Polypropylene synthetic paper stretching device for umbrellas

Abstract

The utility model relates to polypropylene synthetic paper production technical field provides a polypropylene synthetic paper stretching device for umbrella, including work table, the middle part of work table is equipped with the flattening subassembly, work table left part is equipped with the tension buffer subassembly of the link of longitudinal stretching mechanism, the tension buffer subassembly is sent to the flattening subassembly after exerting the gravity of polypropylene synthetic paper that longitudinal stretching mechanism outputted polypropylene synthetic paper adjusted the tension of polypropylene synthetic paper, the flattening subassembly and the adjustable spacing limiting control component between oven body import are equipped with, limiting control component adjusts the limiting of both sides edge movement of polypropylene synthetic paper that flattening subassembly is transported to the oven body, through tension buffer subassembly and limiting control component and flattening subassembly control tension adjustment and position limiting and flatten and eliminate surface transverse wrinkle and edge curl, thereby prevent tension fluctuation to cause film breakage, wrinkling or molecular orientation anomaly, guarantee synthetic paper accurate into longitudinal stretching mechanism.

Description

Technical Field

[0001] This utility model relates to the field of polypropylene synthetic paper production technology, and in particular to a stretching device for polypropylene synthetic paper used in umbrellas. Background Technology

[0002] Umbrella-grade polypropylene synthetic paper uses polypropylene (PP) as its base material and combines lightweight, weather resistance, and printability. It is specifically designed for disposable emergency umbrella canopies and is typically only 0.035–0.080 mm thick, much thinner than general-purpose synthetic paper. It requires longitudinal and transverse stretching and forming under high temperature, high speed, and wide-width conditions. In the transition section between longitudinal stretching and transverse stretching, the ultra-thin, fragile, and easily curled characteristics of the umbrella-grade polypropylene synthetic paper necessitate extremely stringent requirements for transport stability.

[0003] For example, Chinese patent document CN01130609.2 describes a method for improving the yield and output of biaxially stretched polypropylene pearlescent synthetic paper. In the pearlescent synthetic paper manufacturing process (including extrusion, three-layer co-extrusion, cooling molding, biaxial stretching, corona treatment, and winding), inorganic powder is pre-formed into M1B (composite granules) and mixed only with the main raw material, polypropylene. This pre-dispersion process improves upon the known pearlescent synthetic paper manufacturing process where moisture absorption of the inorganic material or the volatilization of surface treatment agents during heating causes the extruded sheets to have a porous or gas-spotted structure, affecting product quality and productivity. Therefore, when the extruder operates at maximum speed and maximum extrusion volume, because the inorganic powder composite granules of this invention pre-dispersion, combined with the design of a vacuum device and a twin-screw extruder to enhance the mixing effect, the yield and output of biaxially stretched polypropylene pearlescent synthetic paper can be effectively improved. As mentioned above, the biaxial stretching process in the preparation of synthetic paper uses continuous longitudinal and transverse stretching, sometimes even without a transition section, directly connecting transverse stretching immediately after longitudinal stretching, or having a transition section but only a passive guide roller. There is a lack of dedicated tension adjustment and side-limiting conveyor structures: on the one hand, there is a speed difference between longitudinal and transverse stretching, and tension fluctuations can easily lead to film breakage, wrinkling, or abnormal molecular orientation, directly weakening the umbrella surface's wind resistance and tear resistance; on the other hand, synthetic paper is prone to transverse deviation during high-speed operation, and the existing guide rollers do not have dynamically adjustable limiting structures at both ends, preventing the edges from accurately entering the transverse stretching section, thus causing the synthetic paper held in the transverse stretching section to shift, easily leading to winding misalignment and a sharp drop in yield. Utility Model Content

[0004] This invention provides a stretching device for polypropylene synthetic paper used in umbrellas, which solves the above-mentioned structural technical problems of speed difference between longitudinal and transverse stretching, and the tendency of polypropylene synthetic paper used in umbrellas to deviate laterally during high-speed operation.

[0005] The present invention provides the following solution to the above-mentioned technical problems: a polypropylene synthetic paper stretching device for umbrellas, comprising a worktable, an oven body at the front end of a transverse stretching mechanism on the right side of the worktable, a traction clamping mechanism running through the interior of the oven body, a flattening component at the left end of the worktable and a tension buffer component at the middle of the worktable; a tension buffer component at the left side of the worktable and connected to the longitudinal stretching mechanism, the tension buffer component applying downward gravity to the polypropylene synthetic paper output by the longitudinal stretching mechanism to adjust the tension of the polypropylene synthetic paper before sending it to the flattening component for flattening; an adjustable spacing limit control component between the flattening component and the oven body inlet; the limit control component adjusts and limits the movement of the polypropylene synthetic paper at both edges when it is conveyed to the oven body by the flattening component.

[0006] The beneficial effects of this utility model are as follows: the worktable mainly provides support, the tension buffer component adjusts the tension of the polypropylene synthetic paper output by the longitudinal stretching mechanism, and the flattening component flattens the polypropylene synthetic paper to eliminate the transverse wrinkles and longitudinal curling generated during the conveying process. The limit control component prevents the polypropylene synthetic paper from shifting or deviating, so that the synthetic paper enters the oven body at the front end of the transverse stretching mechanism in a flat and stretched state. This allows the traction clamping mechanism inside the oven body to stably clamp the polypropylene synthetic paper and begin the transverse stretching heating and softening treatment.

[0007] In a further improvement, the limit control assembly includes two first support plates fixed to the front and rear sides of the worktable. A rotatable conveying roller is provided between the two first support plates. Above the conveying roller, a rotatable bidirectional lead screw is also provided between the two first support plates. Two lead screw nut seats are threadedly connected to the reverse screws at both ends of the bidirectional lead screw body. The two lead screw nut seats are respectively provided with adjustment and limit functions to limit the movement of the two sides of the polypropylene synthetic paper conveyed by the conveying roller. A moving rod is connected to the bottom of each lead screw nut seat, and a limit ring is provided at the free end of each moving rod.

[0008] By setting two lead screw nut seats with automatically adjustable spacing, the moving rod drives the limiting ring to move and adjust the limits on both sides of the polypropylene synthetic paper. In a further improvement, the limiting rings on the moving rod are slidably sleeved on the conveying roller to limit the edges of the polypropylene synthetic paper on both sides.

[0009] In a further improvement, a support frame is fixed to one side of one of the first support plates, and a speed-regulating motor is provided on the top of the support frame. The output end of the speed-regulating motor is connected to one end of the bidirectional lead screw, which drives the bidirectional lead screw to rotate in both directions.

[0010] The beneficial effects of adopting the above-mentioned further solution are: the support frame can support the speed-regulating motor, the speed-regulating motor can rotate the bidirectional lead screw, changing its rotation speed and rotation direction, and the speed-regulating motor can be connected to the controller of the umbrella polypropylene synthetic paper production line. The controller of the umbrella polypropylene synthetic paper production line can control the speed-regulating motor to quickly adjust the limiting position on both sides of the polypropylene synthetic paper.

[0011] In a further improvement, the tension buffer assembly includes support rods fixed on the front and rear sides of the worktable. Each of the two support rods is provided with a movable block that moves up and down along the support rod, and a rotatable buffer roller is provided between the two movable blocks. At least one support rod is provided with a drive device. The output end of the drive device is connected to and drives the movable block on the support rod to move up and down, thereby driving the buffer roller to press down and adjust the gravity applied to the polypropylene synthetic paper.

[0012] In a further improvement, the drive device is a pneumatic cylinder, a hydraulic cylinder, or a lead screw motor.

[0013] In a further improvement, the tension buffer assembly also includes a tension sensor. The tension sensor is installed between the bearing seat of the conveying roller of the limit control assembly and the worktable. The tension sensor detects the conveying tension value of the polypropylene synthetic paper in real time and sends the signal to the controller of the umbrella polypropylene synthetic paper production line. The controller controls the drive device to move the moving block up and down according to the preset target tension value, thereby driving the buffer roller to press down and adjust the gravity applied to the polypropylene synthetic paper.

[0014] In a further improvement, the driving device is an electric telescopic rod located on one side of each of the two support rods. The free ends of the two electric telescopic rods are equipped with connecting frames, and the free ends of the connecting frames are connected to the moving blocks.

[0015] The beneficial effects of adopting the above-mentioned further solution are: the support rod can facilitate the up and down movement of the moving block, the moving block can support the rotating buffer roller, and the drive device drives the moving block to move up and down. In this way, the up and down movement of the buffer roller on the moving block can be controlled, thereby controlling the gravity applied to the polypropylene synthetic paper that bypasses the buffer roller to achieve tension adjustment.

[0016] In a further improvement, the flattening assembly includes a second support plate fixed on the front and rear sides of the worktable. Between the two second support plates, there are two flattening rollers that can clamp and flatten polypropylene synthetic paper. The surface of the flattening rollers is provided with flattening threads that extend spirally from the middle of the rollers to both ends.

[0017] The beneficial effect of adopting the above-mentioned further solution is that the second support plate can support the flattening roller, which removes the transverse wrinkles and longitudinal curls generated during the conveying process of the synthetic paper, allowing the polypropylene synthetic paper to enter the next process in a flat and smooth state.

[0018] By adopting the aforementioned technical solution, the beneficial effects of this utility model are as follows: The tension buffer component, the limit control component, and the flattening component can control tension adjustment and position limiting, as well as flattening to eliminate transverse wrinkles and edge curling on the surface of polypropylene synthetic paper. It is specifically designed for the transitional auxiliary stretching and conveying of umbrella polypropylene synthetic paper with a thickness of 0.035-0.080mm between longitudinal and transverse stretching. First, the tension is buffered and adjusted, then flattened, and finally the limit is moved, achieving a smooth and even conveying of the umbrella polypropylene synthetic paper. This prevents tension fluctuations from causing film breakage, wrinkling, or abnormal molecular orientation, ensuring that the synthetic paper accurately, smoothly, and evenly enters the oven body at the front end of the transverse stretching mechanism. The traction clamping mechanism inside the oven body holds the polypropylene synthetic paper for transverse stretching and heating softening, preventing the polypropylene synthetic paper from shifting after entering the transverse stretching mechanism, thus avoiding misalignment during winding. This effectively ensures the product quality of polypropylene synthetic paper used for umbrella surface production, improves the yield rate, and meets the high consistency requirements of disposable emergency umbrella surfaces for polypropylene synthetic paper.

[0019] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it according to the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. The specific implementation methods of this utility model are given in detail in the following embodiments and their accompanying drawings. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 A perspective view of a polypropylene synthetic paper stretching device for umbrellas is provided for this utility model; Figure 2 This utility model provides a front view structural diagram of a limit control component for a polypropylene synthetic paper stretching device for umbrellas. Figure 3 This utility model provides a front view structural diagram of a tension buffer assembly for a polypropylene synthetic paper stretching device for umbrellas. Figure 4 This utility model presents a partial side view of a polypropylene synthetic paper stretching device for umbrellas.

[0021] Legend: 1. Workbench; 2. Oven body; 3. Traction clamping mechanism; 4. Tension buffer assembly; 5. Limit control assembly; 6. Flattening assembly; 52. First support plate; 53. Conveyor roller; 54. Double-acting lead screw body; 55. Lead screw nut seat; 56. Moving rod; 57. Limiting ring; 58. Support frame; 59. Speed ​​regulating motor; 42. Support rod; 43. Moving block; 44. Buffer roller; 45. Connecting frame; 46. Electric telescopic rod; 61. Second support plate; 62. Flattening roller. Detailed Implementation

[0022] The following is in conjunction with the appendix Figure 1-4 The principles and features of this utility model are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of this utility model. The utility model is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of this utility model will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of this utility model. This utility model is applied to the longitudinal stretching section and the transverse stretching section of an umbrella polypropylene synthetic paper production line as an auxiliary stretching device to replace the existing transition section. The longitudinal stretching mechanism and the transverse stretching mechanism, including the oven body at the front end of the transverse stretching mechanism and the traction clamping mechanism, are all prior art. Therefore, they will not be described in detail in the following embodiments. The following is a detailed description of the new design part of this utility model.

[0023] like Figure 1-4 As shown, the preferred polypropylene synthetic paper stretching device for umbrellas of this utility model includes a worktable 1. The right side of the worktable 1 is an oven body 2 at the front end of the transverse stretching mechanism. A traction clamping mechanism 3 is installed inside the oven body 2. The left end of the worktable 1 is connected to the end of the longitudinal stretching mechanism. A flattening component 6 is provided in the middle of the worktable 1. A tension buffer component 4 is provided near the flattening component 6 on the top left side of the worktable 1. The tension buffer component 4 is used to apply downward gravity to provide constant tension to the polypropylene synthetic paper. A limit control component 5 is provided between the flattening component 6 and the input end of the oven body 2 at the front end of the transverse stretching mechanism on the worktable 1. The limit control component 5 is used to limit the movement of the conveyed polypropylene synthetic paper on both sides.

[0024] The limit control assembly 5 includes first support plates 51 fixed on the front and rear sides of the workbench 1. A rotatable conveyor roller 52 is provided between the two first support plates 51. A rotatable bidirectional lead screw body 53 is provided above the conveyor roller 52 between the two first support plates 51 via a bearing. Two threaded lead screw nut seats 54 are provided on the bidirectional lead screw body 53 at intervals. A moving rod 55 is connected to the bottom of each lead screw nut seat 54. A limit ring 56 is provided at the bottom of each moving rod 55. The limit ring 56 is movably sleeved on the outer circumferential surface of the conveyor roller 52 and can slide along the axial direction of the conveyor roller 52 as the lead screw nut seat 54 moves. Polypropylene synthetic paper passes over or under the conveyor roller 52, and its two side edges are restricted by the inner end faces of the two limit rings 56, thereby preventing the polypropylene synthetic paper from deviating laterally. One of the first support plates 51 has a support frame 57 fixed to one side. A speed-regulating motor 58 is installed on the top of the support frame 57. The output end of the speed-regulating motor 58 is connected to one end of the bidirectional lead screw body 53. The tension buffer assembly 4 includes support rods 41 fixed on the front and rear sides of the left side of the worktable 1. Each support rod 41 has a sliding block 42 slidably connected to the opposite side. A buffer roller 43 is rotatably connected between the two moving blocks 42 by a bearing. A connecting frame 44 is installed on one side of each of the two moving blocks 42. An electric telescopic rod 45 is connected to the bottom of each connecting frame 44. The flattening assembly 6 includes second support plates 61 fixed on the front and rear sides of the worktable 1. A rotatable flattening roller 62 is provided between the two second support plates 61. The surface of the flattening roller 62 is provided with flattening threads that spirally extend from the middle of the roller to both ends. When polypropylene synthetic paper passes between the two flattening rollers 62, the flattening threads apply a frictional force from the center to both sides to the polypropylene synthetic paper, thereby eliminating its transverse wrinkles and edge curling. The force buffer assembly 4 also includes a tension sensor (not shown). The tension sensor is installed between the bearing seat of the conveyor roller 52 of the limit control assembly 5 and the worktable. It is used to detect the radial force of the polypropylene synthetic paper acting on the conveyor roller 52 in real time and calculate the conveying tension value. The signal is sent to the controller of the umbrella polypropylene synthetic paper production line. The controller controls the electric telescopic rod 45 to extend and retract according to the preset target tension value. It works with the connecting frame 44 to drive the moving block 42 and the buffer roller 43 to rise and fall. The electric telescopic rod 45 is an electric cylinder to dynamically adjust the tension of the polypropylene synthetic paper and stabilize it within the preset process range. When the detected real-time tension value is higher than the target value, the controller controls the electric telescopic rod 45 to drive the moving block 42 to rise and then drive the buffer roller 43 to move upward to reduce the tension of the polypropylene synthetic paper. When the real-time tension value is lower than the target value, the controller controls the electric telescopic rod 45 to drive the moving block 42 to fall and then drive the buffer roller 43 to move downward to increase the tension of the polypropylene synthetic paper.The controller of this device adopts the controller of the existing umbrella polypropylene synthetic paper production line for closed-loop tension control. The controller has a built-in PID adjustment algorithm, which can adjust the position of the buffer roller 43 in real time and smoothly according to the signal feedback from the tension sensor, so as to accurately control the conveying tension of the polypropylene synthetic paper within the preset range.

[0025] In this embodiment, the first support plate 51 facilitates the support of the conveyor roller 52, which in turn facilitates the movement of the polypropylene synthetic paper. The bidirectional lead screw 53 allows the distance between the two lead screw nut seats 54 to be adjusted according to the width of the polypropylene synthetic paper. Specifically, the lead screw nut seats 54, connected to the limiting ring 56 via the moving rod 55, limit the polypropylene synthetic paper. The support frame 57 supports the speed-regulating motor 58, which rotates the bidirectional lead screw 53. The speed and direction of rotation are adjusted according to the width requirements of the polypropylene synthetic paper, thereby adjusting the distance between the two limiting rings 56. To achieve dynamic adaptation of polypropylene synthetic paper, support rod 41 facilitates the up-and-down movement of moving block 42, which in turn supports buffer roller 43. Electric telescopic rod 45 moves connecting frame 44 up and down, thus controlling the up-and-down movement of buffer roller 43 on moving block 42. This allows for tension adjustment of polypropylene synthetic paper bypassing buffer roller 43. Second support plate 61 supports flattening roller 62, which eliminates transverse wrinkles and longitudinal curling of synthetic paper during transport, allowing polypropylene synthetic paper to enter the next process in a flat and smooth state.

[0026] Working principle: After being stretched longitudinally, the polypropylene synthetic paper first winds around the buffer roller 43 of the tension buffer assembly 4 and then is sent to the flattening assembly. After entering the tension buffer assembly 4, the electric telescopic rod 45 drives the moving block 42 to rise and fall along the support rod 41 through the connecting frame 44, which drives the buffer roller 43 to move up and down to adjust the gravity of the buffer roller 43 to apply downward pressure to the polypropylene synthetic paper, thereby dynamically adjusting the conveying tension of the polypropylene synthetic paper being conveyed backward, and avoiding excessive stretching or loosening and wrinkling due to speed fluctuations. Among them, after tension adjustment, the polypropylene synthetic paper enters the flattening component 6: the flattening rollers 62 arranged symmetrically on the upper and lower sides apply a spreading force from the center to both sides to the polypropylene synthetic paper, eliminating the transverse wrinkles on the surface and the curling at the edges. After being flattened, the polypropylene synthetic paper enters the limit control component 5: the speed-regulating motor 58 drives the bidirectional lead screw body 53 to rotate, and the two lead screw nut seats 54 move synchronously towards or away from each other. Through the moving rod 55, the limit ring 56 slides along the axial direction of the conveying roller 52, so as to achieve precise limit of the two sides of the polypropylene synthetic paper by the limit ring 56 to prevent deviation. Finally, the flattened synthetic paper enters the oven body 2 at the front end of the transverse stretching mechanism. The traction clamping mechanism 3 holds the polypropylene synthetic paper into the oven body 2 for heating and softening. Then, the transverse stretching mechanism performs a transverse stretching process on the softened polypropylene synthetic paper.

[0027] In summary, by using the tension buffer component 4 and the limit control component 5 in conjunction with the flattening component 6, tension adjustment and position limiting can be controlled, and flattening can be performed to eliminate transverse wrinkles and edge curling on the surface. This can prevent tension fluctuations from causing film breakage, wrinkling, or abnormal molecular orientation. It can also ensure that the polypropylene synthetic paper accurately enters the oven body 2 at the front end of the transverse stretching mechanism, where it is smoothly clamped and pulled into the oven body 2 by the traction clamping mechanism 3 for heating and softening, as well as subsequent transverse stretching.

[0028] In the above embodiments, the structure of the tension buffer assembly connecting frame and the electric telescopic rod can also be replaced by a single drive device. That is, a drive device can be fixed to the support rod, and the output end of the drive device can be connected to a moving block on the support rod. For example, if the drive device is a cylinder, the cylinder can drive the moving block to slide up and down, thereby adjusting the up and down movement of the buffer roller. The drive device can also be a hydraulic cylinder or a lead screw motor. Alternatively, two drive devices can be provided, each mounted on one of the two support rods, to synchronously drive the up and down movement.

[0029] The above are merely preferred embodiments of this utility model and are not intended to limit the utility model in any way. Those skilled in the art can readily implement this utility model based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the utility model's technical solution, utilizing the disclosed technical content, are equivalent embodiments of this utility model. Furthermore, any equivalent changes, alterations, or variations made to the above embodiments based on the essential technology of this utility model are still within the protection scope of this utility model's technical solution.

Claims

1. A stretching device for polypropylene synthetic paper used in umbrellas, comprising a worktable, a drying oven body at the front end of a transverse stretching mechanism on the right side of the worktable, a traction clamping mechanism being installed inside the drying oven body, and the left end of the worktable being connected to the end of a longitudinal stretching mechanism, characterized in that: A flattening assembly is provided in the middle of the worktable; a tension buffer assembly connected to the longitudinal stretching mechanism is provided on the left side of the worktable. The tension buffer assembly applies downward gravity to the polypropylene synthetic paper output by the longitudinal stretching mechanism to adjust the tension of the polypropylene synthetic paper and then sends the polypropylene synthetic paper to the flattening assembly for flattening. An adjustable spacing limit control assembly is provided between the flattening assembly and the oven body inlet; the limit control assembly adjusts and limits the movement of the two edges of the polypropylene synthetic paper conveyed to the oven body by the flattening assembly. The tension buffer assembly includes support rods fixed on the front and rear sides of the worktable. Each of the two support rods is provided with a moving block that moves up and down along the support rod, and a rotatable buffer roller is provided between the two moving blocks. At least one support rod is provided with a driving device. The output end of the driving device is connected to and drives the moving block on the support rod to move up and down, thereby driving the buffer roller to press down and adjust the gravity applied to the polypropylene synthetic paper.

2. The polypropylene synthetic paper stretching device for umbrellas according to claim 1, characterized in that: The limit control assembly includes two first support plates fixed on the front and rear sides of the workbench, a rotatable conveying roller between the two first support plates, and a rotatable bidirectional lead screw body located above the conveying roller between the two first support plates. The two ends of the bidirectional lead screw body are respectively provided with two lead screw nut seats with threaded connections on the reverse screws. The two lead screw nut seats are respectively provided with adjustment limits for the movement of the two sides of the polypropylene synthetic paper conveyed by the conveying roller.

3. The polypropylene synthetic paper stretching device for umbrellas according to claim 2, characterized in that: Each of the aforementioned lead screw nut seats is connected to a movable rod at its bottom, and each movable rod has a limit ring at its free end.

4. The polypropylene synthetic paper stretching device for umbrellas according to claim 3, characterized in that: The limiting rings on the moving rod are slidably sleeved on the conveying roller to limit the two sides of the polypropylene synthetic paper.

5. The polypropylene synthetic paper stretching device for umbrellas according to claim 3, characterized in that: One of the first support plates is fixed with a support frame on one side, and a speed-regulating motor is provided on the top of the support frame. The output end of the speed-regulating motor is connected to one end of the bidirectional lead screw, which drives the bidirectional lead screw to rotate in both directions.

6. The polypropylene synthetic paper stretching device for umbrellas according to claim 1, characterized in that: The driving device is a pneumatic cylinder, a hydraulic cylinder, or a lead screw motor.

7. The stretching device for polypropylene synthetic paper for umbrellas according to claim 1, characterized in that: The tension buffer assembly also includes a tension sensor, which is installed between the bearing seat of the conveying roller of the limit control assembly and the worktable. The tension sensor detects the conveying tension value of the polypropylene synthetic paper in real time and sends the signal to the controller of the umbrella polypropylene synthetic paper production line. The controller controls the drive device to move the moving block up and down according to the preset target tension value, thereby driving the buffer roller to press down and adjust the gravity applied to the polypropylene synthetic paper.

8. The polypropylene synthetic paper stretching device for umbrellas according to claim 1, characterized in that: The driving device is an electric telescopic rod located on one side of each of the two support rods. The free ends of the two electric telescopic rods are equipped with connecting frames, and the free ends of the connecting frames are connected to the moving blocks.

9. The polypropylene synthetic paper stretching device for umbrellas according to claim 1, characterized in that: The flattening assembly includes a second support plate fixed on the front and rear sides of the workbench. Between the two second support plates, there are two flattening rollers that can clamp and flatten polypropylene synthetic paper. The surface of the flattening rollers is provided with flattening threads that extend spirally from the middle of the rollers to both ends.

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