A conveying device and control method for plastic film printing

Abstract

A conveying device and control method for plastic film printing, comprising a plurality of printing units, each of the printing units comprising a printing box and a drying box distributed along the conveying direction of the plastic film, a first conveying roller group being provided in the drying box along the conveying path of the plastic film, corresponding to the drying area of ​​the plastic film, the air guide window being arranged in parallel beside the first conveying roller group, and being configured to guide hot air to the first surface of the plastic film, drying the ink on the plastic film while making the second surface of the plastic film adhere to the outer side surface of the first conveyor belt and being driven by the first conveyor belt to move synchronously, the plastic film is conveyed by the conveyor belt, the wind in the drying process is blown to the surface of the plastic film, the plastic film is kept always attached to the surface of the conveyor belt, and moves synchronously with the conveyor belt, so as to avoid the plastic film being pulled and deformed when heated, and ensure high conveying accuracy, thereby maintaining high accuracy during subsequent color printing.

Description

Technical Field

[0001] The invention belongs to the technical field of film conveying, and in particular relates to a conveying device and a control method for plastic film printing. Background Art

[0002] As an important packaging material, the production process of plastic packaging bags includes multiple steps, such as raw material crushing, melting, extrusion film forming, cooling and hardening, printing and compounding, fine processing into bags, and subsequent process treatment and inspection. Among them, color printing is widely used in plastic packaging bags, which greatly improves the aesthetics, practicality and added value of plastic packaging bags. Color printing is to print different colors of ink on plastic packaging bags through multiple printing units, and each unit is responsible for printing one color.

[0003] During the printing process, each printing unit needs to maintain a high degree of synchronization and precision to ensure that patterns of different colors can be accurately overprinted together. The printed ink needs to be cured between each printing, especially heat-curing ink, which requires hot air drying during the curing process. The hot air acts on the surface of the plastic film. Under the combined action of the traction of the conveyor roller, it will aggravate the deformation of the plastic film, resulting in errors between the various color units of the plastic film and misalignment of the printing area. Therefore, how to ensure the accurate transportation of the plastic film between the various color units during the transportation process has become an urgent problem to be solved. Summary of the invention

[0004] In view of the above situation, in order to overcome the defects of the prior art, the present invention creatively adopts a conveying device and a control method for plastic film printing to at least partially solve the problems raised in the above background technology.

[0005] The technical solution adopted is as follows: The embodiment of the present invention proposes a conveying device for plastic film printing, comprising:

[0006] A plurality of printing units, each of which comprises a printing box and a drying box distributed along the conveying direction of the plastic film, and the printing box and the drying box are respectively provided with a film inlet window and a film outlet window for the plastic film to pass through;

[0007] A printing assembly, disposed in the printing box and capable of printing ink onto the plastic film;

[0008] A guide roller is arranged in the drying box and can output the plastic film from the film output window;

[0009] An air guide window is arranged in the drying box and can dry the ink on the plastic film;

[0010] The plastic film comprises a first surface with printed ink and a second surface without printed ink. A first conveying roller group is provided along the conveying path of the plastic film in the drying box, corresponding to the drying area of ​​the plastic film. The first conveying roller group comprises two first driving rollers and a first conveying belt installed on the outside of the first driving roller. The air guide window is arranged in parallel beside the first conveying roller group and can guide hot air to the first surface of the plastic film, so as to dry the ink on the plastic film and make the second surface of the plastic film adhere to the outer side of the first conveying belt and be driven by the first conveying belt to move synchronously.

[0011] Furthermore, the wind guide window includes:

[0012] The exhaust window is configured as a hollow rectangular frame, and the side facing the plastic film is an open end;

[0013] An air extraction window is fixedly arranged inside the air exhaust window;

[0014] A plurality of partitions are arranged in parallel along the conveying direction of the plastic film;

[0015] Among them, an exhaust window is formed between the exhaust window and the exhaust window, and the exhaust window is connected to an external air supply device. An exhaust window is formed on the inner side of the exhaust window, and the exhaust window is connected to an external exhaust device. A strip window is formed between each adjacent two partitions, and each strip window is provided with an electric heating wire, which is connected to an external temperature controller for adjusting the temperature of the air flow exported from each strip window.

[0016] Furthermore, a cooling box is provided on the inner side of the first conveyor roller group, and two sides of the cooling box are respectively attached to the inner side wall of the first conveyor belt, and the first conveyor belt moves according to a set path during the transmission process;

[0017] A plurality of guide plates are fixedly provided inside the cooling box, and a serpentine guide channel is formed between the guide plates. A water supply pipe and a drainage pipe are respectively installed on the outer wall of the cooling box at both ends corresponding to the guide channel. The water supply pipe is connected to the output end of an external pumping device, and the drainage pipe is connected to the input end of the pumping device. The cooling box is filled with coolant, and the coolant can be driven by the pumping device to circulate and pump in the guide channel for heat exchange with the plastic film attached to the inner wall of the first conveyor belt.

[0018] Furthermore, it also includes a second conveying roller group, which is arranged in the drying box and is used to convey the plastic film between the guide roller and the film outlet window;

[0019] The second conveying roller group includes two second driving rollers and a second conveying belt installed on the outside of the second driving roller. The second conveying roller group is arranged in parallel beside the wind guide window, and the wind guide window can guide airflow to the first surface of the plastic film located on the second conveying belt, so that the second surface of the plastic film is attached to the outer side surface of the second conveying belt and is driven by the second conveying belt to move synchronously.

[0020] Furthermore, a support box is provided inside the second conveyor roller group, and the support box is configured as a rectangular box body. Two side surfaces of the support box respectively fit and slide with the inner wall of the second conveyor belt, so that the second conveyor belt moves along a set path during transmission.

[0021] Furthermore, a transmission box is provided on the outer wall of the drying box, and the shaft ends of the first driving roller, the guide roller and the second driving roller are driven by the transmission box, so that the first driving roller, the guide roller and the second driving roller have the same linear speed, and a motor for driving the transmission box to move is fixedly mounted on the transmission box, and the motor is connected to an external control circuit.

[0022] Furthermore, the first conveyor belt and the second conveyor belt are both constructed as inelastic belts, so that the first conveyor belt and the second conveyor belt maintain a set length and width during the conveying process.

[0023] Furthermore, a plurality of heating wires are provided in the strip window along the width direction, and the plurality of heating wires are independently connected to the temperature controller to control the temperature of the heating wires at different positions according to the printing area on the plastic film, so that the temperature of the airflow derived from the strip window in the printing area is higher than that in the non-printing area.

[0024] Furthermore, the printing assembly includes an ink tank and an ink roller, a printing roller and a pressure roller which are sequentially distributed from bottom to top;

[0025] The ink tank is arranged at the inner bottom end of the printing box and is used to store ink. The ink roller is rotatably installed in the ink tank and is used to dip the ink in the ink tank. The printing roller rotates in contact with the ink roller, and the pressure roller is in contact with the printing roller. During the process of the plastic film being transported between the printing roller and the pressure roller, the ink is printed on the surface of the plastic film through the printing roller.

[0026] The embodiment of the present invention provides a method for controlling a conveying device for plastic film printing, using the above-mentioned conveying device for plastic film printing, comprising the following steps:

[0027] Printing: the plastic film enters the printing box from the film inlet window, and in the process of being transported between the printing roller and the pressure roller, the printing roller prints ink on the first side of the plastic film;

[0028] Drying: After printing is completed, the plastic film is transported by the first conveying roller group, the guide roller and the second conveying roller group and discharged from the film outlet window. When the plastic film passes through the first conveying roller group, the hot air guided by the air guide window is blown toward the first surface of the plastic film to dry the ink on the plastic film;

[0029] In the drying step, the conveying path of the plastic film includes a drying section and a non-drying section. When the plastic film is conveyed in the drying section, it is blown by the hot air output from the air guide window and adheres to the surface of the first conveyor belt, and is driven by the first conveyor belt to move synchronously;

[0030] When the plastic film is conveyed in the non-drying section, it is blown by the airflow guided by the air guide window and adheres to the surface of the second conveyor belt, and is driven by the second conveyor belt to move synchronously, so that the plastic film is conveyed in the drying box without stretching or deformation.

[0031] The beneficial effects achieved by the present invention using the above structure are as follows:

[0032] This solution uses a conveyor belt to transport the plastic film, and the wind during the drying process blows toward the surface of the plastic film, keeping the plastic film always attached to the surface of the conveyor belt and moving synchronously with the conveyor belt. This can prevent the plastic film from being pulled and deformed when heated, and can ensure high conveying accuracy, thereby maintaining high accuracy during subsequent color printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the three-dimensional structure of a conveying device for plastic film printing proposed in an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of the internal structure of a conveying device for plastic film printing proposed in an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of a half-section structure of a box body is provided for an embodiment of the present invention;

[0036] Figure 4 for Figure 3 Schematic diagram of the cross-sectional structure along the AA direction;

[0037] Figure 5 for Figure 3 Schematic diagram of the cross-sectional structure along the BB direction;

[0038] Figure 6A schematic diagram of the three-dimensional structure of a first conveying roller group, a guide roller and a second conveying roller group is provided for an embodiment of the present invention.

[0039] Among them, 01, air supply pipe; 02, exhaust pipe; 03, water supply pipe; 04, drainage pipe; 05, transmission box; 06, motor; 10, printing unit; 1001, printing box; 1002, drying box; 101, film inlet window; 102, film outlet window; 11, ink tank; 12, ink roller; 13, printing roller; 14, pressure roller; 20, first conveying roller group; 21, first driving roller; 22, first conveyor belt; 30, guide roller; 40, air guide window; 401, exhaust window; 402, exhaust window; 41, exhaust window; 42, exhaust window; 43, partition; 44, heating wire; 50, second conveying roller group; 51, second driving roller; 52, second conveyor belt; 60, cooling box; 601, guide channel; 61, guide plate; 70, support box.

[0040] The accompanying drawings are used to provide further understanding of the embodiments and constitute a part of the specification. They are used for explanation together with the embodiments and do not constitute a limitation of the embodiments. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection.

[0042] In the description of the embodiments, it should be understood that terms such as "up", "down", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the embodiments.

[0043] At present, after printing on plastic film, the printed ink needs to be solidified, especially for the dried and solidified ink, hot air needs to be directed to the surface of the plastic film to promote the ink printed on the surface of the plastic film. Since the plastic film is easily deformed after being heated, and the traction of the plastic film mainly depends on the pulling effect of the roller on the plastic film, therefore, when the plastic film is heated, the traction force of the roller when conveying the plastic film will cause the plastic film to deform, resulting in deviations when multiple color units print on the film separately, and cannot print accurately.

[0044] like Figure 1As shown, in an embodiment of the present invention, a conveying device for plastic film printing is provided, which aims to improve the accuracy of the plastic film conveying process, especially when the plastic film is in a hot air drying state, so that the plastic film can be conveyed without deformation, thereby ensuring the accuracy of color registration. The device mainly includes multiple printing units 10.

[0045] Each printing unit 10 includes a printing box 1001 and a drying box 1002 distributed along the conveying direction of the plastic film. The printing box 1001 and the drying box 1002 are respectively provided with a film inlet window 101 and a film outlet window 102 for the plastic film to pass through. The printing component is arranged in the printing box 1001 and can print ink on the plastic film.

[0046] Further, such as Figure 2 and Figure 3 As shown, the printing assembly includes an ink tank 11 and an ink roller 12, a printing roller 13 and a pressing roller 14 which are distributed in sequence from bottom to top. The ink tank 11 is arranged at the inner bottom end of the printing box 1001 and is used to store ink. The ink roller 12 is rotatably installed in the ink tank 11 and is used to dip the ink in the ink tank 11. The printing roller 13 rotates in close contact with the ink roller 12 to transfer the ink on the ink roller 12 to the pattern groove on the surface of the printing roller 13. Then the pressing roller 14 is in close contact with the printing roller 13. During the process of the plastic film being transported between the printing roller 13 and the pressing roller 14, the ink is printed on the surface of the plastic film through the printing roller 13, so that the surface of the plastic film is printed with ink.

[0047] Furthermore, the guide roller 30 is arranged in the drying box 1002 and can output the plastic film from the film output window 102. The air guide window 40 is arranged in the drying box 1002 and can dry the ink on the plastic film. In this way, the plastic film is dried after printing, which can prevent the plastic film from being scratched by the ink during transportation.

[0048] In some embodiments, the plastic film includes a first surface printed with ink and a second surface not printed with ink. A first conveying roller set 20 is provided along the conveying path of the plastic film in the drying box 1002 corresponding to the drying area of ​​the plastic film.

[0049] Among them, the first conveying roller group 20 includes two first driving rollers 21 and a first conveying belt 22 installed on the outside of the first driving roller 21. The air guide window 40 is arranged in parallel on the side of the first conveying roller group 20, and can guide hot air to the first side of the plastic film, thereby drying the ink on the plastic film and making the second side of the plastic film adhere to the outer side of the first conveying belt 22 and be driven by the first conveying belt 22 to move synchronously.

[0050] In this way, during the drying process of the plastic film, the plastic film can be conveyed by the wide first conveyor belt 22, and, under the action of the hot air blown out by the wind guide window 40, the plastic film is entirely attached to the surface of the first conveyor belt 22, which not only dries the ink on the surface of the plastic film, but also the first conveyor belt 22 and the plastic film are conveyed synchronously, which can avoid the deformation of the plastic film caused by unilateral pulling during the conveying process, and can improve the accuracy of the plastic film during the conveying process, preparing for subsequent color printing.

[0051] Compared with the existing method of conveying with a transmission roller, the plastic film is easily deformed due to heat during the drying process, and when the conveying roller is pulled at one end, the plastic film is easily deformed, which affects the accuracy of subsequent color registration. This solution uses a conveyor belt to convey the plastic film, and the wind during the drying process blows toward the surface of the plastic film to keep the plastic film always attached to the surface of the first conveyor belt 22 and move synchronously with the first conveyor belt 22, which can prevent the plastic film from being pulled and deformed when heated, and can ensure high conveying accuracy, thereby maintaining high accuracy during subsequent color registration printing.

[0052] like Figure 3 , Figure 4 and Figure 5 As shown, the air guide window 40 includes an air exhaust window body 41 , an air intake window body 42 and a partition plate 43 .

[0053] The exhaust window 41 is configured as a hollow rectangular frame, and the side facing the plastic film is an open end. The exhaust window 42 is fixedly disposed inside the exhaust window 41, and a plurality of partitions 43 are provided in parallel along the conveying direction of the plastic film.

[0054] In some embodiments, the exhaust window 41 is made of stainless steel or aluminum alloy and is a hollow rectangular body with one side open. The exhaust window 42 is made of stainless steel or aluminum alloy and is a rectangular trough. An exhaust window 402 is formed between the exhaust window 41 and the exhaust window 42. The exhaust window 41 is connected to an external air supply device through an air supply pipe 01 on its outer wall, so that the air supply device can provide airflow into the exhaust window 402 and guide the airflow to the surface of the plastic film.

[0055] Furthermore, an exhaust window 401 is formed on the inner side of the exhaust window 42, and the exhaust window 42 is connected to an external exhaust device through an exhaust pipe 02, so that the exhaust device can draw air from the exhaust window 401, and guide the airflow from the exhaust window 402 to the surface of the plastic film and suck it out from the exhaust window 401, thereby limiting the effective area of ​​the hot air flow and preventing the hot air diffusion from affecting the transportation of the plastic film.

[0056] Furthermore, a strip window is formed between every two adjacent partitions 43 , and a heating wire 44 is provided in each strip window. The heating wire 44 is connected to an external temperature controller for adjusting the temperature of the air flow derived from each strip window.

[0057] In this way, along the direction of plastic film conveying, the temperature of the air flow exported from the strip window can be controlled to be distributed from low to high. Taking the drying temperature of 50℃~90℃ as an example, the temperature of the air flow exported from each strip window can be increased with a gradient of 10℃, so that the plastic film is pre-dried at a low temperature during the conveying process, and then slowly dried at a high temperature. In this way, the time that the plastic film is exposed to high temperature can be reduced, and the ink can be dried more thoroughly.

[0058] like Figure 2 and Figure 3 As shown, in order to prevent hot air from acting on the plastic film and causing large deformation of the plastic film, a cooling box 60 is provided on the inner side of the first conveyor roller group 20. The two sides of the cooling box 60 are respectively attached to the inner wall of the first conveyor belt 22, and the first conveyor belt 22 is made to move according to a set path during the transmission process. In this way, the cooling box 60 is arranged on the inner side of the first conveyor belt 22. On the one hand, the cooling box 60 can support the first conveyor belt 22, keep the first conveyor belt 22 moving according to a preset path, and accurately convey the plastic film on the surface of the first conveyor belt 22. On the other hand, the cooling box 60 can cool the first conveyor belt 22, further cool the plastic film on the surface of the first conveyor belt 22, avoid the plastic film from being overheated during the drying process, and reduce the possibility of deformation of the plastic film.

[0059] Furthermore, a plurality of guide plates 61 are fixedly provided inside the cooling box 60, and a serpentine guide channel 601 is formed between the guide plates 61. A water supply pipe 03 and a drainage pipe 04 are respectively installed at the two ends of the guide channel 601 corresponding to the outer wall of the cooling box 60. The water supply pipe 03 is connected to the output end of the external pumping device, and the drainage pipe 04 is connected to the input end of the pumping device. The cooling box 60 is filled with coolant. In this way, when in use, the coolant can be driven by the pumping device to circulate and pump in the guide channel 601, and is used to exchange heat with the plastic film attached to the inner wall of the first conveyor belt 22, thereby reducing the temperature of the plastic film during the drying process, reducing the risk of deformation of the plastic film, and improving the accuracy of plastic film transportation during the drying process.

[0060] like Figure 3 and Figure 6 As shown, the device also includes a second conveying roller group 50, which is arranged in the drying box 1002 and is used to convey the plastic film between the guide roller 30 and the film outlet window 102, so as to ensure that the plastic film is in a precise conveying process in the conveying path after the drying process, so that the plastic film can be accurately conveyed without deformation between the two color registration processes, thereby improving the accuracy of the color registration.

[0061] Furthermore, the second conveyor roller group 50 includes two second driving rollers 51 and a second conveyor belt 52 installed on the outside of the second driving roller 51. The second conveyor roller group 50 is arranged in parallel beside the wind guide window 40, and the wind guide window 40 can guide the airflow to the first side of the plastic film located on the second conveyor belt 52, so that the second side of the plastic film is attached to the outer side surface of the second conveyor belt 52 and is driven by the second conveyor belt 52 to move synchronously.

[0062] In some embodiments, the air guide window 40 can also blow out airflow toward one side of the second conveying roller group 50. The second conveyor belt 52 and the plastic film are conveyed synchronously, which can avoid the deformation of the plastic film caused by unilateral pulling during the conveying process, and can improve the accuracy of the plastic film during the conveying process, so as to prepare for the subsequent color printing. In addition, during the conveying process, the airflow blows toward the surface of the plastic film, keeping the plastic film always attached to the surface of the second conveyor belt 52, and moving synchronously with the second conveyor belt 52, which can avoid the plastic film from being pulled and deformed, and can ensure high conveying accuracy, thereby maintaining high accuracy during subsequent color printing.

[0063] Furthermore, a support box 70 is provided inside the second conveyor roller group 50. The support box 70 is configured as a rectangular box. The two side surfaces of the support box 70 respectively fit and slide with the inner wall of the second conveyor belt 52, so that the second conveyor belt 52 moves along a set path during the transmission process. The support box 70 can support the second conveyor belt 52 and keep the second conveyor belt 52 moving along a preset path, so that the plastic film on the surface of the second conveyor belt 52 can play a role in precise transportation.

[0064] In some embodiments, in order to keep the plastic film being transported at a set speed in the drying box 1002, a transmission box 05 is provided on the outer wall of the drying box 1002, and the shaft ends of the first drive roller 21, the guide roller 30 and the second drive roller 51 are all driven by the transmission box 05, so that the first drive roller 21, the guide roller 30 and the second drive roller 51 have the same linear speed, and a motor 06 for driving the transmission box 05 to move is fixedly installed on the transmission box 05, and the motor 06 is connected to an external control circuit. In this way, the linear speeds of the first drive roller 21, the guide roller 30 and the second drive roller 51 are the same, that is, the first conveying roller group 20, the guide roller 30 and the second conveying roller group 50 have the same conveying speed for the plastic film, and the plastic film can be kept in high-precision conveyance between two adjacent color registration units, thereby avoiding color registration deviation.

[0065] Furthermore, the first conveyor belt 22 and the second conveyor belt 52 are both constructed as inelastic belts, so that the first conveyor belt 22 and the second conveyor belt 52 maintain a set length and width during the transmission process, avoiding deformation of the plastic film caused by deformation of the conveyor belt, thereby improving transmission accuracy.

[0066] In some embodiments, a plurality of heating wires 44 are provided in the strip window along the width direction, and the plurality of heating wires 44 are independently connected to the temperature controller to control the temperature of the heating wires 44 at different positions according to the printing area on the plastic film, so that the temperature of the airflow derived from the strip window in the printing area is higher than that in the non-printing area. In this way, in the width direction of the plastic film, the area with ink derives hot air, and the rest derives airflow at normal temperature, which can further reduce the scope of action of the hot air and thereby reduce the possibility of deformation of the plastic film.

[0067] An embodiment of the present invention provides a method for controlling a conveying device for plastic film printing, using the above-mentioned conveying device for plastic film printing, comprising the following steps:

[0068] Printing: The plastic film enters the printing box 1001 from the film inlet window 101, wherein the ink tank 11 is arranged at the inner bottom of the printing box 1001 and is used to store ink, the ink roller 12 is rotatably installed in the ink tank 11 and is used to dip the ink in the ink tank 11, the printing roller 13 rotates in close contact with the ink roller 12 to transfer the ink on the ink roller 12 to the pattern groove on the surface of the printing roller 13, and then the pressing roller 14 is in close contact with the printing roller 13. During the transportation of the plastic film between the printing roller 13 and the pressing roller 14, the ink is printed on the first side of the plastic film by the printing roller 13.

[0069] Drying: After printing is completed, the plastic film is discharged from the film outlet window 102 through the conveying of the first conveying roller group 20, the guide roller 30 and the second conveying roller group 50. When the plastic film passes through the first conveying roller group 20, the hot air guided by the air guide window 40 is blown toward the first side of the plastic film to dry the ink on the plastic film.

[0070] In the drying step, the conveying path of the plastic film includes a drying section and a non-drying section. When the plastic film is conveyed in the drying section, the hot air discharged by the wind guide window 40 is blown and adheres to the surface of the first conveyor belt 22, and is driven by the first conveyor belt 22 to move synchronously. The cooling box 60 is arranged on the inner side of the first conveyor belt 22. On the one hand, the cooling box 60 can support the first conveyor belt 22 and keep the first conveyor belt 22 moving along a preset path, so as to accurately convey the plastic film on the surface of the first conveyor belt 22. On the other hand, the cooling box 60 can cool the first conveyor belt 22, further cool the plastic film on the surface of the first conveyor belt 22, avoid the plastic film from being overheated during the drying process, and reduce the possibility of deformation of the plastic film.

[0071] When the plastic film is conveyed in the non-drying section, the airflow guided by the air guide window 40 blows and adheres to the surface of the second conveyor belt 52, and is driven by the second conveyor belt 52 to move synchronously, so that the plastic film is conveyed in the drying box 1002 without stretching or deformation. The air guide window 40 can also blow out airflow toward the side of the second conveying roller group 50. The second conveyor belt 52 and the plastic film are conveyed synchronously, which can avoid deformation of the plastic film caused by unilateral pulling during conveyance, improve the accuracy of the plastic film during conveyance, and prepare for subsequent color printing. In addition, during conveyance, the airflow blows toward the surface of the plastic film, keeping the plastic film always attached to the surface of the second conveyor belt 52 and moving synchronously with the second conveyor belt 52, which can avoid deformation of the plastic film and ensure high conveying accuracy, thereby maintaining high accuracy during subsequent color printing.

[0072] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0073] The above description of the implementation mode is not restrictive, and the drawings show only one of the implementation modes, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the scope of protection.

Claims

1. A conveying device for printing plastic film, characterized in that: include: A plurality of printing units (10), each of the printing units (10) comprising a printing box (1001) and a drying box (1002) distributed along the conveying direction of the plastic film, the printing box (1001) and the drying box (1002) being respectively provided with a film inlet window (101) and a film outlet window (102) for the plastic film to pass through; A printing component, arranged in the printing box (1001) and capable of printing ink on the plastic film; A guide roller (30) disposed in the drying box (1002) and configured to guide the plastic film to be output from the film output window (102); An air guide window (40) is arranged in the drying box (1002); The plastic film comprises a first surface to be printed with ink and a second surface not to be printed with ink; a first conveying roller group (20) is provided along the conveying path of the plastic film in the drying box (1002) corresponding to the drying area of ​​the plastic film; the first conveying roller group (20) comprises two first driving rollers (21) and a first conveying belt (22) installed outside the first driving rollers (21); the air guide window (40) is arranged parallel to the side of the first conveying roller group (20) and can guide hot air to the first surface of the plastic film, thereby drying the ink on the plastic film and making the second surface of the plastic film adhere to the outer side of the first conveying belt (22) and be driven by the first conveying belt (22) to move synchronously; The air guide window (40) comprises an exhaust window (41), an exhaust window (42) and a partition (43); an exhaust window (402) is formed between the exhaust window (41) and the exhaust window (42); an exhaust window (401) is formed inside the exhaust window (42); a strip window is formed between each two adjacent partitions (43); a heating wire (44) is provided in each strip window; the heating wire (44) is connected to an external temperature controller and is used to adjust the temperature of the air flow exported from each strip window, and control the distribution of the temperature of the air flow exported from the strip window from low to high along the direction of plastic film conveyance; A cooling box (60) is provided on the inner side of the first conveying roller group (20), and two sides of the cooling box (60) are respectively attached to the inner side wall of the first conveying belt (22), so that the first conveying belt (22) moves according to a set path during the transmission process; A plurality of guide plates (61) are fixedly provided inside the cooling box (60), and a serpentine guide channel (601) is formed between the guide plates (61). A water supply pipe (03) and a drainage pipe (04) are respectively installed on the outer wall of the cooling box (60) at two ends corresponding to the guide channel (601), the water supply pipe (03) is connected to the output end of an external pumping device, and the drainage pipe (04) is connected to the input end of the pumping device. The cooling box (60) is filled with cooling liquid, and the cooling liquid can be driven by the pumping device to circulate and pump in the guide channel (601) for heat exchange with the plastic film attached to the inner wall of the first conveyor belt (22).

2. The conveying device for plastic film printing according to claim 1, characterized in that: The side of the exhaust window (41) facing the plastic film is an open end, the exhaust window (42) is fixedly arranged inside the exhaust window (41), and a plurality of partitions (43) are arranged in parallel along the conveying direction of the plastic film, wherein the exhaust window (402) is connected to an external air supply device, and the exhaust window (401) is connected to an external exhaust device.

3. The conveying device for plastic film printing according to claim 2, characterized in that: It also includes a second conveying roller group (50), the second conveying roller group (50) is arranged in the drying box (1002) and is used to convey the plastic film between the guide roller (30) and the film outlet window (102); The second conveying roller group (50) comprises two second driving rollers (51) and a second conveying belt (52) mounted on the outside of the second driving roller (51). The second conveying roller group (50) is arranged in parallel beside the wind guide window (40), and the wind guide window (40) can guide airflow to the first surface of the plastic film on the second conveying belt (52), so that the second surface of the plastic film is attached to the outer side surface of the second conveying belt (52) and is driven by the second conveying belt (52) to move synchronously.

4. The conveying device for plastic film printing according to claim 3, characterized in that: A support box (70) is provided inside the second conveying roller group (50), and the support box (70) is configured as a rectangular box body. Two side surfaces of the support box (70) respectively fit and slide against the inner side wall of the second conveying belt (52), so that the second conveying belt (52) moves along a set path during transmission.

5. The conveying device for plastic film printing according to claim 4, characterized in that: A transmission box (05) is provided on the outer wall of the drying box (1002); the shaft ends of the first driving roller (21), the guide roller (30) and the second driving roller (51) are all driven by the transmission box (05), so that the first driving roller (21), the guide roller (30) and the second driving roller (51) have the same linear speed; a motor (06) for driving the transmission box (05) to move is fixedly mounted on the transmission box (05); the motor (06) is connected to an external control circuit.

6. The conveying device for plastic film printing according to claim 4, characterized in that: The first conveyor belt (22) and the second conveyor belt (52) are both constructed as inelastic belts, so that the first conveyor belt (22) and the second conveyor belt (52) maintain a set length and width during the conveying process.

7. The conveying device for plastic film printing according to claim 2, characterized in that: A plurality of the heating wires (44) are arranged in the strip window along the width direction, and the plurality of the heating wires (44) are independently connected to the temperature controller so as to control the temperature of the heating wires (44) at different positions according to the printing area on the plastic film, so that the temperature of the airflow derived from the strip window in the printing area is higher than that in the non-printing area.

8. The conveying device for plastic film printing according to claim 5, characterized in that: The printing assembly comprises an ink tank (11) and an ink roller (12), a printing roller (13) and a pressure roller (14) which are arranged in sequence from bottom to top; The ink tank (11) is arranged at the bottom end of the printing box (1001) and is used to store ink; the ink roller (12) is rotatably installed in the ink tank (11) and is used to dip the ink in the ink tank (11); the printing roller (13) rotates in close contact with the ink roller (12); the pressing roller (14) is in close contact with the printing roller (13); and during the process of the plastic film being transported between the printing roller (13) and the pressing roller (14), the ink is printed on the surface of the plastic film by the printing roller (13).

9. A method for controlling a conveying device for printing plastic film, characterized in that: The use of the conveying device for plastic film printing according to claim 8 comprises the following steps: Printing: the plastic film enters the printing box (1001) from the film inlet window (101), and in the process of being transported between the printing roller (13) and the pressure roller (14), ink is printed on the first side of the plastic film by the printing roller (13); Drying: after printing is completed, the plastic film is discharged from the film outlet window (102) through the conveyance of the first conveying roller group (20), the guide roller (30) and the second conveying roller group (50); when the plastic film passes through the first conveying roller group (20), the hot air guided by the air guide window (40) is blown toward the first surface of the plastic film to dry the ink on the plastic film; In the drying step, the conveying path of the plastic film includes a drying section and a non-drying section. When the plastic film is conveyed in the drying section, it is blown by the hot air output from the air guide window (40) and adheres to the surface of the first conveyor belt (22), and is driven by the first conveyor belt (22) to move synchronously; When the plastic film is conveyed in the non-drying section, it is blown by the airflow guided by the air guide window (40) and adheres to the surface of the second conveyor belt (52), and is driven by the second conveyor belt (52) to move synchronously, so that the plastic film is conveyed in the drying box (1002) without stretching or deformation.

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