A method for producing high-strength, high-modulus and low-shrinkage wire

Abstract

The present invention relates to a method for producing high-strength, high-modulus, low-shrinkage yarns. After polyester slices are extruded through a screw extruder to form a polyester melt, the polyester slices enter a spinning manifold, are extruded from a spinneret, and are sequentially cooled, oiled, drawn, shaped, networked, and wound to obtain high-strength, high-modulus, low-shrinkage yarns. The spinning manifold comprises a spinning manifold shell, a main melt pipe, a branch melt pipe, a melt connecting pipe, a metering pump, and a component. The lower surface of the spinning manifold shell is provided with a double row of component grooves. The upper surface of the spinning manifold shell is provided with a metering pump groove, the number of which is the same as that of the component grooves, and the number of component grooves in each row is 2 to 3. A component is placed in each component groove, and a metering pump is placed in each metering pump groove, and all metering pumps are of the same size. The spinning manifold of the present invention is designed with double-row component grooves, which can reduce the spinning position width and the length of the branch melt pipe inside the spinning manifold, so that the melt residence time is greatly reduced, the melt viscosity drop is reduced, and the breaking strength of the product is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning and relates to a method for producing high-strength, high-modulus and low-shrinkage yarns. Background Art

[0002] Industrial high modulus low shrinkage yarn is mainly used for tire cord, which is the skeleton material of automobile tires. In order to meet the use requirements, it must have high strength, high modulus and low dry heat shrinkage. High strength ensures that the cord is not easy to break under stress, high modulus maintains the shape and structural stability of the tire, and low dry heat shrinkage ensures the dimensional stability of the tire at high temperatures.

[0003] High strength is one of the important indicators of tire skeleton materials. If high modulus low shrinkage yarn has higher strength, it will have better product competitiveness in the market. The literature (A Brief Analysis of the Influencing Factors of Melt Direct Spinning Micro POY Fiber Production [J]. Synthesis Technology and Application, 2002 (04): 36-38.) records that Δη=K·residence time·(melt temperature-A), where K and A are empirical constants. Therefore, during the high-temperature transportation of polyester high-viscosity melt, the change in melt viscosity drop is mainly related to the melt temperature and residence time. The higher the temperature and the longer the residence time, the greater the viscosity drop, and the more difficult it is to ensure product strength during high-speed spinning. Existing technicians usually reduce the viscosity drop by adjusting the temperature of the spinning box, but due to the temperature requirements of spinnability, the temperature reduction of the spinning box is limited, which makes the viscosity drop limited, resulting in limited improvement in product strength.

[0004] Therefore, it is of great significance to study a high-strength, high-modulus and low-shrinkage production method to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the prior art and provide a method for producing high-strength, high-modulus and low-shrinkage wire.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A method for producing high-strength, high-modulus, low-shrinkage yarns, wherein polyester chips are extruded through a screw extruder to form a polyester melt, and then the polyester melt is extruded through a spinning box, and then extruded from a spinneret, and then sequentially cooled, oiled, drawn, shaped, netted, and wound to obtain high-strength, high-modulus, low-shrinkage yarns;

[0008] The spinning box body includes a spinning box shell, a main melt tube, a branch line melt tube, a melt connecting tube, a metering pump and components;

[0009] The lower surface of the spinning box shell is provided with double rows of component grooves; the upper surface of the spinning box shell is provided with metering pump grooves, the number of which is the same as the component grooves, and the number of component grooves in each row is 2 to 3; a component is placed in each component groove, and a metering pump is placed in each metering pump groove, and all metering pumps are of the same size;

[0010] The main melt tube, branch melt tube and melt connection tube are located in the outer shell of the spinning box; the number of the main melt tube is 1, and the number of branch melt tubes and melt connection tubes is the same as the number of components; the lengths of all branch melt tubes are the same, and the lengths of all melt connection tubes are the same; the branch melt and melt connection tubes adopt a spiral structure inside;

[0011] One end of the main melt pipe is the melt inlet, and the other end is the melt outlet. The melt outlet is simultaneously connected to the melt inlets of all branch melt pipes, and the melt outlets of all branch melt pipes are respectively connected to the inlet of a metering pump; one end of the melt connecting pipe is connected to the outlet of the metering pump, and the other end of the melt connecting pipe is connected to the assembly;

[0012] After the melt is melted and extruded by the screw extruder, it enters the spinning box. The spinning box of the present invention adopts a double-row component slot design, which can reduce the spinning position width and the length of the branch line melt tube inside the spinning box, so that the melt residence time is greatly reduced, and the melt viscosity drop is significantly reduced. The decrease in viscosity drop improves the product's fracture strength. The length of the branch line melt tube is shortened, although the melt residence time is greatly reduced and the melt viscosity drop is reduced, but the pressure drop is also reduced at the same time. The pressure drop is different from the viscosity drop. The smaller the better. If the pressure drop is too low, the internal pressure of the branch line melt tube and the melt connecting pipe in the box is too high, the equipment is prone to fatigue, the melt flow of the metering pump and the like changes, the screw pressure fluctuates too much, and the screw is prone to tripping. In order to solve the problem of reducing pressure drop, the present invention adopts a spiral design for the melt tube inside the spinning box, so that the melt can be fully mixed along the tube wall and the center of the branch melt tube and the melt connecting tube, while increasing the movement resistance of the melt to increase the reduced pressure drop. The final pressure drop is controlled within the range of 40 to 60 bar, which not only solves the problem of reducing pressure drop, but also prevents abnormal product fineness due to excessive pressure drop.

[0013] In the prior art, the inner wall of the melt pipe is required to be smooth, otherwise the residence time is increased, resulting in melt degradation. However, for industrial yarns, the high-viscosity melt is a non-Newtonian fluid, and there is also a velocity gradient in the smooth melt pipe, that is, the melt near the bottom of the melt pipe moves slowly, and the melt in the center of the melt pipe moves quickly. The spiral structure utilizes the structural changes to make the central melt flow to the pipe wall, and the wall melt flows to the center, reducing the velocity gradient difference and playing the role of mixing the melt. In this way, the wall melt will not keep moving on the pipe wall, reducing long-term heating, and also playing the role of reducing melt degradation;

[0014] Although CN106811808B also has a double-row component slot structure, it is used to produce civilian silk. The viscosity of civilian silk is low. Theoretically, there is a viscosity drop, but the actual viscosity drop is very small and can be ignored. In addition, the patent adopts melt direct spinning, and the main viscosity drop exists in the melt conveying pipeline (that is, the distance from the polyester final polymerization kettle to the spinning box, which is hundreds of meters long) (the present invention adopts slice spinning, and this pipeline does not exist), and the length of the branch melt pipe and the melt connecting pipe in the spinning box is only 3 to 4 meters, and its viscosity drop can be ignored. It is not within the scope of process considerations. The length of the melt pipe in the box will not be reduced for the double-row design to reduce the viscosity drop. The purpose of designing the double row is to allow the heat of the double-row components to complement each other, thereby improving the thermal insulation effect.

[0015] In addition, the four-head spinning in the prior art to produce high modulus low yarn products is already the limit, which checks and balances the development of high modulus low shrinkage multi-head spinning. The present invention uses a double-row box to achieve six-head spinning technology that the prior art cannot do, which can greatly improve production efficiency.

[0016] As the preferred technical solution:

[0017] In the method for producing high-strength, high-modulus, low-shrinkage yarn as described above, an electric heating device is provided in the groove of the component, and the electric heating device is used to heat the component. Such a design can separate the heating of the component from the heating of the box melt, reduce the temperature of the spinning box, and thus reduce the temperature in the melt pipe to reduce the viscosity drop. The higher the component temperature is, the better the melt fluidity is, and the more stable the filament bundle out of the spinneret is, which is beneficial to the spinning condition.

[0018] In the method for producing high-strength, high-modulus, low-shrinkage wire as described above, the electric heating device is a component heating sleeve; the component heating sleeve includes a hollow circular shell and a resistance wire, and the resistance wire is arranged inside the hollow circular shell; the component heating sleeve and the spinning box are fixedly connected; the component heating sleeve is on the outside of the component and is used to heat the component.

[0019] In the method for producing high-strength, high-modulus and low-shrinkage yarn as described above, the temperature of the three rear zones of the screw is 270~275°C, the temperature of the spinning box is 275~280°C, and the component heating temperature is 295~300°C; the low temperature of the three rear zones of the screw is beneficial to reducing the viscosity drop, but since the component heating and the box melt heating are not separated in the prior art, the three rear zones of the screw in the prior art are generally higher than 270~275°C to avoid poor melt fluidity and affect spinning.

[0020] In the method for producing high-strength, high-modulus, low-shrinkage yarn as described above, the intrinsic viscosity of the polyester chips is 1.13-1.16 dl / g; the melt viscosity is reduced to 0.05-0.1 dl / g; when the polyester chips are used, the melt viscosity of the prior art is reduced to 0.15-0.2 dl / g, and the melt viscosity of the present invention can be controlled to be reduced to 0.05-0.1 dl / g through the above-mentioned process parameters and the design of the device structure.

[0021] The high-strength, high-modulus, low-shrinkage yarn production method described above has a spinning speed of 3100~3500m / min, a winding speed of 6000~6500m / min, and a viscosity drop that is conducive to increasing the spinning and winding speeds. The draft ratio is 2.2~2.5, and a viscosity drop that is conducive to increasing the draft ratio. The product breaking strength can be improved while ensuring the normal yarn quality, thereby achieving high-strength, high-modulus, low-shrinkage (the viscosity drop is reduced, and the viscosity of the final yarn becomes larger, making it easier to obtain higher breaking strength by increasing the draft ratio).

[0022] A method for producing high-strength, high-modulus, low-shrinkage yarn as described in any of the above items, wherein the initial modulus of the high-strength, high-modulus, low-shrinkage yarn obtained is 110~115cN / dtex, the dimensional stability is 7~8.5%, the breaking strength is 7.8~8.0cN / dtex, and the breaking strength of the prior art is 7.3~7.5cN / dtex.

[0023] Beneficial effects:

[0024] (1) In the method for producing high-strength, high-modulus and low-shrinkage yarn of the present invention, the spinning manifold is designed with double-row component slots, which can reduce the spinning position width and the length of the branch line melt tube inside the spinning manifold, so that the melt residence time is greatly reduced, and the melt viscosity drop is significantly reduced. The decrease in viscosity drop improves the breaking strength of the product;

[0025] (2) The present invention provides a method for producing high-strength, high-modulus, low-shrinkage yarns, which separates the heating of the components from the heating of the box melt, thereby lowering the temperature of the spinning box, thereby lowering the temperature in the melt pipe to reduce the viscosity drop. The higher the component temperature is, the better the melt fluidity is, and the more stable the yarn bundle exiting the spinneret is, which is beneficial to the spinning condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a front view structural diagram of the device used in the method for producing high-strength, high-modulus and low-shrinkage wires with two grooves in a single-row assembly of the present invention;

[0027] Among them, 1-spinning manifold, 2-component heating jacket, 3-component, 4-branch line melt pipe, 5-metering pump, 6-main melt pipe. DETAILED DESCRIPTION

[0028] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0029] The test methods involved in the performance indicators in the embodiments and comparative examples of the present invention are as follows:

[0030] (1) Initial modulus: Referring to GB / T 14344-2022 standard, the specimen was stretched until it broke using a STATIMAT 4U automatic tensile tester, and the initial modulus value was automatically calculated by a computer; test conditions: nominal clamping length: 500 mm ± 1 mm, test speed: 500 mm / min, pre-tension: 0.05 ± 0.005 cN / dtex.

[0031] (2) Dimensional stability: Referring to GB / T 16604-2017, dimensional stability is the sum of the elongation of the fiber at a load of 4.0 cN / dtex and the dry heat shrinkage;

[0032] Elongation at 4.0 cN / dtex load: Referring to GB / T 14344-2022 standard, using STATIMAT 4U instrument, under test conditions, the specimen is stretched with an automatic tensile tester until it breaks, and the elongation at 4.0 cN / dtex load is automatically calculated by computer. Test conditions: nominal clamping length: 500 mm ± 1 mm, test speed: 500 mm / min, pre-tension: 0.05 ± 0.005 cN / dtex;

[0033] Dry heat shrinkage rate: refer to GB / T 16604-2017 standard, dry heat shrinkage rate test condition adopts condition 1, use Lanjing TST510 under given pretension (0.05±0.01cN / dtex), temperature (177℃) and time (10min), the sample length of 250mm is subjected to hot air treatment, and the percentage of length shrinkage of the wire before and after heating is calculated;

[0034] The dimensional stability is obtained by adding the elongation and dry heat shrinkage at a load of 4.0 cN / dtex after the test.

[0035] (3) Breaking strength: The linear density shall refer to GB / T 14343-2008. The standard atmosphere for humidity adjustment and testing shall be in accordance with 4.3.2.2. The pre-tension per unit linear density is specified as (0.05±0.005) cN / dtex. The linear density shall be tested by winding 50 turns using a YG086 yarn length measuring instrument. The measured linear density data shall be input into a STATIMAT 4U automatic tensile tester.

[0036] With reference to GB / T 14344-2022 standard, using STATIMAT 4U instrument, the sample was stretched with an automatic tensile tester under test conditions until it broke. According to the formula: breaking strength = strength / linear density, the breaking strength value was automatically calculated by computer. Test conditions: nominal clamping length: 500mm±1mm, test speed: 500mm / min, pre-tension: 0.05±0.005cN / dtex.

[0037] Example 1

[0038] A method for producing high-strength, high-modulus and low-shrinkage wire, the specific process is as follows:

[0039] The polyester chips with an intrinsic viscosity of 1.13dl / g are extruded through a screw extruder to form a polyester melt, and then enter a spinning box, and then extrude from a spinneret, and then go through cooling, oiling, drawing, shaping, networking and winding in sequence to obtain a high-strength, high-modulus, low-shrinkage yarn.

[0040] Among them, the melt viscosity dropped to 0.05dl / g;

[0041] like Figure 1 As shown, the spinning manifold 1 includes a spinning manifold shell, a main melt tube 6, a branch line melt tube 4, a melt connecting tube, a metering pump 5 and an assembly 3;

[0042] The lower surface of the spinning box shell is provided with double rows of component grooves; the upper surface of the spinning box shell is provided with metering pump grooves, the number of which is the same as the component grooves, and the number of component grooves in each row is 2; a component 3 is placed in each component groove, and a metering pump 5 is placed in each metering pump groove, and all metering pumps 5 are of the same size;

[0043] A component heating sleeve 2 is provided in each component groove; the component heating sleeve 2 comprises a hollow ring shell and a resistance wire, and the resistance wire is arranged inside the hollow ring shell; the component heating sleeve 2 is fixedly connected to the spinning manifold 1; the component heating sleeve 2 is outside the component 3;

[0044] The main melt tube 6, the branch melt tube 4 and the melt connection tube are located in the spinning box shell; the number of the main melt tube 6 is 1, and the number of the branch melt tube 4 and the melt connection tube is the same as the number of components; the length of all branch melt tubes 4 is the same, which is 1.5m; the length of all melt connection tubes is the same, which is 0.3m; the branch melt tube 4 and the melt connection tube adopt a spiral structure inside;

[0045] One end of the main melt pipe 6 is a melt inlet, and the other end is a melt outlet, the melt outlet is simultaneously connected to the melt inlets of all branch melt pipes 4, and the melt outlets of all branch melt pipes 4 are respectively connected to the inlet of a metering pump 5; one end of the melt connecting pipe is connected to the outlet of the metering pump 5, and the other end of the melt connecting pipe is connected to the component 3;

[0046] The production process parameters are as follows: the pressure drop is 40 bar; the temperature settings of the screw extruder from the first zone to the sixth zone are 295°C, 310°C, 305°C, 275°C, 275°C, and 275°C respectively; the spinning box temperature is 275°C, the component heating temperature is 295°C, the cooling air temperature is 45°C, the spinning speed is 3100m / min, the winding speed is 6000m / min, and the draft ratio is 2.5; the network pressure is 0.25MPa.

[0047] The final high-strength, high-modulus, low-shrinkage yarn has an initial modulus of 110 cN / dtex, a dimensional stability of 7%, and a breaking strength of 7.8 cN / dtex.

[0048] Comparative Example 1

[0049] A method for producing polyester industrial yarn is basically the same as Example 1, except that the component grooves on the lower surface of the spinning box shell are in a single row, the number of component grooves is 4, the length of all branch line melt tubes is the same, which is 2.8 m, and the spiral structure inside the branch line melt tube and the melt connecting tube is changed so that the pressure drop is the same as that in Example 1.

[0050] Comparative Example 1 cannot be spun successfully because the melt tube is long, the viscosity drop is large, and the viscosity is low. At the spinning speed, draft ratio, and winding speed of Example 1, the filaments are easily broken.

[0051] Comparative Example 2

[0052] A method for producing polyester industrial yarn is basically the same as Example 1, except that the component grooves on the lower surface of the spinning box shell are single-row, the number of component grooves is 4, the length of all branch line melt tubes is the same, which is 2.8m, and the spiral structure inside the branch line melt tube and the melt connecting tube is changed so that the pressure drop is the same as that in Example 1; the spinning speed in the production process parameters is 2700m / min, the winding speed is 5500m / min, and the draft ratio is 2.05.

[0053] The final high-strength high-modulus low-shrinkage yarn has an initial modulus of 104 cN / dtex, a dimensional stability of 8.5%, and a breaking strength of 7.3 cN / dtex. Compared with Example 1, the initial modulus and breaking strength of Comparative Example 1 are lower, and the dimensional stability is higher. This is because the melt tube of Comparative Example 1 is long, the viscosity drop is large, and the viscosity is low, so it can only be spun at a lower spinning speed, draft ratio, and winding speed.

[0054] Example 2

[0055] A method for producing high-strength, high-modulus and low-shrinkage wire, the specific process is as follows:

[0056] The polyester chips with an intrinsic viscosity of 1.13dl / g are extruded through a screw extruder to form a polyester melt, and then enter a spinning box, and then extrude from a spinneret, and then go through cooling, oiling, drawing, shaping, networking and winding in sequence to obtain a high-strength, high-modulus, low-shrinkage yarn.

[0057] Among them, the melt viscosity dropped to 0.07dl / g;

[0058] The spinning box body includes a spinning box shell, a main melt tube, a branch line melt tube, a melt connecting tube, a metering pump and components;

[0059] The lower surface of the spinning box shell is provided with double rows of component grooves; the upper surface of the spinning box shell is provided with metering pump grooves, the number of which is the same as the component grooves, and the number of component grooves in each row is 3; a component is placed in each component groove, and a metering pump is placed in each metering pump groove, and all metering pumps are of the same size;

[0060] A component heating sleeve is arranged in each component groove; the component heating sleeve comprises a hollow ring shell and a resistance wire, and the resistance wire is arranged inside the hollow ring shell; the component heating sleeve is fixedly connected to the spinning box body; the component heating sleeve is on the outside of the component;

[0061] The main melt tube, branch melt tube and melt connection tube are located in the spinning box shell; the number of main melt tube is 1, and the number of branch melt tubes and melt connection tubes is the same as the number of components; the length of all branch melt tubes is the same, which is 2m; the length of all melt connection tubes is the same, which is 0.3m; the branch melt tube and melt connection tube adopt a spiral structure inside;

[0062] One end of the main melt pipe is the melt inlet, and the other end is the melt outlet. The melt outlet is simultaneously connected to the melt inlets of all branch melt pipes, and the melt outlets of all branch melt pipes are respectively connected to the inlet of a metering pump; one end of the melt connecting pipe is connected to the outlet of the metering pump, and the other end of the melt connecting pipe is connected to the assembly;

[0063] The production process parameters are as follows: the pressure drop is 60 bar; the temperature settings of the screw extruder from the first zone to the sixth zone are 295°C, 310°C, 305°C, 270°C, 270°C, and 270°C respectively; the spinning box temperature is 276°C, the component heating temperature is 296°C, the cooling air temperature is 45°C, the spinning speed is 3200m / min, the winding speed is 6100m / min, and the draft ratio is 2.5; the network pressure is 0.27MPa.

[0064] The final high-strength, high-modulus, low-shrinkage yarn has an initial modulus of 112 cN / dtex, a dimensional stability of 7.5%, and a breaking strength of 7.85 cN / dtex.

[0065] Example 3

[0066] A method for producing high-strength, high-modulus and low-shrinkage wire, the specific process is as follows:

[0067] The polyester chips with an intrinsic viscosity of 1.4 dl / g are extruded through a screw extruder to form a polyester melt, and then enter a spinning box, and then extrude from a spinneret, and then go through cooling, oiling, drawing, shaping, networking and winding in sequence to obtain a high-strength, high-modulus, low-shrinkage yarn.

[0068] Among them, the melt viscosity dropped to 0.08dl / g;

[0069] The spinning box body includes a spinning box shell, a main melt tube, a branch line melt tube, a melt connecting tube, a metering pump and components;

[0070] The lower surface of the spinning box shell is provided with double rows of component grooves; the upper surface of the spinning box shell is provided with metering pump grooves, the number of which is the same as the component grooves, and the number of component grooves in each row is 2; a component is placed in each component groove, and a metering pump is placed in each metering pump groove, and all metering pumps are of the same size;

[0071] A component heating sleeve is arranged in each component groove; the component heating sleeve comprises a hollow ring shell and a resistance wire, and the resistance wire is arranged inside the hollow ring shell; the component heating sleeve is fixedly connected to the spinning box body; the component heating sleeve is on the outside of the component;

[0072] The main melt tube, branch melt tube and melt connection tube are located in the spinning box shell; the number of main melt tubes is 1, and the number of branch melt tubes and melt connection tubes is the same as the number of components; the length of all branch melt tubes is the same, which is 1.5m, and the length of all melt connection tubes is the same, which is 0.3m; the branch melt tube and melt connection tube adopt a spiral structure inside;

[0073] One end of the main melt pipe is the melt inlet, and the other end is the melt outlet. The melt outlet is simultaneously connected to the melt inlets of all branch melt pipes, and the melt outlets of all branch melt pipes are respectively connected to the inlet of a metering pump; one end of the melt connecting pipe is connected to the outlet of the metering pump, and the other end of the melt connecting pipe is connected to the assembly;

[0074] The production process parameters are as follows: the pressure drop is 45 bar; the temperature settings of the screw extruder from the first zone to the sixth zone are 290°C, 305°C, 300°C, 275°C, 275°C, and 275°C respectively; the spinning box temperature is 277°C, the component heating temperature is 297°C, the cooling air temperature is 45°C, the spinning speed is 3300m / min, the winding speed is 6200m / min, and the draft ratio is 2.4; the network pressure is 0.3MPa.

[0075] The final high-strength, high-modulus, low-shrinkage yarn has an initial modulus of 113 cN / dtex, a dimensional stability of 7.8%, and a breaking strength of 7.9 cN / dtex.

[0076] Example 4

[0077] A method for producing high-strength, high-modulus and low-shrinkage wire, the specific process is as follows:

[0078] The polyester chips with an intrinsic viscosity of 1.5 dl / g are extruded through a screw extruder to form a polyester melt, and then enter a spinning box, and then extrude from a spinneret, and then go through cooling, oiling, drawing, shaping, networking and winding in sequence to obtain a high-strength, high-modulus, low-shrinkage yarn.

[0079] Among them, the melt viscosity dropped to 0.09dl / g;

[0080] The spinning box body includes a spinning box shell, a main melt tube, a branch line melt tube, a melt connecting tube, a metering pump and components;

[0081] The lower surface of the spinning box shell is provided with double rows of component grooves; the upper surface of the spinning box shell is provided with metering pump grooves, the number of which is the same as the component grooves, and the number of component grooves in each row is 2; a component is placed in each component groove, and a metering pump is placed in each metering pump groove, and all metering pumps are of the same size;

[0082] A component heating sleeve is arranged in each component groove; the component heating sleeve comprises a hollow ring shell and a resistance wire, and the resistance wire is arranged inside the hollow ring shell; the component heating sleeve is fixedly connected to the spinning box body; the component heating sleeve is on the outside of the component;

[0083] The main melt tube, branch melt tube and melt connection tube are located in the spinning box shell; the number of main melt tube is 1, and the number of branch melt tubes and melt connection tubes is the same as the number of components; the length of all branch melt tubes is the same, which is 1.5m; the length of all melt connection tubes is the same, which is 0.3m; the branch melt tube and melt connection tube adopt a spiral structure inside;

[0084] One end of the main melt pipe is the melt inlet, and the other end is the melt outlet. The melt outlet is simultaneously connected to the melt inlets of all branch melt pipes, and the melt outlets of all branch melt pipes are respectively connected to the inlet of a metering pump; one end of the melt connecting pipe is connected to the outlet of the metering pump, and the other end of the melt connecting pipe is connected to the assembly;

[0085] The production process parameters are as follows: the pressure drop is 50 bar; the temperature settings of the screw extruder from the first zone to the sixth zone are 293°C, 308°C, 303°C, 273°C, 273°C, and 273°C respectively; the spinning box temperature is 278°C, the component heating temperature is 298°C, the cooling air temperature is 45°C, the spinning speed is 3400m / min, the winding speed is 6300m / min, and the draft ratio is 2.3; the network pressure is 0.33MPa.

[0086] The final high-strength, high-modulus, low-shrinkage yarn has an initial modulus of 114 cN / dtex, a dimensional stability of 8.2%, and a breaking strength of 7.95 cN / dtex.

[0087] Example 5

[0088] A method for producing high-strength, high-modulus and low-shrinkage wire, the specific process is as follows:

[0089] The polyester chips with an intrinsic viscosity of 1.6 dl / g are extruded through a screw extruder to form a polyester melt, and then enter a spinning box, and then extrude from a spinneret, and then go through cooling, oiling, drawing, shaping, networking and winding in sequence to obtain a high-strength, high-modulus, low-shrinkage yarn.

[0090] Among them, the melt viscosity dropped to 0.1dl / g;

[0091] The spinning box body includes a spinning box shell, a main melt tube, a branch line melt tube, a melt connecting tube, a metering pump and components;

[0092] The lower surface of the spinning box shell is provided with double rows of component grooves; the upper surface of the spinning box shell is provided with metering pump grooves, the number of which is the same as the component grooves, and the number of component grooves in each row is 2; a component is placed in each component groove, and a metering pump is placed in each metering pump groove, and all metering pumps are of the same size;

[0093] A component heating sleeve is arranged in each component groove; the component heating sleeve comprises a hollow ring shell and a resistance wire, and the resistance wire is arranged inside the hollow ring shell; the component heating sleeve is fixedly connected to the spinning box body; the component heating sleeve is on the outside of the component;

[0094] The main melt tube, branch melt tube and melt connection tube are located in the spinning box shell; the number of main melt tube is 1, and the number of branch melt tubes and melt connection tubes is the same as the number of components; the length of all branch melt tubes is the same, which is 1.5m; the length of all melt connection tubes is the same, which is 0.3m; the branch melt tube and melt connection tube adopt a spiral structure inside;

[0095] One end of the main melt pipe is the melt inlet, and the other end is the melt outlet. The melt outlet is simultaneously connected to the melt inlets of all branch melt pipes, and the melt outlets of all branch melt pipes are respectively connected to the inlet of a metering pump; one end of the melt connecting pipe is connected to the outlet of the metering pump, and the other end of the melt connecting pipe is connected to the assembly;

[0096] The production process parameters are as follows: the pressure drop is 55 bar; the temperature settings of the screw extruder from the first zone to the sixth zone are 295°C, 310°C, 305°C, 275°C, 275°C, and 275°C respectively; the spinning box temperature is 280°C, the component heating temperature is 300°C, the cooling air temperature is 45°C, the spinning speed is 3500m / min, the winding speed is 6500m / min, and the draft ratio is 2.2; the network pressure is 0.35MPa.

[0097] The final high-strength, high-modulus, low-shrinkage yarn has an initial modulus of 115 cN / dtex, a dimensional stability of 8.5%, and a breaking strength of 8 cN / dtex.

[0098] Example 6

[0099] A method for producing high-strength, high-modulus, low-shrinkage yarn is basically the same as Example 1, except that in the production process parameters, the spinning speed is 2700m / min, the winding speed is 5500m / min, and the draft ratio is 2.05.

[0100] The final high-strength, high-modulus, low-shrinkage yarn has an initial modulus of 104 cN / dtex, a dimensional stability of 8.5%, and a breaking strength of 7.6 cN / dtex.

[0101] Compared with Example 1, the initial modulus and breaking strength of Example 6 are relatively low, and the dimensional stability is relatively large. This is because the spinning speed, draw ratio and winding speed of Example 6 are relatively low. The initial modulus is the tangent value of the initial point of the strength-strain curve, which is proportional to the spinning speed. As the spinning speed decreases, the initial modulus also decreases. At the same time, as the spinning speed decreases, the fixed load elongation of the product property increases, and the dimensional stability also increases accordingly. The draw ratio decreases, resulting in a decrease in breaking strength. Among them, the winding speed and the spinning speed are adjusted synchronously. When the spinning speed decreases, the winding speed also needs to be adjusted accordingly.

[0102] Compared with Comparative Example 2, Example 6 has greater breaking strength. This is because Example 6 reduces the length of the branch line melt tube inside the spinning manifold, reduces the melt viscosity drop, and improves the breaking strength of the product.

Claims

1. A method for producing high-strength, high-modulus and low-shrinkage wire, It is characterized in that After the polyester chips are melted and extruded through a screw extruder, they enter the spinning box and are extruded from the spinneret. They are then cooled, oiled, drawn, shaped, networked and wound in sequence to produce high-strength, high-modulus and low-shrinkage yarns. The spinning box body includes a spinning box shell, a main melt tube, a branch line melt tube, a melt connecting tube, a metering pump and components; The lower surface of the spinning box shell is provided with double rows of component grooves; the upper surface of the spinning box shell is provided with metering pump grooves, the number of which is the same as the component grooves, and the number of component grooves in each row is 2 to 3; a component is placed in each component groove, and a metering pump is placed in each metering pump groove, and all metering pumps are of the same size; The main melt tube, branch melt tube and melt connection tube are located in the spinning box shell; the number of the main melt tube is 1, and the number of branch melt tubes and melt connection tubes is the same as the number of components; the lengths of all branch melt tubes are the same, and the lengths of all melt connection tubes are the same; the branch melt tubes and melt connection tubes have a spiral structure inside; One end of the main melt tube is the melt inlet, and the other end is the melt outlet. The melt outlet is simultaneously connected to the melt inlets of all branch melt tubes, and the melt outlets of all branch melt tubes are respectively connected to the inlet of a metering pump; one end of the melt connecting tube is connected to the outlet of the metering pump, and the other end of the melt connecting tube is connected to the component.

2. A method for producing high-strength, high-modulus, low-shrinkage wire according to claim 1, It is characterized in that An electric heating device is arranged in the groove of the component.

3. A method for producing high-strength, high-modulus, low-shrinkage wire according to claim 2, It is characterized in that The electric heating device is a component heating sleeve; the component heating sleeve comprises a hollow ring shell and a resistance wire, and the resistance wire is arranged inside the hollow ring shell; the component heating sleeve is fixedly connected to the spinning box body; the component heating sleeve is outside the component.

4. A method for producing high-strength, high-modulus, low-shrinkage wire according to claim 2, It is characterized in that The temperature of the three rear zones of the screw is 270~275℃, the temperature of the spinning box is 275~280℃, and the component heating temperature is 295~300℃.

5. The method for producing high-strength, high-modulus, low-shrinkage wire according to claim 1, It is characterized in that The intrinsic viscosity of polyester chips is 1.13~1.16dl / g.

6. A method for producing high-strength, high-modulus, low-shrinkage wire according to claim 1, It is characterized in that The spinning speed is 3100~3500m / min, the winding speed is 6000~6500m / min, and the draft ratio is 2.2~2.

5.

7. A method for producing high-strength, high-modulus, low-shrinkage wire according to any one of claims 1 to 6, It is characterized in that The initial modulus of the prepared high-strength, high-modulus, low-shrinkage yarn is 110-115 cN / dtex, the dimensional stability is 7-8.5%, and the breaking strength is 7.8-8.0 cN / dtex.

Images