A polytetrafluoroethylene film cross drawing machine

Abstract

The utility model relates to horizontal pulling machine technical field especially polytetrafluoroethylene film horizontal pulling machine, including horizontal pulling top strip, the below of horizontal pulling top strip is equipped with machine base, is equipped with preheating box and heat setting box on machine base, is equipped with feeding frame and material receiving frame on machine base, is equipped with underframe on machine base, is equipped with feeding roller on feeding frame, is equipped with material receiving roller and motor on material receiving frame, is equipped with conveyer belt on feeding roller, is equipped with clamp on conveyer belt, is equipped with connecting frame on underframe, is equipped with synchronous cylinder on connecting frame, is equipped with cylinder rod on synchronous cylinder, is equipped with mounting block on cylinder rod, the top of underframe is equipped with horizontal pulling top strip, is equipped with lock screw rod on mounting block, is equipped with fixed insertion column and top pressure surface on horizontal pulling top strip, is equipped with lock screw groove on horizontal pulling top strip, is equipped with fixed insertion groove on mounting block. The replaceability of horizontal pulling top strip on PTFE polytetrafluoroethylene film production horizontal pulling device is improved, and the anti-rotation positioning limiting property of horizontal pulling top strip on PTFE polytetrafluoroethylene film production horizontal pulling device is improved.

Description

Technical Field

[0001] This utility model relates to the field of cross-stretching machine technology, and in particular to a cross-stretching machine for polytetrafluoroethylene film. Background Technology

[0002] Polytetrafluoroethylene (PTFE) film is produced through the following process: First, fine PTFE powder is uniformly mixed with a liquid extrusion aid (such as solvent oil) to form a paste. Then, the paste is placed into a plunger extruder and extruded through a flat, narrow die at a relatively low temperature to form an unsintered "raw material tape" containing the extrusion aid. Next, the extruded raw material tape is calendered through one or more sets of rollers to achieve uniform thickness and initial orientation. Then, the extrusion aid in the raw material tape is evaporated and removed by heating. The dried film is then stretched longitudinally in the machine direction (MD) through a set of rollers at different speeds. The longitudinally stretched film is then fed into a transverse stretching device, where both sides of the film are clamped and stretched significantly in the transverse width direction (TD) in a hot air box. Next, the biaxially stretched PTFE film is heat-treated to stabilize its structure and shape. Finally, it is cooled and wound up to obtain the finished product.

[0003] The specific transverse stretching process of the aforementioned PTFE (polytetrafluoroethylene) membrane is as follows: First, the longitudinally stretched PTFE base film is cut into a suitable segment. Then, the two edges of this PTFE base film are manually and stably clamped by clamps. Next, the PTFE base film is sent into a preheating box (a sealed box with a hot air circulation system and heating pipes inside, precisely controlling the temperature, existing technology) to heat the PTFE base film to a suitable and elastic state, preparing it for stretching. Then, the preheated PTFE base film continues to be conveyed. At this time, the symmetrical conveyor belt is pressed and separated to both sides by pneumatic transverse stretching top bars, which allows the preheated PTFE base film to be transversely stretched and widened to a certain width. After stretching, the PTFE base film is then conveyed to a heat setting box to prevent shrinkage and deformation later. After cooling down, it is then wound up.

[0004] Currently, when the conveyor belt separates to both sides, a symmetrical horizontal pull bar mechanism is required. A synchronous cylinder is installed on the base frame, and then the horizontal pull bar is installed on the cylinder rod of the synchronous cylinder. After long-term use, the top pressure surface of the horizontal pull bar will wear and needs to be replaced. However, most of the existing horizontal pull devices for PTFE polytetrafluoroethylene film production have their horizontal pull bars directly fixed and welded, which cannot be easily replaced with new ones, greatly reducing the replaceability of the horizontal pull bars on the horizontal pull devices for PTFE polytetrafluoroethylene film production.

[0005] To address this, we designed a transverse stretching device for PTFE (polytetrafluoroethylene) membrane production to meet the needs of practical applications. Utility Model Content

[0006] The purpose of this invention is to address the aforementioned shortcomings in the existing technology by proposing a polytetrafluoroethylene film stretching machine.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: Design a polytetrafluoroethylene (PTFE) film cross-stretching machine, including a cross-stretching top bar, a machine base below the cross-stretching top bar, a preheating box and a heat setting box on the machine base, a feeding rack and a receiving rack on the machine base, a base frame on the machine base, a feeding roller on the feeding rack, a receiving roller and a motor on the receiving rack, a conveyor belt on the feeding roller, a clamp on the conveyor belt, a PTFE base film clamped on the clamp, a connecting frame on the base frame, a synchronous cylinder mounted on the connecting frame, a cylinder rod on the synchronous cylinder, and a mounting block on the cylinder rod; The mounting block is provided with a locking screw, and the horizontal pull strip is provided with a fixed insertion post and a top pressure surface; The horizontal pull bar has a locking groove, the mounting block has a fixed slot, and the locking rod has a handle.

[0008] In detail, the feeding roller is rotatably mounted on the feeding frame, the receiving roller is rotatably mounted on the receiving frame, and the motor shaft of the motor passes through the receiving frame and is fixedly mounted to the receiving roller.

[0009] In detail, the conveyor belt passes laterally through the preheating box and the heat setting box. There are two symmetrical conveyor belts, which are respectively fitted onto the feeding roller and the receiving roller. There are two sets of clamps, each set consisting of five arranged laterally.

[0010] In detail, the synchronized cylinders are in two sets that are symmetrically arranged vertically, and each set consists of two cylinders that are symmetrically arranged horizontally.

[0011] In detail, the mounting block has an overall L-shaped structure, and the locking screw passes through the mounting block and is threadedly connected to the locking screw groove.

[0012] In detail, the top pressing surface is located on the outer wall surface of the horizontal top bar, and the fixed insertion post is located on the inner wall surface of the horizontal top bar and is inserted into the fixed slot.

[0013] In detail, the handle is located at the outer end of the locking screw, and the handle is generally diamond-shaped.

[0014] The design scheme proposed in this utility model has the following beneficial effects in application: 1. This utility model improves the replaceability of the horizontal pull strips in the PTFE membrane production horizontal pull device by setting a mounting block structure with a locking screw on the cylinder rod of each synchronous cylinder and opening a matching locking screw groove structure on the horizontal pull strip. The top pressure surface of the horizontal pull strip is used in sliding friction with the conveyor belt for a long time. When the top pressure surface of a certain horizontal pull strip is worn, the horizontal pull strip with the worn top pressure surface can be easily removed and replaced with a new one.

[0015] 2. This utility model creates a slot on the mounting block and sets a matching fixed post on the horizontal pull strip. When the horizontal pull strip is installed on the mounting block, the fixed post will also be inserted into the fixed slot, effectively preventing the horizontal pull strip from rotating after installation and improving the anti-rotation positioning and limiting performance of the horizontal pull strip on the horizontal pull device for PTFE polytetrafluoroethylene film production. Attached Figure Description

[0016] Figure 1 This is a three-dimensional schematic diagram of the horizontal tie rod of this utility model in its uninstalled state; Figure 2 This is a three-dimensional schematic diagram of the horizontal tie rod of this utility model in its installed state; Figure 3 For the present utility model Figure 2 Enlarged view of a section at point H; Figure 4 For the present utility model Figure 1 A three-dimensional schematic diagram of the base frame with mounting blocks; Figure 5 For the present utility model Figure 1 A three-dimensional schematic diagram of the central horizontal tie rod.

[0017] In the diagram: 1. Machine base; 11. Preheating box; 12. Heat setting box; 2. Feeding rack; 21. Feeding roller; 3. Conveyor belt; 31. Clamp; 32. PTFE base film; 4. Receiving rack; 41. Receiving roller; 42. Motor; 5. Base frame; 51. Connecting frame; 6. Synchronous cylinder; 61. Cylinder rod; 7. Mounting block; 71. Fixed slot; 72. Locking screw; 73. Rod handle; 8. Horizontal pull strip; 81. Fixed insertion post; 82. Locking screw groove; 83. Top pressure surface. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0019] Reference Figures 1-5A polytetrafluoroethylene (PTFE) film stretching machine includes a stretching top bar 8, a machine base 1 below the stretching top bar 8, a preheating box 11 and a heat setting box 12 on the machine base 1, a feeding rack 2 and a receiving rack 4 on the machine base 1, a base frame 5 on the machine base 1, a feeding roller 21 on the feeding rack 2, a receiving roller 41 and a motor 42 on the receiving rack 4, a conveyor belt 3 on the feeding roller 21, a clamp 31 on the conveyor belt 3, a PTFE base film 32 clamped on the clamp 31, a connecting frame 51 on the base frame 5, a synchronous cylinder 6 installed on the connecting frame 51, a cylinder rod 61 on the synchronous cylinder 6, and a mounting block 7 on the cylinder rod 61. The mounting block 7 is provided with a locking screw 72, and the horizontal top strip 8 is provided with a fixed insertion post 81 and a top pressure surface 83. The horizontal top bar 8 has a locking groove 82, the mounting block 7 has a fixed slot 71, and the locking screw 72 has a handle 73.

[0020] It should be further noted that the feeding roller 21 is rotatably mounted on the feeding frame 2, and the receiving roller 41 is rotatably mounted on the receiving frame 4. The motor shaft of the motor 42 passes through the receiving frame 4 and is fixedly mounted on the receiving roller 41. The machine base 1, preheating box 11, heat setting box 12, feeding frame 2, feeding roller 21, conveyor belt 3, clamp 31, receiving frame 4, receiving roller 41, motor 42, base frame 5, and connecting frame 51 described in this patent are all related structures of the horizontal stretching device for PTFE polytetrafluoroethylene film production, which are existing technologies. Some existing structures are not drawn or labeled, and need not be described in detail.

[0021] It should be further noted that the conveyor belt 3 passes laterally through the preheating box 11 and the heat setting box 12. Both sides of the preheating box 11 and the heat setting box 12 are provided with conveying openings to ensure the horizontal conveying effect of the PTFE base film 32 and the conveyor belt 3. At the same time, heating wires and temperature control devices are pre-installed in the preheating box 11 and the heat setting box 12 to achieve a constant temperature heating effect, which is the existing technology.

[0022] The conveyor belts 3 are two symmetrical ones, respectively fitted on the feeding roller 21 and the receiving roller 41. The conveyor belts 3 are made of silicone rubber, which has high elasticity, wear resistance and durability. They can be pressed by the horizontal top bar 8 to form a figure-eight shape.

[0023] The clamps 31 are in two sets, with five in each set arranged horizontally. The clamps 31 are commonly used flat-jaw pliers, similar to a large clothespin with a long handle. The jaws are parallel, and a silicone pad is bonded and fixed to the contact surface between the jaws and the PTFE base film 32. It has excellent damping elasticity and is non-polluting, which is the existing technology.

[0024] It should be further explained that the synchronizing cylinders 6 are in two symmetrical groups, each group consisting of two symmetrical groups, and there are a total of four synchronizing cylinders 6. They are connected to an external preset control box via signal lines. The control box has a preset control switch with three buttons, which can simultaneously control the extension and retraction of the cylinder rods 61 of the four synchronizing cylinders 6 and their real-time stopping.

[0025] It should be further noted that the mounting block 7 has an overall L-shaped structure, and the locking screw 72 passes through the mounting block 7 and is threadedly connected to the locking screw groove 82, which realizes the replaceability of the horizontal pull top bar 8.

[0026] It should be further explained that the top pressure surface 83 is located on the outer wall of the horizontal top bar 8. When the cylinder rods 61 on both sides extend outward, the top pressure surface 83 on both sides can press the conveyor belts 3 on both sides and form a figure-eight shape, so as to achieve the effect of lateral top pressure and stretching of a PTFE base film 32 in the later stage.

[0027] The fixed insertion post 81 is located on the inner wall of the horizontal tie bar 8 and is inserted into the fixed slot 71. The fixed insertion post 81 is made of hard alloy steel, which is high in strength, durable and does not deform.

[0028] It should be further noted that the handle 73 is located on the outer end of the locking screw 72. The handle 73 has a diamond-shaped structure, which can be easily gripped and rotated, further improving the ease of assembly and disassembly of the horizontal pull bar 8.

[0029] Working method: The specific workflow is as follows: First, a suitable segment of the longitudinally stretched PTFE base film 32 is cut (existing technology). Then, the two edges of this PTFE base film 32 are manually and stably clamped by clamps 31 (existing technology). Next, the motor 42 is started, and the motor shaft of the motor 42 drives the receiving roller 41 to rotate at a constant speed. Since the conveyor belt 3 is sleeved on the feeding roller 21, it also drives the feeding roller 21 to rotate. Then, the symmetrical synchronous cylinders 6 are started, and the cylinder rods 61 of the symmetrical synchronous cylinders 6 extend at a constant speed. At this time, the horizontal pull bar 8 pushes the two conveyor belts 3 to the sides and separates them to form a V-shape. When a certain stretching width suitable for the PTFE base film 32 is formed, the synchronous cylinders 6 are stopped. At this point, the clamped PTFE base film 32 is horizontally fed into the preheating box 11 for preheating (a sealed box with a hot air circulation system and heating pipes inside, precisely controlling the temperature, existing technology). The PTFE base film 32 is heated to a suitable, elastic state to prepare for stretching. Then, the preheated PTFE base film 32 continues to be conveyed to the right. At this time, when the PTFE base film 32 passes through the symmetrical conveyor belt 3 that has been held up by the horizontal pull bar 8 and formed a figure-eight shape, the PTFE base film 32 is still firmly clamped by the clamp 31. The figure-eight symmetrical conveyor belt 3 can then stretch and widen the preheated PTFE base film 32 laterally to a certain width. After that, it continues to be conveyed to the right and enters the heat setting box 12 for heating and setting to prevent shrinkage and deformation later. After cooling down, it is then wound onto the take-up roller 41 (the overall process flow is existing technology).

[0030] Because the top pressure surface 83 of the horizontal pull bar 8 is subjected to sliding friction with the conveyor belt 3 for a long time, when the top pressure surface 83 of a certain horizontal pull bar 8 becomes worn, stop the relevant equipment, then hold the handle 73 on the horizontal pull bar 8 with your fingers and rotate it counterclockwise, which will drive the locking screw 72 to rotate counterclockwise and exit the locking screw groove 82. Stop rotating the handle 73, and the currently worn horizontal pull bar 8 can be removed. Then, install the new horizontal pull bar 8 into the matching position, and rotate the handle 73 clockwise, which will drive the locking screw 72 to rotate clockwise into the locking screw groove 82 for thread locking. This allows the horizontal pull bar 8 with worn top pressure surface 83 to be easily removed and replaced with a new one, improving the replaceability of the horizontal pull bar 8 on the horizontal pull device for PTFE polytetrafluoroethylene film production.

[0031] In addition, when the horizontal pull strip 8 is installed onto the mounting block 7, the fixed insertion post 81 will also be inserted into the fixed slot 71, preventing the horizontal pull strip 8 from rotating after installation, thus improving the anti-rotation positioning and limiting performance of the horizontal pull strip 8 on the horizontal pull device for PTFE polytetrafluoroethylene film production. The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A polytetrafluoroethylene film stretching machine, comprising a stretching top strip (8), characterized in that: Below the horizontal pull strip (8) is a machine base (1), on which a preheating box (11) and a heat setting box (12) are provided. On the machine base (1) are a feeding rack (2) and a receiving rack (4), on which a base frame (5) is provided. On the feeding rack (2) are a feeding roller (21), on which a receiving rack (41) and a motor (42) are provided. On the feeding roller (21) are a conveyor belt (3), on which a clamp (31) is provided. On which a PTFE base film (32) is clamped, a connecting frame (51) is provided on the base frame (5), a synchronous cylinder (6) is installed on the connecting frame (51), a cylinder rod (61) is provided on the synchronous cylinder (6), and an mounting block (7) is provided on the cylinder rod (61). The mounting block (7) is provided with a locking screw (72), and the horizontal pull strip (8) is provided with a fixed insertion post (81) and a top pressure surface (83). The horizontal pull bar (8) has a locking groove (82), the mounting block (7) has a fixed slot (71), and the locking screw (72) has a handle (73).

2. The polytetrafluoroethylene film stretching machine according to claim 1, characterized in that: The feeding roller (21) is rotatably mounted on the feeding frame (2), the receiving roller (41) is rotatably mounted on the receiving frame (4), and the motor shaft of the motor (42) passes through the receiving frame (4) and is fixedly mounted with the receiving roller (41).

3. The polytetrafluoroethylene film stretching machine according to claim 1, characterized in that: The conveyor belt (3) passes laterally through the preheating box (11) and the heat setting box (12). There are two symmetrical conveyor belts (3) and they are respectively fitted on the feeding roller (21) and the receiving roller (41). There are two sets of clamps (31), each set consisting of five arranged laterally.

4. The polytetrafluoroethylene film stretching machine according to claim 1, characterized in that: The synchronous cylinders (6) are in two sets that are symmetrical from top to bottom, and each set consists of two cylinders that are symmetrical from left to right.

5. A polytetrafluoroethylene film stretching machine according to claim 1, characterized in that: The mounting block (7) is an L-shaped structure, and the locking screw (72) passes through the mounting block (7) and is threadedly connected to the locking screw groove (82).

6. A polytetrafluoroethylene film stretching machine according to claim 1, characterized in that: The top pressing surface (83) is located on the outer wall of the horizontal top bar (8), and the fixed insertion post (81) is located on the inner wall of the horizontal top bar (8) and is inserted into the fixed slot (71).

7. A polytetrafluoroethylene film stretching machine according to claim 1, characterized in that: The handle (73) is located at the outer end of the locking screw (72), and the handle (73) is generally diamond-shaped.

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