Manufacturing method for high-quality polyester industrial yarn

Abstract

The present invention relates to a method for manufacturing high-quality polyester industrial yarn. After extruding the molten material from the spinneret, it is slowly cooled by a pre-cooler. The pre-cooler includes a hollow ring, an electromagnetic induction coil, a steel outer cylinder, a steel inner cylinder, a gas heating unit, a gas control unit, and a compressed air supply station. The inner wall of the hollow ring is provided with a mesh porous structure, and the outer wall is provided with a plurality of symmetrical small holes. The compressed air supply station is sequentially connected to the gas heating unit and the gas control unit via a main air pipe, and the gas control unit communicates with the plurality of symmetrical small holes via a plurality of branch air pipes. The electromagnetic induction coil heats the steel outer cylinder and the steel inner cylinder. According to the method of the present invention, the yarns located on the inner and outer circumferences of the spinneret can be simultaneously heated and cooled, eliminating cooling non-uniformity caused by the large surface area of ​​the industrial yarn spinneret and the large distance between the inner and outer yarns, and also suppressing the influence of instability in the airflow field and temperature field on the yarn.

Description

Technical Field

[0001] The present invention belongs to the field of fiber technology and relates to a method for manufacturing high-quality polyester industrial yarns.

Background Art

[0002] High-strength industrial yarns or high-modulus, low-shrinkage industrial yarns are required to have good mechanical properties due to their special uses and exhibit high orientation and high crystallinity from the perspective of the polymer molecular structure. In the melt spinning process, the melt is extruded from the spinneret and cooled to form as-spun fibers or undrawn yarns. Since the crystallization and crystal form transition of the polymer occur during the cooling process, the quality control of the cooling affects directly the quality of the industrial yarn products.

[0003] When the melt is extruded from the spinneret, the temperature reaches 300 °C, and moreover, the linear density of the single filament of the industrial yarn is large. Therefore, rapid cooling will affect the molecular structure, resulting in a so-called "skin-core structure", and in severe cases, melt fracture will occur. In order to cool the undrawn yarn slowly, usually a slow cooling zone is provided between the spinneret and the cooling air.

[0004] The slow cooling zone currently used in industrial yarn production is a circular cavity with both ends open, which has a heating and heat preservation function, and realizes slow cooling by passing the undrawn yarn through the cavity.

[0005] As shown in FIG. 1, the slow cooling zone in the prior art mainly heats the aluminum plate 3 by the heating wire 2, and after raising the temperature of the entire aluminum plate 3, heats the air in the circular cavity by heat radiation. The following problems exist in this method: Firstly, heat transfer is slow, the efficiency is low, and the heat loss is large.

[0006] Secondly, the spinneret for industrial yarn has a large surface area (Φ260 mm), and heat is radiated from the inner wall of the annular cavity towards the center, resulting in a high temperature on the outer circumference of the spinneret and a low temperature near the inner circumference. As shown in Table 1, temperature non-uniformity occurs on the inner and outer circumferences of the spinneret, which affects the fluidity of the molten material and the uniformity of molecular chain orientation between single filaments. The literature "Development of the Direct Spinning FDY44D Variety [D]. Suzhou University, 2005" points out that differences in the slow-cooling temperature affect the spinneret surface temperature and yarn running stability, leading to fuzzing and breakage, and making it easy to produce stripes in fiber dyeing. In polyester industrial yarn fibers manufactured using conventional technology, the linear density CV value is ≤1.50%, the single filament strength CV value is ≤1.00%, and the single filament diameter CV value is ≤0.80%.

[0007] Table 1 Measured temperatures of the center and outer periphery of a Φ260 mm spinneret

[0008] [Table 1]

[0009] Thirdly, in conventional slow-cooling regions, the upper end of the circular cavity is sealed to the outer shell of the component by insulating material. As the yarn bundle passes through the circular cavity at high speed, some of the air and heat are carried away, and new cold air from the outside is passively supplied into the cavity. As a result, an unstable airflow field and temperature field are created within the slow-cooling region, making turbulence more likely and increasing the non-uniformity of the yarn. Furthermore, the direction of the supplied cold air is opposite to the direction of fiber movement, hindering fiber movement and being detrimental to improving fiber diameter uniformity.

[0010] Patent CN2063527U discloses a nitrogen-filled pre-cooler, in which an electric heating wire is wrapped around an outer cylinder, small holes are provided in the inner cylinder, nitrogen is passed between the inner and outer cylinders, and the nitrogen is heated by the electric heating wire to keep the yarn bundle warm. However, this device has a complex structure, high nitrogen introduction costs, and fails to solve the problem of uneven cooling of the yarn bundles inside and outside the spinneret.

[0011] Patent CN111910271B discloses a spinning apparatus and its slow-cooling device, which has an exhaust window in the inner wall of the slow-cooling device and actively keeps the yarn bundle warm by blowing hot air out of the exhaust window. However, since the hot air is blown out from the inner wall side, the amount of heat decreases with increasing distance, and thus the uneven cooling of the yarn bundle inside and outside the spinneret cannot be solved.

[0012] Patent CN107906684B discloses a spinning method that extends the spun-up cycle for producing irregularly shaped cross-section fibers. This method involves adding a special heat-retaining plate within the slow-cooling zone to suppress the diffusion of heat generated by the yarn bundle and to retain heat in the initial fibers. However, this device is highly dependent on the heat-retaining material, and its heat retention effect decreases as the material deteriorates.

[0013] As the development of high-value-added industrial yarns progresses, physical properties such as dye uniformity, lot-to-lot color variation, single-fiber linear density (CV) value, and single-fiber strength are becoming increasingly important. Therefore, improving slow-cooling equipment to provide a method for producing high-quality polyester industrial yarn is of paramount importance. [Overview of the project] [Problems that the invention aims to solve]

[0014] The objective of this invention is to solve the problems that exist in the prior art and to provide a method for producing high-quality polyester industrial yarn. [Means for solving the problem]

[0015] To achieve the above objective, the present invention employs the following technical solution.

[0016] In the method for producing a type of high-quality polyester industrial yarn of the present invention, after extruding the molten body from the spinneret, slow cooling with a pre-cooler, cooling in a windless area, cooling with side airflow, application of an oil agent, stretching, shape determination, interlacing, and winding are performed sequentially.

[0017] The pre-cooler includes a hollow ring, electromagnetic induction coil, insulation layer, steel outer cylinder, steel inner cylinder, external power supply, electronic oscillator, controller, gas heating unit, gas control unit, compressed air supply station, and PC terminal.

[0018] The inner wall of the hollow ring is provided with a mesh-like porous structure, and the outer wall is provided with multiple small holes arranged symmetrically with respect to the center of the hollow ring.

[0019] Air supplied from the compressed air station enters the gas heating unit through the main air piping and is heated. The heated air then enters the gas control unit through the main air piping. The gas control unit includes temperature control and flow control. Temperature control regulates the temperature of the hot air, adjusting the heating unit by sending signals from a PC terminal to ensure the air temperature reaches the set process temperature. Flow control regulates the amount of hot air entering the hollow ring, with the PC terminal adjusting the opening of the control valve. After passing through the gas control unit, the hot air is connected to the hollow ring via (two or more) branch air pipes. Multiple small holes (the same number as the branch air pipes from the gas control unit) are symmetrically arranged on the outer surface of the hollow ring, and the branch air pipes are connected to the holes by screws or clamps.

[0020] The upper end of the steel outer cylinder is connected to the spinneret via a hollow ring. A high-temperature resistant insulation block is provided at the upper end of the steel inner cylinder and is fixed to the center of the spinneret via this block. The high-temperature resistant insulation block is screw-connected to the spinneret.

[0021] The hollow ring and the high-temperature resistant insulation block are the same height, and the steel outer cylinder and the steel inner cylinder are also the same height. Furthermore, the cross-sectional area of ​​the region between the inner and outer walls of the steel outer cylinder and the region between the inner and outer walls of the steel inner cylinder are the same. In other words, for both the steel outer cylinder and the steel inner cylinder, the annular cross-sectional area formed by the difference between the outer diameter and the inner diameter is equal.

[0022] The electromagnetic induction coil is mounted on the outer surface of the steel outer cylinder through a heat insulation layer, and an external power supply is connected to the electromagnetic induction coil through an electronic oscillator. The PC terminal is connected to the electronic oscillator through a controller.

[0023] The external power supply applies an oscillating current to the induction coil through the electronic oscillator, causing the electrons in the steel outer cylinder and the steel inner cylinder to generate high-frequency vibrations and heat under the action of the electromagnetic field. The controller controls the on / off of the current, causing the electronic oscillator to generate a high-frequency alternating current in the electromagnetic induction coil. Thereby, the current in the electromagnetic induction coil can be controlled from the PC terminal, making it possible to control the temperatures of the steel outer cylinder and the steel inner cylinder.

[0024] Specifically, according to the principle of electromagnetism, when an alternating current flows through a coil, an alternating magnetic field is formed around it. Let the magnetic flux be Φ, the number of coil turns be N, and the induced electromotive force be e, then the induced electromotive force is

[0025]

Number

[0026] given by. When the magnetic flux Φ changes in a sine wave shape and its maximum value is Φm, then

[0027]

Number

[0028] is obtained, and further from the relationship between equations (1) and (2) and ω = 2πf,

[0029]

Number

[0030] ​​​​​​​​​​​

[0032] It is represented as follows.

[0033] If the effective value of the induced current generated inside the steel cylinder is I, then according to Joule's law, the amount of heat Q generated by electromagnetic induction is

[0034]

number

[0035] It is expressed as follows: The induced current I is determined by the induced electromotive force and the impedance of the material being heated, and is given by Ohm's law.

[0036]

number

[0037] The following is obtained. Here, Φ=BS, R is resistance, B is magnetic flux density, S is area, ρ is resistivity, and L is resistance length, and from this

[0038]

number

[0039]

number

[0040] Given the formula, and assuming c is the specific heat and m is the mass of the steel cylinder, the relationship between heat quantity and temperature can be obtained. Therefore, if the cross-sectional area and height of the outer steel cylinder and the inner steel cylinder are the same, the same temperature can be generated in both.

[0041] Based on the above, the temperatures of the steel outer cylinder and steel inner cylinder are related to the oscillation current frequency f, and temperature control is possible by controlling the frequency of the current in the electromagnetic induction coil from a PC terminal.

[0042] The spinning holes on the spinneret are located between the steel outer cylinder and the steel inner cylinder.

[0043] As a preferred technical solution: In the above-described method for manufacturing high-quality polyester industrial yarn, the outer diameter of the hollow ring is 280-290 mm and the inner diameter is 245-260 mm, while the outer diameter of the steel outer cylinder is 250-265 mm and the inner diameter is 245-260 mm. The reason the outer diameter of the hollow ring is 25-30 mm larger than the outer diameter of the steel outer cylinder is to account for the fact that the outer surface of the steel outer cylinder is covered with an insulating layer 12.5-15 mm thick. The outer diameter of the steel inner cylinder is 80-122 mm and the inner diameter is 62-110 mm. The heights of the electromagnetic induction coil, steel outer cylinder, and steel inner cylinder are all 280-320 mm, and the height of the hollow ring is 10-15 mm.

[0044] In the above-described method for manufacturing high-quality polyester industrial yarn, the precooler may include an insulated outer shell, which covers the outer surface of the hollow ring and the steel outer cylinder, and the electromagnetic induction coil is placed between the steel outer cylinder and the insulated outer shell. The insulated outer shell can reduce heat loss.

[0045] In the above-described method for manufacturing high-quality polyester industrial yarn, the hollow ring's porous network structure consists of 6 to 8 rows of circular holes, with adjacent rows arranged alternately. The diameter of the circular holes is 1 to 2 mm, the horizontal distance between the centerlines of adjacent rows is 1.5 to 2 mm, and the vertical distance between the centers of adjacent circular holes in each row is 4 to 6 mm.

[0046] In the above-described method for manufacturing high-quality polyester industrial yarn, the radial longitudinal section of the hollow ring is two identical inverted right-angled trapezoids, and the angle between its long base and hypotenuse is 40° to 60°. This allows the angle between the direction of hot air discharge and the yarn bundle to be set to 40° to 60°, so that the hot air exerts a slight stretching effect on the yarn bundle.

[0047] In the above-described method for manufacturing high-quality polyester industrial yarn, a filter mesh is provided at the entrance of the small holes to filter the gas introduced into the hollow ring, thereby preventing contamination of the air in the slow-cooling area and avoiding adverse effects on the cooling effect of the undrawn yarn.

[0048] In the above-described method for producing high-quality polyester industrial yarn, the molten material is a polyester molten material with an intrinsic viscosity of 1.10 to 1.15 dL / g. The spindle diameter is 240 to 260 mm, and the spinning holes are arranged in 6 to 8 concentric rows. The diameter of the center circle of the spinning holes in the innermost row is 130 to 135 mm, and the diameter of the spinning holes is 0.5 to 0.8 mm.

[0049] In the above-described method for manufacturing high-quality polyester industrial yarn, the process conditions are as follows: the gas temperature controlled by the gas control unit is 280-310°C, and the flow rate is 1.0-4.0 g / s. The steel outer cylinder temperature and steel inner cylinder temperature are both 280-310°C, the cooling air velocity is 0.5-0.6 m / min, the cooling air temperature is 20-30°C, the stretch ratio is 5-6, and the interlacing pressure is 0.30-0.40 MPa.

[0050] The amount of hot air entering the annular cavity can be adjusted using a gas control unit. Since the amount of hot air removed cannot be directly measured, different hot air flow rates are introduced using the gas control unit under the same process conditions. The resulting yarn bundles are observed with a scanning electron microscope, and the fiber diameter is measured using image software to calculate the diameter distribution. The diameters of 50 to 100 single filaments are measured, and the condition that maximizes the proportion of fibers in the 1.0 to 1.2 mm diameter range is selected as the optimal hot air flow rate. The flow rate range of 1.0 to 4.0 g / s in this invention was determined based on multiple such tests.

[0051] The high-quality polyester industrial yarn fibers obtained by the above-described method for producing high-quality polyester industrial yarn exhibit excellent dye uniformity, with a dye grade of 4.0-4.5, a linear density of 3350-3450 dtex, a linear density CV value of ≤1.20%, a single-fiber strength of ≥0.7 N, a single-fiber strength CV value of ≤0.80%, a single-fiber diameter of 1.0-1.2 mm, and a single-fiber diameter CV value of ≤0.50%. Dye uniformity is evaluated in accordance with GB / T 6508-2015 "Test Method for Dye Uniformity of Polyester Long Fibers".

[0052] In the above-described method for manufacturing high-quality polyester industrial yarn, the high-temperature resistant heat-insulating block is formed from a heat-resistant organic silicone resin, and the heat-resistant organic silicone resin described in patent CN105273197A can be referenced.

[0053] The principle of this invention is as follows:

[0054] The basic principle of electromagnetic induction heating is that when a conductor to be heated is placed inside a closed coil and an alternating current is passed through the coil, an alternating magnetic field with the same frequency as the current is generated inside the closed coil. Due to the principle of electromagnetic induction, electrons in the conductor in the magnetic field oscillate at a high frequency under the action of the alternating magnetic field, resulting in the generation of a large amount of heat.

[0055] In the slow cooling device of the present invention, a steel outer cylinder and a steel inner cylinder are placed inside a closed coil, and both steel conductors are heated by electromagnetic induction to a set temperature, thereby slowly cooling the initial fibers while keeping them warm. The heat generated by the steel outer cylinder is radiated from the inner wall side to the core of the cylinder, and the heat generated by the steel inner cylinder is radiated from the outer wall side to the surroundings. As a result, the yarn extruded from the spinning holes on the inside and outside of the spinneret can be cooled simultaneously, avoiding the non-uniformity of cooling, orientation, and stress between single yarns caused by the temperature difference between the inside and outside of the spinneret, which was a problem in conventional technology.

[0056] In conventional technology, an "∩" shaped structure is formed by sealing the space between the slow-cooling device and the spinning member with insulating material. In this case, the hot air inside the cavity is carried away by the yarn bundle moving downward at high speed, and the surrounding cold air is passively replenished. On the one hand, turbulence is generated inside the cavity, affecting the uniformity of the drying of the primary fibers, and on the other hand, heat exchange occurs due to the inflow of cold air, creating an unstable temperature field, thus impairing the uniformity of cooling between the yarns. In contrast, in the present invention, a hollow ring is provided instead of insulating material, and gas heated to the process temperature by a gas heating unit is supplied into the hollow ring through air piping. The inner wall of the hollow ring has a uniform porous network structure, and hot air is actively supplied from the hollow ring to the annular cavity between the steel outer cylinder and the steel inner cylinder. Even if the yarn bundle carries away a certain amount of hot air, by setting the amount of hot air supplied to be larger than that amount, the inflow of external cold air is prevented, and a stable airflow field and temperature field can be formed inside the annular cavity. This reduces uneven drying of the yarn strands caused by unstable vibrations, as well as uneven cooling of the yarn bundles.

[0057] Furthermore, by making the radial longitudinal section of the hollow ring into two identical inverted right-angled trapezoids, and setting the angle between the long base and the hypotenuse to 40° to 60°, the angle between the direction of hot air discharge and the yarn bundle becomes 40° to 60°. By setting a certain angle between the direction of hot air flow and the direction of fiber travel, the hot air does not act perpendicularly on the yarn, reducing obstruction of yarn travel by the hot air, and the downward-flowing hot air gives a slight stretching effect to the yarn bundle, contributing to improved uniformity of fiber drying. On the other hand, in the method of patent CN111910271B, the amount of gas supplied to the hollow chamber along the direction of travel of the primary fiber gradually increases, and the hot air flow rate is small near the spinneret and increases as it moves away from the spinneret. As a result, the high-flow airflow below the slow-cooling region obstructs yarn travel, and the slight stretching effect cannot be obtained. [Effects of the Invention]

[0058] The advantages of the present invention include, (1) The present invention provides a method for producing high-quality polyester industrial yarn fibers that employs a double metal sleeve and uses electromagnetic induction to heat and cool the yarn bundles simultaneously. This allows the cooling device to keep the yarn bundles warm from the outside to the inside and from the inside to the outside, enabling synchronous heating and cooling of the yarn bundles on the inside and outside of the spinneret. This eliminates the uneven cooling caused by the large surface area of ​​the spinneret for industrial yarns and the large distance between the yarn bundles on the inside and outside, improving the orientation and stress uniformity between individual yarns in high-quality polyester industrial yarn fibers, which is advantageous for improving strength and dye uniformity.

[0059] (2) Because the electromagnetic heating of the present invention is non-contact heating, the temperature rises quickly and abnormalities in the yarn cake bottom layer can be prevented. During the spinning plate cleaning process, the spinneret surface temperature decreases due to the stopping of the metering pump, silicone oil spraying, scraping, etc. However, with conventional electric heating, it takes a certain amount of time to return to the set temperature, during which time abnormalities occur in the yarn cake bottom layer and the quality is compromised. The present invention can mitigate this problem.

[0060] (3) The present invention employs a hollow ring, a gas heating unit, a gas control unit, and a compressed air supply station to actively supply hot air, and by setting the direction of its flow to a constant angle with respect to the fiber running direction, a stable airflow field and temperature field are formed between the double metal sleeves, thereby reducing obstruction of yarn bundle movement due to airflow in the conventional technology and is advantageous for improving the uniformity of fiber drying. [Brief explanation of the drawing]

[0061] [Figure 1] This is a schematic diagram of a conventional slow cooling device. [Figure 2] This is a schematic diagram of the slow cooling device according to the present invention. [Figure 3] This is a bottom view of the slow cooling device according to the present invention. [Figure 4] This is a schematic diagram of the bottom view of the hollow ring according to the present invention. [Figure 5] This is a radial longitudinal cross-sectional view of the hollow ring according to the present invention. [Figure 6] This is a schematic diagram of an inverted right trapezoid. [Figure 7]This is a bottom view of the steel outer cylinder and steel inner cylinder according to the present invention. [Modes for carrying out the invention]

[0062] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as it does not exceed the gist of the invention. Furthermore, while engineers in the art who have read the contents of the present invention may be permitted to modify it in various ways, such modifications are still limited to the claims of the present invention as equivalent forms of the present invention.

[0063] The test methods / criteria used in the examples are as follows: Dye uniformity: In accordance with GB / T 6508-2015 "Test method for dye uniformity of polyester filament fibers".

[0064] Linear density: In accordance with GB / T 14343-2008 "Test Method for Linear Density of Long Fibers of Chemical Fibers" and GB / T 16604-2017 "Test Method for Long Yarns of Polyester for Industrial Use".

[0065] Linear density CV value: Based on 14343-2008 "Test Method for Linear Density of Long Fiber Chemical Fibers".

[0066] Single yarn strength: GB / T 14337-2008 "Test Method for Tensile Performance of Short Fibers of Chemical Fibers".

[0067] Single yarn strength CV value: GB / T, in accordance with 14337-2008 "Test Method for Tensile Performance of Short Fibers of Chemical Fibers".

[0068] Example 1 The specific steps for manufacturing high-quality polyester industrial yarn are as follows: As shown in Figures 1-3, a polyester molten material with an intrinsic viscosity of 1.10 dL / g was extruded from a 240 mm diameter spinneret in the spinning unit 1. After sequential cooling by pre-cooler, airless zone, and side airflow, the resulting yarn bundle 4 was treated with an oil, stretched, shaped, interlaced, and wound to obtain high-quality polyester industrial yarn.

[0069] The pre-cooler includes a hollow ring 11, an electromagnetic induction coil 8, an insulating layer 13, a steel outer cylinder 9, a steel inner cylinder 10, an external power supply, an electronic oscillator 15, a controller 16, a gas heating unit 14, a gas control unit 18, a compressed air supply station, a PC terminal 17, and an insulating outer shell 12.

[0070] As shown in Figures 4-7, the hollow ring 11 has an outer diameter of 280 mm, an inner diameter of 245 mm, and a height of 10 mm. Its radial cross-section is two identical inverted right-angled trapezoids, and the angle between the long base and hypotenuse of the inverted right-angled trapezoids is 40°. A mesh porous structure consisting of six rows of circular holes is formed on the inner wall of the hollow ring 11, and any adjacent rows are arranged alternately. The diameter of the circular holes in the mesh porous structure is 1 mm, the distance between the horizontal lines where the centers of two adjacent rows of circular holes are located is 1.5 mm, and the distance between the vertical lines where the centers of two adjacent circular holes in each row are located is 4 mm. Two symmetrical small holes 20 are provided on the outer wall of the hollow ring 11, and a filter mesh is provided at the entrance of each hole.

[0071] The steel outer cylinder 9 has an outer diameter of 250 mm, an inner diameter of 245 mm, and a height of 280 mm, and its upper end is connected to the spinneret via a hollow ring 11.

[0072] The insulating outer shell 12 is positioned to cover the hollow ring 11 and the outer surface of the steel outer cylinder 9.

[0073] The steel inner cylinder 10 has an outer diameter of 80 mm and an inner diameter of 62.65 mm, and is the same height as the steel outer cylinder 9. It is equipped with a high-temperature resistant insulation block made of heat-resistant organic silicone resin at its upper end, which is the same height as the hollow ring 11. The inner cylinder is fixedly connected to the center of the spinneret via this block, and the high-temperature insulation block is screw-connected to the spinneret.

[0074] The spinning holes in the spinneret are located between the steel outer cylinder 9 and the steel inner cylinder 10, arranged in six concentric rows. The distance between the central circles of two adjacent rows of spinning holes is 5 mm, the diameter of the central circle of the innermost spinning hole is 130 mm, and the diameter of all spinning holes is 0.5 mm.

[0075] The electromagnetic induction coil 8, with a height of 280 mm, is covered on the outer surface of the steel outer cylinder 9 via an insulating layer 13, and the electromagnetic induction coil 8 is located between the steel outer cylinder 9 and the insulating outer shell 12. The external power supply is electrically connected to the electromagnetic induction coil 8 via an electronic oscillator 15, and the PC terminal is electrically connected to the electronic oscillator 15 via a controller 16.

[0076] The compressed air supply station is connected to the gas heating unit 14 and the gas control unit 18 via a main air pipe. The gas control unit 18 is connected to two symmetrical small holes via two branch air pipes. The gas control unit 18 is electrically connected to a PC terminal 17, which transmits signals to drive the gas control unit 18 and control and display the gas flow rate and temperature in real time.

[0077] The spinning process conditions for high-quality polyester industrial yarn are as follows: the gas temperature controlled by the gas control unit 18 is 280°C, the flow rate is 1 g / s, the temperature of the steel outer cylinder 9 is 280°C, the temperature of the steel inner cylinder 10 is 280°C, the cooling air velocity is 0.5 m / min, the cooling air temperature is 20°C, the draw ratio is 5, and the interlacing pressure is 0.3 MPa.

[0078] The obtained high-quality polyester industrial yarn has a dye uniformity grade of 4, a linear density of 3350 dtex, a linear density CV value of 1.1%, a single-fiber strength of 0.7 N, a single-fiber strength CV value of 0.8%, a single-fiber diameter of 1.0 mm, and a single-fiber diameter CV value of 0.5%.

[0079] Example 2 The specific steps for manufacturing high-quality polyester industrial yarn are as follows: A polyester molten material with an intrinsic viscosity of 1.11 dL / g was extruded from a 240 mm diameter spinneret, and high-quality polyester industrial yarn was obtained by sequentially applying a pre-cooler for slow cooling, cooling in a windless area, cooling with side airflow, lubrication, stretching, shape determination, interlacing, and winding.

[0080] The pre-cooler includes a hollow ring, electromagnetic induction coil, insulation layer, steel outer cylinder, steel inner cylinder, external power supply, electronic oscillator, controller, gas heating unit, gas control unit, compressed air supply station, PC terminal, and insulated outer shell.

[0081] The hollow ring has an outer diameter of 284 mm, an inner diameter of 248 mm, and a height of 11 mm. Its radial cross-section consists of two identical inverted right-angled trapezoids, with an angle of 45° between the long base and hypotenuse of the inverted right-angled trapezoids. The inner wall of the hollow ring is formed with a mesh porous structure consisting of seven rows of circular holes, with any adjacent rows arranged alternately. The diameter of the circular holes in the mesh porous structure is 1.2 mm, the distance between the horizontal lines where the centers of two adjacent rows of circular holes are located is 1.6 mm, and the distance between the vertical lines where the centers of two adjacent circular holes in each row are located is 4.4 mm. The outer wall of the hollow ring is provided with four symmetrical small holes, each equipped with a filter mesh at its entrance.

[0082] The steel outer cylinder has an outer diameter of 254 mm, an inner diameter of 248 mm, and a height of 285 mm, and its upper end is connected to the spinneret via a hollow ring.

[0083] The insulating outer shell is positioned to cover the outer surface of the hollow ring and the steel outer cylinder.

[0084] The steel inner cylinder has an outer diameter of 86 mm and an inner diameter of 66.21 mm, and is the same height as the steel outer cylinder. It is equipped with a high-temperature insulating block made of heat-resistant organic silicone resin at its upper end, which is the same height as the hollow ring. The inner cylinder is fixedly connected to the center of the spinneret via this block, and the high-temperature insulating block is screw-connected to the spinneret.

[0085] The spinning holes in the spinneret are located between the steel outer cylinder and the steel inner cylinder, arranged in six concentric rows. The distance between the central circles of two adjacent rows of spinning holes is 5 mm, the central circle diameter of the innermost spinning hole is 130 mm, and the diameter of all spinning holes is 0.6 mm.

[0086] A 290mm high electromagnetic induction coil is covered on the outer surface of the steel outer cylinder via an insulating layer 13, and the electromagnetic induction coil is located between the steel outer cylinder and the insulating outer shell. An external power supply is electrically connected to the electromagnetic induction coil via an electronic oscillator, and a PC terminal is electrically connected to the electronic oscillator via a controller.

[0087] The compressed air supply station is connected to the gas heating unit and gas control unit via a main air pipe. The gas control unit is connected to four symmetrical vents via four branch air pipes. The gas control unit is electrically connected to a PC terminal, which transmits signals to drive the gas control unit and control and display the gas flow rate and temperature in real time.

[0088] The spinning process conditions for high-quality polyester industrial yarn are as follows: the gas temperature controlled by the gas control unit is 285°C, the flow rate is 1.5 g / s, the temperature of the outer steel cylinder is 285°C, the temperature of the inner steel cylinder is 285°C, the cooling air velocity is 0.52 m / min, the cooling air temperature is 22°C, the draw ratio is 5.2, and the interlacing pressure is 0.32 MPa.

[0089] The obtained high-quality polyester industrial yarn has a dye uniformity grade of 4, a linear density of 3380 dtex, a linear density CV value of 1%, a single-fiber strength of 0.72 N, a single-fiber strength CV value of 0.76%, a single-fiber diameter of 1.05 mm, and a single-fiber diameter CV value of 0.45%.

[0090] Example 3 The specific steps for manufacturing high-quality polyester industrial yarn are as follows: A polyester molten material with an intrinsic viscosity of 1.12 dL / g was extruded from a 240 mm diameter spinneret, and high-quality polyester industrial yarn was obtained by sequentially applying a pre-cooler for slow cooling, cooling in a windless area, cooling with side airflow, lubrication, stretching, shape determination, interlacing, and winding.

[0091] The pre-cooler includes a hollow ring, electromagnetic induction coil, insulation layer, steel outer cylinder, steel inner cylinder, external power supply, electronic oscillator, controller, gas heating unit, gas control unit, compressed air supply station, PC terminal, and insulated outer shell.

[0092] The hollow ring has an outer diameter of 284 mm, an inner diameter of 250 mm, and a height of 12 mm. Its radial cross-section consists of two identical inverted right-angled trapezoids, with an angle of 50° between the long base and hypotenuse of the inverted right-angled trapezoids. The inner wall of the hollow ring is formed with a mesh porous structure consisting of eight rows of circular holes, with any adjacent rows arranged alternately. The diameter of the circular holes in the mesh porous structure is 1.4 mm, the distance between the horizontal lines where the centers of two adjacent rows of circular holes are located is 1.7 mm, and the distance between the vertical lines where the centers of two adjacent circular holes in each row are located is 4.8 mm. The outer wall of the hollow ring is provided with four symmetrical small holes, each equipped with a filter mesh at its entrance.

[0093] The steel outer cylinder has an outer diameter of 258 mm, an inner diameter of 250 mm, and a height of 290 mm, and its upper end is connected to the spinneret via a hollow ring.

[0094] The insulating outer shell is positioned to cover the outer surface of the hollow ring and the steel outer cylinder.

[0095] The steel inner cylinder has an outer diameter of 103 mm and an inner diameter of 80.90 mm, and is the same height as the steel outer cylinder. It is equipped with a high-temperature insulating block made of heat-resistant organic silicone resin at its upper end, which is the same height as the hollow ring. The inner cylinder is fixedly connected to the center of the spinneret via this block, and the high-temperature insulating block is screw-connected to the spinneret.

[0096] The spinning holes in the spinneret are located between the steel outer cylinder and the steel inner cylinder, arranged in six concentric rows. The distance between the central circles of two adjacent rows of spinning holes is 5 mm, the central circle diameter of the innermost spinning hole is 130 mm, and the diameter of all spinning holes is 0.65 mm.

[0097] A 300mm high electromagnetic induction coil is covered on the outer surface of the steel outer cylinder via an insulating layer 13, and the electromagnetic induction coil is located between the steel outer cylinder and the insulating outer shell. An external power supply is electrically connected to the electromagnetic induction coil via an electronic oscillator, and a PC terminal is electrically connected to the electronic oscillator via a controller.

[0098] The compressed air supply station is connected to the gas heating unit and gas control unit via a main air pipe. The gas control unit is connected to four symmetrical vents via four branch air pipes. The gas control unit is electrically connected to a PC terminal, which transmits signals to drive the gas control unit and control and display the gas flow rate and temperature in real time.

[0099] The spinning process conditions for high-quality polyester industrial yarn are as follows: the gas temperature controlled by the gas control unit is 290°C, the flow rate is 2 g / s, the temperature of the outer steel cylinder is 290°C, the temperature of the inner steel cylinder is 290°C, the cooling air velocity is 0.54 m / min, the cooling air temperature is 24°C, the draw ratio is 5.4, and the interlacing pressure is 0.34 MPa.

[0100] The obtained high-quality polyester industrial yarn has a dye uniformity grade of 4.5, a linear density of 3400 dtex, a linear density CV value of 0.9%, a single-fiber strength of 0.75 N, a single-fiber strength CV value of 0.7%, a single-fiber diameter of 1.1 mm, and a single-fiber diameter CV value of 0.38%.

[0101] Example 4 The specific steps for manufacturing high-quality polyester industrial yarn are as follows: A polyester molten material with an intrinsic viscosity of 1.13 dL / g was extruded from a 260 mm diameter spinneret, and high-quality polyester industrial yarn was obtained by sequentially applying a pre-cooler for slow cooling, cooling in a windless area, cooling with side airflow, lubrication, stretching, shape determination, interlacing, and winding.

[0102] The pre-cooler includes a hollow ring, electromagnetic induction coil, insulation layer, steel outer cylinder, steel inner cylinder, external power supply, electronic oscillator, controller, gas heating unit, gas control unit, compressed air supply station, PC terminal, and insulated outer shell.

[0103] The hollow ring has an outer diameter of 286 mm, an inner diameter of 255 mm, and a height of 13 mm. Its radial cross-section consists of two identical inverted right-angled trapezoids, with an angle of 55° between the long base and hypotenuse of the inverted right-angled trapezoids. The inner wall of the hollow ring is formed with a mesh porous structure consisting of eight rows of circular holes, with any adjacent rows arranged alternately. The diameter of the circular holes in the mesh porous structure is 1.6 mm, the distance between the horizontal lines where the centers of two adjacent rows of circular holes are located is 1.8 mm, and the distance between the vertical lines where the centers of two adjacent circular holes in each row are located is 5.2 mm. The outer wall of the hollow ring is provided with eight symmetrical small holes, each fitted with a filter mesh at its entrance.

[0104] The steel outer cylinder has an outer diameter of 260 mm, an inner diameter of 255 mm, and a height of 300 mm, and its upper end is connected to the spinneret via a hollow ring.

[0105] The insulating outer shell is positioned to cover the outer surface of the hollow ring and the steel outer cylinder.

[0106] The steel inner cylinder has an outer diameter of 103.32 mm and an inner diameter of 90 mm, and is the same height as the steel outer cylinder. It is equipped with a high-temperature insulating block made of heat-resistant organic silicone resin at its upper end, which is the same height as the hollow ring. The inner cylinder is fixedly connected to the center of the spinneret via this block, and the high-temperature insulating block is screw-connected to the spinneret.

[0107] The spinning holes in the spinneret are located between the steel outer cylinder and the steel inner cylinder, arranged in eight concentric rows. The distance between the central circles of two adjacent rows of spinning holes is 5 mm, the central circle diameter of the innermost spinning hole is 135 mm, and the diameter of all spinning holes is 0.7 mm.

[0108] A 310mm high electromagnetic induction coil is covered on the outer surface of the steel outer cylinder via an insulating layer 13, and the electromagnetic induction coil is located between the steel outer cylinder and the insulating outer shell. An external power supply is electrically connected to the electromagnetic induction coil via an electronic oscillator, and a PC terminal is electrically connected to the electronic oscillator via a controller.

[0109] The compressed air supply station is connected to the gas heating unit and gas control unit via a main air pipe. The gas control unit is connected to eight symmetrical vents via eight branch air pipes. The gas control unit is electrically connected to a PC terminal, which transmits signals to drive the gas control unit and control and display the gas flow rate and temperature in real time.

[0110] The spinning process conditions for high-quality polyester industrial yarn are as follows: the gas temperature controlled by the gas control unit is 295°C, the flow rate is 2.5 g / s, the temperature of the outer steel cylinder is 295°C, the temperature of the inner steel cylinder is 295°C, the cooling air velocity is 0.56 m / min, the cooling air temperature is 26°C, the draw ratio is 5.6, and the interlacing pressure is 0.36 MPa.

[0111] The obtained high-quality polyester industrial yarn had a dye uniformity grade of 4.5, a linear density of 3410 dtex, a linear density CV value of 1.1%, a single-fiber strength of 0.76 N, a single-fiber strength CV value of 0.63%, a single-fiber diameter of 1.12 mm, and a single-fiber diameter CV value of 0.42%.

[0112] Example 5 The specific steps for manufacturing high-quality polyester industrial yarn are as follows: A polyester molten material with an intrinsic viscosity of 1.14 dL / g was extruded from a 260 mm diameter spinneret, and high-quality polyester industrial yarn was obtained by sequentially applying a pre-cooler for slow cooling, cooling in a windless area, cooling with side airflow, lubrication, stretching, shape determination, interlacing, and winding.

[0113] The pre-cooler includes a hollow ring, electromagnetic induction coil, insulation layer, steel outer cylinder, steel inner cylinder, external power supply, electronic oscillator, controller, gas heating unit, gas control unit, compressed air supply station, PC terminal, and insulated outer shell.

[0114] The hollow ring has an outer diameter of 290 mm, an inner diameter of 258 mm, and a height of 14 mm. Its radial cross-section consists of two identical inverted right-angled trapezoids, with an angle of 58° between the long base and hypotenuse of the inverted right-angled trapezoids. The inner wall of the hollow ring is formed with a mesh porous structure consisting of eight rows of circular holes, with any adjacent rows arranged alternately. The diameter of the circular holes in the mesh porous structure is 1.8 mm, the distance between the horizontal lines where the centers of two adjacent rows of circular holes are located is 1.9 mm, and the distance between the vertical lines where the centers of two adjacent circular holes in each row are located is 5.6 mm. The outer wall of the hollow ring is provided with eight symmetrical small holes, each fitted with a filter mesh at its entrance.

[0115] The steel outer cylinder has an outer diameter of 263 mm, an inner diameter of 258 mm, and a height of 310 mm, and its upper end is connected to the spinneret via a hollow ring.

[0116] The insulating outer shell is positioned to cover the outer surface of the hollow ring and the steel outer cylinder.

[0117] The steel inner cylinder has an outer diameter of 112.27 mm and an inner diameter of 100 mm, and is the same height as the steel outer cylinder. It is equipped with a high-temperature insulating block made of heat-resistant organic silicone resin at its upper end, which is the same height as the hollow ring. The inner cylinder is fixedly connected to the center of the spinneret via this block, and the high-temperature insulating block is screw-connected to the spinneret.

[0118] The spinning holes in the spinneret are located between the steel outer cylinder and the steel inner cylinder, arranged in eight concentric rows. The distance between the central circles of two adjacent rows of spinning holes is 5 mm, the diameter of the central circle of the innermost spinning hole is 135 mm, and the diameter of all spinning holes is 0.75 mm.

[0119] An electromagnetic induction coil, 315 mm in height, is covered on the outer surface of the steel outer cylinder via an insulating layer 13, and the electromagnetic induction coil is located between the steel outer cylinder and the insulating outer shell. An external power supply is electrically connected to the electromagnetic induction coil via an electronic oscillator, and a PC terminal is electrically connected to the electronic oscillator via a controller.

[0120] The compressed air supply station is connected to the gas heating unit and gas control unit via a main air pipe. The gas control unit is connected to eight symmetrical vents via eight branch air pipes. The gas control unit is electrically connected to a PC terminal, which transmits signals to drive the gas control unit and control and display the gas flow rate and temperature in real time.

[0121] The spinning process conditions for high-quality polyester industrial yarn are as follows: the gas temperature controlled by the gas control unit is 300°C, the flow rate is 3 g / s, the temperature of the outer steel cylinder is 300°C, the temperature of the inner steel cylinder is 300°C, the cooling air velocity is 0.58 m / min, the cooling air temperature is 28°C, the draw ratio is 5.8, and the interlacing pressure is 0.38 MPa.

[0122] The obtained high-quality polyester industrial yarn has a dye uniformity grade of 4, a linear density of 3430 dtex, a linear density CV value of 1.2%, a single-fiber strength of 0.78 N, a single-fiber strength CV value of 0.65%, a single-fiber diameter of 1.15 mm, and a single-fiber diameter CV value of 0.35%.

[0123] Example 6 The specific steps for manufacturing high-quality polyester industrial yarn are as follows: A polyester molten material with an intrinsic viscosity of 1.15 dL / g was extruded from a 260 mm diameter spinneret, and high-quality polyester industrial yarn was obtained by sequentially applying a pre-cooler for slow cooling, cooling in a windless area, cooling with side airflow, lubrication, stretching, shape determination, interlacing, and winding.

[0124] The pre-cooler includes a hollow ring, electromagnetic induction coil, insulation layer, steel outer cylinder, steel inner cylinder, external power supply, electronic oscillator, controller, gas heating unit, gas control unit, compressed air supply station, PC terminal, and insulated outer shell.

[0125] The hollow ring has an outer diameter of 290 mm, an inner diameter of 260 mm, and a height of 15 mm. Its radial cross-section consists of two identical inverted right-angled trapezoids, with an angle of 60° between the long base and hypotenuse of the inverted right-angled trapezoids. The inner wall of the hollow ring is formed with a mesh porous structure consisting of eight rows of circular holes, with any adjacent rows arranged alternately. The diameter of the circular holes in the mesh porous structure is 2 mm, the distance between the horizontal lines where the centers of two adjacent rows of circular holes are located is 2 mm, and the distance between the vertical lines where the centers of two adjacent circular holes in each row are located is 6 mm. The outer wall of the hollow ring is provided with eight symmetrical small holes, each equipped with a filter mesh at its entrance.

[0126] The steel outer cylinder has an outer diameter of 265 mm, an inner diameter of 260 mm, and a height of 320 mm, and its upper end is connected to the spinneret via a hollow ring.

[0127] The insulating outer shell is positioned to cover the outer surface of the hollow ring and the steel outer cylinder.

[0128] The steel inner cylinder has an outer diameter of 121.35 mm and an inner diameter of 110 mm, and is the same height as the steel outer cylinder. It is equipped with a high-temperature insulating block made of heat-resistant organic silicone resin at its upper end, which is the same height as the hollow ring. The inner cylinder is fixedly connected to the center of the spinneret via this block, and the high-temperature insulating block is screw-connected to the spinneret.

[0129] The spinning holes in the spinneret are located between the steel outer cylinder and the steel inner cylinder, arranged in eight concentric rows. The distance between the central circles of two adjacent rows of spinning holes is 5 mm, the diameter of the central circle of the innermost spinning hole is 135 mm, and the diameter of all spinning holes is 0.8 mm.

[0130] A 320mm high electromagnetic induction coil is covered on the outer surface of the steel outer cylinder via an insulating layer 13, and the electromagnetic induction coil is located between the steel outer cylinder and the insulating outer shell. An external power supply is electrically connected to the electromagnetic induction coil via an electronic oscillator, and a PC terminal is electrically connected to the electronic oscillator via a controller.

[0131] The compressed air supply station is connected to the gas heating unit and gas control unit via a main air pipe. The gas control unit is connected to eight symmetrical vents via eight branch air pipes. The gas control unit is electrically connected to a PC terminal, which transmits signals to drive the gas control unit and control and display the gas flow rate and temperature in real time.

[0132] The spinning process conditions for high-quality polyester industrial yarn are as follows: the gas temperature controlled by the gas control unit is 310°C, the flow rate is 4 g / s, the temperature of the outer steel cylinder is 310°C, the temperature of the inner steel cylinder is 310°C, the cooling air velocity is 0.6 m / min, the cooling air temperature is 30°C, the draw ratio is 6, and the interlacing pressure is 0.4 MPa.

[0133] The obtained high-quality polyester industrial yarn had a dye uniformity grade of 4.5, a linear density of 3450 dtex, a linear density CV value of 1.2%, a single-fiber strength of 0.8 N, a single-fiber strength CV value of 0.78%, a single-fiber diameter of 1.2 mm, and a single-fiber diameter CV value of 0.46%.

[0134] In addition, because the actual processing process is affected by factors such as processing accuracy, the outer diameter and inner diameter data for the steel outer cylinder and the steel inner cylinder in each of the above embodiments are treated as follows: integer values ​​do not retain significant figures after the decimal point, while non-integer values ​​are rounded to retain two significant figures after the decimal point. [Explanation of Symbols]

[0135] 1- Spinning unit, 2- Heating wire, 3- Aluminum plate, 4- Yarn bundle, 8- Electromagnetic induction coil, 9- Steel outer cylinder, 10- Steel inner cylinder, 11- Hollow ring, 12- Insulated outer shell, 13- Insulated layer, 14- Gas heating unit, 15- Electronic oscillator, 16- Controller, 17- PC terminal, 18- Gas control unit, 19- Inner wall of hollow ring, 20- Small hole.

Claims

1. A method for producing high-quality polyester industrial yarn fibers, comprising extruding a molten material from a spinneret, followed by sequential pre-cooling with a pre-cooler, cooling in a windless area, cooling with side airflow, application of an oil agent, stretching, shape determination, interlacing, and winding, The pre-cooler includes a hollow ring, an electromagnetic induction coil, an insulating layer, a steel outer cylinder, a steel inner cylinder, an external power supply, an electronic oscillator, a controller, a gas heating unit, a gas control unit, a compressed air supply station, and a PC terminal. The inner wall of the hollow ring is provided with a mesh-like porous structure, and the outer wall of the hollow ring is provided with multiple small holes arranged symmetrically. The compressed air supply station is sequentially connected to the gas heating unit and gas control unit via the main air piping. The gas control unit communicates with the aforementioned small holes via multiple branch air pipes and is electrically connected to the PC terminal. The upper end of the steel outer cylinder is connected to the spinneret via a hollow ring. A high-temperature resistant heat-insulating block is provided at the upper end of the steel inner cylinder. The steel inner cylinder is fixed to the center of the spinneret via the high-temperature heat-insulating block. The height of the hollow ring and the height of the high-temperature resistant insulation block are the same, the height of the steel outer cylinder and the height of the steel inner cylinder are the same, and the cross-sectional area of ​​the region between the inner and outer walls of the steel outer cylinder and the cross-sectional area of ​​the region between the inner and outer walls of the steel inner cylinder are the same. The electromagnetic induction coil is mounted on the outer surface of the steel outer cylinder via an insulating layer, the external power supply is electrically connected to the electromagnetic induction coil via an electronic oscillator, and the PC terminal is electrically connected to the electronic oscillator via a controller. The spinning holes on the spinneret are located between the steel outer cylinder and the steel inner cylinder. A method for producing high-quality polyester industrial yarn, characterized by the following features.

2. The hollow ring has an outer diameter of 280-290 mm and an inner diameter of 245-260 mm. The steel outer cylinder has an outer diameter of 250 to 265 mm and an inner diameter of 245 to 260 mm. The steel inner cylinder has an outer diameter of 80 to 122 mm and an inner diameter of 62 to 110 mm. The height of the electromagnetic induction coil is 280-320 mm, the height of the steel outer cylinder is 280-320 mm, the height of the steel inner cylinder is 280-320 mm, and the height of the hollow ring is 10-15 mm. A method for producing high-quality polyester industrial yarn as described in feature 1.

3. The precooler further includes an insulating outer shell. The insulating outer shell covers the outer surface of the hollow ring and the steel outer cylinder. The electromagnetic induction coil is placed between the steel outer cylinder and the insulated outer shell. A method for producing high-quality polyester industrial yarn as described in feature 1.

4. The hollow ring's porous network structure consists of 6 to 8 rows of circular holes, with adjacent pairs of circular holes alternately offset from each other. The diameter of each circular hole is 1 to 2 mm, the horizontal spacing between the centers of adjacent pairs of circular holes is 1.5 to 2 mm, and the vertical spacing between the centers of two adjacent circular holes in each row is 4 to 6 mm. A method for producing high-quality polyester industrial yarn as described in feature 1.

5. The longitudinal section of the hollow ring along its radial direction consists of two identical inverted right-angle trapezoids. The angle between the long base of the inverted right trapezoid and the hypotenuse of the inverted right trapezoid is between 40° and 60°. A method for producing high-quality polyester industrial yarn as described in feature 1.

6. A filter is provided at the entrance of the aforementioned small hole. A method for producing high-quality polyester industrial yarn as described in feature 1.

7. The molten material is a polyester molten material, and its intrinsic viscosity is 1.10 to 1.15 dL / g. The spinneret has a diameter of 240–260 mm, with 6–8 spinning holes arranged concentrically. The diameter of the circle where the center of the innermost spinning hole is located is 130–135 mm, and the diameter of the spinning holes is 0.5–0.8 mm. A method for producing high-quality polyester industrial yarn according to any one of claims 1 to 6.

8. The manufacturing parameters are as follows: the gas temperature controlled by the gas control unit is 280-310°C, the flow rate is 1.0-4.0 g / s, the temperature of the steel outer cylinder is 280-310°C, the temperature of the steel inner cylinder is 280-310°C, the cooling air velocity is 0.5-0.6 m / min, the cooling air temperature is 20-30°C, the stretch ratio is 5-6, and the interlacing pressure is 0.30-0.40 MPa. A method for producing high-quality polyester industrial yarn according to feature 7.

9. High-quality polyester industrial yarn is uniformly dyed, The staining level is 4.0 to 4.5, the linear density is 3350 to 3450 dtex, the linear density CV value is 1.20% or less, the filament strength is 0.7 N or more, the filament strength CV value is 0.80% or less, the filament diameter is 1.0 to 1.2 mm, and the filament diameter CV value is 0.50% or less. A method for producing high-quality polyester industrial yarn according to feature 8.

10. The aforementioned high-temperature resistant heat insulating block is made of a heat-resistant organic silicone resin. A method for producing high-quality polyester industrial yarn as described in feature 1.

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