A thermoplastic polyimide film forming apparatus

Abstract

The application relates to the technical field of film stretching, in particular to a thermoplastic polyimide film forming device; the device comprises a base and a plurality of U-shaped frames arranged on the upper surface of the base along the left-right direction; the front and back sides of the U-shaped frames are provided with frame blocks; the front and back frame blocks are rotationally and sealingly connected with rotating rods; the two rotating rods on the U-shaped frame are distributed upwards and downwards and form a transmission gap; the film passes through the transmission gap from left to right; the front end of the rotating rod is fixedly connected with the output end of a motor; the outer wall of the motor is fixedly connected with the outer wall of the corresponding frame block; the rotating speeds of the rotating rods on the plurality of U-shaped frames increase from left to right in sequence; the rotating speeds of the upper and lower corresponding rotating rods are the same and the rotating directions are opposite; the film can be stretched in the length direction and stretched in the width direction through the cooperation of the plurality of differential-speed rotating rods and the plurality of end sleeves on the rotating rods which are far away from the middle sleeve, so that the film stretching efficiency is improved and the quality of the film after stretching is improved.

Description

Technical Field

[0001] This invention relates to the field of film stretching technology, specifically to a thermoplastic polyimide film forming apparatus. Background Technology

[0002] Polyimide film, as one of the best-performing organic polymer films, has been widely used in high-end fields such as electronics, aerospace, new energy, and flexible displays due to its excellent high-temperature resistance, superior mechanical strength, good insulation, chemical corrosion resistance, radiation resistance, as well as its flexibility and dimensional stability. Its production process directly determines the quality and market competitiveness of the product.

[0003] Currently, the mainstream production process of polyimide films has formed a relatively mature system, specifically including the following key steps: First, the amine dissolution and filtration process involves adding acetamide to an amine dissolution vessel, then adding diamine for dissolution. After dissolution, the solution is filtered into a reaction vessel, laying a pure raw material foundation for subsequent resin synthesis. Next, the resin synthesis process begins, where dianhydride is added to the diamine solution in portions. By precisely controlling the reaction temperature and time, the two undergo a polymerization reaction to form a polyamic acid resin solution (PAA solution). To ensure that the PAA solution is free of impurities and bubbles, and to guarantee the quality of subsequent film formation, the PAA solution must first undergo a filtration to remove solid impurities, then enter a defoaming vessel for degassing treatment. After degassing, a second filtration is performed to further improve the purity of the solution. Following this is the casting process, where the purified PAA resin is precisely delivered to the casting die by a metering pump. The die evenly coats the resin onto a continuously running steel belt, forming a uniform liquid film. The liquid film then enters the drying tunnel with the steel belt. In the drying tunnel, the solvent gradually evaporates through gradient heating, eventually forming a solid PAA film. The solid film is then peeled off from the steel strip and enters the next critical process. The peeled PAA film needs to enter the stretching / imidization process, which is the core step that determines the mechanical properties and dimensional stability of the polyimide film. Under high temperature, the PAA film first undergoes an imidization reaction to transform into a polyimide structure, and at the same time, it needs to undergo biaxial stretching treatment to improve the crystallinity and molecular orientation of the film. In terms of waste gas treatment, the solvent waste gas volatilized in the casting and imidization processes is first pre-condensed and recovered by a condenser, and then treated by two-stage molecular sieve adsorption. The waste gas generated in the stretching process is treated by a secondary molecular sieve. Both types of treated waste gas are discharged together through an exhaust stack to meet the standards. Finally, the polyimide film that has undergone stretching / imidization treatment enters the winding and inspection process, where the film's thickness uniformity, mechanical strength, appearance quality, and other indicators are tested. After passing the test, it is packaged to form the final product.

[0004] In the aforementioned stretching / imidization process, the implementation method of biaxial stretching has a crucial impact on film performance and production efficiency. Currently, the industry generally adopts a step-by-step biaxial stretching technology, in which the stretching of the film in the length direction (MD direction) and the stretching in the width direction (TD direction) are carried out separately. Specifically, the stretching in the length direction is usually achieved by cooperating with two sets of feed rollers with different rotational speeds: the first set of feed rollers conveys the film at a lower speed, while the second set of feed rollers pulls the film at a higher speed, using the speed difference between the two sets of rollers to stretch the film in the length direction; while the stretching in the width direction is completed by a dedicated chain clamp device. The chain clamp clamps the two sides of the film, and as the film is transported forward with the conveyor system, the chain clamp gradually and synchronously opens along the width direction, thereby stretching the film in the width direction.

[0005] However, in practical applications, this step-by-step biaxial stretching technology has gradually revealed a series of unavoidable technical problems, becoming a bottleneck restricting the improvement of polyimide film quality and the optimization of production efficiency. The specific problems are as follows:

[0006] a. Lengthy and inefficient production process: Step-by-step stretching requires separate stretching devices for the length and width directions, and the two sets of devices must be arranged in sequence. This not only increases the floor space of the production equipment, but also prolongs the dwell time of the film in the stretching process. For example, after the film is stretched in the length direction, it needs to pass through a transition conveyor section before entering the width stretching device. During the transition, parameters such as the temperature and tension of the film are prone to fluctuation, which increases the difficulty of process control and leads to a longer overall production cycle. It is difficult to increase the output per unit time, which cannot meet the growing market demand for polyimide film.

[0007] b. Higher energy consumption and increased production costs: Biaxial stretching requires a high-temperature environment to ensure good film elongation; in step-by-step stretching, after the film is stretched in the length direction and before it enters the width direction stretching, it needs to be maintained or readjusted to a suitable stretching temperature, which requires a large amount of additional heat energy; at the same time, the two stretching devices operate independently, each requiring its own power system and temperature control system, and the overall equipment energy consumption is significantly higher than that of the integrated process, resulting in increased production costs and weakening the product's market competitiveness;

[0008] c. Difficulty in controlling film thickness uniformity: During the step-by-step stretching process, the initial stretching in the length direction causes local thickness changes in the film. When the subsequent stretching in the width direction is performed, the uneven thickness areas will further exhibit stretching differences, leading to a decrease in the final film thickness uniformity. Especially in the edge areas of the film, due to the influence of the clamping force of the chain clamp, the stretching degree of the edge area differs from that of the middle area during the width stretching. Combined with the thickness fluctuations from the initial stretching in the length direction, this easily results in situations where the edges are thicker than the middle or the thickness is abnormal in some areas, increasing the defect rate and reducing production efficiency. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, this invention proposes a thermoplastic polyimide film forming device. This invention uses multiple differentially driven rotating rods and multiple end sleeves on the rotating rods that cooperate with the middle sleeve, so that the film can be stretched in the length direction and the width direction at the same time, thereby improving the film stretching efficiency and the quality of the film after stretching.

[0010] The technical solution adopted by this invention to solve its technical problem is as follows: A thermoplastic polyimide film forming device of this invention includes a base and multiple U-shaped frames arranged along the left-right direction on the upper surface of the base; each U-shaped frame has a frame block on its front and rear sides; the front and rear frame blocks are rotatably and sealingly connected to rotating rods; two rotating rods on the U-shaped frames are distributed vertically and form a transmission gap; the film passes through the transmission gap from left to right; the front end of each rotating rod is fixedly connected to the output end of a motor; the outer wall of the motor is fixedly connected to the outer wall of the corresponding frame block; the multiple... The rotational speed of the rotating rod on the U-shaped frame increases sequentially from left to right; the upper and lower corresponding rotating rods have the same rotational speed but opposite directions; a middle sleeve is fixedly connected to the middle section of the rotating rod; multiple end sleeves fitted on the rotating rod are slidably connected to the front and rear sides of the middle sleeve; trapezoidal grooves are evenly arranged circumferentially on the outer wall of the end sleeves; the depth of the trapezoidal grooves decreases as they approach the middle sleeve; a trapezoidal block extending outward is slidably connected to the bottom of the trapezoidal groove; the side of the trapezoidal block near the middle sleeve is connected to the inner wall of the trapezoidal groove by an elastic rope; the end sleeves move away from the middle sleeve under the control of a linear element.

[0011] Preferably, the linear element includes a telescopic tube and an adapter; the rotating rod is hollow inside; the rear end of the rotating rod is rotatably and sealed to the adapter; the adapter is connected to an air pump via an air pipe; the adapter communicates with the interior of the rotating rod; the end sleeve has a telescopic hole on the side near the middle sleeve; the telescopic tube is slidably and sealed within the telescopic hole; the telescopic tube near the middle sleeve is fixedly connected to the middle sleeve; the side of the end sleeve facing away from the middle sleeve is fixedly connected to the corresponding telescopic tube; the telescopic holes on two adjacent end sleeves communicate through end holes; the middle sleeve has a central hole inside; one end of the central hole communicates with the interior of the rotating rod, and the other end communicates with the telescopic tube.

[0012] Preferably, the end sleeves on two adjacent rotating rods are arranged in opposite directions when they are unfolded and when they are folded.

[0013] Preferably, the end of the trapezoidal block away from the bottom of the trapezoidal groove is fixedly connected to an end arc-shaped piece; the end arc-shaped pieces are evenly distributed in the circumferential direction of the end sleeve.

[0014] Preferably, the outer wall of the middle sleeve is uniformly provided with clamping grooves along the circumference; a clamping block is slidably connected in the clamping groove; the clamping block is connected to the bottom of the clamping groove by a spring; and a central arc-shaped piece is fixedly connected to the end of the clamping block away from the clamping groove.

[0015] Preferably, the end sleeve has a first threaded hole and a stepped hole on the side away from the middle sleeve; the first threaded hole and the stepped hole on the same end sleeve are staggered; the stepped hole penetrates the end sleeve; the first threaded hole and the stepped hole on two adjacent end sleeves are correspondingly arranged in the front-back direction; a first bolt passes through the stepped hole; the end of the first bolt can be screwed into the first threaded hole.

[0016] Preferably, the U-shaped frame has a through-groove; the frame block is slidably connected to the frame groove; a bolt groove is provided through the left side of the frame groove; a second threaded hole corresponding to the bolt groove is provided on the left side of the frame block; a second bolt passes through the bolt groove; and the second bolt is screwed into the second threaded hole.

[0017] Preferably, the upper surface of the base is fixed to the slide rod by a support block along the left-right direction; the U-shaped frame is slidably connected to the slide rod through a sliding hole; a third threaded hole is provided through the sliding hole facing outward; a third bolt is threadedly connected to the third threaded hole.

[0018] Preferably, a tension spring is provided inside the telescopic hole; one end of the tension spring is fixedly connected to the bottom of the telescopic hole, and the other end is fixedly connected to the telescopic tube.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. The present invention uses multiple differentially driven rotating rods and multiple end sleeves on the rotating rods that cooperate away from the middle sleeve, so that the film can be stretched in the length direction and the width direction at the same time, thereby improving the film stretching efficiency and the quality of the film after stretching.

[0021] 2. During the retraction and reset process of the end sleeve on one of the two adjacent rotating rods in this invention, the end sleeve on the other rotating rod will unfold. This ensures that during the reset process of one part of the end sleeve, the other part of the end sleeve is unfolded, so that the film always has the end sleeve stretched in the width direction, ensuring the continuity and sustainability of the film width stretching, as well as ensuring the clamping effect of the film, making the film transmission more stable.

[0022] 3. Before stretching the film, the present invention folds up the deactivated end sleeves. Specifically, the first bolt is inserted into the stepped hole, and the first bolt in the stepped hole is controlled to pass through the stepped hole and tighten the first threaded hole on the adjacent end sleeve, thereby realizing the folding of the two adjacent deactivated end sleeves. This makes the two adjacent deactivated end sleeves locked and unable to unfold or contract. Thus, the gas only needs to drive the activated end sleeve to unfold and contract, making the activated end sleeve more sensitive and more controllable. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a perspective view of the present invention;

[0025] Figure 2 This is a perspective view of the U-shaped frame in this invention;

[0026] Figure 3 This is a three-dimensional view of the end sleeve after being folded in this invention;

[0027] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0028] Figure 5 This is a three-dimensional view of the end sleeve after it has been unfolded in this invention;

[0029] Figure 6 yes Figure 5 Enlarged view of point B in the middle;

[0030] Figure 7 This is a diagram showing the positions of the clamping groove and the trapezoidal groove in this invention;

[0031] Figure 8 This is a diagram showing the positions of the telescopic tube and telescopic hole in this invention;

[0032] Figure 9 This is a perspective view of the arc-shaped piece in this invention;

[0033] Figure 10 This is a perspective view of the arc-shaped piece at the middle of the middle section of the present invention.

[0034] In the diagram: Base 1, Support Block 11, Slide Rod 12, U-shaped Frame 2, Frame Groove 21, Bolt Groove 22, Sliding Hole 23, Third Threaded Hole 24, Third Bolt 25, Frame Block 3, Second Threaded Hole 31, Second Bolt 32, Rotating Rod 4, Transmission Clearance 41, Motor 42, Adapter 43, Middle Sleeve 5, Middle Hole 51, Clamping Groove 52, Clamping Block 53, Spring 54, Middle Arc-shaped Plate 55, End Sleeve 6, Tension Spring 60, Trapezoidal Groove 61, Trapezoidal Block 62, Elastic Rope 63, Telescopic Hole 64, End Hole 65, End Arc-shaped Plate 66, First Threaded Hole 67, Stepped Hole 68, Telescopic Tube 7. Detailed Implementation

[0035] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0036] like Figures 1 to 10 As shown, the present invention includes the following embodiments:

[0037] Example 1: A thermoplastic polyimide film forming device includes a base 1 and multiple U-shaped frames 2 arranged along the left-right direction on the upper surface of the base 1; each U-shaped frame 2 has a frame block 3 on its front and rear sides; two corresponding front and rear frame blocks 3 are rotatably and sealingly connected to rotating rods 4; two rotating rods 4 on the U-shaped frame 2 are distributed vertically and form a transmission gap 41; the film passes through the transmission gap 41 from left to right; the front end of each rotating rod 4 is fixedly connected to the output end of a motor 42; the outer wall of the motor 42 is fixedly connected to the outer wall of the corresponding frame block 3; the rotating rods 4 on the multiple U-shaped frames 2 rotate at a speed of... The rotation increases sequentially from left to right; the two corresponding rotating rods 4 rotate at the same speed but in opposite directions; the middle section of the rotating rod 4 is fixedly connected to the middle sleeve 5; the middle sleeve 5 is slidably connected to the front and rear sides of the middle sleeve 4 to multiple end sleeves 6 sleeved on the rotating rod 4; the outer wall of the end sleeve 6 is uniformly provided with trapezoidal grooves 61 along the circumference; the depth of the trapezoidal grooves 61 decreases as it approaches the middle sleeve 5; the bottom of the trapezoidal grooves 61 is slidably connected to outwardly extending trapezoidal blocks 62; the side of the trapezoidal block 62 near the middle sleeve 5 is connected to the inner wall of the trapezoidal groove 61 by an elastic rope 63; the end sleeve 6 moves away from the middle sleeve 5 under the control of the linear element.

[0038] In this embodiment, the linear element includes a telescopic tube 7 and an adapter 43; the rotating rod 4 is hollow inside; the rear end of the rotating rod 4 is rotatably and sealed to the adapter 43; the adapter 43 is connected to an air pump through an air pipe; the adapter 43 communicates with the interior of the rotating rod 4; the end sleeve 6 has a telescopic hole 64 on the side near the middle sleeve 5; the telescopic tube 7 is slidably and sealed inside the telescopic hole 64; the telescopic tube 7 near the middle sleeve 5 is fixedly connected to the middle sleeve 5; the side of the end sleeve 6 away from the middle sleeve 5 is fixedly connected to the corresponding telescopic tube 7; the telescopic holes 64 on two adjacent end sleeves 6 are connected through end holes 65; the middle sleeve 5 has a central hole 51 inside; one end of the central hole 51 communicates with the interior of the rotating rod 4, and the other end communicates with the telescopic tube 7.

[0039] The film to be stretched is transported from left to right. When the film passes through the first transmission gap 41 from left to right, the upper and lower rotating rods 4 corresponding to the first transmission gap 41 will rotate in opposite directions at the same speed. During the rotation of the rotating rods 4, the corresponding middle sleeve 5 and end sleeve 6 will rotate, so that the film will pass through the first transmission gap 41 and enter the second transmission gap 41. The upper and lower rotating rods 4 corresponding to the second transmission gap 41 will rotate in opposite directions at the same speed. During the rotation of the rotating rods 4, the corresponding middle sleeve 5 and end sleeve 6 will rotate, so that the film will be screwed in and pass through the second transmission gap 41. This continues until the film passes through all the transmission gaps 41. The film will finally be wound on the winding mechanism (not shown in the figure), completing the loading process before the film is stretched.

[0040] Next, stretching begins. During the rotation of motor 42, the rotating rod 4 rotates, which in turn drives the middle sleeve 5 and end sleeve 6 to rotate synchronously. The outer wall of the middle sleeve 5 contacts the film, and the trapezoidal block 62 on the end sleeve 6 contacts the outer wall of the film. Thus, during the rotation of the two corresponding rotating rods 4, the film is clamped and conveyed. The film is transmitted from left to right, passing through multiple transmission gaps 41. The rotational speed of the rotating rods 4 on the multiple U-shaped frames 2 increases sequentially from left to right. Therefore, with a differential speed between the rotating rods 4 in the left and right directions, the two rotating rods 4 on the left side clamp the film, while the two rotating rods on the right side clamp the film. The film is stretched along its length. The rotating rods 4 on the multiple U-shaped frames 2 rotate continuously, allowing the film to be stretched continuously along its length. During this stretching process, the linear element drives the end sleeves 6 on the rotating rods 4 away from the middle sleeve 5, increasing the distance between adjacent end sleeves 6. As the end sleeves 6 move away from the middle sleeve 5, they rotate with the rotating rods 4. The trapezoidal blocks 62 on the outer wall of the end sleeves 6 contact the film. The trapezoidal blocks 62 move as the end sleeves 6 move away from the middle sleeve 5, exerting a tensile force on the film in the width direction, thus causing the film to be stretched in the width direction. The stretching force exerted on the film provides a reaction force to the trapezoidal block 62, causing it to exert a force towards the middle sleeve 5. The trapezoidal block 62 moves along the trapezoidal groove 61. Since the depth of the groove 61 decreases as it approaches the middle sleeve 5, the trapezoidal block 62 extends further after sliding along the groove 61, thus clamping the film more tightly and improving the stability of the stretched film. Furthermore, as the film is stretched, its thickness also decreases. The elastic rope 63 has a tendency to push the trapezoidal block 62 closer to the middle sleeve 5, allowing the trapezoidal block 62 to meet the clamping requirements of the thinned film. This makes the film clamped more stably. Of course, it is worth noting that the trapezoidal blocks 62 on the two end sleeves 6 at the top and bottom positions correspond to each other, realizing stable clamping of the upper and lower surfaces of the film and stretching in the width direction. The separation distance between two adjacent end sleeves 6 is equal, and the distance between the end sleeve 6 closest to the middle sleeve 5 and the middle sleeve 5 is also equal to the distance between the two adjacent end sleeves 6, thus ensuring that the stretching in the width direction of the film is more uniform. Since the end sleeves 6 rotate continuously, the trapezoidal blocks 62 on the end sleeves 6 are in cyclical contact with the film, thus enabling continuous stretching in the width direction of the film as multiple end sleeves 6 move away from the middle sleeve 5.After the multiple end sleeves 6 on the rotating rod 4 move away from the extreme position of the middle sleeve 5, they will approach the middle sleeve 5 under the control of the linear element. The end sleeves 6 will drive the trapezoidal blocks 62 on the outer wall to approach the middle sleeve 5. The friction between the trapezoidal blocks 62 and the film will cause the trapezoidal blocks 62 to overcome the elastic rope 63 and move in the trapezoidal groove 61. The depth of the trapezoidal groove 61 increases as it moves away from the middle sleeve 5. Thus, as the trapezoidal blocks 62 slide along the trapezoidal groove 61, they will retract into the trapezoidal groove 61. After the trapezoidal blocks 62 on the upper and lower end sleeves move away from each other, they release the film. The membrane is clamped so that as the trapezoidal block 62 moves closer to the middle sleeve 5 along with the end sleeve 6, the trapezoidal blocks 62 on the upper and lower end sleeves 6 cannot clamp the membrane. This allows the end sleeves 6 to approach the middle sleeve 5 without pulling the membrane. When multiple end sleeves 6 approach the extreme position of the middle sleeve 5, multiple end sleeves 6 will move away from the middle sleeve 5 again under the action of the linear element, and this process is repeated. Each time the membrane passes through a transmission gap 41, the membrane is stretched in both the width and length directions. The stretched membrane is finally rolled up.

[0041] Furthermore, the linear element includes a telescopic tube 7 and an adapter 43. When it is necessary to control multiple end sleeves 6 away from the middle sleeve 5, an air pump (not shown in the figure) will introduce gas along an air pipe (not shown in the figure) into the adapter 43. The gas in the adapter 43 will then enter the middle hole 51 along the inside of the rotating rod 4, and finally enter the telescopic tube 7 along the middle hole 51. The telescopic tube 7 is slidably sealed in the telescopic hole 64, and the telescopic holes 64 on two adjacent end sleeves 6 are connected through end holes 65. Therefore, all telescopic holes 64 and telescopic tubes 7 are ventilated. Under the action of air pressure, multiple telescopic tubes 7 will gradually extend from the telescopic holes 64, thus allowing multiple end sleeves 6 to move away from the middle sleeve 5. As the end sleeve 6 moves away from the middle sleeve 5, it causes the trapezoidal block 62 to stretch the film in the width direction. When multiple end sleeves 6 need to move closer to the middle sleeve 5 for resetting, the air pump will draw gas from the air tube. This causes the gas in the telescopic hole 64 and telescopic tube 7 to flow out along the end hole 65, the middle hole 51, the inside of the rotating rod 4, and the adapter 43 under negative pressure. The telescopic tube 7 retracts into the telescopic hole 64, and multiple end sleeves 6 converge towards the position close to the middle sleeve 5 for resetting. When multiple end sleeves 6 are close to the extreme position of the middle sleeve 5, the air pump injects air again. This process is repeated, and the expansion and collapse of multiple end sleeves 6 are achieved through the linear element.

[0042] The present invention uses multiple differentially driven rotating rods 4 and multiple end sleeves 6 on the rotating rods 4 to cooperate with the middle sleeve 5, so that the film can be stretched in the length direction and the width direction at the same time, thereby improving the film stretching efficiency and the quality of the film after stretching.

[0043] Example 2: The end sleeves 6 on the two adjacent rotating rods 4 are set in opposite directions when they are unfolded and folded.

[0044] There are multiple U-shaped frames 2. The end sleeves 6 on two adjacent rotating rods 4 are set in opposite directions of unfolding and folding. This means that when the end sleeve 6 on one of the two adjacent rotating rods 4 unfolds, the end sleeve 6 on the other rotating rod 4 will fold back to its original position. In other words, when the end sleeve 6 on one of the two adjacent rotating rods 4 folds back to its original position, the end sleeve 6 on the other rotating rod 4 will unfold. This ensures that while some of the end sleeves 6 are folded back to their original position, the other end sleeves 6 are unfolded. This allows the film to always have the end sleeves 6 stretched in the width direction, ensuring the continuity and sustainability of the film width stretching, as well as the clamping effect of the film, making the film transmission more stable.

[0045] Example 3: The end of the trapezoidal block 62 away from the bottom of the trapezoidal groove 61 is fixedly connected to the end arc-shaped piece 66; the end arc-shaped piece 66 is evenly distributed around the end sleeve 6.

[0046] In this embodiment, the outer wall of the middle sleeve 5 is uniformly provided with clamping grooves 52 along the circumference; a clamping block 53 is slidably connected in the clamping groove 52; the clamping block 53 is connected to the bottom of the clamping groove 52 by a spring 54; and a central arc-shaped piece 55 is fixedly connected to one end of the clamping block 53 away from the clamping groove 52.

[0047] The end arc-shaped piece 66 on the trapezoidal block 62 acts to make the trapezoidal block 62 contact the film through the end arc-shaped piece 66, thereby increasing the area where the film is clamped. Multiple arc-shaped end arc-shaped pieces 66 cover the circumferential area of ​​the end sleeve 6, improving the film clamping effect. Meanwhile, multiple clamping blocks 53 are elastically arranged on the outer wall of the middle sleeve 5. The middle arc-shaped pieces 55 on the multiple clamping blocks 53 cover the circumferential outer wall of the middle sleeve 5. The spring 54 will give the clamping blocks 53 a force away from the bottom of the clamping groove 52, so that the clamping blocks 53 always press against the film surface through the middle arc-shaped piece 55 under the elastic force of the spring 54. In this way, when the film thins during the stretching process, the film can still be clamped by the middle arc-shaped piece 55, ensuring the stability of the film in the length and width directions of the stretching.

[0048] Example 4: The end sleeve 6 is provided with a first threaded hole 67 and a stepped hole 68 on the side away from the middle sleeve 5; the first threaded hole 67 and the stepped hole 68 on the same end sleeve 6 are staggered; the stepped hole 68 penetrates the end sleeve 6; the first threaded hole 67 and the stepped hole 68 on two adjacent end sleeves 6 are correspondingly arranged in the front-back direction; a first bolt (not shown in the figure) passes through the stepped hole 68; the end of the first bolt can be screwed into the first threaded hole 67.

[0049] Before stretching the film in the width direction using the device, the number of end sleeves 6 to be activated is selected according to the width of the film. For ease of description, the end sleeves 6 that can be covered in the width direction of the film are called activated end sleeves 6, and the end sleeves 6 that cannot be covered in the width direction of the film are called deactivated end sleeves 6. Before stretching the film, the deactivated end sleeves 6 are folded up. Specifically, the first bolt is inserted into the stepped hole 68, and the first bolt in the stepped hole 68 is controlled to pass through the stepped hole 68 and tighten the first threaded hole 67 on the adjacent end sleeve 6, so that the two adjacent deactivated end sleeves 6 are folded up. This makes the two adjacent deactivated end sleeves 6 locked and unable to unfold or contract. Thus, the gas only needs to drive the activated end sleeves 6 to unfold and contract, making the activated end sleeves 6 more sensitive and more controllable.

[0050] Example 5: The U-shaped frame 2 has a frame groove 21 running through it from front to back; the frame block 3 is slidably connected to the frame groove 21; a bolt groove 22 runs through it on the left side of the frame groove 21; a second threaded hole 31 corresponding to the bolt groove 22 is provided on the left side of the frame block 3; the bolt groove 22 passes through a second bolt 32; the second bolt 32 is screwed into the second threaded hole 31.

[0051] Loosening the second bolt 32 reduces the force exerted by the larger end of the second bolt 32 against the opening of the bolt groove 22, thus unlocking the support block 3 within the support groove 21. This allows control over the vertical height of the two support blocks 3 within the support groove 21, which directly affects the film transmission height. Additionally, it controls the spacing between the two support blocks 3 within the support groove 21, making it suitable for stretching films of different thicknesses and offering a wide range of applications. After adjusting the support block 3, tightening the second bolt 32 causes the second bolt 32 to pass through the bolt groove 22 and be screwed into the second bolt 32 hole. The larger end of the second bolt 32 then abuts against the opening of the bolt groove 22, locking the vertical position of the support block 3 within the support groove 21.

[0052] Example 6: The upper surface of the base 1 is fixedly connected to the slide rod 12 along the left and right direction by the support block 11; the U-shaped frame 2 is slidably connected to the slide rod 12 through the slide hole 23; the slide hole 23 is provided with a third threaded hole 24 through the outside; the third threaded hole 24 is internally threaded with a third bolt 25.

[0053] When the third bolt 25 is loosened, the third bolt 25 will disengage from the slide bar 12, and then the U-shaped frame 2 will slide along the length of the slide bar 12. This changes the position of multiple U-shaped frames 2 in the left and right directions, thereby adjusting the spacing between two adjacent U-shaped frames 2. This can meet the various stretching interval requirements in the length direction of the film. After the third bolt 25 is tightened and pressed against the slide bar 12, the U-shaped frame 2 and the slide bar 12 are locked.

[0054] Example 7: A tension spring 60 is provided inside the telescopic hole 64; one end of the tension spring 60 is fixedly connected to the bottom of the telescopic hole 64, and the other end is fixedly connected to the telescopic tube 7.

[0055] When multiple end sleeves 6 need to be extended outward, gas will enter the telescopic hole 64 and the telescopic tube 7. Since the bottom of the telescopic hole 64 is connected to the telescopic tube 7 through the tension spring 60, the telescopic tube 7 needs to overcome the tension of the tension spring 60 as it moves away from the corresponding telescopic hole 64. This ensures that the degree to which multiple telescopic tubes 7 move away from the bottom of the telescopic hole 64 is as consistent as possible under the action of the tension spring 60, further improving the uniformity of film stretching in the width direction.

[0056] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the appendix. Figure 1 The orientations or positional relationships shown are for the convenience of describing the present invention and simplifying the description only, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and should not be construed as indicating or implying relative importance.

[0057] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A thermoplastic polyimide film forming apparatus, comprising a base and a plurality of U-shaped frames arranged along a left-right direction on the upper surface of the base; characterized in that: The U-shaped frame has frame blocks on both the front and rear sides; the front and rear frame blocks are rotatably and sealed to a rotating rod; the two rotating rods on the U-shaped frame are distributed vertically and form a transmission gap; the diaphragm passes through the transmission gap from left to right; the front end of the rotating rod is fixedly connected to the motor output end; the outer wall of the motor is fixedly connected to the outer wall of the corresponding frame block; the rotation speed of the rotating rods on the multiple U-shaped frames increases sequentially from left to right; the upper and lower corresponding rotating rods have the same rotation speed but opposite directions; the middle section of the rotating rod is fixedly connected to a middle sleeve; the front and rear sides of the middle sleeve are slidably connected to multiple end sleeves fitted on the rotating rod; the outer wall of the end sleeve is uniformly provided with trapezoidal grooves along the circumference; the depth of the trapezoidal grooves decreases as they approach the middle sleeve; the bottom of the trapezoidal groove is slidably connected to an outwardly extending trapezoidal block; the side of the trapezoidal block near the middle sleeve is connected to the inner wall of the trapezoidal groove by an elastic rope; the end sleeve moves away from the middle sleeve under the control of a linear element. The linear element includes a telescopic tube and an adapter; the rotating rod is hollow inside; the rear end of the rotating rod is rotatably and sealed to the adapter; the adapter is connected to an air pump via an air pipe; the adapter communicates with the interior of the rotating rod; the end sleeve has a telescopic hole on the side near the middle sleeve; the telescopic tube is slidably and sealed within the telescopic hole; the telescopic tube near the middle sleeve is fixedly connected to the middle sleeve; the side of the end sleeve facing away from the middle sleeve is fixedly connected to the corresponding telescopic tube; the telescopic holes on two adjacent end sleeves communicate through end holes; the middle sleeve has a central hole inside; one end of the central hole communicates with the interior of the rotating rod, and the other end communicates with the telescopic tube; The end sleeves on the two adjacent rotating rods are set to be in the opposite orientation when unfolded and folded. The trapezoidal block is fixed to an end arc-shaped piece at one end away from the bottom of the trapezoidal groove; the end arc-shaped pieces are evenly distributed around the end sleeve in the circumferential direction; The outer wall of the middle sleeve is uniformly provided with clamping grooves along the circumference; a clamping block is slidably connected in the clamping groove; the clamping block is connected to the bottom of the clamping groove by a spring; and a central arc-shaped piece is fixedly connected to the end of the clamping block away from the clamping groove.

2. The thermoplastic polyimide film forming apparatus according to claim 1, characterized in that: The end sleeve has a first threaded hole and a stepped hole on the side away from the middle sleeve; the first threaded hole and the stepped hole on the same end sleeve are staggered; the stepped hole penetrates the end sleeve; the first threaded hole and the stepped hole on two adjacent end sleeves are correspondingly arranged in the front-back direction; a first bolt passes through the stepped hole; the end of the first bolt can be screwed into the first threaded hole.

3. The thermoplastic polyimide film forming apparatus according to claim 1, characterized in that: The U-shaped frame has a through-groove at the front and back; the frame block is slidably connected to the through-groove at the top and bottom; a bolt groove is provided through the left side of the through-groove; a second threaded hole corresponding to the bolt groove is provided on the left side of the frame block; a second bolt passes through the bolt groove; the second bolt is screwed into the second threaded hole.

4. The thermoplastic polyimide film forming apparatus according to claim 1, characterized in that: The upper surface of the base is fixed to the slide rod along the left-right direction by the support block; the U-shaped frame is slidably connected to the slide rod through the slide hole; the slide hole is provided with a third threaded hole facing outward; the third threaded hole is internally threaded with a third bolt.

5. The thermoplastic polyimide film forming apparatus according to claim 1, characterized in that: A tension spring is provided inside the telescopic hole; one end of the tension spring is fixedly connected to the bottom of the telescopic hole, and the other end is fixedly connected to the telescopic tube.

Images