Device and method for preparing high-barrier co-extruded film

Abstract

The invention relates to the technical field of plastic forming and processing, and discloses a preparation device and method of a high-barrier co-extrusion film. The preparation device of the high-barrier co-extrusion film comprises a vertical frame, a film blowing mechanism, an air cooling mechanism and a film pressing mechanism, the film blowing mechanism, the air cooling mechanism and the film pressing mechanism are sequentially arranged in the height direction of the vertical frame, and the film pressing mechanism comprises a preliminary extrusion body used for preliminarily collecting a cylindrical film and a pressing assembly located above the preliminary extrusion body and used for pressing the collected film into a sheet shape; and the film drawing assembly is used for assisting in guiding the film. The film drawing mechanism designed by the invention not only has the capability of drawing a film, but also can be used as an auxiliary lifting structure to replace manual drawing during film guiding operation, so that cooperative operation of multiple persons is not needed, the operation difficulty of drawing the film for the first time is reduced, and the operation efficiency is improved; besides, when the film drawing mechanism guides the film, a small-amplitude left-right transverse moving and swinging mode is adopted, so that the film is stressed more uniformly when being stretched, and is not easy to break, and the preparation quality of the film is further guaranteed.

Description

Technical Field

[0001] This invention relates to the field of plastic molding and processing technology, and more specifically, to an apparatus and method for preparing a high-barrier co-extruded film. Background Technology

[0002] Blown film is a common process for preparing plastic films, especially in the production of high-barrier multilayer co-extruded films. Traditional blown film equipment usually includes an extruder, blown film die, cooling air ring, herringbone clamp, traction roller and winding device. After the equipment is started or the specifications are changed, the cylindrical film preform blown from the die needs to be pulled to the traction and winding section above. This process is called "film drawing".

[0003] In existing technologies, the film drawing operation usually relies on manual labor. Operators need to use tools or manually pull the film preform upwards from a high place (die head exit), passing it through the herringbone clamp and traction roller in sequence, and finally fixing it on the take-up shaft. Because the film preform has a high initial temperature and low strength, and requires a certain height and distance, this process often requires multiple people to work together, which is laborious, inefficient, and poses safety hazards.

[0004] Therefore, there is an urgent need for a high-barrier co-extrusion film preparation device that can simplify the film-drawing operation and reduce labor intensity. Summary of the Invention

[0005] The purpose of this invention is to provide an apparatus and method for preparing a high-barrier co-extruded film to solve the aforementioned technical problems.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions: The present invention provides an apparatus for preparing a high-barrier co-extruded film, comprising: a stand and a blown film mechanism, an air-cooling mechanism and a pressing film mechanism arranged sequentially along the height direction of the stand; a film winding mechanism is provided at the bottom of the stand; and the blown film mechanism is connected to at least two raw material extrusion mechanisms. The film pressing mechanism includes a preliminary extrusion body for initially gathering the cylindrical film, a pressing assembly located above the preliminary extrusion body for pressing the gathered film into a sheet shape, and a film pulling assembly for assisting in film pulling. The clamping assembly includes a first clamping roller and a second clamping roller arranged side by side in parallel, and a displacement drive for driving the first clamping roller and the second clamping roller to move closer and further apart; The film-pulling assembly includes a film-pulling roller located above the first pressing roller and a lifting drive component that drives the film-pulling roller to move up and down along the upright; the rotating end of the film-pulling roller is provided with a locking component, which is used to lock the rotation of the film-pulling roller during the lifting and lowering process, and to release the lock when the film-pulling roller reaches the preset top position.

[0007] Preferably, the lifting drive comprises two symmetrical vertical rotating lead screws arranged on both sides of the stand and two symmetrical vertical sliding rails mounted on the stand, the bottom end of each lead screw is connected with a servo motor; each sliding rail is slidably provided with a connecting seat, the two ends of the film pulling roller are rotatably connected with the two connecting seats respectively; one side of each connecting seat is slidably connected with a support body, and a spring is arranged between the connecting seat and the support body, and the two lead screws are threadedly connected with the support bodies on the corresponding sides.

[0008] Preferably, the two sides of each connecting seat in sliding contact with the corresponding sliding rail are provided with arc-shaped protrusions; the two track side walls of the sliding rail are provided with a plurality of staggered contact protrusions; the arc-shaped protrusions can sequentially contact the contact protrusions on different track side walls when the connecting seat slides along the sliding rail, so that the connecting seat and the film pulling roller produce periodic lateral swinging.

[0009] Preferably, the locking member comprises an electromagnetic clutch arranged at the rotating end of the film pulling roller and an infrared induction switch for detecting the position of the film pulling roller; When the infrared induction switch detects that the film pulling roller does not reach the preset top position, the electromagnetic clutch is controlled to be powered on to lock the film pulling roller; when the infrared induction switch detects that the film pulling roller reaches the preset top position, the electromagnetic clutch is controlled to be powered off to release the film pulling roller.

[0010] Preferably, the displacement drive comprises a sliding seat slidably arranged on the stand, the first compression roller is rotatably mounted on the sliding seat, and the second compression roller is rotatably mounted on the stand; the two ends of one side of the sliding seat are connected with linear extension sources.

[0011] Preferably, the sliding seat is provided with a positioning groove matched with the bottom end of the support body; when the film pulling roller reaches the preset top position and the first compression roller is in the compression station, the bottom end of the support body falls into the positioning groove.

[0012] Preferably, the number of the raw material extrusion mechanisms is three, and they are arranged at equal intervals around the film blowing mechanism.

[0013] Preferably, the preliminary extrusion body is a herringbone-shaped frame.

[0014] Preferably, the stand is provided with a staircase and a work platform for climbing.

[0015] A preparation method of a high-barrier co-extrusion film, comprising the following steps: S100, feeding molten raw materials to the film blowing mechanism through the raw material extrusion mechanism to form a cylindrical film bubble through the film blowing mechanism; S200, cooling the film bubble through the air cooling mechanism; S300, film leading and initial stretching: driving the first compression roller away from the second compression roller to leave a passage, controlling the locking member to lock the rotation of the film pulling roller, and driving the film pulling roller to descend above the film blowing mechanism; the end of the cooled film bubble is pulled and fixed on the film pulling roller; then the film pulling roller is driven to rise, in the process, the film pulling roller is periodically swung laterally under the driving of the lifting driving member, and the film bubble is stretched upward; S400, pressing and winding: when the film pulling roller rises to the preset top position, the locking member is unlocked to the film pulling roller, the first compression roller is driven to reset close to the second compression roller, the film preliminarily gathered by the preliminary extrusion body is guided to the first compression roller and the second compression roller for pressing to form a sheet-shaped film; the sheet-shaped film after pressing is pulled to the film winding mechanism for winding.

[0016] The present application has the following advantages: The film pulling mechanism designed in the present application not only has the stretching capacity for the film, but also can act as an auxiliary lifting structure to replace manual stretching when leading the film, without the need for multiple people to operate cooperatively, reducing the operation difficulty of initial film pulling and improving the operation efficiency; in addition, the film pulling mechanism adopts small-amplitude left-right horizontal swing when leading the film, so that the film is more uniformly stressed during stretching, and is less likely to break, thereby ensuring the preparation quality of the film. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic view of a high-barrier co-extrusion film preparation device of the present application; Figure 2 is a structural schematic view of a film pressing mechanism in a high-barrier co-extrusion film preparation device of the present application; Figure 3 is a structural schematic view of a local part of a film pressing mechanism in a high-barrier co-extrusion film preparation device of the present application; Figure 4 is a structural schematic view of a local part of a film pulling assembly in a high-barrier co-extrusion film preparation device of the present application; Figure 5 is a structural schematic view of a local part between the connecting seat and the slide rail in a high-barrier co-extrusion film preparation device of the present application.

[0018] In the figure: 10, stand; 20, film blowing mechanism; 30, air cooling mechanism; 40, film pressing mechanism; 401, preliminary extrusion body; 402, first compression roller; 403, second compression roller; 404, film pulling roller; 405, lead screw; 406, slide rail; 4061, contact protrusion; 407, servo motor; 408, connecting seat; 4081, arc-shaped protrusion; 409, support body; 410, spring; 411, electromagnetic clutch; 412, infrared induction switch; 413, slide seat; 4131, positioning groove; 414, linear extension source; 50, film winding mechanism; 60, raw material extrusion mechanism. Detailed Implementation

[0019] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0020] Please refer to the following: Figures 1 to 5 An apparatus for preparing a high-barrier co-extruded film includes: a frame 10, with stairs and a platform for climbing; a blown film mechanism 20 at the bottom of the frame 10, with three equally spaced raw material extrusion mechanisms 60 connected to its outer side, supplying extruded raw materials to the blown film mechanism 20 for blowing out; a cooling system 30 in the middle of the frame 10 for rapidly cooling the blown film; a pressing mechanism 40 at the top of the frame 10 for pressing the cylindrical film into a sheet; and a winding mechanism 50 on one side of the bottom of the frame 10 for winding the extruded film.

[0021] Specifically, the film pressing mechanism 40 includes a preliminary extrusion body 401, a pressing assembly disposed above the preliminary extrusion body 401, and a film stretching assembly. The preliminary extrusion body 401 is a conventional herringbone frame. When a cylindrical film enters the inner side of the herringbone frame, it can compress the cylindrical film, causing it to shrink and converge. The pressing assembly includes a first pressing roller 402, a second pressing roller 403, and a displacement drive. The displacement drive includes a slide block 413 slidably mounted on the support frame 10, and the first pressing roller 402 is horizontally rotatably mounted on the slide block 413. Linear telescopic sources 414 (such as electric push rods) are provided at both ends of one side of the slide block 413. The second pressing roller 403 is horizontally rotatably mounted on the support frame 10, parallel and side-by-side with the first pressing roller 402. The film passing through the herringbone frame enters the gap between the first and second pressing rollers 402, further pressing and tightly adhering the film together to form a sheet-like film. By setting a displacement drive component, the first pressing roller 402 can be driven away from or closer to the second pressing roller 403. On the one hand, the distance between the two can be adjusted to adapt to different pressing requirements; on the other hand, the first pressing roller 402 can be moved away so that the upper film stretching assembly can move down smoothly.

[0022] The film-stretching assembly includes a film-stretching roller 404 located above the first pressing roller 402, a lifting drive for linearly raising and lowering the film-stretching roller 404 along the support frame 10, and a locking component for locking the rotating end of the film-stretching roller 404. The lifting drive includes two servo motors 407, two lead screws 405, and two slide rails 406. The two slide rails 406 are vertically and symmetrically mounted on the support frame 10, and each slide rail 406 is slidably provided with a connecting seat 408. The two ends of the film-stretching roller 404 are rotatably connected to the two connecting seats 408 respectively. Each connecting seat 408 has a support body 409 slidably mounted on one side, and a spring 410 is provided between the support body 409 and the connecting seat 408; the servo motor 407 is fixed to the bottom of the stand 10 through a flange seat, and the lead screw 405 is vertically rotatably mounted on the stand 10. The two lead screws 405 are symmetrically and vertically rotatably located on both sides of the stand 10. The bottom end of each lead screw 405 is connected to the servo motor 407, and the servo motor 407 is fixed to the stand 10 through a flange seat; the two lead screws 405 are respectively threadedly connected to the support body 409 on the corresponding side.

[0023] In addition, arc-shaped protrusions 4081 are provided on both sides of the sliding of the connecting seat 408 and the slide rail 406, and a number of linearly equidistant contact protrusions 4061 are provided on the two track side walls of the slide rail 406. The contact protrusions 4061 are mainly distributed in the middle and lower end of the slide rail 406, and the contact protrusions 4061 on the two track side walls are staggered. During the sliding of the connecting seat 408 along the slide rail 406, when the arc-shaped protrusion 4081 contacts the contact protrusion 4061 on one of the track sidewalls, it can generate a lateral thrust on the connecting seat 408, causing the connecting seat 408 and the film pulling roller 404 to move slightly laterally relative to the support body 409. After the arc-shaped protrusion 4081 separates from the contact protrusion 4061, the connecting seat 408 can be reset by the elastic force of the spring 410. Then, as the connecting slide 413 continues to move, after the arc-shaped protrusion 4081 contacts the contact protrusion 4061 on another track sidewall, it will move laterally in the opposite direction again. In this way, by repeatedly contacting the contact protrusion 4061 with contact protrusions 4061 at different positions and on different track sidewalls, the connecting seat 408 can repeatedly perform small-amplitude lateral swings during the sliding process, so that when the film pulling roller 404 pulls up the film laterally, the force is more even and it is less likely to break.

[0024] The locking mechanism includes an infrared sensor switch 412 and an electromagnetic clutch 411. The electromagnetic clutch 411 is located at the rotating end of the film-pulling roller 404 and is used to lock the rotating end of the film-pulling roller 404, preventing it from rotating. The infrared sensor switch 412 is located at the top of the support frame 10 and is used to sense the position of the film-pulling roller 404. When the infrared sensor switch 412 detects that the film-pulling roller 404 is at the top of the support frame 10, the infrared sensor switch 412 sends a de-energizing signal to the electromagnetic clutch 411, causing the electromagnetic clutch 411 to release the locking effect on the film-pulling roller 404, allowing the film-pulling roller 404 to rotate normally. When the infrared sensor switch 412 detects that the film-pulling roller 404 is not at the preset top position of the support frame 10, the infrared sensor switch 412 sends an energizing signal to the electromagnetic clutch 411, causing the electromagnetic clutch 411 to lock the rotating end of the film-pulling roller 404, preventing it from rotating. This achieves automatic sensing and locking of the film-pulling roller 404.

[0025] In addition, positioning grooves 4131 are provided at both ends of the slide block 413 and the two supports 409 respectively. The positioning grooves 4131 are adapted to the bottom of the supports 409. When the film pulling roller 404 is at the top position of the stand 10, the first pressing roller 402 and the second pressing roller 403 are kept close to each other, so that the positioning grooves 4131 are in contact with the bottom of the supports 409, thereby providing vertical support force to the supports 409 and locking the film pulling roller 404 so that it remains stable when it is at the top position of the stand 10.

[0026] Based on the above scheme, the working process of the high-barrier co-extruded film preparation device of the present invention is as follows: When performing film drawing operations, a film pulling mechanism can be used to assist the operation. At this time, only two workers are needed to operate at the top positions of the blown film mechanism 20 and the stand 10, respectively. First, the displacement drive component drives the first pressing roller 402 to move away from the second pressing roller 403. After the first pressing roller 402 moves to the maximum displacement, the distance between the first pressing roller 402 and the second pressing roller 403 is much larger than that of the film pulling roller 404, and no longer causes spatial obstruction to the film pulling roller 404. Then, the servo motor 407 rotates, which causes the lead screw 405 to drive the connecting seat 408 and the film-pulling roller 404 to gradually move down along the slide rail 406. At the same time, the infrared sensor switch 412 detects that the film-pulling roller 404 is no longer in the preset top position, and then sends an energizing signal to the electromagnetic clutch 411, which locks the rotating end of the film-pulling roller 404 so that it cannot rotate until the film-pulling roller 404 moves down to the top of the blown film mechanism 20. At this time, the operator can manually wrap the pulled film around the film-pulling roller 404 and fix it. Then, under the drive of the servo motor 407, the film-pulling roller 404 can slowly move up with the film. During the upward movement, the film can be stretched smoothly by the small left and right lateral swing of the film-pulling roller 404. After the film-pulling roller 404 moves to the top of the stand 10, it is moved and reset by the displacement drive component, which simultaneously locks the position of the film-pulling roller 404 after the reset. At the same time, after the infrared sensor switch 412 detects that the film-pulling roller 404 has returned to the preset top position, it sends a power-off signal to the electromagnetic clutch 411, so that the electromagnetic clutch 411 releases the locking effect on the rotating end of the film-pulling roller 404. After that, the operator only needs to remove the film from the film-pulling roller 404 and then connect it to the winding mechanism.

[0027] Compared to existing technologies, the film-pulling mechanism designed in this invention not only possesses the ability to stretch the film, but also acts as an auxiliary lifting structure when the film is initially retrieved from the blown film mechanism 20, replacing manual stretching. This eliminates the need for multiple operators, reducing the difficulty of initial film-pulling operations and improving work efficiency. Furthermore, the design of the film-pulling roller 404 with its slight left-right lateral oscillation ensures more uniform stress on the film during stretching, reducing the likelihood of breakage and thus guaranteeing the quality of the prepared film. Simultaneously, the film-pulling mechanism of this invention also features an automatic sensing locking function. When the film-pulling roller 404 rises to the top of the stand 10, the locking state of the film-pulling roller 404 is automatically released, allowing it to rotate normally for convenient subsequent film winding operations. Conversely, when the film-pulling roller 404 is not at the preset top position of the stand 10, it is automatically locked to prevent accidental rotation and ensure operational safety.

[0028] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. An apparatus for preparing a high-barrier co-extruded film, characterized in that, include: The frame includes a blown film mechanism, an air-cooling mechanism, and a film pressing mechanism arranged sequentially along the height of the frame. The bottom of the frame is equipped with a film winding mechanism, and the blown film mechanism is connected to at least two raw material extrusion mechanisms. The film pressing mechanism includes a preliminary extrusion body for initially gathering the cylindrical film, a pressing assembly located above the preliminary extrusion body for pressing the gathered film into a sheet shape, and a film pulling assembly for assisting in film pulling. The clamping assembly includes a first clamping roller and a second clamping roller arranged side by side in parallel, and a displacement drive for driving the first clamping roller and the second clamping roller to move closer and further apart; The film-pulling assembly includes a film-pulling roller located above the first pressing roller and a lifting drive component that drives the film-pulling roller to move up and down along the upright; the rotating end of the film-pulling roller is provided with a locking component, which is used to lock the rotation of the film-pulling roller during the lifting and lowering process, and to release the lock when the film-pulling roller reaches the preset top position.

2. The apparatus for preparing a high-barrier co-extruded film according to claim 1, characterized in that, The lifting drive includes two symmetrically vertically rotating lead screws on both sides of the frame and two symmetrically vertically mounted slide rails on the frame. A servo motor is connected to the bottom end of each lead screw. A connecting seat is slidably provided on each slide rail. The two ends of the film pulling roller are rotatably connected to the two connecting seats respectively. A support body is slidably connected to one side of each connecting seat, and a spring is provided between the connecting seat and the support body. The two lead screws are threadedly connected to the support body on the corresponding side respectively.

3. The apparatus for preparing a high-barrier co-extruded film according to claim 2, characterized in that, Each of the connecting seats has arc-shaped protrusions on both sides that make sliding contact with the corresponding slide rail; the two track sidewalls of the slide rail have several staggered contact protrusions; when the connecting seat slides along the slide rail, the arc-shaped protrusions can sequentially contact the contact protrusions on different track sidewalls, causing the connecting seat and the film pulling roller to oscillate periodically.

4. The apparatus for preparing a high-barrier co-extruded film according to claim 2, characterized in that, The locking device includes an electromagnetic clutch located at the rotating end of the film-pulling roller and an infrared sensor switch for detecting the position of the film-pulling roller. When the infrared sensor detects that the film-pulling roller has not reached the preset top position, it controls the electromagnetic clutch to be energized and lock the film-pulling roller; when it detects that the film-pulling roller has reached the preset top position, it controls the electromagnetic clutch to be de-energized and release the film-pulling roller.

5. The apparatus for preparing a high-barrier co-extruded film according to claim 4, characterized in that, The displacement drive includes a slide block slidably mounted on the upright, a first pressing roller rotatably mounted on the slide block, and a second pressing roller rotatably mounted on the upright; both ends of one side of the slide block are connected to linear telescopic sources.

6. The apparatus for preparing a high-barrier co-extruded film according to claim 5, characterized in that, The slide block is provided with a positioning groove that matches the bottom end of the support body; when the film pulling roller reaches the preset top position and the first pressing roller is in the pressing position, the bottom end of the support body falls into the positioning groove.

7. The apparatus for preparing a high-barrier co-extruded film according to claim 1, characterized in that, The raw material extrusion mechanism consists of three parts, which are arranged at equal intervals around the blown film mechanism.

8. The apparatus for preparing a high-barrier co-extruded film according to claim 1, characterized in that, The initial extrusion body is a herringbone frame.

9. The apparatus for preparing a high-barrier co-extruded film according to claim 1, characterized in that, The support frame is equipped with stairs and a work platform for people to climb.

10. A method for preparing a high-barrier co-extruded film, using the apparatus for preparing a high-barrier co-extruded film as described in any one of claims 1-9, characterized in that, Includes the following steps: S100, molten raw material is fed to the blown film mechanism through the raw material extrusion mechanism, and the blown film mechanism blows the raw material into a cylindrical film bubble; S200 uses an air-cooling mechanism to cool the membrane bubble; S300, Film drawing and initial stretching: Drive the first pressure roller away from the second pressure roller to make way, control the locking element to lock the rotation of the film stretching roller, and drive the film stretching roller down to above the film blowing mechanism; pull and fix the cooled film bubble end to the film stretching roller; then drive the film stretching roller up. During this process, the film stretching roller generates periodic lateral swing under the drive of the lifting drive element, stretching the film bubble upward. S400, Pressing and winding: When the film pulling roller rises to the preset top position, the locking member releases the lock on the film pulling roller, drives the first pressing roller to reset and approach the second pressing roller, guides the film that has been initially gathered by the initial extrusion body to the first pressing roller and the second pressing roller for pressing, forming a sheet film; the pressed sheet film is then pulled to the film winding mechanism for winding.

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