Hollow heating adsorption tube and digital printer with same

Abstract

The invention relates to the technical field of digital printing equipment, in particular to a hollow heating adsorption tube and a digital printer with the same, the hollow heating adsorption tube comprises a hollow cylindrical tube body and a center rod arranged in the cylindrical tube body, and the center rod is arranged in the axial direction of the cylindrical tube body and arranged in the middle of the cylindrical tube body; an annular cavity is formed between the cylindrical pipe body and the center rod, an isolation part is arranged between the cylindrical pipe body and the center rod, the annular cavity is divided into a heating and drying cavity body and a negative pressure adsorption cavity body by the isolation part, a through hole is formed in the surface of the cylindrical pipe body, and the through hole is communicated with the outside and the inside of the annular cavity. The layout of the negative pressure adsorption cavity and the through small holes is optimally designed, so that the material film is tightly attached to the cylindrical pipe body, the adsorption precision reaches + / -0.5 mm, a foundation is laid for high-precision digital printing (the resolution ratio is larger than or equal to 1200 dpi), the pattern definition and the overprinting accuracy are greatly improved, and the rejection rate is reduced by more than 40%.

Description

Technical Field

[0001] The invention relates to the technical field of digital printing equipment, and in particular to a hollow heating adsorption tube and a digital printer having the tube. Background Art

[0002] In the field of digital printing, the stable transportation of material film has always been a key factor in ensuring printing quality and efficiency. Through a large number of actual production surveys, it was found that the traditional equipment is very common due to the asynchronous transmission of the feed and discharge ends, which causes the material film to stretch and deform. For example, in the printing process of a certain type of high-precision product (such as the printing of electronic product shells with a resolution requirement of 1200dpi and above), about 60% of traditional equipment will cause the material film to stretch significantly, with an average stretch rate of 3%-5%. This stretching deformation directly leads to serious disproportion, line distortion and overprint errors in the product pattern, and the scrap rate is as high as more than 50%, which greatly reduces production efficiency and increases production costs. It has become a core obstacle restricting the development of the digital printing industry towards high precision and high speed. Innovative solutions are urgently needed to optimize the material film processing process and improve printing quality and production efficiency.

[0003] In view of this, the present invention provides a hollow heating adsorption tube and a digital printer having the tube. Summary of the invention

[0004] The object of the present invention is to provide a hollow heating adsorption tube and a digital printer having the tube in view of the deficiencies of the prior art.

[0005] In order to solve the above technical problems, the following technical solutions are adopted:

[0006] The hollow heating adsorption tube includes a hollow cylindrical tube body and a center rod disposed in the cylindrical tube body. The center rod is disposed along the axial direction of the cylindrical tube body and is disposed in the middle of the cylindrical tube body. An annular cavity is formed between the cylindrical tube body and the center rod. An isolation portion is disposed between the cylindrical tube body and the center rod. The isolation portion divides the annular cavity into a heating and drying cavity and a negative pressure adsorption cavity. A through hole is disposed on the surface of the cylindrical tube body. The through hole connects the outside and the inside of the annular cavity. By optimizing the layout of the through hole 11, the adsorption force is evenly distributed on the surface of the tube body, and the adsorption force can reach 30N / m 2 -1000N / m 2 , thereby accurately adsorbing the material film.

[0007] Furthermore, the cylindrical side area of ​​the negative pressure adsorption cavity accounts for 1 / 3 to 1 / 2 of the cylindrical side area of ​​the annular cavity, and the cylindrical side area of ​​the heating and drying cavity accounts for 1 / 2 to 2 / 3 of the cylindrical side area of ​​the annular cavity.

[0008] Furthermore, the isolation portion divides the annular cavity into a plurality of heating and drying cavities and negative pressure adsorption cavities, and the heating and drying cavities and negative pressure adsorption cavities are spaced apart from each other, and the cylindrical side area of ​​the heating and drying cavity is larger than the cylindrical side area of ​​the negative pressure adsorption cavity.

[0009] Furthermore, a suction pump is provided in the negative pressure adsorption chamber.

[0010] Furthermore, a heating patch is arranged outside the central rod of the heating and drying cavity.

[0011] Furthermore, there are a plurality of through holes, and the diameter of the through holes is 0.5 mm-2 mm, the hole spacing of the through holes is 5 mm-10 mm, and the through holes are arranged in a circular matrix on the cylindrical surface of the cylindrical tube body.

[0012] Furthermore, the isolation part is a rubber type partition.

[0013] Furthermore, a roller core is sleeved on the exterior of the central rod, and a groove body for mounting the rubber-type partition is provided on the roller core.

[0014] Furthermore, a bearing structure and a sealing ring are installed on the inner side surfaces of both ends of the cylindrical tube body, and the sealing ring is pressed into the sealing groove of the bearing cover of the bearing structure, thereby realizing a sealed connection between the sealing ring and the bearing structure.

[0015] The present invention proposes another technical solution: a digital printer, comprising the hollow heated adsorption tube as described above, and also comprising a platform, an active roller, a driving assembly and a transmission assembly, wherein the output end of the driving assembly is connected to a driving shaft and a first synchronous belt assembly, the outer sleeve of the active shaft is provided with an active roller, and the transmission assembly is connected to the adsorption tube; the adsorption tube is arranged at the front end of the platform, and the active roller is arranged at the rear end of the platform; the first synchronous belt assembly is connected to the second synchronous belt assembly, and the second synchronous belt assembly is connected to the adsorption tube.

[0016] The above technical solution has the following beneficial effects:

[0017] 1. Accurate and efficient adsorption positioning: The optimized design of the negative pressure adsorption chamber and the through-hole layout allows the material film to fit tightly to the cylindrical tube body, with an adsorption accuracy of ±0.5mm, laying the foundation for high-precision digital printing (resolution ≥1200dpi), greatly improving pattern clarity and overprint accuracy, and reducing scrap rate by more than 40%.

[0018] 2. Excellent drying quality and fast speed: Nano-ceramic heating patches have precise temperature control and efficient heat radiation, ensuring that the ink is evenly dried and cured, increasing color vividness by 30% and adhesion by 50%. At the same time, it shortens the production cycle and increases output per unit time by 20%-30%, enhancing the company's market competitiveness.

[0019] 3. Stable and reliable drive transmission: high-precision synchronous belt drive and servo motor closed-loop control make the material film conveying speed stable and the tension uniform, and the stretching rate is controlled within 0.5%, effectively avoiding quality problems such as pattern distortion and dimensional deviation caused by stretching deformation, improving product consistency and yield rate, and reducing equipment operation and maintenance costs and energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below in conjunction with the accompanying drawings:

[0021] Figure 1 Schematic diagram of the three-dimensional structure of the adsorption tube in Example 1 of the present invention.

[0022] Figure 2 This is a schematic diagram of the main structure of the adsorption tube in Example 1 of the present invention.

[0023] Figure 3 Embodiment 1 of the present invention Figure 2 Schematic diagram of the cross-sectional structure along the A direction.

[0024] Figure 4 This is a schematic diagram of the three-dimensional structure of the adsorption tube of Example 1 of the present invention without the outer cylindrical tube body.

[0025] Figure 5 It is a schematic diagram of the side structure of the adsorption tube of Example 1 of the present invention.

[0026] Figure 6 Embodiment 1 of the present invention Figure 5 Schematic diagram of the cross-sectional structure along the B direction.

[0027] Figure 7 Schematic diagram of the cross-sectional structure of the adsorption tube according to Example 2 of the present invention.

[0028] Figure 8 It is a schematic diagram of the three-dimensional structure of an adsorption tube installed on a platform according to an embodiment of the present invention.

[0029] Fig. 9 It is a schematic diagram of the three-dimensional structure of the adsorption tube installed on the platform from another perspective according to an embodiment of the present invention.

[0030] Fig.10 It is a schematic diagram of the front view structure of the driving device of the hollow heating adsorption tube in an embodiment of the present invention.

[0031] Fig.11 It is a schematic diagram of the top view of the structure of the driving device of the hollow heating adsorption tube in an embodiment of the present invention.

[0032] Fig.12 Schematic diagram of the test structure of the driving device of the hollow heating adsorption tube in an embodiment of the present invention.

[0033] Fig.13 It is a schematic diagram of the structure of the hollow heating adsorption tube J and its driving device installed on the digital printer in an embodiment of the present invention.

[0034] In the figure: 1-cylindrical tube; 2-center rod; 3-annular cavity; 4-isolating part; 5-roller core; 6-platform; 8-driving shaft; 9-driving assembly; 10-transmission assembly; 11-through hole; 12-bearing structure.

[0035] 51-Trough body.

[0036] 31-heating and drying chamber; 32-negative pressure adsorption chamber.

[0037] 81-active roller.

[0038] 91-driving motor; 92-reducing machine; 93-driving mounting seat.

[0039] 101 - a first synchronous belt assembly; 102 - a second synchronous belt assembly.

[0040] 1011 - first driving synchronous pulley; 1012 - first driven synchronous pulley; 1013 - first synchronous belt.

[0041] 1021 - second driving synchronous pulley; 1022 - second driven synchronous pulley; 1023 - second synchronous belt; 1024 - transmission shaft. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0043] Example 1

[0044] See also Figure 1-6 In practical applications, when a plastic material film with a thickness of 0.1 mm is used, the material film can fit closely to the cylindrical tube body under the conditions of a suction pump flow rate of 20 L / min and a negative pressure of -20 kPa, and the adsorption accuracy can reach ±0.4 mm, meeting the requirements of high-precision digital printing. When the temperature of the heating patch is set to 80°C, the ink drying time is shortened by 40%, the color vividness is significantly improved, and the elongation rate of the material film is controlled within 0.3%, ensuring the printing quality.

[0045] Specifically, the hollow heating adsorption tube includes a hollow cylindrical tube body 1 and a center rod 2 arranged in the cylindrical tube body 1. The cylindrical tube body 1 is made of high-strength aluminum alloy and is formed into a cylindrical hollow structure through precision extrusion. This material and molding process give the tube body good strength and stability, and can withstand the pressure and external force during the working process, ensuring the long-term and reliable operation of the adsorption tube. The tube body is also anodized on the surface, which can ensure its smoothness (roughness Ra <0.8μm) and wear resistance. Taking into account the differences in the requirements for the width of the material film in different production scales, the diameter of the tube body is set in multiple specifications (such as 50mm-500mm series) to adapt to different production scenarios. The center rod 2 is made of stainless steel and the surface is chrome-plated, which can not only effectively prevent the center rod 2 from rusting and corrosion and extend its service life, but the chrome plating layer can also reduce the friction coefficient and reduce the friction that may be generated during the material film transportation process.

[0046] The center rod 2 is arranged along the axial direction of the cylindrical tube body 1 and the center rod 2 is arranged in the middle of the cylindrical tube body 1. Thus, an annular cavity 3 is formed between the cylindrical tube body 1 and the center rod 2, and an isolation portion 4 is provided between the cylindrical tube body 1 and the center rod 2, and the isolation portion 4 is a rubber-type partition. The isolation portion 4 divides the annular cavity 3 into a heating and drying cavity 31 and a negative pressure adsorption cavity 32. The good flexibility and sealing of the rubber material can accurately separate the annular cavity 3 into the heating and drying cavity 31 and the negative pressure adsorption cavity 32, effectively preventing the airflows between the two cavities from interfering with each other, and ensuring that their respective functions are independently and efficiently realized.

[0047] In order to verify its ability to prevent airflow interference, a series of pressure tests were carried out. When the pressure difference gradually increased from 10kPa to 50kPa, the gas leakage between the two cavities always remained at an extremely low level, with an average leakage rate of less than 0.1%. This fully proves that it can effectively prevent the airflow between the two cavities from interfering with each other, thereby ensuring that the functions of the heating and drying chamber 31 and the negative pressure adsorption chamber 32 can be realized independently and efficiently, providing a stable and reliable basic condition for the processing of material film in the entire digital printing process.

[0048] The surface of the cylindrical tube body 1 is provided with a through hole 11, and the through hole 11 connects the outside and the inside of the annular cavity 3. There are multiple through holes 11, and the diameter of the through holes 11 is 0.5mm-2mm, the hole spacing of the through holes 11 is 5mm-10mm, and the through holes 11 are arranged in a circular matrix on the cylindrical surface of the cylindrical tube body 1. Specifically, the small hole layout of the through holes 11 has been optimized through fine fluid mechanics simulation, and the optimal hole position distribution and pore size parameters have been determined through a large number of simulation calculations and actual tests. This optimized layout can ensure that the adsorption force is evenly distributed on the surface of the tube body, and the adsorption force can reach 30N / m 2-1000N / m 2 , which can accurately adsorb material films. For example, when dealing with plastic material films with low air permeability, smaller diameter through holes and relatively close hole spacing can better play the adsorption role; while for softer paper material films, the hole diameter and spacing need to be appropriately adjusted to avoid damage to the material film. This carefully optimized layout makes the adsorption force evenly distributed on the surface of the tube, and its adsorption force can reach 30N / m 2 -1000N / m 2 In actual applications, whether it is a thin silk material film or a relatively thick leather material film, precise adsorption can be achieved, effectively ensuring the stability of the material film during the printing process.

[0049] As a further explanation of this embodiment, the cylindrical side area of ​​the negative pressure adsorption chamber 32 accounts for 1 / 3 to 1 / 2 of the cylindrical side area of ​​the annular chamber 3. This ratio range is determined through multiple experimental verifications and theoretical analysis. Through comparative tests of different area ratios, it is found that when the cylindrical side area of ​​the negative pressure adsorption chamber 32 is within this range, it can provide the best adsorption force for the material film, and can ensure the stable adsorption of the material film under different pipe diameter specifications and material film widths. Specifically, when the adsorption area ratio is close to 1 / 3, for thinner material films, such as plastic films with a thickness of 0.1mm, a better adsorption effect can be achieved; and when the ratio is close to 1 / 2, for slightly thicker material films, such as 0.3mm plastic films or paper films, the adsorption stability is more outstanding.

[0050] The cylindrical side area of ​​the heating and drying cavity 31 accounts for 1 / 2 to 2 / 3 of the cylindrical side area of ​​the annular cavity 3. This ratio range is also carefully designed. Considering the heat transfer and distribution requirements during the drying process, when the cylindrical side area of ​​the heating and drying cavity 31 is within this range, the drying efficiency can be effectively improved in practical applications. Under the same heating power, a larger heating and drying cavity area ratio (close to 2 / 3) can make the heat distribution more uniform, which can significantly shorten the drying time for inks that require higher drying temperatures or thicker material films; and a relatively small ratio (close to 1 / 2) can avoid damage to the material film caused by local overheating for thin material films and low-viscosity inks that need to be dried quickly, while ensuring uniform drying of the ink, color vividness and adhesion.

[0051] Through this reasonable allocation of the cylindrical side areas of the negative pressure adsorption chamber and the heating and drying chamber, good adsorption effect and efficient drying effect can be guaranteed under different material film characteristics and printing conditions, thereby improving the performance and stability of the entire digital printing system.

[0052] As a further illustration of this embodiment, a suction pump (not shown) is provided in the negative pressure adsorption chamber 32. The suction pump is a micro suction pump (flow rate 10L / min-50L / min adjustable, negative pressure -10kPa--50kPa controllable). The suction pump provides a stable negative pressure environment for the adsorption material film. When the material film is thin, the flow rate and negative pressure can be reduced to avoid damage to the material film; when the material film is thick, the flow rate and negative pressure are appropriately increased to ensure that the material film can fit tightly to the cylindrical tube body. By precisely adjusting the parameters of the suction pump, a stable and suitable negative pressure environment is provided for the adsorption material film, thereby ensuring the reliability and consistency of the adsorption process.

[0053] As a further illustration of the present embodiment, a heating patch is provided outside the center rod 2 of the heating and drying chamber 31. The heating patch adopts a nano-ceramic heating patch, which has good thermal conductivity and thermal stability. The power of the nano-ceramic heating patch is adjustable in sections between 50W and 500W, and can be intelligently temperature controlled in the range of 50°C to 150°C according to the printing speed and the ink characteristics such as the type, thickness, and viscosity of the ink. During the intelligent temperature control process, the system will monitor the drying state of the ink in real time, and dynamically adjust the heating power according to the preset drying curve and ink parameters to ensure that the ink can be dried under the optimal temperature conditions. For example, for quick-drying inks, the heating patch will automatically reduce the power and temperature to avoid excessive drying of the ink; for slow-drying inks, the power and temperature will be appropriately increased to ensure that the ink can be evenly dried in the shortest time. Compared with traditional heating and drying methods, the use of this nano-ceramic heating patch can shorten the drying cycle by 30%-50%, while significantly improving the drying quality of the ink, making the product color more vivid and the ink adhesion stronger, effectively improving production efficiency and product quality, reducing product scrap rate, and providing strong guarantees for high-quality digital printing.

[0054] As a further explanation of this embodiment, the outer sleeve of the center rod 2 is provided with a roller core 5, and the roller core 5 is provided with a groove body 51 for installing the rubber-type partition. This structural design facilitates the installation of the isolation part 4. At the same time, the roller core 5 is tightly matched with the cylindrical tube body 1, and a very small gap (the gap range is 0.1-0.3mm) is maintained between its outer diameter and the inner diameter of the cylindrical tube body 1, ensuring that the isolation part 4 can be accurately positioned during the installation process, and when the equipment is running, the roller core 5 can withstand various forces from the material film conveying and heating and drying process. In actual use, after multiple continuous operation tests, even in the high-speed printing state, due to the design of this roller core 5, the vibration amplitude of the entire system is controlled within ±0.2mm, which greatly ensures the stability of the overall structure, avoids problems such as material film offset and uneven adsorption caused by structural looseness or deformation, and provides a stable structural foundation for achieving high-quality and high-precision digital printing.

[0055] As a further explanation of this embodiment, a bearing structure 12 and a sealing ring are installed on the inner side surfaces of both ends of the cylindrical tube body 1, and the sealing ring is pressed into the sealing groove of the bearing cover of the bearing structure 12, so as to realize the sealing connection between the sealing ring and the bearing structure. Among them, the bearing structure 12 adopts a deep groove ball bearing. This type of bearing has the advantages of low friction, strong load-bearing capacity, and high operating precision. It can effectively support the stable rotation of the cylindrical tube body 1 and ensure that the material film maintains uniform motion during the conveying process. In an actual working environment, even if the equipment is under high pressure and temperature changes (such as a temperature range of -20°C to 80°C and a pressure range of 0 to 100kPa), the sealing structure can still maintain good sealing performance, avoiding problems such as bearing wear, corrosion, and internal cavity function failure caused by the entry of impurities, thereby ensuring the reliability and service life of the entire equipment, and providing a strong guarantee for achieving efficient and stable digital printing operations.

[0056] Example 2

[0057] The difference from Example 1 is: Figure 7 The isolation portion 4 divides the annular cavity 3 into a plurality of heating and drying cavities 31 and negative pressure adsorption cavities 32, and the heating and drying cavities 31 and the negative pressure adsorption cavities 32 are spaced apart from each other, and the cylindrical side area of ​​the heating and drying cavity 31 is larger than the cylindrical side area of ​​the negative pressure adsorption cavity 32.

[0058] The heating and drying chamber 31 and the negative pressure adsorption chamber 32 are arranged at intervals from each other. This interval arrangement is conducive to forming alternating heating and adsorption areas. During the material film conveying process, the material film can be alternately subjected to uniform heating and stable adsorption in a short time, thereby improving the overall efficiency of material film processing. For example, when processing a material film of high-viscosity ink, this alternating effect can prevent the ink from being locally overheated or not dried, ensuring uniform drying of the ink and good adsorption of the material film. In addition, the cylindrical side area of ​​the heating and drying chamber 31 is larger than the cylindrical side area of ​​the negative pressure adsorption chamber 32. This area setting is determined based on experimental research on the drying and adsorption properties of different inks and material films. After a large number of experimental tests, it was found that when the cylindrical side area of ​​the heating and drying chamber 31 is larger than the cylindrical side area of ​​the negative pressure adsorption chamber 32, for material films that need to be dried quickly and have relatively low adsorption requirements, such as thin plastic films, the drying speed of the ink can be accelerated while maintaining sufficient adsorption force, so that the ink drying cycle is shortened by about 20%, and the elongation rate of the material film is reduced by about 15%, thereby improving the overall printing quality and efficiency. In printing equipment of different specifications, by adjusting the area ratio of the two, the processing effect of material films of different materials and thicknesses can be optimized to better meet diversified production needs.

[0059] Based on the hollow heating adsorption tube of the above-mentioned embodiment 1 or embodiment 2, see Figure 8-13 , and install it on the digital printer. Specifically, the digital printer includes the hollow heating adsorption tube as described in Example 1 or Example 2, and also includes a platform 6, an active roller 81, a driving component 9 and a transmission component 10, the transmission component 10 includes a first synchronous belt component 101 and a second synchronous belt component 102, the output end of the driving component 9 is connected to the active shaft 8 and the first synchronous belt component 101, the outer sleeve of the active shaft 8 is provided with an active roller 81, and the transmission component 10 is connected to the hollow heating adsorption tube; the hollow heating adsorption tube is arranged at the front end of the platform 6, and the active roller 81 is arranged at the rear end of the platform 6; the first synchronous belt component 101 is connected to the second synchronous belt component 102, and the second synchronous belt component 102 is connected to the hollow heating adsorption tube.

[0060] As a further explanation of this embodiment, the first synchronous belt assembly 101 includes a first active synchronous pulley 1011, a first driven synchronous pulley 1012 and a first synchronous belt 1013, the first active synchronous pulley 1011 is arranged on the active shaft 8, and the first active synchronous pulley 1011 is connected to the first driven synchronous pulley 1012 through the first synchronous belt 1013; the second synchronous belt assembly 102 includes a transmission shaft 1024, a second active synchronous pulley 1021, a second driven synchronous pulley 1022 and a second synchronous belt 1023, one end of the transmission shaft 1024 is connected to the first driven synchronous pulley 1012, the other end of the transmission shaft 1024 is connected to the second active synchronous pulley 1021, the second active synchronous pulley 1021 is connected to the second driven synchronous pulley 1022 through the second synchronous belt 1023, and the second driven synchronous pulley 1022 is connected to the hollow heating adsorption tube. Specifically, the transmission method of multi-stage synchronous belt assemblies, combined with precise component connections, can ensure the stability and efficiency of power during transmission, keep the material film conveying speed stable, avoid problems such as material film jitter and jamming caused by unstable power transmission, and effectively improve the continuity and reliability of the printing process.

[0061] As a further explanation of this embodiment, the drive assembly 9 includes a drive motor 91 and a reducer 92. The drive motor 91 is used as a power source, and the high-speed rotation power output by the drive motor 91 needs to be adjusted to meet the working requirements of the driving shaft 8, so the reducer 92 is connected. The reducer 92 can convert the high-speed, low-torque power output by the drive motor 91 into low-speed, high-torque power according to actual working requirements, and then stably transmit the power to the driving shaft 8 through the coupling. This connection method ensures the stability and reliability of power transmission and can adapt to different workload requirements.

[0062] In addition, the drive assembly 9 also includes a drive mounting seat 93. One side of the drive mounting seat 93 is firmly connected and fixed to the frame, which plays a role in supporting and positioning the drive assembly 9 and ensuring the stability of the entire drive system during operation; the other side is connected to the reducer 92, and the reducer 92 is firmly installed in a specified position, so that the various parts of the drive assembly 9 can work together.

[0063] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.

Claims

1. Hollow heating adsorption tube, characterized by: It includes a hollow cylindrical tube body and a center rod arranged in the cylindrical tube body, the center rod is arranged along the axial direction of the cylindrical tube body and the center rod is arranged in the middle of the cylindrical tube body, an annular cavity is formed between the cylindrical tube body and the center rod, an isolation part is arranged between the cylindrical tube body and the center rod, the isolation part divides the annular cavity into a heating and drying cavity and a negative pressure adsorption cavity, and a through hole is arranged on the surface of the cylindrical tube body, and the through hole connects the outside and the inside of the annular cavity.

2. The hollow heating adsorption tube according to claim 1, characterized in that: The cylindrical side area of ​​the negative pressure adsorption cavity accounts for the cylindrical side area of ​​the annular cavity. 1 / 3 to 1 / 2, the cylindrical side area of ​​the heating and drying cavity accounts for the cylindrical side area of ​​the annular cavity 1 / 2 to 2 / 3.

3. The hollow heating adsorption tube according to claim 1, characterized in that: The isolation part divides the annular cavity into a plurality of heating and drying cavities and negative pressure adsorption cavities, and the heating and drying cavities and the negative pressure adsorption cavities are arranged at intervals from each other, and the cylindrical side area of ​​the heating and drying cavity is larger than the cylindrical side area of ​​the negative pressure adsorption cavity.

4. The hollow heating adsorption tube according to any one of claims 1 to 3, characterized in that: A suction pump is arranged in the negative pressure adsorption chamber.

5. The hollow heating adsorption tube according to any one of claims 1 to 3, characterized in that: A heating patch is arranged outside the central rod of the heating and drying cavity.

6. The hollow heating adsorption tube according to claim 1, characterized in that: There are multiple through holes, and the diameter of the through holes is 0.5mm-2mm, the hole spacing of the through holes is 5mm-10mm, and the through holes are arranged in a circular matrix on the cylindrical surface of the cylindrical tube body.

7. The hollow heating adsorption tube according to claim 1, characterized in that: The isolating part is a rubber type partition.

8. The hollow heating adsorption tube according to claim 1, characterized in that: The outer sleeve of the central rod is provided with a roller core, and the roller core is provided with a groove body for installing the rubber type partition.

9. The hollow heating adsorption tube according to claim 1, characterized in that: A bearing structure and a sealing ring are installed on the inner side surfaces of both ends of the cylindrical tube body, and the sealing ring is pressed into the sealing groove of the bearing cover of the bearing structure, thereby realizing a sealed connection between the sealing ring and the bearing structure.

10. A digital printer, characterized in that: It includes the hollow heating adsorption tube as described in any one of claims 1-3 and 6-9 above, and also includes a platform, an active roller, a driving assembly and a transmission assembly, the output end of the driving assembly is connected to a driving shaft and a first synchronous belt assembly, the outer sleeve of the active shaft is provided with an active roller, and the transmission assembly is connected to the adsorption tube; the adsorption tube is arranged at the front end of the platform, and the active roller is arranged at the rear end of the platform; the first synchronous belt assembly is connected to the second synchronous belt assembly, and the second synchronous belt assembly is connected to the adsorption tube.

Images