spinning channel, a stretching fixation and winding process is performed to obtain an industrial polyester long fiber made from coal-based polyester chips produced from industrial flue gas, specifically, after oiling the surface of the yarn body, stretching fixation and winding are performed; wherein, the stretching fixation is completed through five pairs of rollers; the temperature of the first roller pair is 90°C and the stretching speed is 403 meters / min, the temperature of the second roller pair is 120°C and the stretching speed is 413 meters / min, the temperature of the third roller pair is 120°C and the stretching speed is 1314 meters / min, the temperature of the fourth roller pair is 230°C and the stretching speed is 2457 meters / min, the fifth roller pair is not heated and the stretching speed is 2400 meters / min; wherein, the parameters of the stretching fixation: the total stretching factor is 6.09; The total relaxation rate is 2.34%, and industrial polyester long fibers are obtained by winding and molding under conditions of a winding speed of 2400 meters / min using coal-based polyester chips produced from industrial flue gas.

[0169] Comparative Examples 1 to 4

[0170] The coal-based chips of Examples 1 to 4 were each replaced with petroleum-based PET chips of 0.67 dl / g, and long polyester fibers for different products were manufactured using the petroleum-based chips by referring to the methods of Examples 1 to 4. The relevant parameters during the steps are as shown in Tables 1 to 4.

[0171] In Examples 1 to 4 and Comparative Examples 1 to 4, the filter mesh of the spinning assembly (1) uses a 4-layer metal filter mesh, which has good high-temperature antioxidant properties, erosion resistance and corrosion resistance against the molten material, and good structural stability. In addition, the filtration precision is gradually reduced layer by layer, which can remove impurities and gel particles that may remain in the coal-based chip molten material, prevent clogging of the spinning holes of the spinning assembly (1), and form a stable spinning pressure, which is advantageous for uniformly distributing the molten material to all spinning holes of the spinning plate and ensuring that the molten material has the same flow path length, flow rate, and pressure. For example, looking from top to bottom, the precision of the first layer metal filter mesh is 20 μm or 25 μm, the precision of the second layer metal filter mesh is 15 μm, the precision of the third layer metal filter mesh is 10 μm, and the precision of the fourth layer metal filter mesh is 5 μm. The 4-layer metal filter mesh is compressed to form an integral structure.

[0172] [Table 1] Screw Extruder Related Parameters

[0173]

[0174] [Table 2] Radiation-related parameters 1

[0175]

[0176] [Table 3] Radiation-related parameters 2

[0177]

[0178] [Table 4] Parameters related to the elongation section

[0179]

[0180] The relevant performance parameters of the industrial polyester long fibers obtained in Examples 1 to 4 and Comparative Examples 1 to 4 are shown in Tables 5 to 7.

[0181] [Table 5] Relevant Performance Parameters of Industrial Polyester Long Fibers

[0182]

[0183] [Table 6] Relevant Performance Parameters of Industrial Polyester Long Fibers

[0184]

[0185] [Table 7] Relevant Performance Parameters of Industrial Polyester Long Fibers

[0186]

[0187] Here, fineness, coefficient of variation of fineness CV, breaking strength, breaking strength, coefficient of variation of breaking strength CV, breaking elongation, breaking elongation CV, intermediate elongation, and dry heat shrinkage are measured according to the GB / T 16604 standard. The adhesion rate is measured according to the GB / T6504-NMR standard. The degree of networking is measured according to the Hook Needle Method.

[0188] The relevant performance parameters of the petroleum-based chips used in Comparative Examples 1 to 4 are as shown in Table 8 below, and the relevant performance parameters of the coal-based chip used in Example 3 are also as shown in Table 8 below.

[0189] [Table 8] Performance comparison of oil-based chips and coal-based chips manufactured from flue gas

[0190]

[0191] Here, the L and B values ​​are measured using the Lab color analysis method.

[0192] Comparative Example 5

[0193] Adjusting the esterification reaction temperature, polycondensation reaction temperature, amount of catalyst, and use of inhibitor all affect the performance of the chip, as shown in Table 9.

[0194] [Table 9] Performance parameters of coal-based chips produced from industrial flue gas under different polyester reaction process conditions

[0195]

[0196] Here, viscosity and DEG are measured according to the GB / T 14190 standard, and terminal carboxyl groups are measured by a potentiometric titrator.

[0197] As can be seen from the data in Table 9, other performance characteristics of the chips did not change significantly after the addition of the inhibitor, but the diethylene glycol (DEG) content decreased significantly. Since the DEG content in polyester essentially represents the ether bond content, the presence of ether bonds disrupts the regularity of the polymer's orderly arrangement to a certain extent, making crystallization difficult, lowering the fiber strength, and increasing the dry heat shrinkage rate. Furthermore, ether bonds in diethylene glycol can alter the ethylene glycol segments of the polyester polymer, leading to an increase in ether bonds within the polymer. Since ether bonds are groups with an affinity for dyes, they affect the dyeing performance of polyester fibers.

[0198] Comparative Example 6

[0199] Compared to Example 4, the distinguishing feature of Comparative Example 6 is that the 4-layer metal filter mesh is replaced with a 3-layer filtration structure commonly used in petroleum-based chips, the middle layer is a felt mesh, the upper and lower layers are supported by screen plates, and the filtration precision is 20 μm.

[0200] Comparative Example 7

[0201] Compared to Example 4, the distinguishing feature of Comparative Example 7 is that the ratio of the lengths of the material input section, the melting section, and the metering section is 1:1:1, and the lengths of the material input section, the melting section, and the metering section are all 864 mm.

[0202] The inspection results of the polyester industrial long fibers prepared in Comparative Examples 6 and 7 are as shown in Table 10 below, and the inspection data for the single yarn count and lint amount during the process of preparing the polyester industrial long fibers in Comparative Examples 6, 7, 4 and 4 are as shown in Table 11 below.

[0203] [Table 10] Inspection results of industrial polyester long fibers prepared in Comparative Examples 6 and 7

[0204]

[0205] [Table 11] Single yarn count and lint amount measurement data for Comparative Example 6, Comparative Example 7, Example 4, and Comparative Example 4

[0206]

[0207] In summary, since the filter mesh structure used in Comparative Example 6 is a felt mesh, the filtration structure becomes clogged due to the relatively large amount of impurities in the process of manufacturing industrial long fibers of polyester from coal-based chips, and the pressure rise of the spinning assembly (1) increases rapidly. As the pressure of the assembly rises, the metering pump efficiency decreases, the fineness decreases, the melt decomposition intensifies, the strength and elongation decrease, and the fluff and single yarn increase significantly.

[0208] Oxalic acid is present in the reaction byproduct of ethylene glycol produced from waste industrial flue gas, and oxalic acid remains in ethylene glycol; the boiling point of oxalic acid is 150 As it cannot be removed from the process tower, oxalic acid is discharged along with the ethylene glycol product at the bottom of the process tower and enters the production system of the polymerization section, causing an increase in flexible chains during the polymerization process, which lowers the thermal stability of the polyester product. Consequently, although a large amount of decomposition occurs due to the high screw temperature, if the temperature is low and the length of the metering section is not increased, the fluidity of the melt decreases, it is not mixed uniformly, the spinnability decreases, and the uniformity of stretching is affected. Therefore, in Comparative Example 7, the fineness decreases, the fineness CV increases, the strength and elongation rate decrease, the strength CV increases, and fluff and single yarns increase significantly.

[0209] The present application controls the terminal carboxyl group content, intrinsic viscosity, and viscosity increase of coal-based chips, extends the residence time by appropriately extending the melting or metering section, and installs a multilayer metal filter mesh, thereby enabling the performance parameters of industrial polyester long fibers made from coal-based chips to be closer to those of industrial polyester long fibers made from petroleum-based chips.

[0210] The above-described embodiments are intended to explain the technical solution of the present application and are not intended to limit it. The present application has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of the present application, and that all such modifications and substitutions that do not depart from the spirit and scope of the technical solution of the present application should be included in the claims of the present application.

[0211] Industrial applicability

[0212] The present application selects and uses ethylene glycol produced from industrial flue gas as a raw material to prepare a slurry with an EG:PTA molar ratio of 1.0 to 1.3, synthesizes coal-based PET chips with an intrinsic viscosity of 0.6 to 0.8 dl / g and a terminal carboxyl group content of 25 to 30 mol / t using an antimony-containing catalyst and an acetic acid-based inhibitor, obtains coal-based high-viscosity chips with a viscosity of 1.00 to 1.2 dl / g after increasing the viscosity, and then spins them in an industrial filament production line; controls the screw temperature and adjusts the lengths of the material input section and the metering section to ensure that the chips are sufficiently melted, thereby ensuring that no additional chain breakage occurs due to pyrolysis by including a small amount of flexible chains in the molten material, and guarantees the safety of the screw outlet pressure; and installs a filter member in the spinning assembly to improve the problem of the pressure in the spinning assembly rising rapidly due to the high impurity content in the coal-based chips. Adjust the stretching fixation conditions to optimize them so that physical properties, fluffiness, and spinnability all meet the requirements.

[0213] In addition, the method for producing polyester chips and manufacturing long polyester fibers for the polyester industry using ethylene glycol produced from industrial flue gas disclosed in this application, and the long polyester fibers for the polyester industry produced therefrom, can be applied to various industries. For example, the method for producing polyester chips and manufacturing long polyester fibers for the polyester industry using ethylene glycol produced from industrial flue gas, and the long polyester fibers for the polyester industry produced therefrom, can be applied to the chemical fiber field.

Claims

Claim 1 A method for producing polyester chips and manufacturing industrial polyester long fibers using ethylene glycol produced from industrial flue gas, comprising: adding terephthalic acid (PTA), ethylene glycol (EG) produced from industrial flue gas, a catalyst preparation solution, and 1 to 5 ppm of an acetic acid-based inhibitor to a slurry preparation system and stirring to prepare a slurry having an EG:PTA molar ratio of 1.0 to 1.3; transferring the slurry to an esterification reaction vessel to obtain an initial esterification product; transferring the initial esterification product into a pre-condensation reaction vessel to perform a pre-condensation reaction to obtain a polyester prepolymer; and performing a final condensation reaction on the polyester prepolymer to obtain a polyester melt. Step 1, manufacturing PET polyester chips of 0.6~0.8 dL / g by cooling and pelletizing the above polyester melt; Step 2, placing the manufactured PET polyester chips of 0.6~0.8 dL / g into a reaction vessel of a batch polymerization reactor to obtain PET polyester chips of 1.00~1.2 dL / g; Step 3, transferring the PET polyester chips of 1.00~1.2 dL / g to a screw extruder and extruding the melt through the screw extruder; Step 4, distributing the melt extruded from the screw extruder to a spinning box to form a spinning melt, and after filtration under conditions of 295~305°C, discharging the spinning melt from a spinning plate to obtain a melt flow; Step 5, after slow cooling the above melt flow, cooling the melt flow using an annular blowing or lateral blowing method to obtain a filament body; A method characterized by including step 6, which involves passing a cooled filament body through a spinning channel and then performing stretching, fixing, and winding treatments to obtain a polyester industrial long fiber made from coal-based polyester chips. Claim 2 A method according to claim 1, wherein the catalyst preparation solution is a catalyst having an antimony content of 150 to 180 ppm; and / or, the pressure of the esterification reaction vessel is set to 0.06 to 0.1 MPa and the temperature is set to 253 to 273°C; and / or, the vacuum of the preliminary polycondensation reaction is 8 to 11 kPa and the temperature is 260 to 280°C; and / or, the vacuum of the final polycondensation reaction is 150 to 250 Pa and the temperature is 272 to 293°C. Claim 3 A method according to claim 1 or 2, wherein the esterification reaction vessel comprises a first esterification reaction vessel and a second esterification reaction vessel, wherein the temperature of the first esterification reaction vessel is set to 258 to 262°C; and the temperature of the second esterification reaction vessel is set to 262 to 276°C. Claim 4 A method according to any one of claims 1 to 3, wherein, under conditions where the vacuum level inside the reaction vessel of the batch polymerization reactor is 20 Pa or less, the temperature inside the reaction vessel is uniformly raised to 90 to 120°C by heating the heat transfer fluid piping and heated for 2 to 10 hours, then the temperature is subsequently raised to 130 to 180°C and heated for 5 to 17 hours to obtain a preliminary crystallization chip, and then the temperature is subsequently raised uniformly to 200 to 240°C and heated for 27 to 33 hours, so that after solid-state polymerization, the viscosity of the polyester chip is improved from 0.6 to 0.8 dl / g to 1.00 to 1.2 dL / g, and the moisture content of the final high-viscosity chip is 15 ppm or less. Claim 5 A method according to any one of claims 1 to 4, wherein the screw outlet temperature of the screw extruder is ≥280℃; and / or, the length ratio of the material input section, melting section, and metering section of the screw extruder is 1:(1.0~3.0):(1.0~4.0), preferably, the length ratio of the material input section, melting section, and metering section of the screw extruder is 1:(1.5~2.5):(2.5~4); and more preferably, the length ratio of the material input section, melting section, and metering section of the screw extruder is 1:(1.8~2.2):(2.8~4). Claim 6 A method according to any one of claims 1 to 5, characterized in that the screw diameter of the screw extruder is 75 to 170 mm and the screw length ratio is 24 to 33. Claim 7 A method according to any one of claims 1 to 6, wherein the filtration uses a multilayer metal filter mesh, the filtration precision of the multilayer metal filter mesh decreases layer by layer along the direction of travel of the radiating melt, and the radiating melt is uniformly distributed to the radiating holes. Claim 8 A method according to claim 7, characterized in that the ratio of the micropore passage length of the radiating hole to the diameter of the radiating hole is 1.0 to 3.0; and / or, the filtration precision is 5 to 30 μm; preferably, the filtration precision is 20 to 30 μm. Claim 9 A method according to any one of claims 1 to 8, wherein the slow cooling treatment is completed through a heating cover having a temperature of 300 to 330°C and an insulating tube having a height of 50 to 500 mm; the annular blower temperature is 50 to 70°C, the dynamic pressure is 0.02 to 0.06 kPa, and the humidity is 50 to 70%; the side blower temperature is 18 to 25°C, the wind speed is 0.4 to 0.6 m / s, and the humidity is 50 to 70%. Claim 10 A method according to any one of claims 1 to 9, wherein the parameters of the stretching fixation include a traction speed of 300 to 4000 meters / min; a total stretching factor of 2.0 to 6.5; a fixation temperature of 230℃ to 260℃; a total relaxation rate of 1.6 to 9%; and a winding speed of 2000 to 7000 meters / min. Claim 11 A method according to any one of claims 1 to 10, wherein the terminal carboxyl group content of the polyester chip produced from the industrial flue gas is 25 to 30 mol / t; and / or, the color value L of the polyester chip produced from the industrial flue gas is ≥79; and / or, the color value b of the polyester chip produced from the industrial flue gas is 1.5 ± 2.0; and / or, the moisture content of the polyester chip produced from the industrial flue gas is ≤0.40%; and / or, the diethylene glycol content of the polyester chip produced from the industrial flue gas is 0.80 to 1.00%. Claim 12 A method according to any one of claims 1 to 11, wherein the fineness of the polyester industrial filament is 100 to 3300 dtex, preferably the fineness of the polyester industrial filament is 167 to 3300 dtex; and / or, the breaking strength of the polyester industrial filament is ≥7.15 cN / dtex; and / or, the coefficient of variation of the breaking strength of the polyester industrial filament is ≤4.0%; and / or, the breaking elongation of the polyester industrial filament is 11.5 to 24%; and / or, the intermediate elongation of the polyester industrial filament is 5 to 10%. Claim 13 A method according to any one of claims 1 to 12, characterized in that the ethylene glycol content in the ethylene glycol produced from the industrial flue gas is 99% or more. Claim 14 A method according to any one of claims 1 to 12, characterized in that the ethylene glycol content in the ethylene glycol produced from the industrial flue gas is 99.9% or higher. Claim 15 Polyester industrial long fibers, characterized by being manufactured based on a method according to any one of claims 1 to 14. Claim 16 In claim 15, the above-mentioned polyester industrial long fiber is characterized as being for manufacturing tire cord fabric, safety belt, airbag, or sewing yarn.

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