Waste gas purification plastic packaging bag printing machine

Abstract

The invention relates to the technical field of printing waste gas treatment. The waste gas purification plastic packaging bag printing machine comprises a conveying line used for conveying printed materials and a printing machine body arranged on the conveying line and used for conducting printing treatment on printed patterns. A lower-row side suction device used for treating volatile waste gas on the surface of a printing stock is arranged on the portion, behind the printing machine body, of the conveying line. The lower row side suction device comprises an air curtain device arranged above the conveying line in the length direction of the conveying line and suction plates arranged on the left side and the right side of the conveying line. According to the near-field suction device, near-field suction can be carried out on waste gas volatilized by a printing stock in printing rear-section conveying, the problem of diffusion of harmful waste gas in the conveying process can be effectively solved, a traditional shell structure is abandoned, and normal use of a printing machine by an operator is not affected.

Description

Technical Field

[0001] This invention relates to the field of printing exhaust gas treatment technology, specifically to a printing machine for purifying plastic packaging bags. Background Technology

[0002] During the operation of a plastic bag printing machine, the main source of exhaust gas is the volatilization of ink and thinner. During printing, ink is transferred to the surface of the plastic film via rollers. Volatile organic compounds (VOCs) contained in the ink, such as benzene, esters, and ketones, are released into the air due to the heat generated by the machine's operation and the ambient temperature. Simultaneously, thinners added to adjust the ink viscosity (such as alcohol and gasoline) also volatilize in large quantities during the printing process, forming organic exhaust gas. These exhaust gases are complex in composition, not only having an irritating odor but also potentially containing toxic substances. If emitted directly without treatment, they will pollute the operating environment and the surrounding air.

[0003] Printing press exhaust gas treatment often focuses on areas where ink is directly transferred, such as the press head and printing rollers, using local collection devices like fume hoods to treat high-concentration exhaust gases that evaporate instantly. However, ink evaporation during the transport stage is often overlooked, especially since residual ink on printed substrates (such as plastic films and bags) continues to release VOCs during transport. This is particularly true for ink that hasn't fully cured after drying; due to its large exposure area and long transport time, the amount of evaporation is significant. Therefore, installing collection and treatment devices at the transport stage enables end-to-end pollution control, preventing exhaust gas leaks and spills, and is a necessary supplement to ensure treatment effectiveness and compliance with environmental standards.

[0004] Currently, in traditional methods, due to the large distance between the gas collection hood and the surface of the substrate, it is difficult to directly collect the low concentration of gas on the substrate surface (compared to the printing roller position), resulting in poor exhaust gas treatment. Some solutions propose to install a closed shell on the conveyor line to create a relatively sealed environment to prevent exhaust gas diffusion. However, this method not only blocks the printing press outlet and makes it difficult to observe the condition of the substrate, but also makes it difficult to manually correct any issues such as substrate wrinkles or deviations. It requires stopping the machine and handling the issue through the maintenance door on the shell, which does not meet the actual needs of on-site use. Summary of the Invention

[0005] The purpose of this invention is to provide a plastic packaging bag printing machine with an air curtain-type exhaust gas purification system that can effectively control the volatilization of exhaust gas during the transportation process.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is: a waste gas purification plastic packaging bag printing machine, comprising a conveyor line for conveying the substrate and a printing machine body disposed on the conveyor line for printing the substrate;

[0007] A downward-exhaust side-suction device is installed on the conveyor line behind the main body of the printing press to treat the volatile waste gas on the surface of the printing substrate. The downward-exhaust side-suction device includes an air curtain arranged along the length of the conveyor line above it and suction plates arranged on the left and right sides of the conveyor line. The suction plates have air ducts connected to the exhaust fan inside, and the side of the suction plate facing the conveyor line has a side suction port extending along the length of the conveyor line. The air curtain can blow an air curtain obliquely downward to both sides of the conveyor line and form an airlock zone between the air curtain and the conveyor line. The far end of the air curtain blown by the air curtain is opposite to the side suction port on the suction plate, and the blowing air volume of the air curtain is less than the exhaust air volume of the exhaust fan.

[0008] Preferably, the suction plates located on both sides of the conveyor line can adjust their spacing along the width direction of the conveyor line so that the suction plates can adapt to the width of the printed material on the conveyor line; the air curtain can adjust the blowing direction of the air curtain according to the position of the suction plates so that the far end of the air curtain can adapt to the side suction port on the suction plate.

[0009] Preferably, the air curtain includes a rectangular hanger, with two air blowing pipes extending along the length of the hanger located below both sides of the hanger. The two ends of the air blowing pipes are rotatably engaged with the end plates at both ends of the hanger, and the air blowing pipes are connected to an air source. The air blowing pipes are provided with strip-shaped air outlets extending along the length of the air blowing pipes. The air curtain also includes a rotary drive mechanism mounted on the hanger, which enables the air blowing pipes to rotate on the hanger under the drive of the rotary drive mechanism to adjust the orientation of the air outlets.

[0010] Preferably, the blower tube includes a central tube and an outer tube. A side through hole connecting the central tube and the outer tube is provided on one side wall of the central tube. Two air guide plates are provided on the side of the outer tube near the side through hole, extending tangentially along the outer tube and the central tube respectively. An air outlet is formed between the edges of the air guide plates. A spiral pressurized air passage is formed between the side through hole and the air guide plates.

[0011] Preferably, the two ends of the central tube extend beyond the outer tube and are mounted on the end plate of the hanger via bearings; the same end of the central tubes of the two blower tubes are connected to the two ends of the bends via swivel joints, and the two central tubes and the two bends together form an air supply loop; the air supply loop is connected to the air source.

[0012] Preferably, the rotary drive mechanism includes a linkage gear disposed at one end of two central tubes and meshing with each other, and a driven wheel disposed at the other end of one central tube. A rotary drive motor is disposed at the top of the hanger at the position of the driven wheel; and a drive wheel that meshes with the driven wheel is disposed at the output end of the rotary drive motor.

[0013] Preferably, a U-shaped mounting frame is provided below the conveyor line, with two sides of the mounting frame located outside the suction plate. The outer side of the suction plate is provided with multiple sliding guide rods extending along the width direction of the conveyor line. The sliding guide rods pass through the sides of the mounting frame and form a sliding engagement with the mounting frame.

[0014] The outer side of the air intake plate is provided with a corrugated expansion tube, which is connected to the exhaust fan through the corrugated expansion tube.

[0015] It also includes a lateral drive mechanism, under which the suction plates located on both sides of the conveyor line can move closer or separate from each other to adjust the spacing.

[0016] Preferably, the lateral drive mechanism includes multiple pairs of take-up reels corresponding to the sliding guide rods, located in the middle of the mounting frame, and multiple pairs of drive ropes; guide wheels are provided at the corners of the U-shaped mounting frame corresponding to each pair of take-up reels, and on the inner sidewalls of the mounting frame sides; one end of the drive rope is connected to the take-up reel, and the other end passes around the guide wheel and through the side of the mounting frame before connecting to the end of the sliding guide rod; a section of the sliding guide rod between the end of the sliding guide rod and the mounting frame is fitted with a return spring; the lateral drive mechanism also includes a drive assembly for rotating the take-up reels.

[0017] Preferably, the upper ends of the two paired take-up reels are respectively provided with first synchronous pulleys, and are connected by a first synchronous belt on the first synchronous pulleys; the lower end of the take-up reel located on the same side of the conveyor line is provided with a second synchronous pulley, and is connected by a second synchronous belt on the second synchronous pulley; the shaft of one of the take-up reels is connected to a take-up motor fixedly installed at the bottom of the mounting frame.

[0018] Preferably, the exhaust fan device includes a purification fan box fixedly installed at the bottom of the mounting frame. Inside the purification fan box, an activated carbon adsorption module and a photocatalytic module are arranged sequentially along the air path. The air inlet of the purification fan box is connected to a corrugated telescopic pipe through an air pipe, and the air outlet is connected to the air supply loop of the air curtain through an air pipe, and is provided with an external exhaust port.

[0019] The beneficial effects of this invention are mainly reflected in its ability to perform near-field suction of waste gas emitted from the substrate during the post-printing conveyor process, effectively solving the problem of harmful waste gas diffusion during transport. Furthermore, it eliminates the need for a traditional outer shell structure, ensuring uninterrupted operation of the printing press. Specifically, during use, the lower-row side suction device is positioned on the conveyor line behind the main body of the printing press. After printing, the substrate is subsequently conveyed along the conveyor belt and rapidly dried during this process. This invention, through the use of an air curtain, forms a relatively enclosed airlock zone on the conveyor line, reducing the risk of waste gas diffusion and escape from the substrate surface. Combined with a suction plate that directly suctions from the side near the substrate surface, this "near-field suction" rapidly extracts waste gas before it diffuses, resulting in high overall suction efficiency and a low waste gas escape rate. Because the exhaust fan draws in more air than the air curtain blows out, and the far end of the air curtain is aligned with the side suction port on the suction plate, it effectively prevents the diffusion of airflow at the far end of the air curtain from interfering with the exhaust gas path while ensuring rapid extraction and guidance of the exhaust gas. The overall exhaust gas purification effect is excellent. Since the air curtain is used to lock in the airflow and prevent exhaust gas escape, it does not interfere with the normal operation of the operator, allowing the operator to flexibly correct wrinkles, curling edges, and deviations on-site according to the printing press's condition. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention;

[0021] Figure 2 for Figure 1 Top view;

[0022] Figure 3 for Figure 2 The structure shown is viewed from direction AA.

[0023] Figure 4 for Figure 3 Enlarged view of section B in the middle;

[0024] Figure 5 for Figure 3 Enlarged view of section C;

[0025] Figure 6 for Figure 3 Enlarged view of section D in the middle. Detailed Implementation

[0026] like Figure 1As shown, this invention is an automated plastic packaging bag printing machine, including a conveyor line 1 for conveying substrates (plastic bag rolls, individual plastic bags, etc.) and a printing machine body 2 mounted on the conveyor line 1 for printing on the substrates. The printing machine body 2 is typically mounted on the conveyor line 1 and is enclosed except for the inlet and outlet. The casing of the printing machine body 2 allows for direct collection of waste gas during the printing process, which is then connected to the workshop waste gas treatment system for centralized discharge and treatment. After printing by the printing machine body, the main volatile waste gases are collected and discharged through the casing on the printing machine body 2. However, inevitably, some volatile waste gases will continue to evaporate from the surface of the substrate. This waste gas concentration is relatively low and close to the surface of the substrate. Although traditional methods can collect this waste gas by installing a gas collection hood, the escape rate of the waste gas is extremely high in a large space because the gas collection hood is close to the surface of the substrate, making it difficult to achieve a good treatment effect.

[0027] Before being conveyed to sorting, winding, or other equipment, the present invention, such as Figure 1 and 2 As shown, a downward-exhaust side-suction device 3 for treating volatile waste gas from the surface of the printing substrate is installed on the conveyor line 1 behind the main body 2 of the printing machine. Figure 2 As shown, the lower side suction device 3 includes an air curtain 4 arranged along the length of the conveyor line 1 above the conveyor line 1 and suction plates 5 arranged on the left and right sides of the conveyor line 1. The suction plates 5 have internal air ducts connected to the exhaust system, and the side of the suction plate 5 facing the conveyor line 1 has a side suction port 6 extending along the length of the conveyor line 1. The air curtain 4 can blow an air curtain obliquely downwards towards both sides of the conveyor line 1, forming an airlock zone 7 between the air curtain and the conveyor line 1. The far end of the air curtain blown by the air curtain 4 is opposite to the side suction port 6 on the suction plate 5, and the blowing air volume of the air curtain 4 is less than the exhaust air volume of the exhaust system.

[0028] 2. The waste gas purification plastic packaging bag printing machine according to claim 1, characterized in that: the suction plates 5 located on both sides of the conveyor line 1 can adjust the spacing along the width direction of the conveyor line 1 so that the suction plates 5 adapt to the width of the printed material on the conveyor line 1. The air curtain 4 can adjust the blowing direction of the air curtain according to the position of the suction plates 5 so that the far end of the air curtain adapts to the side suction port 6 on the suction plates 5.

[0029] 3. The waste gas purification plastic packaging bag printing machine according to claim 2, characterized in that: the air curtain 4 includes a rectangular hanger 8, and two air blowing pipes 9 extending along the length direction of the hanger 8 are arranged below both sides of the hanger 8. The two ends of the air blowing pipes 9 are rotatably engaged with the end plates 10 at both ends of the hanger 8, and the air blowing pipes 9 are connected to the air source. A strip-shaped air outlet 11 extending along the length direction of the air blowing pipe 9 is provided on the air blowing pipe 9. The air curtain 4 also includes a rotary drive mechanism arranged on the hanger 8, and the air blowing pipes 9 can rotate on the hanger 8 under the drive of the rotary drive mechanism to adjust the orientation of the air outlet 11.

[0030] 4. The waste gas purification plastic packaging bag printing machine according to claim 3, characterized in that: the blowing pipe 9 includes a central pipe 12 and an outer pipe 13, and a side through hole 14 connecting the central pipe 12 and the outer pipe 13 is provided on one side wall of the central pipe 12. Two air guide plates 15 are provided on the side of the outer pipe 13 near the side through hole 14, extending tangentially along the outer pipe 13 and the central pipe 12 respectively, and the edges of the air guide plates 15 form an air outlet 11. A spiral pressurized air passage 16 is formed between the side through hole 14 and the air guide plate 15.

[0031] 5. The waste gas purification plastic packaging bag printing machine according to claim 4, characterized in that: both ends of the central tube 12 extend beyond the outer tube 13 and are mounted on the end plate 10 of the hanger 8 via bearings. The same end of the central tube 12 of the two blowing pipes 9 is connected to both ends of the bent pipe 18 via a rotary joint 17, and the two central tubes 12 and the two bent pipes 18 together form an air supply loop. The air supply loop is connected to an air source.

[0032] 6. The waste gas purification plastic packaging bag printing machine according to claim 5, characterized in that: the rotary drive mechanism includes a linkage gear 19 disposed at one end of two central tubes 12 and meshing with each other, and a driven wheel disposed at the other end of one central tube 12, wherein a rotary drive motor 20 is disposed on the top of the hanger 8 at the position of the driven wheel. The output end of the rotary drive motor 20 is provided with a driving wheel that meshes with the driven wheel.

[0033] 7. The waste gas purification plastic packaging bag printing machine according to claim 6, characterized in that: a U-shaped mounting frame 21 is provided below the conveyor line 1, the two sides of the mounting frame 21 are located outside the suction plate 5, and the outer side of the suction plate 5 is provided with a plurality of sliding guide rods 22 extending along the width direction of the conveyor line 1, the sliding guide rods 22 passing through the side of the mounting frame 21 and forming a sliding fit with the mounting frame 21.

[0034] The air intake plate 5 is provided with a corrugated telescopic tube 23 on its outward-facing side, and is connected to the exhaust fan through the corrugated telescopic tube 23.

[0035] It also includes a lateral drive mechanism, in which the suction plates 5 located on both sides of the conveyor line 1 can move closer or separate from each other under the drive of the lateral drive mechanism to adjust the spacing.

[0036] 8. The waste gas purification plastic packaging bag printing machine according to claim 7, characterized in that: the transverse drive mechanism includes multiple pairs of take-up reels 24 disposed in the middle of the mounting frame 21 and corresponding to the sliding guide rod 22, and multiple pairs of drive ropes 25. Guide wheels 26 are provided at the U-shaped corner of the mounting frame 21 corresponding to each pair of take-up reels 24, and on the inner sidewall of the side of the mounting frame 21. One end of the drive rope 25 is connected to the take-up reel 24, and the other end passes around the guide wheel 26 and through the side of the mounting frame 21 before connecting to the end of the sliding guide rod 22. A return spring 27 is sleeved on a section of the sliding guide rod 22 between the end of the sliding guide rod 22 and the mounting frame 21. The transverse drive mechanism also includes a drive assembly for driving the take-up reels 24 to rotate.

[0037] 9. The waste gas purification plastic packaging bag printing machine according to claim 8, characterized in that: a first synchronous pulley 28 is correspondingly provided on the upper end of the two paired take-up reels 24, and a transmission engagement is formed by a first synchronous belt 29 provided on the first synchronous pulley 28. A second synchronous pulley 30 is provided on the lower end of the take-up reel 24 located on the same side of the conveyor line 1, and a transmission engagement is formed by a second synchronous belt 31 provided on the second synchronous pulley 30. The shaft of one of the take-up reels 24 is connected to a take-up motor 32 fixedly provided at the bottom of the mounting frame 21.

[0038] 10. The waste gas purification plastic packaging bag printing machine according to claim 9, characterized in that: the exhaust fan device includes a purification fan box 33 fixedly installed at the bottom of the mounting frame 21, and an activated carbon adsorption module and a photocatalytic module are sequentially arranged inside the purification fan box 33 along the air path direction. The air inlet of the purification fan box 33 is connected to the corrugated telescopic pipe 23 through an air pipe, and the air outlet is connected to the air supply loop of the air curtain 4 through an air pipe, and is provided with an external exhaust port 34.

Claims

1. A waste gas purification plastic packaging bag printing machine, characterized in that: It includes a conveyor line (1) for conveying the substrate and a printing press body (2) disposed on the conveyor line (1) for printing the substrate. The printing press body (2) is equipped with a lower side suction device (3) for treating the volatile waste gas on the surface of the printing substrate on the conveyor line (1). The lower side suction device (3) includes an air curtain (4) arranged above the conveyor line (1) along the length of the conveyor line (1) and suction plates (5) arranged on the left and right sides of the conveyor line (1). The suction plate (5) is provided with an air duct connected to the exhaust fan. The side of the suction plate (5) facing the conveyor line (1) is provided with a side suction port (6) extending along the length of the conveyor line (1). The air curtain (4) can blow the air curtain obliquely downward to both sides of the conveyor line (1) and form an airlock zone (7) between the air curtain and the conveyor line (1). The far end of the air curtain blown by the air curtain (4) is opposite to the side suction port (6) on the suction plate (5), and the blowing air volume of the air curtain (4) is less than the exhaust air volume of the exhaust fan.

2. The waste gas purification plastic packaging bag printing machine according to claim 1, characterized in that: The suction plates (5) located on both sides of the conveyor line (1) can adjust the spacing along the width direction of the conveyor line (1) so that the suction plates (5) can adapt to the width of the printed material on the conveyor line (1); the air curtain (4) can adjust the blowing direction of the air curtain according to the position of the suction plates (5) so that the far end of the air curtain can adapt to the side suction port (6) on the suction plates (5).

3. The waste gas purification plastic packaging bag printing machine according to claim 2, characterized in that: The air curtain (4) includes a rectangular hanger (8), and two air pipes (9) extending along the length of the hanger (8) are provided on the lower sides of both sides of the hanger (8). The two ends of the air pipes (9) are rotatably engaged with the end plates (10) at both ends of the hanger (8), and the air pipes (9) are connected to the air source. The air pipes (9) are provided with strip-shaped air outlets (11) extending along the length of the air pipes (9). The air curtain (4) also includes a rotary drive mechanism provided on the hanger (8). The air pipes (9) can rotate on the hanger (8) under the drive of the rotary drive mechanism to adjust the orientation of the air outlets (11).

4. The waste gas purification plastic packaging bag printing machine according to claim 3, characterized in that: The blower pipe (9) includes a central pipe (12) and an outer pipe (13). A side through hole (14) connecting the central pipe (12) and the outer pipe (13) is provided on one side wall of the central pipe (12). Two air guide plates (15) are provided on the side of the outer pipe (13) near the side through hole (14), which extend tangentially along the outer pipe (13) and the central pipe (12) respectively. An air outlet (11) is formed between the edges of the air guide plates (15). A spiral pressurized air passage (16) is formed between the side through hole (14) and the air guide plate (15).

5. The waste gas purification plastic packaging bag printing machine according to claim 4, characterized in that: The two ends of the central tube (12) extend beyond the outer tube (13) and are mounted on the end plate (10) of the hanger (8) through bearings; the same end of the central tube (12) of the two blower tubes (9) is connected to the two ends of the bend (18) through a rotary joint (17), and the two central tubes (12) and the two bends (18) together form an air supply loop; the air supply loop is connected to the air source.

6. The waste gas purification plastic packaging bag printing machine according to claim 5, characterized in that: The rotary drive mechanism includes a linkage gear (19) that is disposed at one end of two central tubes (12) and meshes with each other, and a driven wheel disposed at the other end of one central tube (12). A rotary drive motor (20) is disposed on the top of the hanger (8) at the position of the driven wheel. A drive wheel that meshes with the driven wheel is disposed at the output end of the rotary drive motor (20).

7. The waste gas purification plastic packaging bag printing machine according to claim 6, characterized in that: A U-shaped mounting bracket (21) is provided below the conveyor line (1). The two sides of the mounting bracket (21) are located outside the suction plate (5). The outer side of the suction plate (5) is provided with multiple sliding guide rods (22) extending along the width direction of the conveyor line (1). The sliding guide rods (22) pass through the side of the mounting bracket (21) and form a sliding fit with the mounting bracket (21). The air intake plate (5) is provided with a corrugated telescopic tube (23) on the outward side, and is connected to the exhaust fan through the corrugated telescopic tube (23); It also includes a lateral drive mechanism, in which the suction plates (5) located on both sides of the conveyor line (1) can move closer to each other or separate under the drive of the lateral drive mechanism to adjust the spacing.

8. The waste gas purification plastic packaging bag printing machine according to claim 7, characterized in that: The lateral drive mechanism includes multiple pairs of take-up reels (24) located in the middle of the mounting frame (21) and corresponding to the sliding guide rod (22), as well as multiple pairs of drive ropes (25); each pair of take-up reels (24) is provided with a guide wheel (26) at the U-shaped corner of the mounting frame (21) and on the inner side wall of the side of the mounting frame (21); one end of the drive rope (25) is connected to the take-up reel (24), and the other end passes around the guide wheel (26) and through the side of the mounting frame (21) and is connected to the end of the sliding guide rod (22); a section of the sliding guide rod (22) between the end of the sliding guide rod (22) and the mounting frame (21) is fitted with a return spring (27); the lateral drive mechanism also includes a drive assembly for driving the take-up reels (24) to rotate.

9. The waste gas purification plastic packaging bag printing machine according to claim 8, characterized in that: The upper ends of the two paired take-up reels (24) are respectively provided with first synchronous pulleys (28), and are connected by a first synchronous belt (29) provided on the first synchronous pulleys (28); the lower end of the take-up reel (24) located on the same side of the conveyor line (1) is provided with a second synchronous pulley (30), and is connected by a second synchronous belt (31) provided on the second synchronous pulley (30); the shaft of one of the take-up reels (24) is connected to the take-up motor (32) fixedly provided at the bottom of the mounting frame (21).

10. The waste gas purification plastic packaging bag printing machine according to claim 9, characterized in that: The exhaust fan device includes a purification fan box (33) fixedly installed at the bottom of the mounting frame (21). The purification fan box (33) is provided with an activated carbon adsorption module and a photocatalytic module in sequence along the air path. The air inlet of the purification fan box (33) is connected to the corrugated telescopic pipe (23) through an air pipe, and the air outlet is connected to the air supply loop of the air curtain (4) through an air pipe, and is provided with an external exhaust port (34).

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