A polyethylene naphthalate film production process and a production system thereof

Abstract

The present application belongs to the technical field of film production, and particularly relates to a polyethylene naphthalate film production process and a production system thereof. The production process comprises the following steps: first, polyethylene naphthalate chips and opening master batches are selected and dried; the two types of raw materials after drying are uniformly premixed according to a mass ratio; the premixed material is sent into a double-screw extruder, and melting plasticization is completed in a temperature range of 280-320 DEG C; the molten material is extruded and cast through a die head and cooled to form a cast sheet; the cast sheet is subjected to longitudinal and transverse stretching treatment; finally, the stretched film is subjected to heat setting treatment, and after winding, a PEN film is obtained. By adopting the opening master batch premixing mode, the traditional direct addition of inorganic opening powder is replaced, the problem of poor powder dispersion effect is effectively improved, defects such as powder agglomeration, small molecule precipitation, film surface crystal point and yellowing in the high-temperature processing process are avoided, and the production quality of the PEN film is effectively guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of thin film production technology, and particularly relates to a production process and system for polyethylene naphthalate thin film. Background Technology

[0002] Polyethylene naphthalate (PEN) film is a high-performance polyester film that has higher heat resistance, dimensional stability, mechanical strength and electrical insulation properties compared to traditional PET film. It is widely used in high-end insulation, photovoltaics, flexible circuits and high-voltage film capacitors.

[0003] In existing PEN film production processes, inorganic silicon / calcium-based opening powder is usually added directly to PEN chips. This only achieves the anti-blocking effect. Furthermore, conventional opening aids have poor thermodynamic compatibility with PEN resin. In the high-temperature processing range of 280-320℃ for PEN films, defects such as powder agglomeration, small molecule precipitation, film surface crystal points, and yellowing are prone to occur. These defects not only affect the appearance and light transmittance of the film, but also significantly reduce the dielectric breakdown stability of ultrathin capacitor films, resulting in the degradation of the product's electrical performance. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned technical problems by providing a production process and system for polyethylene naphthalate (PEG) films, which improves the powder agglomeration and precipitation defects during high-temperature film processing, and enhances the film's appearance quality and dielectric breakdown stability.

[0005] In view of this, the present invention provides a process for producing polyethylene naphthalate film, comprising the following steps: S1: Select polyethylene naphthalate chips and open-faced masterbatch, and dry them; S2: Premix the dried polyethylene naphthalate chips and open masterbatch evenly according to the mass ratio; S3: The premixed material is fed into a twin-screw extruder for melt plasticization, and the processing temperature range is controlled at 280-320℃; S4: Molten material is extruded through a die and cast, then cooled to form a cast sheet; S5: Bi-directional stretching of the casting in both longitudinal and transverse directions; S6: Heat-set the stretched polyester film and then wind it up to obtain a PEN film.

[0006] In the above technical solution, further: Open-face masterbatch includes silicon-based open-face masterbatch or silicon-based open-face masterbatch and calcium-based open-face masterbatch; Among them, when the open-end masterbatch is silicon-based open-end masterbatch, the particle size is 2μm; when the open-end masterbatch is silicon-based open-end masterbatch and calcium-based open-end masterbatch, the particle sizes are 3μm silicon-based open-end masterbatch and 0.6μm calcium-based open-end masterbatch, respectively.

[0007] In the above technical solution, further: The carrier resin for the open-ended masterbatch is polyethylene naphthalate.

[0008] This invention provides a production system for manufacturing polyethylene naphthalate (PEG) films, including a mixing device comprising: The mixing tank has internal partitions forming a mixing chamber and a weighing chamber, and there are multiple weighing chambers located above the mixing chamber; A stirring mechanism, installed inside the mixing chamber, is used to mix the materials inside the mixing chamber; The weighing hopper is rotatably installed inside the weighing chamber, and a weighing sensor is installed in the weighing chamber, with the weighing sensor located below the weighing hopper; The drive mechanism, mounted on the partition, is used to drive the weighing hopper to rotate; A connecting mechanism is connected between the output end of the drive mechanism and the weighing hopper. It is used to allow relative rotation between the output end of the drive mechanism and the weighing hopper during weighing and to prohibit relative rotation between the output end of the drive mechanism and the weighing hopper during unloading. The weighing chamber has a discharge port on its inner wall, which allows the material to enter the mixing chamber from the discharge port after the weighing hopper rotates. The mixing chamber has a feeding port at the top corresponding to the weighing hopper and a discharge port at the bottom.

[0009] In the above technical solution, further: The weighing hopper is provided with a first guide chamfer on the side near the discharge port to increase the tilt angle of the bottom surface when the weighing hopper discharges material, and a through hole is provided at the first guide chamfer; The mixing tank is equipped with a feed hopper at the feeding port, and a cover is connected to the feed hopper.

[0010] In the above technical solution, the connecting mechanism further includes: The rotating shaft is installed in the through hole, and its two ends pass through the partitions on both sides of the weighing chamber and are rotatably connected to the partitions. It has mounting holes along the axial direction. The ratchet component, mounted on the rotating shaft, is used to connect the rotating shaft to the weighing hopper; A locking element, installed in the mounting hole of the rotating shaft, is used to lock the unidirectional transmission characteristic of the ratchet component so that torque can be transmitted in both directions, or to unlock the unidirectional transmission characteristic of the ratchet component.

[0011] In the above technical solution, the ratchet component further includes: The mounting bracket is fitted onto the rotating shaft and has multiple pawls installed at equal intervals around its circumference. A torsion spring is provided at the connection between the pawls and the mounting bracket. The inner wall of the through hole of the weighing hopper is provided with multiple ratchet teeth that mesh with the pawl, and the pawl and ratchet teeth do not get stuck when the weighing hopper rotates toward the weighing sensor.

[0012] In the above technical solution, the locking element further includes: The slide cylinder is slidably connected in the mounting hole of the rotating shaft, and baffles and mounting seats are respectively provided at both ends of the axial direction, and a stop rod is hinged to the mounting seat; The fixed cylinder is installed in the mounting hole of the rotating shaft and is located at the end of the slide cylinder near the mounting base, forming a guide surface for guiding the stop rod radially outward; A sleeve is fitted onto the end of the fixed cylinder that is close to the sliding cylinder, and a spring is provided between the sleeve and the baffle. A ferromagnetic material is installed at the end of the baffle near the fixed cylinder; An electromagnet is installed at one end of the fixed cylinder near the sliding cylinder. When energized, it attracts the ferromagnet and the attraction force is greater than the spring return force, causing the baffle to compress the spring and drive the sliding cylinder to slide towards the fixed cylinder. When de-energized, it releases the attraction to the ferromagnet and causes the spring to push the baffle and the sliding cylinder back to their original positions. The inner wall of the rotating shaft mounting hole is provided with a slot corresponding to the pawl. When the slide cylinder moves to the side of the fixed cylinder, the push stop rod is turned by the guide surface and extends out of the slot to limit the rotation of the pawl.

[0013] In the above technical solution, the driving mechanism further includes: The drive motor is mounted on the partition and has a drive gear at the output end; The driven gear is fitted onto the end of the rotating shaft near the drive motor and meshes with the driving gear.

[0014] In the above technical solution, further: A second guide chamfer is formed between the bottom wall and the side wall of the mixing chamber near the discharge port.

[0015] The beneficial effects of this invention are as follows: 1. By adopting the PEN homologous carrier open masterbatch premixing process to replace the traditional powder direct addition method, the defects of powder agglomeration, small molecule precipitation, film surface crystal points and yellowing under high temperature processing are completely solved; by different particle sizes and different types of masterbatch compounding, the production needs of general thin films and ultra-thin capacitor films are taken into account, and the mechanical, optical and electrical properties of the film are optimized.

[0016] 2. The integrated weighing and mixing equipment, relying on the ratchet locking adaptive structure and electromagnetic automatic control, realizes automatic material weighing and unloading, eliminates material errors caused by secondary transfer, and ensures batching accuracy.

[0017] 3. The drive mechanism for the connecting mechanism adopts non-coaxial transmission, and the electromagnetic automatic control provides wiring space, which facilitates the installation and subsequent maintenance of the electromagnet body circuit, and improves the overall assembly rationality and practicality of the equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the mixing device of the present invention; Figure 2 This is a top view of the mixing device of the present invention; Figure 3 This is the present invention. Figure 2 Sectional view at point AA; Figure 4 This is the present invention. Figure 3 Sectional view at point BB; Figure 5 This is a schematic diagram of the connection structure of the present invention; Figure 6 This is a side view of the connection structure of the present invention; Figure 7 This is the present invention. Figure 6 Sectional view at CC; Figure 8 This is the present invention. Figure 7 Enlarged view of point D in the middle; The markings in the diagram represent: 1. Mixing tank; 2. Baffle plate; 3. Mixing chamber; 4. Weighing chamber; 5. Stirring mechanism; 6. Weighing hopper; 7. Weighing sensor; 8. Drive mechanism; 80. Drive motor; 81. Driving gear; 82. Driven gear; 9. Connecting mechanism; 90. Rotating shaft; 91. Mounting hole; 92. Ratchet; 920. Mounting bracket; 921. Pawl; 922. Ratchet tooth; 93. Locking element; 9 30. Slide cylinder; 931. Baffle; 932. Mounting base; 933. Stop bar; 934. Fixed cylinder; 935. Guide surface; 936. Sleeve; 937. Spring; 938. Ferromagnetic body; 939. Electromagnetic body; 94. Slot; 10. Discharge port; 11. Feed port; 12. Discharge port; 13. First guide chamfer; 14. Through hole; 15. Guide hopper; 16. Cover; 17. Second guide chamfer. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0020] Example 1:

[0021] This embodiment provides a process for producing polyethylene naphthalate (PEG) films, including the following steps: S1: Select polyethylene naphthalate chips and open-faced masterbatch, and dry them; S2: Premix the dried polyethylene naphthalate chips and open masterbatch evenly according to the mass ratio; S3: The premixed material is fed into a twin-screw extruder for melt plasticization, and the processing temperature range is controlled at 280-320℃; S4: Molten material is extruded through a die and cast, then cooled to form a cast sheet; S5: Bi-directional stretching of the casting in both longitudinal and transverse directions; S6: Heat-set the stretched polyester film and then wind it up to obtain a PEN film.

[0022] As can be seen from this embodiment, by pre-preparing open-end masterbatch as raw material, and then drying PEN chips and open-end masterbatch and pre-mixing them evenly and thoroughly according to the mass ratio, the problem of poor powder dispersion caused by directly adding inorganic open-end powder to PEN chips in the traditional process is effectively solved. This avoids defects such as powder agglomeration, small molecule precipitation, film surface crystal points, and yellowing in the high-temperature processing range of 280-320℃ for PEN films, thus ensuring product quality.

[0023] Example 2:

[0024] This embodiment provides a process for producing polyethylene naphthalate (PEG) films, which, in addition to the technical solutions of the above embodiments, also has the following technical features: Open-face masterbatch includes silicon-based open-face masterbatch or silicon-based open-face masterbatch and calcium-based open-face masterbatch; Among them, when the open-end masterbatch is silicon-based open-end masterbatch, the particle size is 2μm; when the open-end masterbatch is silicon-based open-end masterbatch and calcium-based open-end masterbatch, the particle sizes are 3μm silicon-based open-end masterbatch and 0.6μm calcium-based open-end masterbatch, respectively.

[0025] As can be seen from this embodiment, by selecting two types of open-ended masterbatches, the differentiated application requirements of general-purpose PEN films and ultra-thin capacitor-grade PEN films can be taken into account. When using 2μm silicon-based open-ended masterbatch alone, the anti-blocking requirements of general-purpose PEN films can be met, balancing the film's slip performance and light transmittance. When 3μm silicon-based open-ended masterbatch and 0.6μm calcium-based open-ended masterbatch are combined, the distribution of fillers inside the film is optimized by the staggered arrangement of particles of different sizes, reducing the stress concentration points inside the ultra-thin film, effectively improving the dielectric breakdown stability of the ultra-thin capacitor-grade PEN film, and alleviating the problem of electrical performance degradation during long-term use of the product.

[0026] Example 3:

[0027] This embodiment provides a process for producing polyethylene naphthalate (PEG) films, which, in addition to the technical solutions of the above embodiments, also has the following technical features: The carrier resin for the open-ended masterbatch is polyethylene naphthalate.

[0028] As can be seen from this embodiment, by using polyethylene naphthalate as the carrier resin for the open-ended masterbatch, which is a homologous resin to the film substrate, the two have excellent interfacial compatibility. During the high-temperature melting process at 280-320℃, no small molecule precipitates caused by incompatibility are generated, further suppressing the aggregation of inorganic open-ended particles, improving the dispersion uniformity of open-ended particles in the resin matrix, and ensuring the appearance quality of the film.

[0029] Example 4:

[0030] This embodiment provides a production system for manufacturing polyethylene naphthalate (PEG) films, including a mixing device, which comprises: The mixing tank 1 has a partition 2 inside, forming a mixing chamber 3 and a weighing chamber 4. There are multiple weighing chambers 4, which are located above the mixing chamber 3. The stirring mechanism 5 is installed in the mixing chamber 3 and is used to mix the materials in the mixing chamber 3; The weighing hopper 6 is rotatably installed in the weighing chamber 4, and a weighing sensor 7 is installed in the weighing chamber 4, with the weighing sensor 7 located below the weighing hopper 6. Drive mechanism 8, mounted on partition 2, is used to drive the weighing hopper 6 to rotate; The connecting mechanism 9 is connected between the output end of the drive mechanism 8 and the weighing hopper 6. It is used to allow relative rotation between the output end of the drive mechanism 8 and the weighing hopper 6 during weighing and to prohibit relative rotation between the output end of the drive mechanism 8 and the weighing hopper 6 during unloading. The inner wall of the weighing chamber 4 is provided with a discharge port 10, which is used to allow the material to enter the mixing chamber 3 from the discharge port 10 after the weighing hopper 6 rotates. The top of the mixing chamber 3 is provided with a feeding port 11 corresponding to the weighing hopper 6, and the bottom is provided with a discharge port 12. The production system also includes screw extruders, which are existing mature technologies and are known to those skilled in the art from traditional polyester film production systems, and will not be described in detail here. The specific structures of the weighing sensor 7 and the stirring mechanism 5, as well as the baffle 931 at the discharge port 12 that can be pulled to open and close the discharge port 12, are all existing mature technologies, which are known to those skilled in the art from traditional equipment or devices, and will not be described in detail here.

[0031] As can be seen from this embodiment, by opening a mixing chamber 3 and a weighing chamber 4 in the mixing tank 1, the PEN chips and open-faced masterbatch can be weighed separately by the weighing hopper 6 in the weighing chamber 4. After weighing, the driving mechanism 8 drives the connecting mechanism 9 to rotate, so that the material enters the mixing chamber 3 through the discharge port 10. Then, the stirring mechanism 5 stirs and mixes the PEN chips and open-faced masterbatch in the mixing chamber 3. There is no need for secondary material transfer, which effectively avoids problems such as material loss and ratio deviation, improves the accuracy of raw material ratio and the convenience of batching, and thus ensures the quality of subsequent products. Furthermore, during weighing, the connecting mechanism 9 allows relative rotation between the output end of the drive mechanism 8 and the weighing hopper 6, thereby enabling the weighing hopper 6 to deflect toward the weighing sensor 7, which facilitates the weighing sensor 7 in weighing it. When unloading, the relative rotation between the output end of the drive mechanism 8 and the weighing hopper 6 is prohibited, thereby facilitating the output end of the drive mechanism 8 to drive the weighing hopper 6 to flip over to complete unloading and resetting. It should be noted that the weighing sensor 7 is also connected to a control unit and a display screen, which is used to monitor and display the weight of the material in the corresponding weighing hopper 6 in real time. This is a conventional setting and technical means of traditional weighing devices, which is known to those skilled in the art from traditional devices, and will not be described in detail here.

[0032] Example 5:

[0033] This embodiment provides a production system for manufacturing polyethylene naphthalate (PEG) films. In addition to the technical solutions described in the above embodiments, it also has the following technical features: The weighing hopper 6 is provided with a first guide chamfer 13 on the side near the discharge port 10, which is used to increase the inclination angle of the bottom surface of the weighing hopper 6 when discharging, and a through hole 14 is provided at the first guide chamfer 13. The mixing tank 1 is equipped with a feed hopper 15 at the feed port 11, and a cover 16 is connected to the feed hopper 15.

[0034] As can be seen from this embodiment, by providing a first guide chamfer 13 on the side of the weighing hopper 6 near the discharge port 10, the discharge tilt angle is increased, enabling the material to slide down quickly and completely. At the same time, it also facilitates the opening of the through hole 14, providing convenience for the installation of the connecting mechanism 9. The feed hopper 15 ensures that the PEN chips or open masterbatch entering from the feed port 11 are accurately fed into the weighing hopper 6, ensuring the accuracy of the batching. The cover 16 can open and close the feed hopper 15, effectively reducing the entry of impurities or dust, and further ensuring the accuracy of the batching.

[0035] Example 6:

[0036] This embodiment provides a production system for the production of polyethylene naphthalate (PEG) films. In addition to the technical solutions described in the above embodiments, it also has the following technical features: the connecting mechanism 9 includes: The rotating shaft 90 is installed in the through hole 14, and its two ends pass through the partitions 2 on both sides of the weighing chamber 4 respectively, and are rotatably connected to the partitions 2. The shaft is provided with mounting holes 91 along the axial direction. Ratchet 92 is mounted on rotating shaft 90 and is used to connect rotating shaft 90 and weighing hopper 6; Locking element 93 is installed in the mounting hole 91 of the rotating shaft 90 to lock the unidirectional transmission characteristic of the ratchet element 92 so that it can transmit torque in both directions, or to unlock the unidirectional transmission characteristic of the ratchet element 92. The rotational connection between the rotating shaft 90 and the partition 2 can be achieved by using a bearing connection.

[0037] As can be seen in this embodiment, the installation of the ratchet 92 is facilitated by the rotating shaft 90. The ratchet 92 then enables unidirectional transmission of the hopper 6, allowing it to rotate independently during weighing. This ensures that after material is added to the hopper 6, it can properly press the weighing sensor 7, thus guaranteeing accurate weighing. The locking component 93 locks the unidirectional transmission of the ratchet 92 after weighing, allowing it to transmit torque in both directions. This, in turn, drives the rotating shaft 90 via the drive mechanism 8, thereby rotating the hopper 6. Rotation allows material to be poured from discharge port 10 into mixing chamber 3. After pouring, drive mechanism 8 drives rotating shaft 90 to reverse and reset weighing hopper 6. Then, locking part 93 releases the unidirectional transmission characteristic of ratchet part 92, ready for the next weighing. Thus, in weighing mode, weighing hopper 6 can rotate freely and independently, ensuring accurate data detection by weighing sensor 7. In unloading mode, locking part 93 locks the bidirectional transmission function of ratchet, which can drive weighing hopper 6 to stably flip and unload and accurately reset through drive mechanism 8. It perfectly adapts to the dual working conditions of weighing and unloading, taking into account both weighing accuracy and unloading efficiency.

[0038] Example 7:

[0039] This embodiment provides a production system for manufacturing polyethylene naphthalate (PEG) films. In addition to the technical solutions described in the above embodiments, it also has the following technical features: the ratchet component 92 includes: Mounting bracket 920 is sleeved on rotating shaft 90 and has multiple pawls 921 installed at equal intervals around its circumference. A torsion spring is provided at the connection between the pawls 921 and mounting bracket 920. The inner wall of the through hole 14 of the weighing hopper 6 is provided with a plurality of ratchet teeth 922 that mesh with the pawl 921, and the pawl 921 and the ratchet teeth 922 do not engage when the weighing hopper 6 rotates toward the weighing sensor 7. Meanwhile, the installation of the torsion spring 937 is a mature existing technology. It is not shown in the accompanying drawings of this application specification, but is known to those skilled in the art from the conventional ratchet component 92, and will not be described in detail here.

[0040] As can be seen from this embodiment, the mounting bracket 920 facilitates the installation of multiple pawls 921 on the rotating shaft 90, ensuring the installation stability of the pawls 921. Meanwhile, multiple ratchet teeth 922 that mesh with the pawls 921 are provided on the inner wall of the through hole 14 of the weighing hopper 6, thereby realizing unidirectional transmission between the weighing hopper 6 and the rotating shaft 90, ensuring the flexibility and accuracy of the weighing operation.

[0041] Example 8:

[0042] This embodiment provides a production system for manufacturing polyethylene naphthalate (PEG) films. In addition to the technical solutions described in the above embodiments, it also has the following technical features: the locking member 93 includes: The slide cylinder 930 is slidably connected in the mounting hole 91 of the rotating shaft 90, and has a baffle 931 and a mounting seat 932 at both ends of the axial direction, and a stop rod 933 is hinged to the mounting seat 932. The fixed cylinder 934 is installed in the mounting hole 91 of the rotating shaft 90 and is located at one end of the slide cylinder 930 near the mounting base 932, and forms a guide surface 935 for guiding the stop bar 933 radially outward; Sleeve 936 is sleeved on the end of fixed sleeve 934 near slide sleeve 930, and spring 937 is provided between sleeve 936 and baffle 931; Ferromagnetic material 938 is installed on one end of baffle 931 near fixed cylinder 934; An electromagnet 939 is installed at one end of the fixed cylinder 934 near the sliding cylinder 930. When energized, it attracts the ferromagnet 938, and the attraction force is greater than the reset force of the spring 937, causing the baffle 931 to compress the spring 937 and drive the sliding cylinder 930 to slide towards the fixed cylinder 934. When de-energized, it releases the attraction to the ferromagnet 938, causing the spring 937 to push the baffle 931 and the sliding cylinder 930 to reset. The inner wall of the mounting hole 91 of the rotating shaft 90 is provided with a slot 94 corresponding to the pawl 921. When the slide cylinder 930 moves to the side of the fixed cylinder 934, the push rod 933 is turned by the guide surface 935 and extends out of the slot 94 to limit the rotation of the pawl 921. The specific structure of the electromagnet 939 is a mature existing technology. It attracts the ferromagnet 938 when energized and releases the ferromagnet 938 when de-energized. This is known to those skilled in the art from the conventional electromagnet 939, and will not be described in detail here.

[0043] As can be seen from this embodiment, by setting the slide cylinder 930, it is convenient to set the mounting base 932 and hinge the stop rod 933 on the mounting base 932. With the cooperation of the guide surface 935 on the fixed cylinder 934, when the slide cylinder 930 slides, it can push the stop rod 933 to turn through the guide surface 935 and extend out from the slot 94 to abut against the pawl 921. This ensures that the pawl 921 is always embedded between two adjacent ratchet teeth 922, thereby locking the unidirectional transmission characteristic of the ratchet component 92. This makes it easy to ensure that the ratchet component 92 can transmit torque in both directions during unloading. The baffle 931 facilitates the installation of the ferromagnetic body 938 and the contact of the end of the spring 937. When the electromagnet 939 is energized, it attracts the ferromagnetic body 938 and compresses the spring 937 to drive the slide cylinder 930 to slide. The stop bar 933 extends from the slot 94 to lock the pawl 921. When the electromagnet 939 is de-energized, it releases the attraction to the ferromagnetic body 938. Then, under the reset of the compressed spring 937, it pushes the slide cylinder 930 to slide back to its original position and causes the stop bar 933 to retract from the slot 94, releasing the lock on the pawl 921 and restoring the pawl 921 to its unidirectional transmission characteristics. Furthermore, a groove is provided on the inner wall of the rotating shaft 90 along the axial direction, and a protrusion adapted to the groove is provided on the radial surface of the baffle 931 to limit the range of rotation of the slide cylinder 930 in the radial direction and the range of movement in the axial direction.

[0044] Example 9:

[0045] This embodiment provides a production system for the production of polyethylene naphthalate (PEG) films. In addition to the technical solutions described in the above embodiments, it also has the following technical features: the drive mechanism 8 includes: A drive motor 80 is mounted on the partition 2 and has a drive gear 81 at its output end; Driven gear 82 is sleeved on one end of rotating shaft 90 near drive motor 80 and meshes with drive gear 81; The specific structure of the drive motor 80 is a mature existing technology and is a conventional choice that those skilled in the art can make based on the drive gear 81 to drive the driven gear 82 and the rotating shaft 90 to rotate. It will not be described in detail here.

[0046] As can be seen from this embodiment, by adopting a drive structure that combines a motor with gear meshing, stable transmission of the rotating shaft 90 is achieved. At the same time, the drive motor 80 and the rotating shaft 90 are arranged non-coaxially, avoiding structural interference problems, reserving space for wire routing, facilitating the installation and later maintenance of the electromagnet body 939 circuit, and improving the overall assembly rationality and practicality of the equipment.

[0047] Example 10:

[0048] This embodiment provides a production system for manufacturing polyethylene naphthalate (PEG) films. In addition to the technical solutions described in the above embodiments, it also has the following technical features: A second guide chamfer 17 is formed between the bottom wall and the side wall of the mixing chamber 3 near the discharge port 12.

[0049] As can be seen from this embodiment, by forming a second guide chamfer 17 between the bottom wall and the side wall of the mixing chamber 3 near the discharge port 12, it is easier to completely discharge the material during discharge and reduce the residue of material in the mixing chamber 3.

[0050] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A process for producing polyethylene naphthalate film, characterized in that, Includes the following steps: S1: Select polyethylene naphthalate chips and open-faced masterbatch, and dry them; S2: Premix the dried polyethylene naphthalate chips and open masterbatch evenly according to the mass ratio; S3: The premixed material is fed into a twin-screw extruder for melt plasticization, and the processing temperature range is controlled at 280-320℃; S4: Molten material is extruded through a die and cast, then cooled to form a cast sheet; S5: Bi-directional stretching of the casting in both longitudinal and transverse directions; S6: Heat-set the stretched polyester film and then wind it up to obtain a PEN film.

2. The poly(ethylene naphthalate) film production process according to claim 1, characterized in that: The open-face masterbatch includes silicon-based open-face masterbatch or silicon-based open-face masterbatch and calcium-based open-face masterbatch. Among them, when the open-end masterbatch is silicon-based open-end masterbatch, the particle size is 2μm; when the open-end masterbatch is silicon-based open-end masterbatch and calcium-based open-end masterbatch, the particle sizes are 3μm silicon-based open-end masterbatch and 0.6μm calcium-based open-end masterbatch, respectively.

3. The poly(ethylene naphthalate) film production process according to claim 2, characterized in that: The carrier resin of the open masterbatch is polyethylene naphthalate.

4. A production system applied to the polyethylene naphthalate film production process according to any one of claims 1-3, comprising a mixing device, characterized in that, The mixing device includes: The mixing tank (1) has a partition (2) inside to form a mixing chamber (3) and a weighing chamber (4), and there are multiple weighing chambers (4) located above the mixing chamber (3); A stirring mechanism (5) is installed in the mixing chamber (3) to mix the materials in the mixing chamber (3); The weighing hopper (6) is rotatably installed in the weighing chamber (4), and a weighing sensor (7) is installed in the weighing chamber (4), with the weighing sensor (7) located below the weighing hopper (6); The drive mechanism (8) is mounted on the partition (2) and is used to drive the weighing hopper (6) to rotate; A connecting mechanism (9) is connected between the output end of the drive mechanism (8) and the weighing hopper (6) to allow relative rotation between the output end of the drive mechanism (8) and the weighing hopper (6) during weighing, and to prohibit relative rotation between the output end of the drive mechanism (8) and the weighing hopper (6) during unloading. The inner wall of the weighing chamber (4) is provided with a discharge port (10) for the material to enter the mixing chamber (3) from the discharge port (10) after the weighing hopper (6) rotates. The mixing chamber (3) is provided with a feeding port (11) corresponding to the weighing hopper (6) at the top and a discharge port (12) at the bottom.

5. The production system for producing polyethylene naphthalate film according to claim 4, characterized in that: The weighing hopper (6) is provided with a first guide chamfer (13) on the side near the discharge port (10) to increase the tilt angle of the bottom surface when the weighing hopper (6) discharges material, and a through hole (14) is provided at the first guide chamfer (13). The mixing tank (1) is equipped with a feed hopper (15) at the feed port (11) and a cover (16) is connected to the feed hopper (15).

6. The production system for producing polyethylene naphthalate film according to claim 5, characterized in that, The connecting mechanism (9) includes: The rotating shaft (90) is installed in the through hole (14) and its two ends pass through the partitions (2) on both sides of the weighing chamber (4) and are rotatably connected to the partitions (2). It has an installation hole (91) along the axial direction. A ratchet (92) is mounted on a rotating shaft (90) and is used for the connection between the rotating shaft (90) and the weighing hopper (6); The locking element (93) is installed in the mounting hole (91) of the rotating shaft (90) to lock the unidirectional transmission characteristic of the ratchet element (92) so that it can transmit torque in both directions, or to unlock the unidirectional transmission characteristic of the ratchet element (92).

7. The production system for the production process of polyethylene naphthalate film according to claim 6, characterized in that, The ratchet component (92) includes: Mounting bracket (920) is sleeved on rotating shaft (90) and has multiple pawls (921) installed at equal intervals around its circumference. A torsion spring (937) is provided at the connection between the pawls (921) and mounting bracket (920). The inner wall of the through hole (14) of the weighing hopper (6) is provided with a plurality of ratchet teeth (922) that mesh with the pawl (921), and when the weighing hopper (6) rotates toward the weighing sensor (7), the pawl (921) and the ratchet teeth (922) do not engage.

8. The production system for producing polyethylene naphthalate film according to claim 7, characterized in that, The locking element (93) includes: The slide cylinder (930) is slidably connected in the mounting hole (91) of the rotating shaft (90), and the two ends of the axial direction are respectively provided with baffle (931) and mounting seat (932), and a stop rod (933) is hinged on the mounting seat (932). The fixed cylinder (934) is installed in the mounting hole (91) of the rotating shaft (90) and is located at one end of the slide cylinder (930) near the mounting base (932), and forms a guide surface (935) for guiding the stop bar (933) radially outward. A sleeve (936) is fitted onto one end of the fixed cylinder (934) near the slide cylinder (930), and a spring (937) is provided between it and the baffle (931). A ferromagnetic object (938) is installed at one end of the baffle (931) near the fixed cylinder (934); An electromagnet (939) is installed at one end of a fixed cylinder (934) near a sliding cylinder (930). When energized, it attracts a ferromagnet (938), and the attraction force is greater than the reset force of the spring (937), causing the baffle (931) to compress the spring (937) and drive the sliding cylinder (930) to slide towards the fixed cylinder (934). When de-energized, it releases the attraction to the ferromagnet (938), causing the spring (937) to push the baffle (931) and the sliding cylinder (930) to reset. The inner wall of the mounting hole (91) of the rotating shaft (90) is provided with a slot (94) corresponding to the pawl (921). When the slide cylinder (930) moves to the side of the fixed cylinder (934), the push rod (933) is turned through the guide surface (935) and extends out from the slot (94) to limit the rotation of the pawl (921).

9. The production system for producing polyethylene naphthalate film according to claim 6, characterized in that, The drive mechanism (8) includes: A drive motor (80) is mounted on a partition (2) and has a drive gear (81) at its output end. The driven gear (82) is sleeved on one end of the rotating shaft (90) near the drive motor (80) and meshes with the driving gear (81).

10. The production system for producing polyethylene naphthalate film according to claim 4, characterized in that: A second guide chamfer (17) is formed between the bottom wall and the side wall of the mixing chamber (3) near the discharge port (12).

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