Pressure-resistant hydrolysis-resistant nylon material preparation system

Abstract

The invention relates to the field of nylon material preparation, and particularly discloses a pressure-resistant hydrolysis-resistant nylon material preparation system, which comprises an extrusion die head and a granulator which are arranged at the output end of a screw rod, a composite cooling frame arranged between the extrusion die head and the granulator, a tensioning roller and a traction roller are arranged on the composite cooling frame, and the tensioning roller comprises tensioning discs which are arranged in a linear array and are in one-to-one correspondence with the strip materials. According to the invention, the elastic piece provides a force for pushing the strip material to the tensioning disc, the strip material is stretched and lengthened, the strip material is subjected to primary shaping, at the moment, when the size of the strip material extruded by the extrusion die head is changed due to pressure and the like, the tensioning disc moves under the pushing of the elastic piece to compensate the melt size deviation of the strip material, and the strip material is extruded by the extrusion die head. The uniform traction tension is ensured, the problem of uneven particles caused by excessive or insufficient local stretching is effectively avoided, and the pelletizing precision and the material forming stability are improved.

Description

Technical Field

[0001] This invention relates to nylon material preparation technology, specifically a system for preparing pressure-resistant and hydrolysis-resistant nylon materials. Background Technology

[0002] As is well known, nylon (polyamide fiber), abbreviated as PA, is a synthetic fiber. The main base materials are nylon 6, nylon 66 and nylon 12, etc. For harsh environments, such as water treatment systems and engine compartments, glass fiber and anti-hydrolysis agents are added to nylon to improve performance.

[0003] For example, the academic paper titled "Influence of PHE with Different Initial Particle Sizes on the Mechanical Properties of PA66 / PHE Blends," published on CNKI on November 2, 2010, proposed preparing PA66 / PHE blends by blending polyphenolic oxide (PHE) with nylon (PA) 66 using a twin-screw extruder. The mechanical properties were tested and characterized using scanning electron microscopy (SEM). The study found that PA66 / PHE blends prepared with small-sized PHE had a smaller, more uniform dispersed phase size and improved impact strength, exhibiting a synergistic effect, while the tensile strength remained essentially the same as pure PA66. Conversely, PA66 / PHE blends prepared with large-sized PHE had a larger dispersed phase size and were prone to aggregation, resulting in decreased impact strength but increased tensile strength.

[0004] The shortcomings of existing technologies lie in the fact that in the preparation of pressure-resistant and hydrolysis-resistant nylon materials, the nylon base material and additives are first premixed and fed into a screw extruder for heating and shearing melting. Then, glass fibers are added in the middle section for further melting. The prepared nylon material is then extruded from the die into a continuous strip of melt. The melt enters a water tank for cooling and is guided and stretched by guide rollers. Finally, it is pelletized in a pelletizer to complete the preparation of the nylon material. During this process, the strip of melt is initially cooled after entering the water, while the other end is stretched by the pelletizer. This causes the strip of melt to be stretched during the cooling process to reach the desired size. However, due to the lack of shaping ability of the guide rollers, if the size of the strip of melt extruded from the die changes, it is easy to cause differences in the size of the cut particles. These size differences affect the mechanical parameters such as the melting state, tensile strength, and flowability of the particles during subsequent injection molding. Summary of the Invention

[0005] The purpose of this invention is to provide a pressure-resistant and hydrolysis-resistant nylon material preparation system to overcome the above-mentioned shortcomings in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a pressure-resistant and hydrolysis-resistant nylon material preparation system, comprising an extrusion die and a pelletizer disposed at the output end of a screw, wherein the extrusion die extrudes a plurality of strips, the strips are pulled by the pelletizer, and a composite cooling frame disposed between the extrusion die and the pelletizer is further comprising a tension roller and a pulling roller disposed on the composite cooling frame, wherein the tension roller comprises tensioning discs arranged in a linear array corresponding one-to-one with the strips, and an elastic element is disposed between the tensioning discs and the tension roller.

[0007] As a further description of the above technical solution: the pulling roller is provided with a number of auxiliary plasticizing mechanisms corresponding to the strip material. The auxiliary plasticizing mechanism includes a shaping disk rotatably connected to the pulling roller. The shaping disk is symmetrically arranged with shaping pieces in a circumferential array. Two shaping pieces are driven to close together to shape the strip material.

[0008] As a further description of the above technical solution: the traction roller is fixedly mounted on the composite cooling frame, and a plurality of limiting plates are fixedly mounted on the traction roller, the limiting plates being provided with limiting protrusions corresponding to the shaping plates.

[0009] As a further description of the above technical solution: the composite cooling frame includes a first cooling frame, a second cooling frame and a return liquid frame, and an auxiliary roller is provided in the second cooling frame, and the strip material is restricted to entering the second cooling frame by the auxiliary roller.

[0010] As a further description of the above technical solution: the second cooling frame is provided with a liquid outlet bottom plate, the liquid outlet bottom plate is located at the bottom of the first cooling frame, the return liquid frame covers the first cooling frame, and the first cooling frame is provided with a seepage groove facing the return liquid frame.

[0011] As a further description of the above technical solution: a scraper roller is provided on the composite cooling frame, and a plurality of shaping discs are rotatably connected to the scraper roller. The shaping discs are obstructed and move misaligned with the strip material.

[0012] As a further description of the above technical solution: the wiper roller is provided with pushers at both ends, and the pushers push against the shaping disc.

[0013] As a further description of the above technical solution: a limiting plate is rotatably connected to the wiper roller, the limiting plate is disposed on both sides of the shaping disc, a limiting ring is provided on the limiting plate, and a shaping plate is rotatably connected to the shaping disc, the shaping plate being driven to adhere to the strip material.

[0014] As a further description of the above technical solution: the composite cooling frame includes a liquid return frame, and the wiper roller is disposed on the liquid return frame.

[0015] As a further description of the above technical solution: an auxiliary roller is provided inside the composite cooling frame, and the tensioning roller and the auxiliary roller restrict the strip material from being pressed into the water.

[0016] In the above technical solution, the pressure-resistant and hydrolysis-resistant nylon material preparation system provided by the present invention has the following beneficial effects: the elastic element provides a pushing force to the tensioning disc to stretch and elongate the strip, and the shape of the tensioning disc performs a preliminary shaping of the strip. At this time, when the size of the strip extruded by the extrusion die changes due to pressure or other reasons, the tensioning disc moves under the pushing force of the elastic element to compensate for the melt size deviation of the strip, ensure uniform tension, effectively avoid the problem of uneven particle size caused by excessive or insufficient local stretching, and improve pelletizing accuracy and material forming stability. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention;

[0019] Figure 2 This is an exploded view of the composite cooling frame structure provided in an embodiment of the present invention;

[0020] Figure 3 This is a schematic cross-sectional view of the composite cooling frame structure provided in an embodiment of the present invention;

[0021] Figure 4 This is an exploded view of the structure of the traction roller and the auxiliary plasticizing mechanism provided in an embodiment of the present invention;

[0022] Figure 5 This is an exploded view of the tension roller structure provided in an embodiment of the present invention;

[0023] Figure 6 This is a schematic cross-sectional view of the tension roller structure provided in an embodiment of the present invention;

[0024] Figure 7 This is an exploded view of the wiper roller structure provided in an embodiment of the present invention;

[0025] Figure 8 This is a schematic cross-sectional view of the plasticizing mechanism provided in an embodiment of the present invention;

[0026] Figure 9 for Figure 8 Enlarged view of point A in the middle;

[0027] Figure 10 This is a schematic cross-sectional view of the shaping disc structure on the wiper roller provided in an embodiment of the present invention.

[0028] Explanation of reference numerals in the attached figures:

[0029] 1. Composite cooling frame; 11. First cooling frame; 111. Drainage tank; 112. Bottom tank; 12. Second cooling frame; 121. Opening groove; 122. Liquid outlet bottom plate; 13. Liquid return frame; 2. Extrusion die head; 21. Strip material; 3. Pulling roller; 31. First fixed shaft; 32. Restricting piece; 33. Restricting protrusion; 34. Gradient protrusion; 4. Auxiliary roller; 5. Squeegee roller; 51. Second fixed shaft; 52. Base plate; 53. Pushing part; 54. Restricting ring; 6. Tensioning roller; 61. Tensioning disc; 62. Fixed plate; 621. Slide groove; 63. Slide plate; 631. Elastic part; 7. Auxiliary molding mechanism; 71. Shaping disc; 72. Rotating groove; 73. Shaping groove; 74. Shaping piece. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0031] Please see Figure 1-10 This invention provides a technical solution: a pressure-resistant and hydrolysis-resistant nylon material preparation system, including an extrusion die 2 located at the screw output end (specifically, the output end of a twin-screw extruder) and a pelletizer. Nylon resin, hydrolysis-resistant agent, toughening agent, antioxidant, and lubricant are accurately weighed and placed into the twin-screw extruder for shearing and intensive mixing. After melting and mixing, glass fiber is added near the extrusion stage, and the gas generated during heating is vacuum-assisted and transported to the extrusion die 2 after continuous mixing. The extrusion die 2 then extrudes several strips 21, which are pulled by the pelletizer. A composite cooling frame 1 is provided between the extrusion die 2 and the pelletizer, filled with cooling water (pure water or purified tap water) at a temperature of 40-60°C to prevent surface embrittlement of the strips 21 due to rapid cooling. Figure 2As shown, tension rollers 6 and pull rollers 3 are sequentially arranged on the composite cooling frame 1 along the pelletizer direction. The tension rollers 6 include tension discs 61 arranged in a linear array, each corresponding to a strip 21. An elastic element 631 is arranged between the tension discs 61 and the tension rollers 6. The elastic element 631 provides a force to the tension discs 61 to push against the strip 21, stretching and elongating the strip 21. The shape of the tension discs 61 also provides a preliminary shaping of the strip 21. When the size of the strip 21 extruded by the extrusion die 2 changes due to pressure or other reasons, the tension discs 61 move under the push of the elastic element 631, resulting in an increase in the diameter of the output strip 21 over a period of time. This is because the total output... The length between the extrusion die 2 and the traction roller 3 remains unchanged, and the strip 21 with increased diameter is more difficult to tension. At this time, the tensioning disc 61 squeezes the elastic element 631 to increase the tension force, which will lengthen the strip 21 with increased diameter. When the diameter of the strip 21 output decreases over a period of time, the length between the extrusion die 2 and the traction roller 3 increases. At this time, the tensioning disc 61 stretches the elastic element 631 to reduce the tension force, reduce the stretching and shaping of the already stretched strip 21, compensate for the melt size deviation of the strip 21, ensure uniform tension, effectively avoid particle unevenness caused by local overstretching or understretching, and improve pelletizing accuracy and material forming stability.

[0032] Preferably, the elastic element 631 can be a spring, a fixing plate 62 is snapped into the inner wall of the composite cooling frame 1, a groove 621 is provided on the fixing plate 62, a sliding plate 63 is slidably connected in the groove 621, the elastic element 631 is disposed between the sliding plate 63 and the groove 621, and the tensioning disc 61 is rotatably connected to the sliding plate 63.

[0033] In another embodiment of the present invention, the pull roller 3 is provided with several sets of auxiliary plasticizing mechanisms 7 corresponding to the strip 21. Each auxiliary plasticizing mechanism 7 includes a shaping disk 71 rotatably connected to the pull roller 3. The shaping disk 71 has a shaping groove 73. The pull roller 3 is detached from the liquid surface and does not contact the cooling water, thus allowing for better shaping of the reheated strip 21 through the shaping groove 73. The shaping disk 71 has symmetrically arranged rotating grooves 72 in a circular array. Shaping sheets 74 are rotatably connected to the rotating grooves 72. Figure 4 As shown, the side of the forming sheet 74 facing the strip 21 is curved. During operation, as... Figure 3As shown, only a portion of the strip 21 contacts the shaping disc 71, with the contact area forming an arc-shaped trajectory. During contact, the first section of the arc-shaped trajectory is clamped by two shaping plates 74 driven to adhere to each other, thereby driving the shaping disc 71 to rotate along the traction roller 3. As the material moves continuously, this section is always pulled by subsequent shaping plates 74, which, together with the tensioning disc 61, shape the strip 21. In the latter section of the arc-shaped trajectory, the positions of the two shaping plates 74 change with the movement, playing a role in auxiliary restriction of the strip 21 and ensuring that the diameter error of the strip 21 is reduced after subsequent cooling.

[0034] Preferably, the composite cooling frame 1 is provided with an auxiliary roller 4, a tension roller 6, and an auxiliary roller 4 to restrict the strip 21 from being pressed into the water. The design of two water immersions keeps the water out at the pull roller 3, prolongs the overall cooling time of the strip 21, avoids catalysis, and facilitates the discharge of air bubbles in the strip 21.

[0035] Preferably, the pull roller 3 includes a first fixed shaft 31 fixedly connected to the inner wall of the composite cooling frame 1, and a plurality of limiting plates 32 are fixedly disposed on the first fixed shaft 31. The limiting plates 32 cannot rotate or move. Figure 8 As shown, the limiting plates 32 are disposed on both sides of the shaping disc 71. The limiting plates 32 are provided with limiting protrusions 33 and gradient protrusions 34 corresponding to the shaping plates 74. The limiting protrusions 33 push the shaping plates 74 to flip, thereby realizing the clamping function of the first segment of the arc-shaped trajectory. The gradient protrusions 34 are also used to push the shaping plates 74 to flip, thereby realizing the latter segment of the arc-shaped trajectory, so that the flipped plastic sheet squeezes the strip 21 for shaping. After shaping, the gradient protrusions 34 have a gradually decreasing size, allowing the two shaping plates 74 to flip and move away from each other, so that the strip 21 can be released from the shaping plates 74 without damage.

[0036] In another embodiment provided by the present invention, such as Figure 2 As shown, the composite cooling frame 1 includes a first cooling frame 11, a second cooling frame 12, and a return frame 13. An auxiliary roller 4 is provided inside the second cooling frame 12. The strip 21 is restricted to entering the second cooling frame 12 by the auxiliary roller 4. The cooling water temperature in the first cooling frame 11 is 50~60℃, and the cooling water temperature in the second cooling frame 12 is 40~50℃. The two cooling frames have different cooling water temperatures. The first cooling frame 11 is used for initial cooling to facilitate stretching and shaping, while the second cooling frame 12 is used to enhance shaping. The return frame 13 is used to cool the overflowing cooling water at a higher temperature. An opening groove 121 is provided on the second cooling frame 12 for the strip 21 to pass through.

[0037] Preferably, the second cooling frame 12 is provided with a liquid outlet bottom plate 122, and the first cooling frame 11 is provided with a bottom groove 112. The liquid outlet bottom plate 122 and the bottom groove 112 correspond to each other. The liquid outlet bottom plate 122 is located at the bottom of the first cooling frame 11. The return frame 13 covers the first cooling frame 11. The first cooling frame 11 is provided with a seepage groove 111 facing the return frame 13. The cooling water is circulated from the second cooling frame 12 into the first cooling frame 11 along the liquid outlet bottom plate 122. The first cooling frame 11 is cooled in the return frame 13 along the seepage groove 111. The cooling can be carried out by a fan or a compressor. After cooling, the water pump in the return frame 13 is reintroduced into the second cooling frame 12 to complete the circulation of the coolant.

[0038] In another embodiment of the present invention, a scraper roller 5 is provided on the composite cooling frame 1, and a plurality of shaping discs 71 are rotatably connected to the scraper roller 5. When the strip 21 is pulled by the pelletizer, the shaping discs 71 are obstructed and move misaligned with the strip 21, so that the shaping grooves 73 opened on the shaping discs 71 scrape off the residual cooling water on the strip 21 when misaligned with the strip 21, thereby reducing water residue and reducing the processing time of subsequent water removal steps.

[0039] Preferred, such as Figure 7 As shown, the wiper roller 5 includes a second fixed shaft 51 disposed on the composite cooling frame 1. The two ends of the second fixed shaft 51 are provided with base plates 52. The base plates 52 are provided with pushers 53. The pushers 53 can be composed of friction discs and springs. The springs push the two friction discs closer to each other, thereby restricting the multiple shaping discs 71 on the wiper roller 5, giving the shaping discs 71 resistance when rotating, so as to realize the misalignment of the shaping discs 71 relative to the strip 21 and realize the wiping operation.

[0040] Preferably, a limiting plate 32 is rotatably connected to the wiper roller 5. The limiting plate 32 is disposed on both sides of the shaping disc 71. The limiting plate 32 on the wiper roller 5 can rotate or slide along the wiper roller 5. A limiting ring 54 is provided on the limiting plate 32. A shaping plate 74 is rotatably connected to the shaping disc 71. When the spring pushes the friction disc to move, pressure is applied to the limiting plate 32 and the shaping disc 71 at the same time. At this time, the shaping plate 74 on the shaping disc 71 is pushed by the limiting ring 54 and flipped to fit the strip material 21, increasing the wiping ability and wiping the strip material 21 in multiple directions.

[0041] Preferably, the composite cooling frame 1 includes a return frame 13, and the squeegee roller 5 is disposed on the return frame 13 so that the cooling water scraped off by the shaping disc 71 and the shaping sheet 74 on the squeegee roller 5 can be collected and recycled by the return frame 13 for reuse. The shaping disc 71 and the shaping sheet 74 are respectively moved and fixed on the squeegee roller 5 and the pull roller 3 to realize the squeegee and shaping steps.

[0042] In use, nylon resin, hydrolysis resistant agent, toughening agent, antioxidant, and lubricant are first accurately weighed and placed into a twin-screw extruder for shearing and intensive mixing. After melting and mixing, glass fiber is added just before extrusion, and the gas generated during heating is drawn off using a vacuum suction method. After continuous mixing, the mixture is conveyed to the extrusion die 2. The extrusion die 2 then extrudes several strips 21. The strips 21 are then passed sequentially over the tension roller 6, the traction roller 3, the auxiliary roller 4, and the scraper roller 5 before being placed on a pelletizer. The pelletizer pulls the strips 21 and cuts them. The strips 21 extruded from the extrusion die 2 first pass through the tension roller 6, and the elastic element 631 provides tension. The tensioning disc 61 applies a pushing force to the strip 21, stretching and elongating it. The shape of the tensioning disc 61 also provides initial shaping for the strip 21. When the size of the strip 21 extruded from the extrusion die 2 changes due to pressure or other factors, the tensioning disc 61 moves under the pushing force of the elastic element 631. This results in an increase in the diameter of the output strip 21 over a period of time. Since the total output remains constant, the length between the extrusion die 2 and the traction roller 3 decreases, and the strip 21 with its increased diameter is more difficult to tension. At this point, the tensioning disc 61 compresses the elastic element 631, increasing the tension force and thus elongating the strip with the increased diameter. After the strip 21 is added, if the diameter of the output strip 21 decreases over a period of time, the length between the extrusion die 2 and the traction roller 3 increases. At this time, the tensioning disc 61 stretches the elastic element 631, reducing the tension force and reducing the stretching and shaping of the already elongated strip 21, compensating for the melt size deviation of the strip 21. Subsequently, the strip 21 leaves the cooling water and enters the shaping disc 71 on the traction roller 3. Upon contact, the first segment of the arc-shaped trajectory is clamped by two shaping plates 74 driven to adhere to the strip 21, thereby driving the shaping disc 71 to rotate along the traction roller 3. As the material continues to move, this segment always has subsequent shaping plates. 74 pulls the strip 21 and, together with the tensioning disc 61, shapes the strip 21. In the latter part of the arc trajectory, the positions of the two shaping discs 74 change with the movement, which plays an auxiliary role in restricting the strip 21, ensuring that the diameter error of the strip 21 is reduced after subsequent cooling. In addition, the restricting protrusions 33 and the gradient protrusions 34 on the restricting disc 32 restrict the shaping disc 74, so that the rotating shaping disc 74 shapes the strip 21. Then, the strip 21 enters the water along the auxiliary roller 4 for secondary cooling. After cooling, the strip 21 passes through the shaping disc 71 and the shaping disc 74 on the scraper roller 5 to scrape off the attached water droplets, and can enter the pelletizer for pelletizing.

[0043] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A system for preparing pressure-resistant and hydrolysis-resistant nylon material, comprising an extrusion die (2) disposed at the output end of a screw and a pelletizer, wherein the extrusion die (2) extrudes a plurality of strips (21), the strips (21) being pulled by the pelletizer, characterized in that, It also includes a composite cooling frame (1) disposed between the extrusion die (2) and the pelletizer. The composite cooling frame (1) is provided with a tension roller (6) and a pull roller (3). The tension roller (6) includes tension discs (61) arranged in a linear array corresponding to the strip (21). An elastic element (631) is disposed between the tension disc (61) and the tension roller (6).

2. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 1, characterized in that, The traction roller (3) is provided with several sets of auxiliary plasticizing mechanisms (7) corresponding to the strip (21). The auxiliary plasticizing mechanism (7) includes a shaping disk (71) rotatably connected to the traction roller (3). The shaping disk (71) is symmetrically arranged with shaping pieces (74) in a circular array. Two shaping pieces (74) are driven to close together to shape the strip (21).

3. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 2, characterized in that, The traction roller (3) is fixedly mounted on the composite cooling frame (1). A plurality of limiting plates (32) are fixedly mounted on the traction roller (3). The limiting plates (32) are provided with limiting protrusions (33) corresponding to the shaping plate (74).

4. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 1, characterized in that, The composite cooling frame (1) includes a first cooling frame (11), a second cooling frame (12) and a return frame (13). An auxiliary roller (4) is provided in the second cooling frame (12), and the strip (21) is restricted to enter the second cooling frame (12) by the auxiliary roller (4).

5. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 4, characterized in that, The second cooling frame (12) is provided with a liquid outlet bottom plate (122), which is located at the bottom of the first cooling frame (11). The return liquid frame (13) covers the first cooling frame (11), and the first cooling frame (11) has a seepage groove (111) facing the return liquid frame (13).

6. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 1, characterized in that, The composite cooling frame (1) is provided with a scraper roller (5), and a number of shaping discs (71) are rotatably connected to the scraper roller (5). The shaping discs (71) are obstructed from moving misaligned with the strip material (21).

7. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 6, characterized in that, The wiper roller (5) is provided with pushers (53) at both ends, and the pushers (53) push against the shaping disc (71).

8. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 7, characterized in that, A limiting plate (32) is rotatably connected to the wiper roller (5). The limiting plate (32) is disposed on both sides of the shaping disc (71). A limiting ring (54) is disposed on the limiting plate (32). A shaping plate (74) is rotatably connected to the shaping disc (71). The shaping plate (74) is driven to adhere to the strip material (21).

9. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 8, characterized in that, The composite cooling frame (1) includes a return frame (13), and the wiper roller (5) is disposed on the return frame (13).

10. The pressure-resistant and hydrolysis-resistant nylon material preparation system according to claim 1, characterized in that, An auxiliary roller (4) is provided inside the composite cooling frame (1), and the tension roller (6) and the auxiliary roller (4) restrict the strip (21) from being pressed into the water.

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