Preparation method of high-performance sheath-core composite industrial yarn

Abstract

The invention provides a preparation method of a high-performance skin-core composite industrial yarn, and belongs to the technical field of high-performance textile materials. A functional high polymer material is used as a skin layer material, a high-strength material is used as a core layer material, the skin layer material and the core layer material are pre-crystallized, dried until the water content is less than or equal to 100ppm and then respectively fed into a screw extruder for melt extrusion, and a melt corresponding to the skin layer material and a melt corresponding to the core layer material are respectively guided into an inner layer and an outer layer of a spinning nozzle through a composite spinning assembly; a spinneret plate of the composite spinning assembly is a special-shaped spinneret plate, and the skin-core type composite industrial yarn is obtained through spinning drafting, cooling solidification, stretching heat setting and winding.

Description

Technical Field

[0001] The present application relates to a method for preparing a high-performance sheath-core composite industrial yarn, and belongs to the technical field of high-performance textile materials. Background Art

[0002] In the chemical fiber industry, chemical fibers with high strength, high modulus, high temperature resistance, chemical resistance, and weather resistance are collectively referred to as high-performance fibers. In addition to the above-mentioned mechanical properties, in order to give high-performance fibers better use effects, they will also use composite, skin-core and other materials, and structural improvements. Two or more polymer spinning solutions are input into the same spinning assembly and extruded through the same spinneret to obtain composite fibers. During the compounding process, different spinnerets are set to form a skin-core or parallel structure.

[0003] With the rapid development of industrial technology, the demand for high-performance fiber materials is growing. Common core-skin composite industrial yarns are mostly improved from the material composition, such as: a concentric core-skin composite structure composed of polyester or polyamide as the skin layer, in-situ polymerized graphene polyester or wear-resistant polyamide containing nano inorganic minerals as the core layer, which gives the fiber anti-pilling properties; a core-skin structure with a blended modified polymer as the skin layer and polyester as the core layer, which gives the fiber normal pressure easy dyeing curling properties; a polyester-polyamide block copolymer with polyamide as the skin layer, polyester as the core layer, and unsaturated groups dispersed between the skin and the core, and so on. This circular interface facilitates the batch processing of spinning components and the control of the spinning process, but for applications, as we know, the friction force of the circular surface is relatively small, resulting in poor performance of the circular skin-core structure. Some literatures change the skin-core structure to an island structure to improve the easy peeling, but it is still a circular interface. Traditional high-performance fiber materials with this structure are difficult to meet the stringent requirements of high-end industrial fields in terms of strength, wear resistance, thermal stability, etc. Summary of the invention

[0004] In view of this, the present application provides a method for preparing a high-performance sheath-core composite industrial yarn, which can not only realize the composite of multiple fibers, but also give the composite industrial yarn a sheath-core structure. The sheath-core structure has good interface bonding strength, thereby giving the finished composite industrial yarn higher strength.

[0005] Specifically, the present application is implemented through the following scheme:

[0006] A method for preparing a high-performance sheath-core composite industrial yarn, using a functional polymer material as a sheath material and a high-strength material as a core material, and performing the following steps on the sheath material and the core material:

[0007] Step 1: After pre-crystallization of the skin layer material and the core layer material, they are dried to a moisture content of ≤100ppm;

[0008] Step 2: The skin layer material and the core layer material are respectively fed into a screw extruder for melt extrusion.

[0009] The die head pressure of the screw extruder corresponding to the skin material is 70-81 bar.

[0010] The die head pressure of the screw extruder corresponding to the core material is 80-84 bar;

[0011] Step three, the melt corresponding to the skin layer material and the melt corresponding to the core layer material are respectively introduced into the inner and outer layers of the spinning nozzle through the composite spinning component. The spinneret of the composite spinning component is a special-shaped spinneret. The spinning is stretched, cooled and solidified, stretched and heat-set, and wound to obtain a skin-core composite industrial yarn.

[0012] This application adopts a unique two-component skin-core composite structure design. The skin material and the core material are composed of different polymer materials. The functional polymer material focuses on functionality, such as wear resistance, UV resistance and processability, and the high-strength material uses conventional polyester PET with higher strength, etc., and pays more attention to high strength, high modulus and excellent thermal stability. This structural design not only realizes the complementary advantages of material properties, but also cooperates with the special-shaped spinneret melt extrusion and composite spinning to obtain special-shaped skin-core industrial yarn, which effectively increases the interface contact area between the skin and the core layer, and improves the bonding performance between the two components, thereby giving the composite fiber specific functionality, such as wear resistance, flexibility, and compatibility with other materials, while ensuring the strength of the fiber.

[0013] Further, as a preference:

[0014] The pre-crystallization temperature of the core layer material is 90-120°C, and the drying temperature is 110-140°C.

[0015] The parameters of each drafting roller in the spinning drafting are set as follows:

[0016] The first pair of rollers GR1+2: roller speed is 400-600m / min,

[0017] The second pair of rollers GR3+4: roller speed is 420-620 m / min, roller temperature is 80-100°C,

[0018] The third pair of rollers GR5+6: roller speed is 1800-2000 m / min, roller temperature is 90-110°C,

[0019] The fourth pair of rollers GR7+8: roller speed is 2700-2900 m / min, roller temperature is 120-240°C,

[0020] The fifth pair of rollers GR9+10: the roller speed is 2650-2850 m / min, and the roller temperature is 140-160°C.

[0021] The drafting multiple, that is, the ratio of the highest roller speed to the lowest roller speed, is: 4.5~7.5.

[0022] In order to ensure the performance of the core-sheath composite industrial yarn, the drafting roller parameters in the spinning and stretching are as follows: the roller speed of GR1+2 is 420-560 m / min (and preferably 460-480 m / min), the drafting multiple is 5.5-6.5 times, that is, the roller speed of GR7+8 is 2750-2900 m / min. The roller temperature of GR7+8 is 230-240°C.

[0023] The cooling adopts side-blowing cooling to perform solidification molding, the side-blowing wind speed is set to 0.5-2.0 m / s, and the temperature is set to 20-40°C.

[0024] The composite spinning assembly includes a main box and a sub-box. The heat medium systems of the main box and the sub-box are independent of each other and separated by a heat preservation plate. The melt corresponding to the skin material and the melt corresponding to the core material are respectively introduced into the inner and outer layers of the spinning nozzle through the main box and the sub-box. The composite spinning box adopts a composite box structure composed of the main box and the sub-box. The two boxes use independent heat medium systems with different temperatures for heat preservation and sample supply, and a heat preservation plate is provided in the middle to reduce the heat transfer between the main box and the sub-box, thereby ensuring the uniformity of the two-component melt.

[0025] In order to achieve good interface bonding of the sheath-core structure and improve fiber performance, the special-shaped spinneret selects a sheath-core spinneret assembly with a special cross-section. The cross-section of the composite spinning assembly is serrated or cross-star shaped. In this way, the two-component melt passes through the main and auxiliary spinning boxes to reach the spinning assembly, and under the action of the spinneret assembly with a special structure, a sheath-core composite fiber with a special interface shape is formed.

[0026] The above scheme does not need to fix the combination of the skin layer material and the core layer material, and can be matched at will to obtain composite industrial yarns with different properties. As some preferred schemes:

[0027] The skin material is any one of PA6, PA66, LMPET, CDP and ECDP, and the temperature of the screw extruder corresponding to the skin material is set to 240-300°C.

[0028] The core layer material is conventional polyester, and the temperature of the screw extruder corresponding to the core layer material is set to: 275-305°C.

[0029] The added mass ratio of the skin layer material to the core layer material is 1-3:9-7.

[0030] By changing and coordinating the specific composition of the skin layer material and the core layer material and the ratio of the skin layer material to the core layer material, the finished composite industrial yarn is endowed with different functional characteristics.

[0031] More preferably, in the above scheme, when polyester is the core layer material, the skin layer material is different, and the corresponding pre-crystallization temperature, drying temperature, and melt extrusion conditions are also different:

[0032] When PA66 is the skin material, the corresponding pre-crystallization temperature is 70-90°C, the drying temperature is 90-110°C, the five-zone temperature settings of the screw extruder are: 270-280°C, 285-290°C, 288-295°C, 288-295°C, 295-300°C, and the die pressure is 70-76 bar.

[0033] When PA6 is the skin material, the corresponding pre-crystallization temperature is 60-80°C, the drying temperature is 80-100°C, the five-zone temperature settings of the screw extruder are: 240-252°C, 255-265°C, 258-264°C, 260-268°C, 269-273°C, and the die pressure is 75-81 bar.

[0034] When LMPET is the skin material, the corresponding pre-crystallization temperature is 70-90°C, the drying temperature is 90-110°C, the five-zone temperature settings of the screw extruder are: 248-252°C, 259-264°C, 265-270°C, 296-270°C, 268-272°C, and the die pressure is 75-78 bar.

[0035] In the above scheme, after drying, the water content of the skin material and the core material is controlled below 100ppm, which can suppress the hydrolysis reaction that may occur during the spinning process to the greatest extent, and ensure the spinnability of the composite fiber and the quality of the finished yarn. The skin material and the core material are respectively placed in a screw extruder for melt extrusion, and the melting temperature and die pressure of each component are controlled to ensure that the two components have similar melt viscosity and flow properties in the subsequent spinning process, so that they have good bonding properties during the spinning process and optimize the quality of the finished yarn. The temperature of the spinning assembly can well match the thermal properties, melt viscosity and shear viscosity of the skin material and the core material, ensuring that the melt viscosity difference of the two components is small and the flowability is uniform. The composite fiber flowing out of the spinning assembly is quickly cooled and solidified by the side blowing device to maintain the stability of its skin-core structure. The cooled composite fiber is further stretched and heat-set to improve the strength and orientation of the composite fiber. Finally, the skin-core composite fiber after stretching and setting is wound and packaged.

[0036] The implementation of the present invention will bring significant economic and social benefits. On the one hand, the wide application of high-performance core-sheath composite industrial silk fibers will promote the development and upgrading of related industries and improve the added value and market competitiveness of products; on the other hand, efficient production processes and reasonable raw material combinations will further enrich the differentiated varieties of industrial silk fibers, broaden the application scenarios of industrial silk fibers, and increase their market share.

[0037] With its excellent performance and environmental protection characteristics, the high-performance core-sheath composite industrial silk fiber of the present invention has shown broad application prospects in multiple fields such as textiles, automobiles, medical treatment, and aerospace. In the textile industry, it can be used to produce high-performance clothing fabrics and industrial fabrics; in the automotive field, it can be used for airbags and tire cords; in the medical field, it can be used to manufacture surgical sutures, etc. In addition, its excellent comprehensive performance can also make the core-sheath composite industrial silk fiber have potential application value in the fields of electronics, electrical engineering, and construction.

[0038] In summary, the high-performance sheath-core composite industrial silk fiber of the present invention has achieved important breakthroughs and innovations in structural design, interface strengthening, performance improvement and environmental protection requirements, injecting new vitality into the development of the textile and composite materials industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 It is a schematic diagram of the structure of the spinning device in this application;

[0041] Figure 2 This is a schematic diagram of the first cross-sectional structure of the spinneret corresponding to the core layer in this application;

[0042] Figure 3 This is a schematic diagram of the second cross-sectional structure of the spinneret corresponding to the core layer in the present application.

[0043] Numbers in the figure: 1. Main screw extruder (core layer); 2. Auxiliary screw extruder (skin layer); 3. Core layer material melt pipeline; 4. Skin layer material melt pipeline; 5. Main insulation box; 6. Auxiliary insulation box; 7. Insulation board; 8. Spinning assembly; 9. Primary fiber; 10. Side blowing device; 11. First roller GR1; 12. Second roller GR2; 13. Third roller GR3; 14. Fourth roller GR4; 15. Fifth roller GR5; 16. Sixth roller GR6; 17. Seventh roller GR7; 18. Eighth roller GR8; 19. Ninth roller GR9; 20. Tenth roller GR10; 21. Winding device; 22. Skin layer material area; 23. Core layer material area. DETAILED DESCRIPTION

[0044] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer, the technical solutions in the embodiments of this application will be further described in detail below in conjunction with the drawings in the embodiments of this application. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit the technical solutions of this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0045] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly or indirectly located on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The directions or positions indicated by the terms "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positions shown in the accompanying drawings and are only for the convenience of description and should not be construed as limitations on the present technical solution.

[0046] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0047] Example 1

[0048] The preparation method of the high-performance sheath-core composite industrial yarn in this embodiment uses PA66 as the sheath material and conventional polyester PET as the core material. The raw material mass ratio of the sheath material PA66 and the core layer material PET is set to 3:7. The raw materials are subjected to pre-crystallization and drying, melt extrusion, co-blending spinning, cooling and oiling, drawing and shaping, and winding to obtain the finished yarn.

[0049] The specific process is as follows:

[0050] Step 1: Pre-crystallize and dry the PA66 slices and PET slices;

[0051] The pre-crystallization temperature of PA66 slices was set at 80°C and the drying temperature was set at 100°C; the pre-crystallization temperature of PET slices was set at 115°C and the drying temperature was set at 130°C, and the vacuum degree was kept below 100 Pa. The pre-crystallization time was set at 2.5h and the drying time was set at 20h. The moisture content of PA66 slices and PET slices after drying was 70ppm and 50ppm respectively.

[0052] The physical properties of PA66 slices and PET slices are shown in Table 1.

[0053] Table 1: Physical properties of PA66 and PET

[0054] project PA66 project PET Relative viscosity 3.12 Intrinsic viscosity (dl / g) 1.013 Terminal carboxyl group (mol / t) 11.4 Melting point(℃) 260.2 Diethylene glycol (%) 1.04 L value 88.7 b-value 4.6 .

[0055] Step 2: If Figure 1 As shown, the dried PET slices and PA66 slices enter the main screw extruder 1 and the auxiliary screw extruder 2 respectively for melt extrusion. The parameter settings of each zone of the screw of the PET slices and the PA66 slices are shown in Table 2.

[0056] Table 2: Parameters of each zone of screw extruder

[0057] Screw Zones PET(core layer) PA66(cortex) Zone 1(℃) 280 275 Zone 2(℃) 292 287 Zone 3(℃) 295 293 Zone 4 (℃) 295 293 Die head(℃) 300 298 Head pressure (bar) 84 76 .

[0058] Step 3: If Figure 1 As shown, after the core layer material PET and the skin layer material PA66 are extruded by the screw, they flow into the spinning assembly 8 through the melt pipes 3 and 4 respectively, and the spinning assembly includes a filter element and a spinneret. During the flow, the melt passes through the main insulation box 5 and the auxiliary insulation box 6 respectively. An insulation plate 7 is arranged between the main insulation box and the auxiliary insulation box to reduce the heat transfer between the two boxes.

[0059] The spinneret corresponding to the core structure can be Figure 2 The serrated structure shown forms a sheath-core composite fiber in which the cross-section of the inner core layer structure is set to a special shape, so that the inner core layer structure can better support the first fiber, i.e., the sheath structure, and increase the interface bonding force between the sheath structure and the core layer structure, thereby enhancing the comprehensive performance of the composite fiber.

[0060] Step 4: After the nascent fibers are ejected from the spinneret of the spinning assembly 8, they are solidified and formed by side-blowing cooling, with the side-blowing wind speed set to 1.5 m / s and the temperature set to 30°C.

[0061] Step 5: After cooling, the tow is oiled, stretched, shaped and wound. Since the cortex is PA66 fiber, the oil is a nylon-specific oil and an oil nozzle is used for oiling.

[0062] The parameter settings of each drafting roller in spinning are shown in Table 3.

[0063] Table 3: Process parameters of spinning drafting roller

[0064] Roller Name Speed ​​(m / min) Temperature(℃) GR1+2 480 / GR3+4 500 90 GR5+6 1900 100 GR7+8 2800 240 GR9+10 2750 150 .

[0065] The PA66 / PET sheath-core composite industrial yarn obtained in this embodiment not only has the advantages of high modulus and high strength, but also has the high wear resistance and heat resistance of PA66 material, and can be applied to high-end clothing, carpets, airbags, tire cords and other fields.

[0066] Example 1-1

[0067] This embodiment is the same as the embodiment 1, except that the raw material mass ratios of the skin material PA66 and the core material PET are replaced with 2:8, 1:9, 4:6, and 5:5, respectively. Different ratios can achieve relatively good holding performance, but the composite industrial yarns with different ratios have slight differences in mechanical strength and other aspects. Therefore, the present application scheme can achieve the acquisition of composite industrial yarns with different performances by changing the ratio of the skin and core materials.

[0068] Example 1-2

[0069] The configuration of this embodiment is the same as that of embodiment 1, except that the spinneret adopts a conventional circular cross section. Compared with the product of embodiment 1, the holding performance of the product obtained in this embodiment is relatively poor. It can be seen that the serrated spinneret adopted in embodiment 1 can well increase the contact area of ​​the skin-core interface, and compared with the spinneret of conventional circular cross section, embodiment 1 is easier to obtain higher strength.

[0070] Example 2

[0071] This embodiment provides a method for preparing a high-performance core-skin composite industrial silk fiber. Different from the first embodiment, this embodiment uses PA6 as the skin material and conventional polyester PET as the core material. The raw material mass ratio of the skin material PA6 and the core material PET is 3:7. The raw materials are pre-crystallized and dried, melt-extruded, co-spun, cooled and oiled, drawn and shaped, and wound to obtain the finished silk. The specific process is as follows:

[0072] Step 1: Pre-crystallize and dry PA6 slices and PET slices;

[0073] The pre-crystallization temperature of PA6 chips was set at 65°C and the drying temperature was set at 90°C; the pre-crystallization temperature of PET chips was set at 115°C and the drying temperature was set at 130°C, and the vacuum degree was kept below 100 Pa. The pre-crystallization time was set at 2.5h and the drying time was set at 24h. The moisture content of PA6 chips and PET chips after drying was 50ppm and 50ppm respectively.

[0074] The physical properties of the PA6 slices and PET slices used are shown in Table 4.

[0075] Table 4: Physical properties of PA6 and PET

[0076] project PA6 project PET Relative viscosity 3.45 Intrinsic viscosity (dl / g) 1.013 Terminal carboxyl group (mol / t) 11.4 Melting point(℃) 260.2 Diethylene glycol (%) 1.04 L value 88.7 b-value 4.6 .

[0077] Step 2: If Figure 1 As shown, the dried PET slices and PA6 slices enter the main screw extruder 1 and the auxiliary screw extruder 2 respectively for melt extrusion. The screw zone parameter settings of the PET slices and PA6 slices are shown in Table 5.

[0078] Table 5: Parameters of each zone of screw extruder

[0079]

[0080]

[0081] Step 3: If Figure 1 As shown, after the core layer material PET and the skin layer material PA6 are extruded by the screw, they flow into the spinning assembly 8 through the melt pipes 3 and 4 respectively, and the spinning assembly includes a filter element and a spinneret. During the flow, the melt passes through the main insulation box 5 and the auxiliary insulation box 6 respectively. An insulation plate 7 is arranged between the main insulation box and the auxiliary insulation box to reduce the heat transfer between the two boxes.

[0082] The spinneret corresponding to the core structure adopts Figure 3 The cross-star structure shown. The spinneret selects a skin-core spinneret assembly with a special cross-section shape. In the formed skin-core composite fiber, the cross-section of the inner core structure is set to a special shape, so that the inner core structure can better support the first fiber, i.e., the skin structure, and increase the interface bonding force between the skin structure and the core structure, thereby enhancing the comprehensive performance of the composite fiber.

[0083] Step 4: After the nascent fibers are ejected from the spinneret of the spinning assembly 8, they are solidified and formed by side-blowing cooling. The side-blowing wind speed is set to 2.0 m / s and the temperature is set to 20°C.

[0084] Step 5: After cooling, the tow is oiled, stretched, shaped and wound. Since the cortex is PA6 fiber, the oil is a nylon-specific oil and an oil nozzle is used for oiling.

[0085] The parameter settings of each drafting roller in spinning are shown in Table 6.

[0086] Table 3: Process parameters of spinning drafting roller

[0087] Roller Name Speed ​​(m / min) Temperature(℃) GR1+2 460 / GR3+4 480 85 GR5+6 1870 95 GR7+8 2750 230 GR9+10 2700 145 .

[0088] The PA6 / PET sheath-core composite industrial yarn obtained in this embodiment not only has the advantages of high modulus and high strength, but also has the high impact resistance, high wear resistance and good surface quality of PA6 material, and can be applied to various high-end fabrics, pipeline skeletons, ropes and conveyor belts and other fields.

[0089] Example 3

[0090] This embodiment provides a method for preparing a high-performance core-skin composite industrial silk fiber. Different from the first embodiment, this embodiment uses low melting point polyester (LMPET) as the skin material, conventional polyester PET as the core material, and the raw material mass ratio of the skin material LMPET to the core material PET is 3:7. The raw materials are pre-crystallized and dried, melt-extruded, co-spun, cooled and oiled, drawn and shaped, and wound to obtain the finished silk. The specific process is as follows:

[0091] Step 1: Pre-crystallize and dry the LMPET slices and PET slices;

[0092] The pre-crystallization temperature of LMPET slices was set at 85°C and the drying temperature was 105°C; the pre-crystallization temperature of PET slices was set at 110°C and the drying temperature was set at 120°C, and the vacuum degree was kept below 100 Pa. The pre-crystallization time was set at 2h and the drying time was set at 18h. The moisture content of LMPET slices and PET slices after drying was 50ppm and 40ppm respectively.

[0093] The physical properties of the LMPET slices and PET slices used are shown in Table 7.

[0094] Table 7: Physical properties of LMPET and PET

[0095] project PET LMPET Intrinsic viscosity (dL / g) 1.013 1.018 Terminal carboxyl group (mol / t) 11.4 14.4 Melting point(℃) 260.2 223.6 Diethylene glycol (%) 1.04 1.32 L value 88.7 74.6 b-value 4.6 3.3 .

[0096] Step 2: If Figure 1 As shown, the dried PET slices and PA6 slices enter the main screw extruder 1 and the auxiliary screw extruder 2 respectively for melt extrusion. The screw zone parameter settings of the PET slices and LMPET slices are shown in Table 8.

[0097] Table 8: Parameters of each zone of screw extruder

[0098] Screw Zones PET(core layer) LMPET (cortex) Zone 1(℃) 280 250 Zone 2(℃) 292 262 Zone 3(℃) 295 265 Zone 4 (℃) 295 265 Die head(℃) 300 270 Head pressure (bar) 84 78

[0099] Step 3: If Figure 1 As shown, after the core layer material PET and the skin layer material LMPET are extruded by the screw, they flow into the spinning assembly 8 through the melt pipes 3 and 4 respectively, and the spinning assembly includes a filter element and a spinneret. During the flow, the melt passes through the main insulation box 5 and the auxiliary insulation box 6 respectively. An insulation plate 7 is arranged between the main insulation box and the auxiliary insulation box to reduce the heat transfer between the two boxes.

[0100] The spinneret corresponding to the core structure can be Figure 2 The sawtooth structure shown can also be used Figure 3 In the formed core-skin composite fiber structure, the cross section of the inner core structure is set to a special shape, so that the inner core structure can better support the first fiber, i.e., the skin structure, and increase the interface bonding force between the skin structure and the core structure, thereby enhancing the comprehensive performance of the composite fiber.

[0101] Step 4: After the nascent fibers are ejected from the spinneret of the spinning assembly 8, they are solidified and formed by side-blowing cooling, with the side-blowing wind speed set to 1.0 m / s and the temperature set to 40°C.

[0102] Step 5: After cooling, the tow is oiled, stretched, shaped and wound.

[0103] The parameter settings of each drafting roller in spinning are shown in Table 9.

[0104] Table 9: Process parameters of spinning drafting roller

[0105]

[0106]

[0107] The LMPET / PET sheath-core composite industrial yarn obtained in this embodiment not only has the advantages of high modulus and high strength, but also has excellent melt fluidity, crystallinity, dyeability and spinnability, and can be applied to high-end clothing textiles and industrial textiles, non-woven fabrics, the automotive industry, the construction industry, and the coatings industry.

[0108] The above-mentioned embodiments only express several feasible implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention, and the embodiments are not used to limit the scope of protection in the claims of the present invention. For ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and all equivalent implementations or changes that do not depart from the present invention should be included in the technology of the present invention.

Claims

1. A method for preparing a high-performance sheath-core composite industrial yarn, characterized in that: The functional polymer material is used as the skin material, and the high-strength material is used as the core material. The skin material and the core material are processed in the following steps: Step 1: After pre-crystallization of the skin layer material and the core layer material, they are dried to a moisture content of ≤100ppm; Step 2: The skin layer material and the core layer material are respectively fed into a screw extruder for melt extrusion. The die head pressure of the screw extruder corresponding to the skin material is 70-81 bar. The die pressure of the screw extruder corresponding to the core material is 80-84 bar; Step three, the melt corresponding to the skin layer material and the melt corresponding to the core layer material are respectively introduced into the inner and outer layers of the spinning nozzle through the composite spinning component. The spinneret of the composite spinning component is a special-shaped spinneret. After spinning and stretching, cooling and solidification, stretching and heat setting, and winding, a skin-core composite industrial yarn is obtained.

2. The method for preparing a high-performance core-sheath composite industrial yarn according to claim 1, characterized in that: The pre-crystallization temperature of the core layer material is 90-120°C, and the drying temperature is 110-140°C.

3. The method for preparing a high-performance core-sheath composite industrial yarn according to claim 1, characterized in that: The parameters of each drafting roller in the spinning drafting are set as follows: The first pair of rollers GR1+2: roller speed is 400~600m / min, The second pair of rollers GR3+4: roller speed is 420-620 m / min, roller temperature is 80-100°C, The third pair of rollers GR5+6: roller speed is 1800-2000 m / min, roller temperature is 90-110°C, The fourth pair of rollers GR7+8: roller speed is 2700-2900 m / min, roller temperature is 120-240°C, The fifth pair of rollers GR9+10: the roller speed is 2650-2850 m / min, and the roller temperature is 140-160°C.

4. The method for preparing a high-performance core-sheath composite industrial yarn according to claim 3, characterized in that: The roller speed of the first pair of rollers GR1+2 is 420-560 m / min, the drafting ratio is 5.5-6.5 times, and the roller temperature of the fourth pair of rollers GR7+8 is 230-240°C.

5. The method for preparing a high-performance core-sheath composite industrial yarn according to claim 1, characterized in that: The cooling adopts side-blowing cooling to perform solidification molding, the side-blowing wind speed is set to 0.5-2.0 m / s, and the temperature is set to 20-40°C.

6. The method for preparing a high-performance core-sheath composite industrial yarn according to claim 1, characterized in that: The composite spinning assembly includes a main box and a sub-box. The heat medium systems of the main box and the sub-box are independent of each other and are separated by an insulation board. The melt corresponding to the skin material and the melt corresponding to the core layer material are respectively introduced into the inner and outer layers of the spinning nozzle through the main box and the sub-box.

7. The method for preparing a high-performance core-sheath composite industrial yarn according to claim 1, characterized in that: The cross section of the special-shaped spinneret is sawtooth or cross star shaped.

8. A method for preparing a high-performance core-sheath composite industrial yarn according to any one of claims 1 to 7, characterized in that: The skin material is any one of PA6, PA66, LMPET, CDP and ECDP, and the temperature of the screw extruder corresponding to the skin material is set to: 240-300°C.

9. A method for preparing a high-performance core-sheath composite industrial yarn according to any one of claims 1 to 7, characterized in that: The core layer material is conventional high-viscosity polyester PET, and the temperature of the screw extruder corresponding to the core layer material is set to: 275-305°C.

10. A method for preparing a high-performance core-sheath composite industrial yarn according to any one of claims 1 to 7, characterized in that: The added mass ratio of the skin layer material to the core layer material is 1-3:9-7.

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