PP stationery sealing film injection mold

Abstract

The invention relates to the technical field of injection molding, in particular to a PP stationery sealing film injection mold which comprises a fixed mold body and further comprises a mold cavity, a movable mold body, a mold core, a pressing plate, a pressure applying assembly, an air pressure film, a locking assembly and a flow guide pipe, the movable mold body is connected to the upper side of the fixed mold body, and the opposite ends of the fixed mold body and the movable mold body are provided with a cavity and a cavity opening correspondingly; the mold cavity and the mold core are connected to the cavity and the cavity opening correspondingly, the pressing plate is connected between the fixed mold and the movable mold, the pressure applying assembly is connected to the right side of the pressing plate, the air pressure film is connected to the lower side of the pressure applying assembly, the middle of the pressure applying assembly and the air pressure film jointly form a sealing cavity, and the locking assembly is connected to the upper side of the air pressure film. The expansion rate of the air pressure film and the extension rate of the film are set according to the same ratio, and the heating duration of the film is in direct proportion to the vertical distance of the mold, so that the extension rate of the middle part of the film is effectively improved, and the purpose of ensuring the appearance quality of a product is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of injection molding, and particularly to an injection mold for PP stationery sealing film. Background Art

[0002] PP is the abbreviation of polypropylene material, which has the advantages of light weight, heat resistance, chemical corrosion resistance and non-toxicity. Therefore, PP material has been widely used in the stationery field. In order to improve the aesthetics of the surface of PP stationery, manufacturers will decorate the surface of the stationery when producing PP stationery. The sealing film injection mold is a mold that combines vacuum sealing film technology and injection molding process, and is mainly used for producing plastic products with complex surface decoration, and is well applicable to the production of PP stationery.

[0003] The production process of the sealing film injection mold is as follows: First, cover the film on the cavity of the mold, compact the film through the pressing plate, then evacuate the air in the cavity, and the air pressure forces the film to deform and adhere to the inner wall of the cavity. At this time, combine the core and the cavity and perform injection molding. The film covers the surface of the injection-molded product, thereby effectively reducing the subsequent decoration processes. However, when the film is covered, it realizes negative pressure adsorption and adhesion by extracting the air in the cavity. During the production process, when the film adheres to the surface of the cavity, wrinkles are likely to appear, which will affect the appearance quality of the product. In order to reduce the appearance of wrinkles, some enterprises will reduce the air extraction speed, so that the film adheres slowly to reduce the generation of wrinkles. However, slow air extraction will affect the production speed of the product.

[0004] In view of the above problems, some solutions have been proposed in the prior art. For example, an IMD decorative panel mold with the publication number of CN109228159B inflates the film pressing device to make the film pressing device expand the film, and through the inflation and expansion of the film pressing device, the film is flattened on the cavity. However, since the surface of some stationery boxes is arc-shaped, the horizontal distance between the inner wall of the cavity and the film increases continuously as it moves towards the center, resulting in a higher temperature at the edge of the film and a lower temperature at the center of the film. The film is unevenly heated, resulting in different film ductility. When the film pressing device expands and squeezes the film, some areas of the film are prone to be overstretched, resulting in a decrease in aesthetics and affecting the appearance quality of the product.

[0005] Therefore, an injection mold for PP stationery sealing film is proposed. Summary of the Invention

[0006] The object of the present invention is to provide a PP stationery film injection mold, which solves the problem that when the film is attached to the surface of the arc-shaped mold, the uneven spacing between the arc-shaped surface of the mold and the vertical film causes uneven heating of the film, which in turn affects the elongation rate of the film and results in poor appearance quality of the product. By attaching the pneumatic film to the film, the relative movement between the pneumatic film and the film is eliminated, and then the elongation rate of the film is controlled by the expansion rate of the pneumatic film, achieving the purpose of ensuring uniform expansion of the pneumatic film. At the same time, the expansion of the pneumatic film gradually expands from both sides to the middle. When expanding the film, the pneumatic film first makes the film on both sides fit the mold, and then pushes the middle part of the film closer to the mold, effectively increasing the heating time of the middle part of the film, making the heating time of the film proportional to the vertical distance of the mold, and then effectively increasing the elongation rate of the film, achieving the purpose of ensuring the appearance quality of the product.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A PP stationery film injection mold includes a fixed mold, and also includes a cavity, a movable mold, a core, a pressing plate, a pressing component, a pneumatic film, a locking component and a diversion pipe. The movable mold is connected to the upper side of the fixed mold. The opposite ends of the fixed mold and the movable mold are respectively provided with a chamber and an orifice. The cavity and the core are respectively connected to the chamber and the orifice. The pressing plate is connected between the fixed mold and the movable mold. The pressing component is connected to the right side of the pressing plate. The pneumatic film is connected to the lower side of the pressing component. A sealing cavity is jointly formed between the middle part of the pressing component and the pneumatic film. The locking component is connected to the upper side of the pneumatic film. The two ends of the diversion pipe are respectively connected to the chamber and the sealing cavity. When the movable mold moves upward, the pressing component drives the pneumatic film to move above the cavity and pushes the pneumatic film to gradually fit the cavity from both sides to the center. After the fitting is completed, the locking component separates the pneumatic film from the cavity from both sides.

[0009] Through the above solution, the pneumatic film is attached to the film, so that the elongation amount of the film is controlled by the deformable amount of the pneumatic film. By adjusting the deformable amount of the pneumatic film, the pneumatic film fits the cavity after deforming to the limit, and then the purpose of uniformly unfolding and attaching the film to the cavity is achieved.

[0010] Preferably, a notch matching the shape of the pressing plate is provided on the lower side of the movable mold. A sliding rod is connected to the left side of the movable mold, and the sliding rod is slidably connected to the pressing plate. A clamping rod is connected to the lower side of the sliding rod, and the diameter value of the clamping rod is greater than the diameter value of the sliding rod.

[0011] Through the above solution, during the movement of the movable mold, the clamping rod will be driven by the sliding rod to contact the pressing plate. The diameter value of the clamping rod is greater than the diameter value of the sliding rod. When the clamping rod contacts the pressing plate, it can drive the pressing plate to move, separating the pressing plate from the fixed mold, which is convenient for feeding the film.

[0012] Preferably, inverted holes are opened at the four corners of the chamber. A push spring is connected in the inverted hole, and the other end of the push spring is connected to the bottom of the cavity. An extraction pipe is connected to the middle of the chamber. The extraction pipe is in an "L" shape, and the top end of the extraction pipe extends to the bottom wall of the inner cavity of the cavity.

[0013] By providing the extraction pipe and connecting the extraction pipe to the inner cavity of the cavity, when the air pressure film presses the film to fit the cavity, the inner cavity of the cavity can be evacuated.

[0014] Preferably, the pressing component includes a guide frame, a sliding box, a hinge frame and an air pipe. The guide frame is connected to the right end of the pressing plate. The sliding box is slidably connected to the middle of the guide frame. Sliding grooves are opened on the left and right sides of the pressing plate, and the sliding grooves are adaptively clamped with the sliding box. One end of the hinge frame is connected to the right end of the sliding box, and the other end of the hinge frame is connected to the right side of the moving mold. The hinge frame is in a "C" shape, and the air pipe is connected to the lower side of the sliding box.

[0015] Through the above solution, the hinge frame is in a "C" shape. When the fixed mold and the moving mold are fitted, the hinge frame can avoid the sliding box.

[0016] Preferably, the air pressure film includes clamping plates, an extrusion film, a high-elastic film and a tension spring. The two clamping plates are respectively slidably connected to the front and rear sides of the lower side of the sliding box. The opposite ends of the two clamping plates extend out of the sliding box. The extrusion film is connected to the middle of the opposite ends of the two clamping plates. The high-elastic film is connected to both sides of the extrusion film. The tension spring is connected to the clamping plate. The thickness value of the extrusion film gradually increases from both sides to the middle.

[0017] Through the above solution, when the extrusion film expands, the thinner position expands first. The thickness value of the extrusion film gradually increases from both sides to the middle, so that the extrusion film gradually expands from both sides to the middle, effectively prolonging the heating time of the middle part of the film.

[0018] Preferably, the locking component includes a fixed rod, a movable rod, a slider, a pulling rope, a clamping frame and a limiting member. The fixed rod is connected to the top of the inner cavity of the sliding box, and the fixed rod is coaxially arranged with the vertical section of the extraction pipe. The movable rod is sleeved outside the fixed rod, and the lower end of the movable rod is connected to the extrusion film. The slider is connected to the front and rear sides of the movable rod. One end of the pulling rope is connected to the slider. The clamping frame is connected to the top of the inner cavity of the sliding box. The pulling rope passes through the clamping frame. The limiting member is connected to the other end of the pulling rope.

[0019] Through the above solution, the fixed rod is coaxially arranged with the vertical section of the extraction pipe, so that the movable rod is on the axis of the extraction pipe, which is convenient for the air pressure film to press the film at the extraction pipe.

[0020] Preferably, a card slot is formed in the middle of the card board. The limiting member includes a clamping block and a reed. The clamping block is slidably connected in the card slot. One end of the reed is connected to the tops of the left and right sides of the card slot, and the other end of the reed is in contact with the top of the clamping block. A limiting groove is formed in the bottom of the sliding box, and the clamping block is adaptively clamped with the limiting groove.

[0021] Through the above solution, the clamping block is adaptively clamped with the limiting groove. Thus, when the clamping block moves into the limiting groove, the card board can be limited.

[0022] Preferably, the outer diameter value of the movable rod is equal to the inner diameter value of the vertical section of the extraction pipe. When the pressing plate is attached to the fixed mold, the lower surface of the extrusion film is in the same plane as the upper surface of the fixed mold.

[0023] Through the above solution, the outer diameter value of the movable rod is equal to the inner diameter value of the vertical section of the extraction pipe. Thus, when the air pressure film expands, by pulling the extrusion film through the movable rod, it can be avoided that the extrusion film presses on the extraction pipe, effectively ensuring the flatness of the film.

[0024] Preferably, a thimble is connected to the top of the cavity opening. In the initial state, the bottom surface of the thimble is flush with the bottom surface of the core. The lower end surface of the pressing plate has magnetism.

[0025] Through the above solution, after the core moves, a height difference will be formed with the thimble, enabling the molten plastic to flow to the thimble. When the core is reset, the plastic at the thimble can quickly push the product away from the core to achieve demolding.

[0026] Preferably, the core is slidably connected in the cavity, the mold cavity is slidably connected in the cavity chamber, and the height value of the cavity chamber is greater than the height value of the mold cavity.

[0027] Through the above solution, the mold release agent is filled between the mold cavity and the cavity chamber, and the height value of the cavity chamber is greater than the height value of the mold cavity. When the core pushes the mold cavity to move deep into the cavity chamber for injection molding, both ends of the mold cavity move to the positions where the mold release agent is smeared on the surface of the cavity chamber, thus facilitating the demolding of the product.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. The present invention solves the problem that when the film is fitted to the surface of the arc-shaped mold, the uneven spacing between the arc-shaped surface of the mold and the vertical film causes uneven heating of the film, which in turn affects the elongation rate of the film and leads to poor product appearance quality. By setting an air pressure film, the thickness of the air pressure film gradually increases from both sides to the middle, and then when the pressure-applying component squeezes the air pressure film during air injection, the air pressure film gradually expands from both sides to the middle, and then the film gradually stretches from both sides to the middle and fits on the cavity, and in the process of fitting the two sides of the film, the middle part of the film gradually approaches the cavity, which effectively prolongs the heating time of the middle part of the film and ensures the elongation rate of the middle part of the film, thereby achieving the purpose of ensuring the appearance quality of the product.

[0030] 2. By setting a locking component, when the movable rod moves to the specified position, it drives the slider to pull the pull rope to move, and the pull rope drives the card block to move, so that the card block is separated from the limit groove to release the lock of the card plate, and the expanded extrusion film pulls the card plates on both sides to move toward the middle of the cavity. The two ends of the extrusion film are connected to the card plate, and then when the card plate moves, the two ends of the extrusion film can be driven to gradually separate from the film, thereby achieving the purpose of ensuring the fit between the film and the cavity, and effectively ensuring the appearance quality of the product.

[0031] 3. By setting the cavity, during injection molding, the core pushes the cavity to squeeze the cavity, so that the release agent that absorbs the heat of the cavity flows to the inner cavity of the slide box and contacts the air pressure film, thereby preheating the air pressure film. On the one hand, the extension effect of the air pressure film is improved, and on the other hand, the air pressure film heats the film. After the injection molding is completed, the push spring pushes the cavity to reset, so that negative pressure is generated in the cavity to draw back the release liquid, thereby filling the cavity with the release liquid. During injection molding, the sides of the cavity constitute the two ends of the cavity, and then the two ends of the product are formed on the side of the cavity. The filling of the release agent facilitates the demolding of the product, thereby achieving the purpose of ensuring the production quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2 It is a structural schematic diagram of the movable mold part of the present invention;

[0034] Figure 3 It is a schematic diagram of the structure of the movable mold after being turned over and unfolded in the present invention;

[0035] Figure 4 It is a structural schematic diagram of the pressure-applying component part of the present invention;

[0036] Figure 5 It is a schematic structural diagram of the air pressure membrane part of the present invention;

[0037] Figure 6 It is a structural schematic diagram of the locking component part of the present invention;

[0038] Figure 7 The structural schematic diagram of the extrusion film expansion of the present invention;

[0039] Figure 8 The state schematic diagram during injection of the present invention.

[0040] In the figure: 1, fixed mold; 101, chamber; 102, inverted hole; 103, push spring; 104, extraction tube; 2, cavity; 3, moving mold; 301, cavity opening; 302, notch; 303, slide bar; 304, clamping bar; 305, ejector pin; 4, core; 5, pressing plate; 501, chute; 6, pressure application assembly; 601, guide frame; 602, sliding box; 6021, limiting groove; 603, hinge frame; 604, air pipe; 7, pneumatic film; 701, clamping plate; 7011, clamping groove; 702, extrusion film; 703, high-elastic film; 704, tension spring; 8, locking assembly; 801, fixed rod; 802, movable rod; 803, slider; 804, pull rope; 805, clamping frame; 806, limiting member; 8061, clamping block; 8062, reed; 9, diversion pipe; 10, sealing cavity. Specific embodiments

[0041] Next, in combination with the drawings of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described, making its working state and structural characteristics more detailed. Obviously, the described embodiments are only partial embodiments of the present invention, not complete embodiments. Based on the embodiments of the present invention, other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] Please refer to Figures 1 to 8 , the present invention provides a PP stationery sealing film injection mold, and the technical solution is as follows:

[0043] Specifically, please refer to Figures 1 to 8, a PP stationery sealing film injection mold, which is applied to an injection molding machine. The sealing film injection mold includes a fixed mold 1, and also includes a cavity 2, a moving mold 3, a core 4, a pressing plate 5, a pressing assembly 6, a pneumatic film 7, a locking assembly 8 and a diversion tube 9. A chamber 101 is opened in the middle of the top of the fixed mold 1, and the cavity 2 is connected in the chamber 101. A guide post for guiding the installation of the moving mold 3 is connected to the upper side of the fixed mold 1. The moving mold 3 is connected to the upper side of the fixed mold 1. A cavity opening 301 is opened on the lower side of the moving mold 3, and the core 4 is connected in the cavity opening 301. Injection holes are opened on the surface of the core 4. The fixed mold 1 is connected to the fixed end of the injection molding machine, and the moving mold 3 is connected to the movable end of the injection molding machine. The injection nozzle of the injection molding machine passes through the moving mold 3 and is connected to the injection holes on the surface of the core 4. When the cavity 2 and the core 4 are combined, both sides of the cavity 2 are open ends. The cavity 2, the core 4 and the side walls of the chamber 101 form a molding chamber for producing products. The pressing plate 5 is connected between the fixed mold 1 and the moving mold 3. The pressing assembly 6 is connected to the right side of the pressing plate 5. The pneumatic film 7 is connected to the lower side of the pressing assembly 6. A sealing chamber 10 is jointly constructed by the middle part of the pressing assembly 6 and the pneumatic film 7. The locking assembly 8 is connected to the upper side of the pneumatic film 7. One end of the diversion tube 9 is connected to the chamber 101, and the other end of the diversion tube 9 extends into the sealing chamber 10. When the moving mold 3 moves upward, the pressing assembly 6 drives the pneumatic film 7 to move above the cavity 2, and pushes the pneumatic film 7 to gradually fit the cavity 2 from both sides to the center. After the fitting is completed, the locking assembly 8 separates the pneumatic film 7 from the cavity 2 from both sides.

[0044] By setting the pneumatic film 7, the pneumatic film 7 is attached to the film, and the relative fixation between the two is achieved through the frictional force between the two. When the pneumatic film 7 expands, it will drive the film to extend. Furthermore, the extension amount of the film is controlled by the deformable amount of the pneumatic film 7. By controlling the deformable amount of the pneumatic film 7, the uniform extension of the film is effectively ensured. At the same time, when the pressing assembly 6 drives the pneumatic film 7 to expand, the expansion of the pneumatic film 7 gradually expands from the front and rear sides to the central part. The film at both sides is close to the cavity 2 and is heated faster. The film at the center gradually approaches the cavity 2, realizing the heating of the middle part of the film and ensuring the uniform extension of the film.

[0045] As an implementation manner of the present invention, refer to Figure 2 , Figure 3 , Figure 7 and Figure 8, the lower end face of the pressing plate 5 has magnetism. A notch 302 that fits the shape of the pressing plate 5 is provided on the lower side of the moving die 3. The pressing plate 5 can be clamped with the moving die 3 through the notch 302. A sliding rod 303 is connected to the left side of the moving die 3. The sliding rod 303 faces the fixed die 1 and is slidably connected to the pressing plate 5. A clamping rod 304 is connected to the lower side of the sliding rod 303. The diameter value of the clamping rod 304 is greater than the diameter value of the sliding rod 303. When the moving die 3 moves, the sliding rod 303 will drive the clamping rod 304 to contact the pressing plate 5. Since the diameter value of the clamping rod 304 is greater than the diameter value of the pressing plate 5, when the moving die 3 moves further, the pressing plate 5 can be driven to move through the sliding rod 303 and the clamping rod 304, so that the pressing plate 5 is separated from the fixed die 1, which facilitates the feeding of the film. After the feeding is completed, the moving die 3 resets, and the sliding rod 303 and the clamping rod 304 drive the pressing plate 5 to reset. The magnetic force on the lower end face of the pressing plate 5 adsorbs and fits with the fixed die 1 to fix the film. Chamfered holes 102 are provided at the four corners of the chamber 101. A push spring 103 is connected in the chamfered holes 102. The height value after the push spring 103 contracts can be less than the height value of the chamfered holes 102. The other end of the push spring 103 is connected to the bottom of the cavity 2. When the cavity 2 is not stressed, the push spring 103 can push the cavity 2 up to a specified position. A suction pipe 104 is connected to the middle of the chamber 101. The suction pipe 104 is in an "L" shape. The top end of the suction pipe 104 extends to the bottom wall of the inner cavity of the cavity 2. The suction pipe 104 is divided into a vertical section and a horizontal section. The vertical section of the suction pipe 104 is connected to the inner cavity of the cavity 2. One end of the suction pipe 104 away from the cavity 2 is externally connected to an air pump. Through the air pump, the inner cavity of the cavity 2 can be evacuated. The air extraction of the air pump will gradually evacuate as the air pressure film 7 presses the film.

[0046] By providing the notch 302, when the moving die 3 fits with the fixed die 1, the pressing plate 5 fits in the notch 302. When the moving die 3 moves away from the fixed die 1, the sliding rod 303 can drive the pressing plate 5 to move away from the fixed die 1 through the clamping rod 304, which facilitates the feeding of the film. After the feeding is completed, the moving die 3 approaches the fixed die 1, so that the pressing plate 5 approaches the fixed die 1. The lower side of the pressing plate 5 has magnetism. During the process of the pressing plate 5 approaching the fixed die 1, the magnetism of the pressing plate 5 will make the pressing plate 5 fit on the fixed die 1, thus realizing the fixation of the film.

[0047] As an implementation mode of the present invention, refer to Figure 4 , Figure 5 , Figure 7 and Figure 8, the pressing component 6 includes a guide frame 601, a sliding box 602, a hinge frame 603 and an air pipe 604. The guide frame 601 is fixedly connected to the right end of the pressing plate 5. The sliding box 602 is slidably connected to the middle of the guide frame 601. Chute 501 is provided on both the left and right sides of the pressing plate 5. The sliding box 602 can slide through the guide frame 601 in the chute 501. One end of the hinge frame 603 is connected to the right end of the sliding box 602, and the other end of the hinge frame 603 is connected to the right side of the moving mold 3. When the moving mold 3 moves, it can drive the sliding box 602 to move through the hinge frame 603. That is, when the moving mold 3 moves away from the fixed mold 1, the hinge frame 603 drives the sliding box 602 to move to the upper side of the cavity 2. When the moving mold 3 approaches the fixed mold 1, the hinge frame 603 drives the sliding box 602 to move away from the upper side of the cavity 2. The hinge frame 603 is in a "C" shape. Thus, when the moving mold 3 is in contact with the fixed mold 1, the hinge frame 603 can avoid the side wall of the sliding box 602. The air pipe 604 is connected to the lower side of the sliding box 602, and the air pipe 604 is connected to the sealing cavity 10. Through the air pipe 604, the sealing cavity 10 can be inflated, so that the air pressure film 7 expands and presses the film. The air pressure film 7 includes a clamping plate 701, a pressing film 702, a high-elastic film 703 and a tension spring 704. The two clamping plates 701 are respectively slidably connected to the front and rear sides of the lower side of the sliding box 602. The opposite ends of the two clamping plates 701 extend out of the sliding box 602. A rectangular groove for the clamping plate 701 to slide is provided on the sliding box 602. The pressing film 702 is connected to the middle of the opposite ends of the two clamping plates 701. The high-elastic film 703 is connected to both sides of the pressing film 702. The sliding box 602, the clamping plate 701, the pressing film 702 and the high-elastic film 703 form the sealing cavity 10. When inflating, the pressing film 702 fits on the arc surface of the inner wall of the cavity 2, and the high-elastic film 703 fits on the left and right sides of the inner wall of the cavity 2. The tension spring 704 is connected to the clamping plate 701. The thickness value of the pressing film 702 gradually increases from both sides to the middle. When heating the pressing film 702, the thinner two sides of the pressing film 702 are heated faster, thereby further improving the heating efficiency of both sides of the film.

[0048] By setting the pressing component 6, the hinge frame 603 can adjust the position of the sliding box 602 according to the position of the moving mold 3. Thus, when the moving mold 3 is in contact with the fixed mold 1, the sliding box 602 moves away from the cavity 2, which is convenient for the cavity 2 to be fitted and installed with the core 4. When the moving mold 3 moves away from the fixed mold 1, the hinge frame 603 can drive the sliding box 602 to move to the cavity 2. At this time, the sealing cavity 10 can be inflated through the air pipe 604, so that the air pressure film 7 expands. The two ends of the clamping plate 701 are limited by the locking component 8 and cannot move. Thus, the pressing film 702 expands and presses the film, so that the film fits on the cavity 2. At the same time, the high-elastic film 703 forms the two end faces on both sides after the pressing film 702 expands, effectively ensuring the tightness of the sealing cavity 10.

[0049] As an implementation manner of the present invention, refer to Figure 6 , Figure 7 and Figure 8, the locking assembly 8 includes a fixed rod 801, a movable rod 802, a slider 803, a pulling rope 804, a clamping frame 805 and a limiting member 806. The fixed rod 801 is fixedly connected to the top inside the sliding box 602, and the fixed rod 801 is coaxially arranged with the vertical section of the extraction pipe 104. The movable rod 802 is sleeved outside the fixed rod 801 and can slide on the surface of the fixed rod 801. The lower end of the movable rod 802 is connected to the extrusion film 702. When the extrusion film 702 expands, it will drive the movable rod 802 to move. The slider 803 is slidably connected to the front and rear sides of the movable rod 802. One end of the pulling rope 804 is connected to the slider 803. The clamping frame 805 is connected to the top inside the sliding box 602. The pulling rope 804 passes through the clamping frame 805. The limiting member 806 is connected to the other end of the pulling rope 804. The length of the pulling rope 804 is fixed. When the extrusion film 702 expands, the extrusion film 702 will drive the movable rod 802 to move. When the movable rod 802 moves, the slider 803 slides on the surface of the movable rod 802. As the movable rod 802 moves, when the slider 803 moves to the extreme position on the movable rod 802, at this time, the movement of the movable rod 802 will cause the slider 803 to move. The slider 803 pulls the limiting member 806 through the pulling rope 804. A clamping groove 7011 is opened in the middle of the clamping plate 701. The limiting member 806 includes a clamping block 8061 and a reed 8062. The clamping block 8061 is slidably connected in the clamping groove 7011. The pulling rope 804 is connected to the clamping block 8061. When the pulling rope 804 moves, it can drive the clamping block 8061 to move. One end of the reed 8062 is connected to the top on the left and right sides of the clamping groove 7011. The other end of the reed 8062 is in contact with the top of the clamping block 8061. The reed 8062 is inclined. When the clamping block 8061 moves upward, the clamping block 8061 will squeeze the reed 8062 to bend. When the clamping block 8061 loses the pulling force from the pulling rope 804, the reed 8062 will push the clamping block 8061 to reset. A limiting groove 6021 is opened at the bottom of the sliding box 602. The clamping block 8061 is adapted to be clamped with the limiting groove 6021. When the clamping block 8061 is clamped with the limiting groove 6021, the clamping block 8061 will limit the clamping plate 701. The outer diameter value of the movable rod 802 is equal to the inner diameter value of the vertical section of the extraction pipe 104. Furthermore, through the movable rod 802, the pressure value of the extrusion film 702 at the air hole of the film can be reduced, thereby ensuring the flatness of the film. When the pressing plate 5 is attached to the fixed mold 1, the lower surface of the extrusion film 702 and the upper surface of the fixed mold 1 are in the same plane. The ejector pin 305 is connected to the top of the cavity opening 301. In the initial state, the bottom surface of the ejector pin 305 is flush with the bottom surface of the core 4. When the core 4 moves, the ejector pin 305 is separated from the surface of the core 4. The core 4 is slidably connected in the cavity opening 301. The cavity 2 is slidably connected in the cavity 101. The height value of the cavity 101 is greater than the height value of the cavity 2. Furthermore, when the core 4 pushes the cavity 2 to move deep into the cavity 101, the side surface of the cavity 101 can cover both sides of the cavity 2. By applying the release agent to the cavity 101, it is convenient for product demolding.

[0050] By setting the locking component 8, the reed 8062 pushes the latch 8061 to be clamped in the limiting groove 6021, thereby realizing the position of the clamping plate 701. At this time, the sealing cavity 10 is inflated, and the extrusion film 702 will deform. The deformation of the extrusion film 702 will pull the movable rod 802 to move. After the movable rod 802 moves to the specified position, it will pull the pull rope 804 through the slider 803, thereby causing the latch 8061 to move. When the latch 8061 moves, it will separate from the limiting groove 6021, thereby enabling the clamping plate 701 to move. At this time, the inflated extrusion film 702 will generate a pulling force on the clamping plate 701, causing the clamping plate 701 to move from both sides to the middle. The movement of the clamping plate 701 will pull the extrusion film 702, causing the extrusion film 702 to separate from the film from both sides to the middle. After the extrusion film 702 separates from the film for a certain distance, the air pipe 604 starts to exhaust. At this time, the tension spring 704 will drive the clamping plate 701 to reset. The reset clamping plate 701 will drive the extrusion film 702 to be straightened, thereby causing the extrusion film 702 to separate from the film forming an arc surface.

[0051] In this solution, by setting the pneumatic film 7, the pneumatic film 7 gradually squeezes the film from both sides to the center, giving sufficient heating time to the middle part of the film to ensure the stretching effect of the film. At the same time, by setting the diversion pipe 9 to connect the chamber 101 with the sealing cavity 10, during injection molding, the demolding liquid in the chamber 101 is diverted into the sealing cavity 10, so that the demolding liquid contacts the pneumatic film 7 to preheat the pneumatic film 7. After the injection molding is completed, the demolding liquid flows back into the chamber 101, absorbs the heat of the mold cavity 2, accelerates the cooling of the product, and improves the production efficiency:

[0052] Specifically, during injection molding preparation, the heated demolding liquid is injected into the chamber 101, and the injection molding machine is started. The movable end drives the moving mold 3 to move upward (the moving direction refers to Figure 1 ), the moving mold 3 drives one end of the hinge frame 603 to move upward, and the other end of the hinge frame 603 drives the sliding box 602 to slide horizontally along the guide frame 601 to the upper side of the mold cavity 2. At the same time, when the moving mold 3 moves upward, it will drive the pressing plate 5 to move upward through the sliding rod 303 and the clamping rod 304, so that the pressing plate 5 is separated from the fixed mold 1;

[0053] Before starting injection molding, pass the film through between the fixed mold 1 and the pressing plate 5, and move the patterned area on the film to the cavity 2. The moving end drives the moving mold 3 to move down a certain distance, so that the pressing plate 5 fits on the fixed mold 1 to complete the fixation of the film. At this time, the extrusion film 702 fits with the film and is located on the side of the film away from the cavity 2. Inject air into the sliding box 602 through the air pipe 604. As the gas is injected, the pressure of the gas acts on the air pressure film 7, and the extrusion film 702 begins to expand. Since the two sides of the extrusion film 702 are thinner and the middle is thicker, the expansion of the extrusion film 702 gradually proceeds from the two sides to the middle. The expansion of the extrusion film 702 will make the film fit with the cavity 2, and then the film gradually fits with the cavity 2 from the two sides to the middle. During the process of the film fitting from the two sides to the middle, the middle part of the film continuously approaches the cavity 2, realizing the heating of the middle part of the film, effectively improving the ductility of the middle area of the film. At the same time, as the extrusion film 702 is extruded, the extraction pipe 104 will extract the gas between the film and the cavity 2, so that after the extrusion film 702 is separated from the film, the film can be kept in contact with the cavity 2. When the extrusion film 702 expands, it will drive the movable rod 802 to move down. When the movable rod 802 starts to move, the slider 803 slides on the surface of the movable rod 802. When the extrusion film 702 expands to the middle and is close to fitting with the cavity 2, the slider 803 slides to the end point on the surface of the movable rod 802. At this time, the movable rod 802 will drive the slider 803 to move down, and the slider 803 drives the clamping block 8061 to move up through the pull rope 804 and separate from the limit groove 6021. At this time, the clamping plate 701 can move, and then the expanding extrusion film 702 pulls the clamping plate 701 to move towards the middle of the cavity 2. The two ends of the extrusion film 702 are connected to the clamping plate 701, so when the clamping plate 701 moves, it can drive the two ends of the extrusion film 702 to gradually separate from the film. Subsequently, air is extracted from the sliding box 602 through the air pipe 604. Furthermore, when the extrusion film 702 contracts and the tension spring 704 drives the clamping plate 701 to move towards both sides, the extrusion film 702 can be quickly separated from the film;

[0054] When injection molding is carried out, the moving mold 3 moves down and approaches the fixed mold 1. The guide frame 601 pushes the sliding box 602 out to avoid the core 4. The hydraulic cylinder on the injection molding machine pushes the core 4 towards the chamber 101 through the injection nozzle. The core 4 fits with the cavity 2 and pushes the cavity 2 to move. The cavity 2 moves and extrudes the demolding liquid in the chamber 101, so that the demolding liquid flows to the sealing chamber 10 through the diversion pipe 9. At this time, the demolding liquid heats the air pressure film 7, which is convenient for the air pressure film 7 to heat the film. As the cavity 2 moves, the open ends on both sides of the cavity 2 move to the area on the side wall of the chamber 101 covered with the demolding liquid. After the cavity 2 moves to the end of the chamber 101, injection molding begins. Since the surface of the cavity 2 is covered with a film, the adhesion is small during injection molding, and the side wall of the chamber 101 is coated with the demolding liquid, and the product is formed on the side wall of the chamber 101;

[0055] After injection molding, the product adheres to the core 4. The movable end of the injection molding machine drives the core 4 to move upward through the moving mold 3 to disengage from the chamber 101. The push spring 103 pushes the cavity 2 to remain in contact with the core 4 until the cavity 2 disengages from the chamber 101. After the core 4 disengages, the hydraulic cylinder drives the injection nozzle to reset, and the ejector pin 305 ejects the product from the core 4. At the same time, when the cavity 2 resets, a negative pressure is generated in the chamber 101, causing the demolding liquid to flow back into the chamber 101 and be heated. The upward movement of the moving mold 3 will drive the hinge bracket 603 to move upward again, and cause the sliding box 602 to slide horizontally along the guide frame 601 to the upper side of the cavity 2. At the same time, when the moving mold 3 moves upward, it will drive the pressing plate 5 to move upward through the sliding rod 303 and the clamping rod 304, causing the pressing plate 5 to separate from the fixed mold 1, and the film is loaded.

[0056] Although the embodiments of the present invention have been described, for those of ordinary skill in the art, under the understanding of the principles and spirit of the present invention, the embodiments can be changed and modified to obtain other effects. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A PP stationery film sealing injection mold, comprising a fixed mold (1), characterized in that: The mold further comprises a mold cavity (2), a movable mold (3), a mold core (4), a pressure plate (5), a pressure assembly (6), a pneumatic film (7), a locking assembly (8) and a guide tube (9); the movable mold (3) is connected to the upper side of the fixed mold (1); the facing ends of the fixed mold (1) and the movable mold (3) are respectively provided with a cavity (101) and a cavity opening (301); the mold cavity (2) and the mold core (4) are respectively connected to the cavity (101) and the cavity opening (301); the pressure plate (5) is connected between the fixed mold (1) and the movable mold (3); the pressure assembly (6) is connected to the right side of the pressure plate (5); the pneumatic film (7) is connected to the lower side of the pressure-applying component (6), the middle part of the pressure-applying component (6) and the air pressure membrane (7) together form a sealed cavity (10), the locking component (8) is connected to the upper side of the air pressure membrane (7), and the two ends of the guide tube (9) are respectively connected to the chamber (101) and the sealed cavity (10), when the movable mold (3) moves upward, the pressure-applying component (6) drives the air pressure membrane (7) to move to the top of the cavity (2), and pushes the air pressure membrane (7) from both sides to the center to gradually fit with the cavity (2), and after the fitting is completed, the locking component (8) separates the air pressure membrane (7) from the cavity (2) from both sides.

2. A PP stationery film sealing injection mold according to claim 1, characterized in that: The lower side of the movable mold (3) is provided with a notch (302) that matches the shape of the pressing plate (5); the left side of the movable mold (3) is connected with a sliding rod (303), and the sliding rod (303) is slidably connected to the pressing plate (5); the lower side of the sliding rod (303) is connected with a clamping rod (304), and the diameter of the clamping rod (304) is greater than the diameter of the sliding rod (303).

3. A PP stationery film sealing injection mold according to claim 2, characterized in that: The four corners of the chamber (101) are provided with inverted holes (102), a push spring (103) is connected to the inverted hole (102), the other end of the push spring (103) is connected to the bottom of the cavity (2), and the middle of the chamber (101) is connected to an extraction tube (104), the extraction tube (104) is in an "L" shape, and the top end of the extraction tube (104) extends to the bottom wall of the inner cavity of the cavity (2).

4. A PP stationery film sealing injection mold according to claim 3, characterized in that: The pressure-applying assembly (6) comprises a guide frame (601), a slide box (602), a hinge frame (603) and an air pipe (604); the guide frame (601) is connected to the right end of the pressure plate (5); the slide box (602) is slidably connected to the middle of the guide frame (601); slide grooves (501) are provided on the left and right sides of the pressure plate (5); the slide grooves (501) are adapted to be snap-fitted with the slide box (602); one end of the hinge frame (603) is connected to the right end of the slide box (602); the other end of the hinge frame (603) is connected to the right side of the movable mold (3); the hinge frame (603) is in a "C" shape; and the air pipe (604) is connected to the lower side of the slide box (602).

5. A PP stationery sealing film injection mold according to claim 3, characterized in that: The air pressure membrane (7) includes a card plate (701), an extrusion membrane (702), a high elastic membrane (703) and a tension spring (704). The two card plates (701) are respectively slidably connected to the front and rear sides of the lower side of the slide box (602). The facing ends of the two card plates (701) extend out of the slide box (602). The extrusion membrane (702) is connected to the middle of the facing ends of the two card plates (701). The high elastic membrane (703) is connected to the two sides of the extrusion membrane (702). The tension spring (704) is connected to the card plate (701). The thickness of the extrusion membrane (702) gradually increases from the two sides to the middle.

6. A PP stationery film sealing injection mold according to claim 5, characterized in that: The locking assembly (8) comprises a fixed rod (801), a movable rod (802), a slider (803), a pull rope (804), a bracket (805) and a limit piece (806); the fixed rod (801) is connected to the top of the inner cavity of the sliding box (602), and the fixed rod (801) is coaxially arranged with the vertical section of the extraction tube (104); the movable rod (802) is sleeved on the outer side of the fixed rod (801), and the lower end of the movable rod (802) is connected to the extrusion membrane (702); the slider (803) is connected to the front and rear sides of the movable rod (802); one end of the pull rope (804) is connected to the slider (803); the bracket (805) is connected to the top of the inner cavity of the sliding box (602); the pull rope (804) passes through the bracket (805); and the limit piece (806) is connected to the other end of the pull rope (804).

7. A PP stationery film sealing injection mold according to claim 6, characterized in that: A card slot (7011) is provided in the middle of the card plate (701), and the limiting member (806) comprises a card block (8061) and a spring (8062), wherein the card block (8061) is slidably connected in the card slot (7011), one end of the spring (8062) is connected to the top of the left and right sides of the card slot (7011), and the other end of the spring (8062) is in contact with the top of the card block (8061), and a limiting slot (6021) is provided at the bottom of the sliding box (602), and the card block (8061) is adapted to be engaged with the limiting slot (6021).

8. A PP stationery film sealing injection mold according to claim 6, characterized in that: The outer diameter of the movable rod (802) is equal to the inner diameter of the vertical section of the extraction tube (104), and when the pressing plate (5) and the fixed mold (1) are in contact, the lower surface of the extrusion film (702) and the upper surface of the fixed mold (1) are in the same plane.

9. A PP stationery film sealing injection mold according to claim 8, characterized in that: The top of the cavity (301) is connected to an ejector pin (305); in an initial state, the bottom surface of the ejector pin (305) is flush with the bottom surface of the core (4); and the lower end surface of the pressing plate (5) is magnetic.

10. A PP stationery film sealing injection mold according to claim 9, characterized in that: The core (4) is slidably connected in the cavity opening (301), and the cavity (2) is slidably connected in the chamber (101), and the height of the chamber (101) is greater than the height of the cavity (2).

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