An extrusion-type step-by-step coating machine for plastic film

Abstract

The present invention relates to the coating field, and discloses an extrusion-type step-by-step coating machine for plastic film, including a coating cabin, a film inlet and a film outlet formed on the two side walls of the coating cabin, a plurality of feeding pipes installed in the coating cabin, a coating wall body provided in the coating cabin, a material dividing plate and a coating plate installed at the downstream end of the coating wall body, the coating on the composite film is initially scraped off by the material dividing plate, and is scraped off for a second time by the coating plate, a slide seat is installed in the coating cabin along the transport direction of the composite film, the material dividing plate can move along the direction of the slide seat and approach the coating wall body, so that the coating retained on the surface of the material dividing plate is squeezed onto the surface of the composite film, and the coating plate can move along the direction of the slide seat and approach the material dividing plate, so that the coating retained on the surface of the coating plate is squeezed onto the surface of the composite film. In the present invention, the coating on the composite film is initially scraped off by the material dividing plate, and is scraped off for a second time by the coating plate, and the coating is scraped off in steps to avoid the situation where excessive coating spreads over a large area and causes waste of coating.

Description

Technical Field

[0001] The invention relates to the technical field of coating, in particular to an extrusion-type step-by-step coating machine for plastic films. Background Art

[0002] Degradable plastic film can be made into packaging products such as express bags, and the packaging products produced can be recycled. Degradable plastic film can be made into a composite film by melt blending a certain amount of PBAT and starch, and then the surface of the composite film is treated with lubricants, coatings, etc., and subsequently cut, sealed, and other processes are performed to finally make degradable plastic products.

[0003] A common method for coating composite films is the blade coating method. The film is placed at the bottom of the blade and transported forward. A sufficient amount of coating is sprayed onto the film surface upstream of the blade. When the film is transported forward and passes through the blade, the blade intercepts the excess coating, forming an extremely thin coating layer on the film surface.

[0004] Because the paint has certain ductility and adhesion, if the paint sprayed onto the film surface is continuously excessive, a large amount of paint intercepted by the scraper will spread to the scraper. The paint on the scraper surface will gradually solidify after being exposed to the air for a long time, resulting in a large amount of paint waste. In addition, the solidified layer on the scraper surface will accumulate after long-term use, which is difficult to clean. Summary of the Invention

[0005] To this end, the present invention provides an extrusion-type step-by-step coating machine for plastic film, which effectively solves the technical problems in the prior art that the paint on the scraper surface will gradually solidify when exposed to the air for a long time, resulting in a large amount of paint waste, and the solidified layer on the scraper surface will accumulate and be difficult to clean after long-term use.

[0006] To solve the above technical problems, the present invention specifically provides the following technical solutions: an extrusion-type step-by-step coating machine for plastic film, comprising a coating chamber, wherein a film inlet and a film outlet are formed on two opposite side walls of the coating chamber, respectively, and a composite film enters the coating chamber through the film inlet and exits the coating chamber through the film outlet;

[0007] A plurality of feeding pipes are installed in the coating chamber, and a coating wall body facing the composite film is provided in the coating chamber, and the feeding pipes inject coating into the surface of the composite film facing the coating wall body;

[0008] The downstream end of the coating wall is sequentially installed with a separator plate and a coating plate, and the coating on the composite film is initially scraped off by the separator plate and then scraped off again by the coating plate;

[0009] A slide is installed in the coating cabin along the transport direction of the composite film, and the material separation plate and the coating plate can move along the direction of the slide;

[0010] A displacement driving structure is provided in the direction opposite to the slide, and the displacement driving structure can drive the separation plate to move along the direction of the slide and approach the coating wall, so that when the separation plate is attached to the coating wall, the paint scraped off the surface of the separation plate is squeezed to the surface of the composite film, and then the coating plate can move along the direction of the slide and approach the separation plate under the drive of the displacement driving structure, so that when the coating plate is attached to the separation plate, the paint scraped off the surface of the coating plate is squeezed to the surface of the composite film.

[0011] Furthermore, a sealing plate is connected to the bottom of the coating wall away from the material dividing plate, and the bottom of the sealing plate is in close contact with the composite film;

[0012] The feeding pipe port passes through the sealing plate and extends to the bottom of the coating wall.

[0013] Furthermore, the distance from the bottom of the dividing plate to the surface of the composite film is greater than the distance from the bottom of the coating plate to the surface of the composite film;

[0014] The distance from the bottom of the dividing plate to the surface of the composite film is equal to the distance from the bottom of the coating wall to the surface of the composite film.

[0015] Furthermore, the displacement drive structure includes a driving cylinder fixed in the coating cabin and a push shaft connected to a driving end of the driving cylinder;

[0016] The driving cylinder is arranged along the movement direction of the material dividing plate and the coating plate, and the slide is fixedly mounted on the driving cylinder by a threaded bolt;

[0017] The end of the push shaft is connected to a first movable frame, and the coating plate is fixedly installed at the bottom of the first movable frame;

[0018] A second movable frame is installed on the bottom of the first movable frame away from the coating plate, and the material dividing plate is fixedly installed on the bottom of the second movable frame.

[0019] Furthermore, at least two first mounting shafts are installed in the first movable frame, at least two second mounting shafts are installed in the second movable frame, and a movable bolt is movably installed between the first mounting shaft and the second mounting shaft, and one end of the movable bolt can rotate around the first mounting shaft, and the other end can rotate around the second mounting shaft;

[0020] The movable bolts are parallel to each other, a fixed plate is connected to the end of the slide seat, the first movable frame and the second movable frame are both opposite to the fixed plate, and the distance between the first movable frame and the fixed plate is greater than the distance between the second movable frame and the fixed plate;

[0021] Wherein, the bottom of the fixing plate is connected to the coating wall.

[0022] Furthermore, a strong magnet is provided at the bottom of the first movable frame, and a metal block is provided at the top of the second movable frame. Under the action of magnetic attraction, the second movable frame is tightly attached to the bottom of the first movable frame;

[0023] The push shaft pushes the first movable frame and the second movable frame to move synchronously toward the side of the fixed plate, so as to drive the dividing plate to gradually fit the coating wall. The second movable frame gradually contacts the fixed plate and moves toward the side of the composite film under the reaction force of the fixed plate. The first movable frame continues to move to gradually approach the second movable frame, so as to drive the coating plate to gradually fit the dividing plate.

[0024] Furthermore, a movable groove for the second movable frame to move is provided on the coating wall at a position corresponding to the second movable frame.

[0025] Furthermore, a first sealing groove is provided on the outer wall of the coating wall body close to the material dividing plate, and a first sealing block is provided on the outer wall of the material dividing plate close to the coating wall body and directly opposite to the first sealing groove;

[0026] The lengths of the first sealing block, the first sealing groove, the dividing plate, and the coating wall are all consistent. The first sealing block can fit along its own length direction with the inner wall of the first sealing groove to form a strip-shaped sealing area between the dividing plate and the coating wall at the height position of the first sealing groove.

[0027] Furthermore, a second sealing groove is provided on the outer wall of the material dividing plate close to the coating plate, a second sealing block is provided on the outer wall of the coating plate close to the material dividing plate, and a rubber bladder strip is provided on the second sealing block in the direction facing the second sealing groove;

[0028] The coating plate, the dividing plate, the second sealing block, the second sealing groove, and the rubber bladder strip are all of the same length;

[0029] The rubber bladder strip can be squeezed into the second sealing groove to form a strip-shaped sealing area between the coating plate and the dividing plate at the height of the second sealing groove.

[0030] Furthermore, a plurality of supporting rollers are installed in the coating chamber, and the supporting rollers support the composite film so that the composite film in the coating chamber forms a straight film surface;

[0031] Two feeding rollers are installed opposite to each other at the film inlet, and the composite film passes through the feeding rollers at the film inlet and enters the coating chamber;

[0032] At least part of the outer walls of the two feed rollers fits with the inner wall of the film inlet;

[0033] A discharge roller is installed at the film outlet, and the discharge roller supports the composite film. There is a gap between the inner wall of the film outlet and the film surface of the composite film.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] In the present invention, a separator plate and a coating plate are sequentially arranged in the coating chamber to scrape off the coating on the surface of the composite film. A scraping method is adopted to scrape off the coating in steps. In the case of excessive coating, the excess coating is diverted to the separator plate and the coating plate, and the amount of coating intercepted at each scraping structure is controlled to avoid the situation where excessive coating spreads over a large area and causes coating waste.

[0036] Furthermore, driven by the displacement driving structure, the dividing plate can move relatively close to the coating wall, and the coating plate can move relatively close to the dividing plate, periodically squeezing and removing the coating on the surface of the dividing plate and the coating plate to avoid coating condensation. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are merely exemplary, and those skilled in the art can, without inventive effort, derive other implementation drawings based on the provided drawings.

[0038] Figure 1 A schematic structural diagram of an extrusion-type step-by-step coating machine for a plastic film provided by an embodiment of the present invention;

[0039] Figure 2 A schematic top view of a plastic film extrusion-type step-by-step coating machine provided by an embodiment of the present invention;

[0040] Figure 3 for Figure 2 Stereoscopic cross-sectional view in the AA direction;

[0041] Figure 4 Schematic diagram of the internal structure of the coating cabin in an embodiment of the present invention;

[0042] Figure 5 This is a schematic structural diagram of a displacement drive structure in an embodiment of the present invention when no slide is installed;

[0043] Figure 6 for Figure 5 Side view of;

[0044] Figure 7 for Figure 5 Schematic diagram of the structure of the middle coating wall, the material distribution plate, the coating plate and the displacement drive structure;

[0045] Figure 8 for Figure 7 Schematic diagram of the enlarged structure of A;

[0046] Figure 9 Schematic diagram of the structure of the initial state of the material separation plate and the coating plate in the embodiment of the present invention;

[0047] Figure 10 This is a structural schematic diagram of the first movable frame and the second movable frame moving toward the fixed plate in an embodiment of the present invention;

[0048] Figure 11 Schematic diagram of the structure in which the second movable frame moves downward under the reaction force of the fixed plate in an embodiment of the present invention.

[0049] The numbers in the figure represent the following:

[0050] 1- coating cabin; 2- film inlet; 3- film outlet; 4- composite film; 5- feeding pipe; 6- coating wall; 7- material distributor; 8- coating plate; 9- displacement drive structure; 10- sealing plate; 11- slide; 12- movable groove; 13- first sealing groove; 14- first sealing block; 15- second sealing groove; 16- second sealing block; 17- support roller; 18- feeding roller; 19- discharging roller;

[0051] 91 - driving cylinder; 92 - pushing shaft; 93 - threaded bolt; 94 - first movable frame; 95 - second movable frame; 96 - first mounting shaft; 97 - second mounting shaft; 98 - movable bolt; 99 - fixing plate. DETAILED DESCRIPTION

[0052] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0053] like Figure 1 、 Figure 2 and Figure 3 As shown, the present invention provides an extrusion-type step-by-step coating machine for plastic film, comprising a coating cabin 1, with a film inlet 2 and a film outlet 3 formed on opposite side walls of the coating cabin 1, respectively. A composite film 4 enters the coating cabin 1 from the film inlet 2 and exits the coating cabin 1 from the film outlet 3, and the coating work is carried out in the coating cabin 1.

[0054] Several feeding pipes 5 are installed in the coating chamber 1, and the feeding pipes 5 inject coating into the surface of the composite film 4. The feeding pipes 5 can be connected to external feeding structures, such as a suction pump, a coating supply chamber, etc.

[0055] A coating wall 6 is provided in the coating chamber 1 , and a separator plate 7 and a coating plate 8 are sequentially installed at the downstream end of the coating wall 6 . The coating on the composite film 4 is initially scraped off by the separator plate 7 and then scraped off again by the coating plate 8 .

[0056] A slide 11 is installed in the coating cabin 1 along the transport direction of the composite film 4. The dividing plate 7 can move along the direction of the slide 11 and approach the coating wall 6, so that the coating intercepted on the surface of the dividing plate 7 is squeezed to the surface of the composite film 4. The coating plate 8 can move along the direction of the slide 11 and approach the dividing plate 7, so that the coating intercepted on the surface of the coating plate 8 is squeezed to the surface of the composite film 4.

[0057] In the present invention, a coating wall 6, a dividing plate 7, and a coating plate 8 are sequentially arranged in the coating cabin 1. The coating on the composite film 4 is initially scraped off by the dividing plate 7 and is scraped off for the second time by the coating plate 8. The scraping method of multiple scrapings is adopted to scrape the coating in steps, which can avoid the situation where excessive coating causes large-area spreading and leads to waste of coating.

[0058] Furthermore, the dividing plate 7 can move relatively close to the coating wall 6, so that the coating retained on the surface of the dividing plate 7 is squeezed to the surface of the composite film 4, and the coating plate 8 can move relatively close to the dividing plate 7, periodically squeezing and removing the coating on the surface of the dividing plate 7 and the coating plate 8 to avoid condensation of the coating.

[0059] In the present invention, in order to prevent the paint from adhering to the outer wall of the coating wall 6 on the side that has not been squeezed and cannot be squeezed and cleaned, the present invention makes the following design: the bottom of the coating wall 6 away from the dividing plate 7 is connected to a sealing plate 10, and the bottom of the sealing plate 10 is in close contact with the composite film 4 in the coating chamber 1, and the pipe end of the feeding pipe 5 passes through the sealing plate 10 and extends to the bottom of the coating wall 6.

[0060] A material cavity is formed between the coating wall 6 and the composite film 4, and the coating is injected into the material cavity. Since the composite film 4 is in close contact with the sealing plate 10, the coating cannot flow to the upstream end of the coating wall 6, ensuring that the coating cannot adhere to the outer wall of the coating wall 6 that is not squeezed.

[0061] Furthermore, a rounded corner can be formed at the bottom corner of the coating wall 6 close to the separator plate 7 so that the coating between the coating wall 6 and the separator plate 7 can more easily enter the bottom of the coating wall 6, which can prevent the coating from overflowing from between the separator plate 7 and the composite film 4 to between the separator plate 7 and the coating plate 8 during the extrusion process.

[0062] In order to further realize the step-by-step scraping, the present invention makes the following design: Figure 6 As shown, the distance from the bottom of the dividing plate 7 to the surface of the composite film 4 is greater than the distance from the bottom of the coating plate 8 to the surface of the composite film 4;

[0063] The distance from the bottom of the dividing plate 7 to the surface of the composite film 4 is equal to the distance from the bottom of the coating wall 6 to the surface of the composite film 4 .

[0064] The paint overflows from the bottom of the coating wall 6 to between the coating wall 6 and the dividing plate 7, passes through the dividing plate 7, and the paint on the composite film 4 that exceeds the height position of the bottom of the dividing plate 7 is scraped off, passes through the coating plate 8, and the paint on the composite film 4 that exceeds the height position of the bottom of the coating plate 8 is scraped off.

[0065] As an embodiment of the present invention, the coating wall 6, the dividing plate 7, and the coating plate 8 are all in a vertical state. The height of the bottom of the coating wall 6 is consistent with the height of the bottom of the dividing plate 7. The height of the bottom of the dividing plate 7 is higher than the height of the bottom of the coating plate 8. The higher layer of paint can be scraped off at the dividing plate 7, and the lower layer of paint can be scraped off at the coating plate 8. After two scrapings, a layer of paint is formed on the composite film 4.

[0066] The step-by-step scraping method can avoid excessive accumulation of paint on the dividing plate 7 or the coating plate 8. If too much paint accumulates on the dividing plate 7 or the coating plate 8, the paint at the bottom will be squeezed by gravity to pass through the gap between the dividing plate 7 and the composite film 4, and the gap between the coating plate 8 and the composite film 4, resulting in poor coating effect. Therefore, the step-by-step scraping method can disperse the paint and avoid paint accumulation.

[0067] In order to extrude the coating between the coating wall 6 and the dividing plate 7, and between the dividing plate 7 and the coating plate 8, a displacement driving structure 9 is provided in the coating chamber 1. The displacement driving structure can drive the dividing plate 7 and the coating plate 8 to move, so as to realize the extrusion of the coating between the coating wall 6 and the dividing plate 7, and between the dividing plate 7 and the coating plate 8.

[0068] The displacement driving structure 9 of the present invention adopts the following preferred embodiments: Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 9 As shown, the displacement drive structure 9 includes a drive cylinder 91 fixed in the coating cabin 1 and a push shaft 92 connected to the drive end of the drive cylinder 91;

[0069] The driving cylinder 91 is arranged along the moving direction of the dividing plate 7 and the coating plate 8. The slide 11 is fixedly mounted on the driving cylinder 91 through a threaded bolt 93. The main body of the driving cylinder 91 is fixed, and the entire slide 11 is also fixed.

[0070] The end of the push shaft 92 is connected to the first movable frame 94, the coating plate 8 is fixedly installed at the bottom of the first movable frame 94, and the second movable frame 95 is installed at the bottom of the first movable frame 94 away from the coating plate 8, and the material dividing plate 7 is fixedly installed at the bottom of the second movable frame 95.

[0071] The driving cylinder 91 is driven to move along the direction of the slide 11 through the push shaft 92, thereby driving the first movable frame 94 and the second movable frame 95 to move synchronously.

[0072] Furthermore, at least two first mounting shafts 96 are installed in the first movable frame 94, and at least two second mounting shafts 97 are installed in the second movable frame 95. A movable bolt 98 is movably installed between the first mounting shafts 96 and the second mounting shafts 97. One end of the movable bolt 98 can rotate around the first mounting shaft 96, and the other end can rotate around the second mounting shaft 97.

[0073] The movable bolts 98 are parallel to each other, and the end of the slide 11 is connected to a fixed plate 99. The first movable frame 94 and the second movable frame 95 are both opposite to the fixed plate 99. The distance between the first movable frame 94 and the fixed plate 99 is greater than the distance between the second movable frame 95 and the fixed plate 99.

[0074] The movable bolt 98 and the connecting line between the first mounting axis 96 and the second mounting axis 97 can be regarded as a parallelogram, which can be deformed and deforms when the second movable frame 95 moves relative to the first movable frame 94. During the deformation of the parallelogram, one end of the movable bolt 98 rotates around the first mounting axis 96 and the other end rotates around the second mounting axis 97.

[0075] The bottom of the fixed plate 99 is connected to the coating wall 6 , the slide 11 is a fixed structure, and the fixed plate 99 and the coating wall 6 are also a fixed structure in the coating chamber 1 , and their positions remain unchanged.

[0076] To ensure that the second movable frame 95 can still fit closely to the first movable frame 94 under the action of gravity in the initial state, so that the second movable frame 95 can move synchronously with the movement of the first movable frame 94, the present invention has the following design: a strong magnet is provided at the bottom of the first movable frame 94, and a metal block is provided at the top of the second movable frame 95. Under the action of the magnetic attraction, the second movable frame 95 is tightly fitted to the bottom of the first movable frame 94;

[0077] The push shaft 92 pushes the first movable frame 94 and the second movable frame 95 to move synchronously toward the side of the fixed plate 99, so as to drive the dividing plate 7 to gradually fit the coating wall 6. The second movable frame 95 gradually contacts the fixed plate 99 and moves toward the side of the composite film 4 under the reaction force of the fixed plate 99. The first movable frame 94 continues to move to gradually approach the second movable frame 95, so as to drive the coating plate 8 to gradually fit the dividing plate 7.

[0078] In the above embodiment, the first movable frame 94 is connected to the end of the push shaft 92, and the first movable frame 94 can only move along the direction of the slide 11, while the second movable frame 95 can not only move along the direction of the slide 11, but also move along the vertical direction. However, under the action of magnetic attraction, in the absence of other external forces, the second movable frame 95 will fit the bottom of the first movable frame 94. In addition, due to the length limitation of the movable bolt 98, the second movable frame 95 is not completely overlapped with the bottom of the first movable frame 94, but there is a certain position offset between it and the first movable frame 94.

[0079] like Figure 10 As shown, in the process of the push shaft 92 pushing the first movable frame 94 and the second movable frame 95 to move synchronously toward the side of the fixed plate 99, the dividing plate 7 gradually fits the coating wall 6, and squeezes the coating on the wall of the dividing plate 7 out between the coating wall 6 and the dividing plate 7, and flows to the surface of the composite film 4. Due to the positional offset of the first movable frame 94 and the second movable frame 95, the second movable frame 95 will first contact the fixed plate 99, as shown in FIG. Figure 11 As shown, under the reaction force of the fixed plate 99, the second movable frame 95 moves toward the side of the composite film 4, the movable bolt 98 rotates, and the second movable frame 95 moves downward along the direction of the fixed plate 99. The first movable frame 94 continues to move under the force to gradually approach the second movable frame 95. During this process, the coating plate 8 gradually fits the dividing plate 7, and the first movable frame 94 moves until the coating plate 8 fits the dividing plate 7 and stops moving.

[0080] After completing the above actions, the dividing plate 7 is attached to the coating wall 6, and the coating plate 8 is attached to the dividing plate 7, that is, a coating extrusion and removal action is completed. After completing the above coating extrusion and removal action, the first movable frame 94 needs to be driven to reset by the push shaft 92. At this time, the movable bolt 98 is still in an inclined state (not yet reaching a vertical state). During the reset process, the first movable frame 94 gradually moves away from the fixed plate 99, and the second movable frame 95 is affected by the magnetic attraction force of the strong magnet on the first movable frame 94, so that the second movable frame 95 moves upward along the fixed plate 99 and gradually attaches to the bottom of the first movable frame 94. The relative position of the first movable frame 94 and the second movable frame 95 is reset to the initial state, and then the push shaft 92 drives the first movable frame 94 and the second movable frame 95 to reset to the initial position as a whole.

[0081] The above process realizes the extrusion of coating between the coating wall 6 and the separator 7, and the extrusion of coating between the separator 7 and the coating plate 8. Since the initial height of the bottom of the separator 7 is higher than the height of the bottom of the coating plate 8, the separator 7 will move downward during the above process, realizing the horizontal overlap of the separator 7 and the coating plate 8, and also ensuring that the separator 7 can completely squeeze out the coating on the wall of the coating plate 8.

[0082] Since the second movable frame 95 will move in the vertical direction during the above process, in order to avoid collision with the coating wall 6, a movable groove 12 for the second movable frame 95 to move is opened on the coating wall 6 at a position opposite to the second movable frame 95. When the second movable frame 95 moves, the second movable frame 95 can enter the movable groove 12.

[0083] In the present invention, the inner walls of the coating wall 6, the separator plate 7, and the coating plate 8 are in close contact with the inner wall of the coating chamber 1, so when the coating is squeezed between the coating wall 6 and the separator plate 7, and between the separator plate 7 and the coating plate 8, the coating will not overflow to the sides. In addition, in order to avoid the coating from overflowing upward when the coating is squeezed between the coating wall 6 and the separator plate 7, and between the separator plate 7 and the coating plate 8, the present invention also makes the following designs:

[0084] like Figure 8 As shown, a first sealing groove 13 is provided on the outer wall of the coating wall 6 close to the dividing plate 7, and a first sealing block 14 is provided on the outer wall of the dividing plate 7 close to the coating wall 6 and directly opposite to the first sealing groove 13;

[0085] The lengths of the first sealing block 14, the first sealing groove 13, the dividing plate 7, and the coating wall 6 are all consistent. The first sealing block 14 can fit with the inner wall of the first sealing groove 13 along its own length direction to form a strip-shaped sealing area between the dividing plate 7 and the coating wall 6 at the height position of the first sealing groove 13.

[0086] Since the dividing plate 7 can also move in the vertical direction relative to the coating wall 6, the first sealing groove 13 and the second sealing block 14 are not completely matched. The height of the first sealing groove 13 is greater than the height of the first sealing block 14, so that after the first sealing block 14 is fitted in the first sealing groove 13, it can also move downward along the height direction of the first sealing groove 13. During the movement, the first sealing block 14 always fits the groove wall of the first sealing groove 13 to ensure that the paint does not overflow upward.

[0087] Furthermore, if Figure 8 As shown, a second sealing groove 15 is provided on the outer wall of the material dividing plate 7 close to the coating plate 8, and a second sealing block 16 is provided on the outer wall of the coating plate 8 close to the material dividing plate 7. A rubber bladder strip is provided on the second sealing block 16 in the direction opposite to the second sealing groove 15;

[0088] The lengths of the coating plate 8, the dividing plate 7, the second sealing block 16, the second sealing groove 15, and the rubber bladder strip are all consistent;

[0089] The rubber bladder strip can be squeezed into the second sealing groove 15 to form a strip-shaped sealing area between the coating plate 8 and the dividing plate 7 at the height of the second sealing groove 15 .

[0090] In the above embodiments, the rubber bladder strip is a shrinkable and resilient strip structure. When the rubber bladder strip contacts the second sealing groove 15, a sealing area is formed, and the paint can no longer overflow upward. When the rubber bladder strip just contacts the second sealing groove 15, the coating plate 8 is not in contact with the dividing plate 7. Before the coating plate 8 gradually contacts the dividing plate 7 and squeezes out the paint, a sealing area has been formed above, and the paint can no longer overflow upward but can only overflow downward. In this process, the rubber bladder strip is gradually compressed.

[0091] In addition, when the coating plate 8 approaches the dividing plate 7, the dividing plate 7 is moving downward. Therefore, the position of the coating plate 8 relative to the dividing plate 7 changes not only in the horizontal direction but also in the vertical direction. In this process, the rubber bag strip will also move relatively in the second sealing groove 15.

[0092] Overall, the process of coating extrusion is as follows:

[0093] like Figure 9 and Figure 10 As shown, the push shaft 92 pushes the first movable frame 94 and the second movable frame 95 to move synchronously toward the side of the fixed plate 99, the separator 7 gradually fits the coating wall 6, and the first sealing block 14 fits the groove wall of the first sealing groove 13 to ensure that the coating does not overflow upward. The coating on the plate wall of the separator 7 is squeezed out from between the coating wall 6 and the separator 7 and flows to the surface of the composite film 4;

[0094] The second movable frame 95 gradually contacts the fixed plate 99. Figure 11 As shown, under the reaction force of the fixed plate 99, the second movable frame 95 moves toward the side of the composite film 4, the movable bolt 98 rotates, and the first movable frame 94 is forced to continue to move toward the side of the fixed plate 99 to gradually approach the second movable frame 95. The rubber bag strip gradually contacts the inner wall of the second sealing groove 15, and the paint can no longer overflow upward. The coating plate 8 gradually fits the dividing plate 7, and the paint on the coating plate 8 is squeezed out between the coating plate 8 and the dividing plate 7 and flows to the surface of the composite film 4.

[0095] Among them, the process of paint extrusion is carried out periodically, which can effectively avoid the accumulation of paint on the board surface.

[0096] In order to ensure that the composite film 4 in the coating chamber 1 is in a stretched state, the present invention makes the following design: a plurality of supporting rollers 17 are installed in the coating chamber 1, and the supporting rollers 17 support the composite film 4 so that the composite film 4 in the coating chamber 1 forms a stretched film surface.

[0097] Two feeding rollers 18 are installed opposite to each other at the film inlet 2 , and the composite film 4 passes through the feeding rollers 18 at the film inlet 2 and enters the coating cabin 1 .

[0098] Among them, at least part of the outer wall of the two feeding rollers 18 fits with the inner wall of the film inlet 2.

[0099] Due to the material properties of the composite film 4 itself, a certain amount of coating is coated on the composite film 4 in the coating chamber 1. The composite film 4 cannot be completely in a straight state, and a small amount of coating may overflow from the bottom of the sealing plate 10. The tight design of the feed roller 18 can effectively prevent a small amount of coating from overflowing.

[0100] In addition, a discharge roller 19 is installed at the film outlet 3 , and the discharge roller 19 supports the composite film 4 . There is a gap between the inner wall of the film outlet 3 and the film surface of the composite film 4 .

[0101] The above embodiments are merely exemplary embodiments of the present application and are not intended to limit the scope of the present application. The scope of protection of the present application is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present application within the essence and scope of protection of the present application, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present application.

Claims

1. An extrusion-type step-by-step coating machine for plastic film, characterized in that: It comprises a coating chamber (1), wherein a film inlet (2) and a film outlet (3) are respectively formed on two opposite side walls of the coating chamber (1); a composite film (4) enters the coating chamber (1) from the film inlet (2) and exits the coating chamber (1) from the film outlet (3); A plurality of feeding pipes (5) are installed in the coating chamber (1), a coating wall (6) facing the composite film (4) is provided in the coating chamber (1), and the feeding pipes (5) inject coating material into the surface of the composite film (4) facing the coating wall (6); A material separation plate (7) and a coating plate (8) are sequentially installed at the downstream end of the coating wall (6); the coating on the composite film (4) is initially scraped off by the material separation plate (7) and is then scraped off for a second time by the coating plate (8); A slide seat (11) is installed in the coating chamber (1) along the transport direction of the composite film (4), and the material distribution plate (7) and the coating plate (8) are both capable of moving along the direction of the slide seat (11); A displacement driving structure (9) is provided in the direction opposite to the slide seat (11), and the displacement driving structure (9) can drive the dividing plate (7) to move along the direction of the slide seat (11) and approach the coating wall (6), so that when the dividing plate (7) is in contact with the coating wall (6), the paint scraped off the surface of the dividing plate (7) is squeezed onto the surface of the composite film (4), and then, driven by the displacement driving structure (9), the coating plate (8) can move along the direction of the slide seat (11) and approach the dividing plate (7), so that when the coating plate (8) is in contact with the dividing plate (7), the paint scraped off the surface of the coating plate (8) is squeezed onto the surface of the composite film (4).

2. The extrusion-type step-by-step coating machine for plastic film according to claim 1, characterized in that: A sealing plate (10) is connected to the bottom of the coating wall (6) on a side away from the material dividing plate (7), and the bottom of the sealing plate (10) is in close contact with the composite film (4); The pipe port of the feeding pipe (5) passes through the sealing plate (10) and extends to the bottom of the coating wall (6).

3. The extrusion-type step-by-step coating machine for plastic film according to claim 1 or 2, characterized in that: The distance between the bottom of the dividing plate (7) and the surface of the composite film (4) is greater than the distance between the bottom of the coating plate (8) and the surface of the composite film (4); The distance from the bottom of the dividing plate (7) to the surface of the composite film (4) is equal to the distance from the bottom of the coating wall (6) to the surface of the composite film (4).

4. The extrusion-type step-by-step coating machine for plastic film according to claim 3, characterized in that: The displacement drive structure (9) comprises a drive cylinder (91) fixed in the coating chamber (1), and a push shaft (92) connected to a drive end of the drive cylinder (91); The driving cylinder (91) is arranged along the movement direction of the material distribution plate (7) and the coating plate (8), and the slide seat (11) is fixedly mounted on the driving cylinder (91) via a threaded bolt (93); The end of the push shaft (92) is connected to a first movable frame (94), and the coating plate (8) is fixedly mounted on the bottom of the first movable frame (94); A second movable frame (95) is installed on the bottom of the first movable frame (94) on a side away from the coating plate (8), and the material dividing plate (7) is fixedly installed on the bottom of the second movable frame (95).

5. The extrusion-type step-by-step coating machine for plastic film according to claim 4, characterized in that: At least two first mounting shafts (96) are installed in the first movable frame (94), at least two second mounting shafts (97) are installed in the second movable frame (95), a movable bolt (98) is movably installed between the first mounting shaft (96) and the second mounting shaft (97), one end of the movable bolt (98) is rotatable around the first mounting shaft (96), and the other end is rotatable around the second mounting shaft (97); The movable bolts (98) are parallel to each other, the end of the slide seat (11) is connected to a fixed plate (99), the first movable frame (94) and the second movable frame (95) are both directly opposite to the fixed plate (99), and the distance between the first movable frame (94) and the fixed plate (99) is greater than the distance between the second movable frame (95) and the fixed plate (99); Wherein, the bottom of the fixing plate (99) is connected to the coating wall (6).

6. The extrusion-type step-by-step coating machine for plastic film according to claim 5, characterized in that: A strong magnet is arranged at the bottom of the first movable frame (94), and a metal block is arranged at the top of the second movable frame (95); under the action of magnetic attraction, the second movable frame (95) is tightly attached to the bottom of the first movable frame (94); The push shaft (92) pushes the first movable frame (94) and the second movable frame (95) to move synchronously toward the side of the fixed plate (99) to drive the dividing plate (7) to gradually fit the coating wall (6); the second movable frame (95) gradually contacts the fixed plate (99) and moves toward the side of the composite film (4) under the reaction force of the fixed plate (99); the first movable frame (94) continues to move to gradually approach the second movable frame (95) to drive the coating plate (8) to gradually fit the dividing plate (7).

7. The extrusion-type step-by-step coating machine for plastic film according to claim 6, characterized in that: A movable groove (12) for the second movable frame (95) to move is provided on the coating wall (6) at a position corresponding to the second movable frame (95).

8. The extrusion-type step-by-step coating machine for plastic film according to claim 7, characterized in that: A first sealing groove (13) is provided on the outer wall of the coating wall (6) close to the material dividing plate (7), and a first sealing block (14) is provided on the outer wall of the material dividing plate (7) close to the coating wall (6) and at a position directly opposite to the first sealing groove (13); The first sealing block (14), the first sealing groove (13), the dividing plate (7) and the coating wall (6) are all of the same length; the first sealing block (14) is capable of being fitted with the inner wall of the first sealing groove (13) along its own length direction to form a strip-shaped sealing area between the dividing plate (7) and the coating wall (6) at a height position of the first sealing groove (13).

9. The extrusion-type step-by-step coating machine for plastic film according to claim 8, characterized in that: A second sealing groove (15) is provided on the outer wall of the material dividing plate (7) on the side close to the coating plate (8), a second sealing block (16) is provided on the outer wall of the coating plate (8) on the side close to the material dividing plate (7), and a rubber bladder strip is provided on the second sealing block (16) in a direction opposite to the second sealing groove (15); The coating plate (8), the material dividing plate (7), the second sealing block (16), the second sealing groove (15), and the rubber bladder strip are all of the same length; The rubber bladder strip can be squeezed into the second sealing groove (15) to form a strip-shaped sealing area between the coating plate (8) and the dividing plate (7) at the height of the second sealing groove (15).

10. The extrusion-type step-by-step coating machine for plastic film according to claim 1, characterized in that: A plurality of supporting rollers (17) are installed in the coating chamber (1), and the supporting rollers (17) support the composite film (4) so ​​that the composite film (4) in the coating chamber (1) forms a stretched film surface; Two feed rollers (18) are installed opposite to each other at the film inlet (2), and the composite film (4) passes through the feed rollers (18) at the film inlet (2) and enters the coating chamber (1); At least part of the outer walls of the two feed rollers (18) fit with the inner wall of the film inlet (2); A discharge roller (19) is installed at the film outlet (3), the discharge roller (19) supports the composite film (4), and a gap exists between the inner wall of the film outlet (3) and the film surface of the composite film (4).

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