Energy-saving circulating water-based gravure drying device

Abstract

The application discloses an energy-saving and circulating water-based gravure printing drying device, which comprises a supporting assembly for supporting a printing object, an isolation cover arranged on the outer side of the supporting assembly, a drying cavity for drying ink of the printing object formed by the gap between the supporting assembly and the isolation cover, and the drying cavity is airtight closed around; a return air inlet is arranged on the side of the drying cavity away from the supporting assembly, a pre-drying section with a partition air nozzle is arranged between the return air inlet and a feeding inlet, a strong drying section with a main air nozzle is arranged between the air inlet and a discharging outlet; the return air inlet is communicated with the air inlet of a main air blower, the air outlet of the main air blower is communicated with the main air nozzle and the partition air nozzle respectively; and an air treatment assembly is arranged between the air blower and the return air inlet. The application adopts a drying mode combining relatively low-speed pre-drying based on closed air circulation and relatively high-speed strong drying, reduces the influence of high-speed air flow on ink marks, simultaneously purifies and controls the temperature of circulating air, and realizes energy saving while guaranteeing the quality and drying speed of water-based gravure printing.

Description

Technical Field

[0001] This invention relates to the field of printing drying technology, and in particular to an energy-saving, circulating water-based gravure printing drying device. Background Technology

[0002] Gravure printing is irreplaceable due to its outstanding print quality. In recent years, with the development of water-based ink technology, water-based inks have been increasingly used in gravure printing. However, because water-based inks primarily use water as a solvent, they have a slower drying speed compared to solvent-based inks. With the development of gravure printing technology, printing speeds have exceeded 600 meters per minute, and the drying speed of existing drying equipment has severely limited the improvement of water-based gravure printing speed. Incomplete drying of the ink during printing can lead to serious print quality problems such as residual moisture and stickiness.

[0003] Therefore, it is urgent to design a drying device for water-based gravure printing based on the characteristics of water-based inks and gravure printing processes. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the present invention aims to provide an energy-saving circulating water-based gravure drying device. Based on the characteristics of water-based inks and gravure printing processes, it adopts a drying method that combines relatively low-speed pre-drying and relatively high-speed strong drying to reduce the impact of high-speed airflow on ink marks. It also adopts a closed-loop air circulation method to reduce heat loss, while purifying and temperature-controlling the circulating air. This achieves energy saving while ensuring the quality and drying speed of water-based gravure printing.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] An energy-saving circulating water-based gravure printing drying device is characterized in that it includes a planar or arc-shaped support component (10) for supporting the printed material (80), an isolation cover (40) is provided on the outside of the support component (10), the gap between the isolation cover (40) and the support component (10) forms a drying chamber (43) for drying the ink of the printed material (80), the drying chamber (43) is airtightly sealed around, and an inlet (41) and an outlet (42) for the printed material (80) to enter and exit are respectively provided at both ends;

[0007] The support assembly (10) includes a heating plate (11) that is close to and heats the printed material (80), and a plurality of rollers (14) are provided between the heating plate (11) and the printed material (80) to isolate the printed material (80) from the heating plate (11), and the rollers (14) make rolling contact with the printed material 80.

[0008] A return air vent (33) is provided on the side of the drying chamber (43) away from the support assembly (10). The area between the return air vent (33) and the feed inlet (41) is a pre-drying section, and a partition air nozzle (31) is provided in the pre-drying section. The area between the return air vent (33) and the discharge outlet (42) is a strong drying section, and a main air nozzle (30) is provided in the strong drying section. The air outlet of the main air nozzle (30) faces the return air vent (33). The relative velocity between the airflow and the printed material (80) in the pre-drying section is lower than the relative velocity between the airflow and the printed material (80) in the strong drying section.

[0009] The return air inlet (33) is equipped with a main fan (20) at the end away from the isolation cover (40). The main air nozzle (30) and the isolation air nozzle (31) are connected to the air outlet of the main fan (20) through the air outlet pipe (32). The air inlet of the main fan (20) is connected to the return air inlet (33).

[0010] A baffle (44) is provided on the isolation cover (40) between the main air nozzle (30) and / or the partition air nozzle 31 and the return air inlet (33);

[0011] An air handling unit (60) is provided between the main fan (20) and the return air outlet (33) and / or on the air outlet duct (32), the air handling unit (60) including at least a gas-liquid separator.

[0012] Preferably, the spoiler (44) is a thin-walled arc-shaped structure, with one end of the spoiler (44) connected to the isolation cover (40) and the other end being a free end; the normal of the arc faces the return air inlet (33).

[0013] Preferably, the return air inlet (33) is close to the feed inlet (41), one isolation air nozzle (31) is provided, two or more main air nozzles (30) are provided, and an air volume valve (70) is provided on the air outlet pipe (32) corresponding to the main air nozzle (30) and / or the isolation air nozzle (31).

[0014] Preferably, the main air blowing angle (a) of the main air nozzle (30) is ≥30 degrees.

[0015] Preferably, the air handling assembly (60) includes one or a combination of a purification module (61) and a heat exchange module (62).

[0016] Preferably, the purification module (61) includes one or a combination of a centrifugal gas-liquid separator and an adsorption filter.

[0017] Preferably, the air handling unit (60) is disposed between the main fan (20) and the return air outlet (33), a return air fan (50) is disposed between the main fan (20) and the return air outlet (33), and a pressure balancing valve (71) is disposed between the return air fan (50) and the main fan (20).

[0018] Preferably, a heat insulation plate (12) is provided on the outside of the heating plate (11) and / or the isolation cover (40) and / or the air outlet pipe (32).

[0019] Preferably, a follower belt (13) is provided between the rollers (14) of the support assembly (10) and the printed material (80), and at least one of the rollers (14) is connected to a driver;

[0020] The follower belt (13) has a thin-walled annular structure and the follower belt (13) has a non-slip friction surface contact with the printed material (80).

[0021] Preferably, an air-insulating wheel (45) is provided between the feed inlet (41) and the air-insulating nozzle (31) and / or the discharge outlet (42) and the main air nozzle (30).

[0022] Preferably, the main air nozzle (30) and / or the partition air nozzle (31) are provided with an angle adjustment device, the angle adjustment device including a fixed end and a rotating end for changing the relative angle between the main air nozzle (30), the partition air nozzle (31) and the printed material (80); the fixed end is connected to the isolation cover (40), and the rotating end is connected to the main air nozzle (30) and the partition air nozzle (31).

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] 1. The drying chamber is divided into a pre-drying section and a strong drying section. By using different relative drying air velocities, the gravure ink is dried quickly while the ink film of the gravure ink does not spread.

[0025] 2. Install a baffle nozzle at the feed inlet to seal the drying chamber through airflow, ensuring good sealing while maintaining ink film quality;

[0026] 3. The closed-loop structure, consisting of a closed drying chamber, main air nozzle, isolation air nozzle, and return air inlet, allows the air used for drying to be circulated, thereby minimizing heat loss and reducing energy consumption.

[0027] 4. At the same time, a baffle is installed in the drying chamber to generate high-speed, vortex-like airflow away from the printed material, thereby increasing the contact between air and printing ink and improving drying efficiency.

[0028] 5. Since water-based inks contain high levels of moisture, and other volatile substances and particulate matter inevitably accumulate during air circulation, in order to ensure the quality of the circulating dry air and reduce the moisture and impurities in the air, a centrifugal gas-liquid separator that is easy to maintain and has low maintenance costs is first used to separate the moisture and impurities in the circulating dry air, and then further purification is carried out through an adsorption filter. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view of the overall structure of the present invention;

[0030] Figure 2 for Figure 1 A magnified view of part A.

[0031] The components include: support assembly 10, heating plate 11, heat insulation plate 12, follower belt 13, roller 14, main fan 20, main air nozzle 30, partition air nozzle 31, air outlet duct 32, return air inlet 33, isolation cover 40, feed inlet 41, discharge outlet 42, drying chamber 43, baffle plate 44, air baffle wheel 45, return air fan 50, air handling assembly 60, purification module 61, heat exchange module 62, air volume valve 70, air pressure balance valve 71, printed material 80, and main blowing angle a. Detailed Implementation

[0032] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0033] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," "up," "down," and similar expressions used in this document are for illustrative purposes only.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0035] The present invention will now be further described with reference to the accompanying drawings and specific embodiments:

[0036] like Figure 1 , 2 As shown, an energy-saving circulating water-based gravure printing drying device includes a planar or arc-shaped support component 10 that supports the printed material 80. A uniformly spaced isolation cover 40 is provided on the outside of the support component 10. The gaps form a drying chamber 43 for drying the ink on the printed material 80. The drying chamber 43 is airtight and has an inlet 41 and an outlet 42 at both ends for the printed material 80 to enter and exit.

[0037] The supporting assembly 10 includes a heating plate 11 that is close to and heats the printed material 80. A plurality of rollers 14 are disposed between the heating plate 11 and the printed material 80 to isolate the printed material 80 from the heating plate 11. The rollers 14 are in rolling contact with the printed material 80.

[0038] A return air vent 33 is provided on the side of the drying chamber 43 away from the support assembly 10. The area between the return air vent 33 and the feed inlet 41 is a pre-drying section, and a partition air nozzle 31 is provided in the pre-drying section. The area between the return air vent 33 and the discharge outlet 42 is a strong drying section, and a main air nozzle 30 is provided in the strong drying section. The air outlet of the main air nozzle 30 faces the return air vent 33.

[0039] The return air vent 33 is equipped with a main fan 20 at the end away from the isolation cover 40. The main air nozzle 30 and the isolation air nozzle 31 are respectively connected to the air outlet of the main fan 20 through the air outlet pipe 32. The air inlet of the main fan 20 is connected to the return air vent 33.

[0040] An air handling assembly 60 is provided between the main fan 20 and the return air outlet 33 and / or on the air outlet duct 32. The air handling assembly 60 includes at least a gas-liquid separator, and an air volume valve 70 is provided on the air outlet duct 32.

[0041] Water-based gravure inks, compared to solvent-based inks, have a slower drying speed. Besides the ink formulation, the main factors affecting ink drying speed are temperature and airflow. For some printing materials, such as PE and PVC, the ink has poor absorbency, and the drying temperature needs to be controlled below 50 degrees Celsius. Therefore, higher requirements are placed on the drying airflow and airflow. The heating plate providing the required drying temperature and the main fan requiring the necessary airflow consume a significant amount of electrical energy.

[0042] The present invention adopts a closed-loop structure consisting of a closed drying chamber 43, a main air nozzle 30, a partition air nozzle 31, and a return air vent 33, so that the air used for drying is circulated, thereby minimizing heat loss and reducing the power consumption of the heating plate.

[0043] In existing technologies, gravure printing speeds have exceeded 10 m / s, and drying air speeds are approximately 20-50 m / s. Furthermore, the ink film thickness in gravure printing is relatively large. While drying air speed significantly impacts drying speed, air utilization efficiency and the potential impact of excessively high air speeds on the ink film must also be considered. Since the ink on the printed material 80 is still in a wet, sticky state when it enters the feed inlet 41, it is impossible to isolate the feed inlet 41 from the drying chamber 43 using a partition pressed against the printed material 80. Therefore, in this embodiment, a partition nozzle 31 is provided on one side of the feed inlet 41. By adjusting the outlet angle and air speed of the partition nozzle 31, the airflow from the partition nozzle 31, under the influence of its direction and the negative pressure of the return air inlet 33, prevents the airflow from overflowing the drying chamber 43. This also isolates outside air from entering the drying chamber 43, making it an important structure for achieving closed-loop circulation and preventing heat loss.

[0044] In this embodiment, the isolation nozzle 31 is positioned on one side of the feed inlet 41, and the airflow direction of the isolation nozzle 31 is the same as that of the printed material 80. This reduces the relative velocity between the airflow and the printed material 80, thus achieving good blocking even with a relatively low-speed airflow. Simultaneously, it ensures that the ink residue from the wet, sticky ink does not spread or cause quality defects in the low-speed pre-drying section. Correspondingly, in this embodiment, the main nozzle 30 is positioned on one side of the discharge outlet 42, and the airflow of the main nozzle 30 flows in the opposite direction to the conveying direction of the printed material 80. This further increases the relative velocity between the airflow and the printed material 80, thereby forming a relatively higher-speed drying airflow. After preliminary drying by the isolation nozzle 31, the high-speed drying airflow in the high-speed strong drying section will also not cause ink spread.

[0045] By combining a low-speed pre-drying section and a high-speed strong drying section, the efficiency of airflow utilization is improved while ensuring drying speed and ink quality, thus achieving energy saving and consumption reduction.

[0046] In order to increase the length of the drying section while minimizing the size of the printing equipment, the support assembly 10 and the isolation cover 40 are arc-shaped, but can also be set as planar structures if needed.

[0047] Furthermore, a baffle plate 44 is provided on the isolation cover 40 between the main air nozzle 30 and / or the partition air nozzle 31 and the return air outlet 33. The baffle plate 44 is a thin-walled arc-shaped structure. One end of the baffle plate 44 is connected to the isolation cover 40, and the other end is a free end. The normal of the arc is directed towards the return air outlet 33.

[0048] In this embodiment, a thin-walled, arc-shaped spoiler is used, and the protrusion height of the spoiler is less than 1 / 3 of the height of the drying chamber 43. In other embodiments, depending on the structure of the drying chamber, an arc-shaped boss structure may also be used.

[0049] Since the surface area of ​​the ink cannot be increased to increase the contact area with the airflow in a pre-designed printed material, airflow velocity is a crucial factor affecting ink drying speed under the same contact area, flow rate, pressure, temperature, and humidity conditions. However, in unsaturated air conditions, repeatedly exposing the ink to air can achieve good drying results while reducing airflow. Increasing airflow requires increasing the power of the fan, thus necessitating more electricity.

[0050] Therefore, in this embodiment, the airflow away from the printed material is generated at high speed and in a vortex by the baffle plate 44, thereby increasing the contact between the air and the printing ink and improving the drying efficiency.

[0051] Furthermore, in order to improve the utilization efficiency of airflow and increase the drying speed under the same drying chamber length, the return air inlet 33 is close to the feed inlet 41, one isolation air nozzle 31 is provided, two or more main air nozzles 30 are provided, and air volume valves 70 are provided on the air outlet pipes 32 corresponding to the main air nozzles 30 and / or isolation air nozzles 31.

[0052] By adjusting the airflow valve 70 corresponding to each nozzle, the airflow speed in each drying section can be further segmented and precisely controlled.

[0053] Furthermore, in order to obtain a good drying airflow and reduce the impact of high-speed airflow on the printed material 80, the main air blowing angle α of the main air nozzle 30 is ≥30 degrees.

[0054] The main blowing angle is the angle between the main air nozzle 30 and the normal of the printed material 80 at the corresponding location of the main air nozzle 30.

[0055] Furthermore, the air handling assembly 60 includes one or a combination of a purification module 61 and a heat exchange module 62.

[0056] Furthermore, the purification module 61 includes one or a combination of a centrifugal gas-liquid separator and an adsorption filter.

[0057] In this embodiment, since water-based inks contain high levels of moisture, and other volatile substances and particulate matter inevitably accumulate during air circulation, a combination of a centrifugal gas-liquid separator and an adsorption filter is used to treat the circulating air in order to ensure the quality of the circulating dry air, reduce the moisture and impurities in the air, and make the airflow temperature more stable.

[0058] To extend the lifespan of the adsorption filter, a centrifugal gas-liquid separator that is easy to maintain and has low maintenance costs is first used to separate moisture and impurities from the circulating dry air, and then the air is further purified by the adsorption filter; the heat exchange module 62 is used to control the temperature of the circulating air.

[0059] Furthermore, the air handling unit 60 is disposed between the main fan 20 and the return air outlet 33, a return air fan 50 is disposed between the main fan 20 and the return air outlet 33, and a pressure balancing valve 71 is disposed between the return air fan 50 and the main fan 20.

[0060] In this embodiment, the return air fan 50 is used to increase the air pressure and speed of the return air, especially when an air handling unit 60 is provided, it can improve the air circulation efficiency.

[0061] The pressure balancing valve 71 opens and closes by monitoring the set air pressure value in the air circulation duct (default is normally closed). It opens when the positive or negative air pressure in the circulation duct exceeds a threshold. After opening, the pressure balancing valve 71 exhausts or intakes air to stabilize the pressure of the circulating air in the duct, ensuring stable fan load and improving working efficiency. In this embodiment, the return air fan 50 and the main fan 20 are variable frequency fans. An alarm device is installed on the pressure balancing valve 71 to alert the operator of any abnormality when the valve opens.

[0062] Furthermore, in order to reduce heat loss, a heat insulation plate 12 is provided on the outside of the heating plate 11 and / or the isolation cover 40 and / or the air outlet duct 32.

[0063] Furthermore, in order to reduce the vibration of the printed material 80 when subjected to high-speed airflow, a follower belt 13 is provided between the rollers 14 of the support assembly 10 and the printed material 80, and at least one of the rollers 14 is connected to a driver.

[0064] The follower belt 13 has a thin-walled annular structure, and the follower belt 13 has a non-slip friction surface contact with the printed material 80.

[0065] In this embodiment, the driver drives the roller 14 to rotate the follower belt 13. The linear velocity of the follower belt 13 is the same as that of the printed material 80, reducing friction between the printed material 80 and the follower belt 13. To meet the requirements of heat conduction and strength, the follower belt 13 is made of stainless steel.

[0066] Furthermore, in order to improve the isolation between the drying chamber 43 and the outside world, an air-insulating wheel 45 is provided between the feed inlet 41 and the isolation air nozzle 31 and / or the discharge port 42 and the main air nozzle 30.

[0067] In this embodiment, the wind deflector 45 is rotatably connected to the isolation cover 40. Since the ink at the inlet 41 is not dry, the wind deflector 45 on the inlet 41 side is close to but does not contact the printed material 80; the ink at the outlet 42 is dry, so the wind deflector 45 on the outlet 42 side can be in close contact with the printed material 80.

[0068] Furthermore, the main air nozzle 30 and / or the partition air nozzle 31 are provided with an angle adjustment device (not shown in the figure). The angle adjustment device includes a fixed end and a rotating end for changing the relative angle between the main air nozzle 30, the partition air nozzle 31 and the printed material 80. The fixed end is connected to the isolation cover 40, and the rotating end is connected to the main air nozzle 30 and the partition air nozzle 31.

[0069] Those skilled in the art can make various other corresponding changes and modifications based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. An energy-saving circulating water-based gravure printing drying device, characterized in that: The device includes a planar or arc-shaped support assembly (10) for supporting the printed material (80). An isolation cover (40) is provided on the outside of the support assembly (10). The gap between the isolation cover (40) and the support assembly (10) forms a drying chamber (43) for drying the ink of the printed material (80). The drying chamber (43) is airtight and has an inlet (41) and an outlet (42) at both ends for the printed material (80) to enter and exit. The support assembly (10) includes a heating plate (11) that is close to and heats the printed material (80), and a plurality of rollers (14) are provided between the heating plate (11) and the printed material (80) to isolate the printed material (80) from the heating plate (11), and the rollers (14) make rolling contact with the printed material 80. A return air vent (33) is provided on the side of the drying chamber (43) away from the support assembly (10). The area between the return air vent (33) and the feed inlet (41) is a pre-drying section, in which a partition nozzle (31) is provided. The area between the return air vent (33) and the discharge outlet (42) is a strong drying section, in which a main nozzle (30) is provided, with its outlet facing the return air vent (33). The relative velocity between the airflow and the printed material (80) in the pre-drying section is lower than that in the strong drying section. The relative velocity between the airflow within the section and the printed material (80), the airflow direction of the isolation nozzle (31) moves in the same direction as the printed material (80), and the airflow of the main nozzle (30) flows in the opposite direction to the conveying direction of the printed material (80); the return air inlet (33) is provided with a main fan (20) at the end away from the isolation cover (40), the main nozzle (30) and the isolation nozzle (31) are respectively connected to the air outlet of the main fan (20) through the air outlet pipe (32), and the air inlet of the main fan (20) is connected to the return air inlet (33); A baffle (44) is provided on the isolation cover (40) between the main air nozzle (30) and / or the partition air nozzle 31 and the return air inlet (33); An air handling unit (60) is provided between the main fan (20) and the return air outlet (33) and / or on the air outlet duct (32). The air handling unit (60) includes at least a gas-liquid separator. An angle adjustment device is provided on the main air nozzle (30) and / or the isolation air nozzle (31).

2. The energy-saving circulating water-based gravure printing drying device as described in claim 1, characterized in that: The spoiler (44) is a thin-walled arc-shaped structure. One end of the spoiler (44) is connected to the isolation cover (40), and the other end is a free end. The normal of the arc is directed toward the return air inlet (33).

3. The energy-saving circulating water-based gravure printing drying device as described in claim 1, characterized in that: The return air inlet (33) is close to the feed inlet (41). One isolation air nozzle (31) is provided, and two or more main air nozzles (30) are provided. An air volume valve (70) is provided on the air outlet pipe (32) corresponding to the main air nozzle (30) and / or the isolation air nozzle (31).

4. The energy-saving circulating water-based gravure printing drying device as described in claim 1, characterized in that: The main air nozzle (30) has a main air blowing angle (a) ≥ 30 degrees.

5. The energy-saving circulating water-based gravure printing drying device as described in claim 1, characterized in that: The air handling assembly (60) includes one or a combination of an air purification module (61) for purifying air and a heat exchange module (62) for controlling air temperature.

6. The energy-saving circulating water-based gravure drying device as described in claim 5, characterized in that: The purification module (61) includes one or a combination of a centrifugal gas-liquid separator and an adsorption filter.

7. The energy-saving circulating water-based gravure printing drying device as described in claim 1 or 5, characterized in that: The air handling unit (60) is disposed between the main fan (20) and the return air outlet (33). A return air fan (50) is disposed between the main fan (20) and the return air outlet (33). A pressure balancing valve (71) is disposed between the return air fan (50) and the main fan (20).

8. The energy-saving circulating water-based gravure printing drying device as described in claim 1, characterized in that: A follower belt (13) is provided between the roller (14) of the support component (10) and the printed material (80), at least one of the rollers (14) being connected to a driver; the follower belt (13) has a thin-walled annular structure, and the follower belt (13) and the printed material (80) are in surface contact without sliding friction.

9. The energy-saving circulating water-based gravure printing drying device as described in claim 1, characterized in that: An air-insulating wheel (45) is placed between the feed inlet (41) and the isolation air nozzle (31) and / or the discharge outlet (42) and the main air nozzle (30).

10. The energy-saving circulating water-based gravure drying device as described in claim 1, characterized in that: The angle adjustment device includes a fixed end and a rotating end for changing the relative angle between the main air nozzle (30), the partition air nozzle (31) and the printed material (80); the fixed end is connected to the isolation cover (40), and the rotating end is connected to the main air nozzle (30) and the partition air nozzle (31).

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