Double-sided digital ink-jet device for washing label

Abstract

The invention relates to the technical field of washing labels, in particular to a washing label double-face digital ink jet device which comprises a double-face digital ink jet unit and a rear coating unit which are arranged in an L shape, and a parallel guide unit is arranged between the double-face digital ink jet unit and the rear coating unit. The parallel guide unit is used for receiving the washing labels output by the double-face digital ink jet unit, turning the washing labels by 90 degrees and then conveying the washing labels to the rear coating unit. According to the invention, the double-sided digital ink-jet unit and the post-coating unit are arranged in an L shape, and the washing labels output by the double-sided digital ink-jet unit are received by virtue of the parallel guide unit and are conveyed in a 90-degree steering manner, so that an online continuous production link of printing, steering and coating is constructed; the defect that in the prior art, printing and coating procedures are separated is overcome in a targeted mode, and on the premise that the printing and coating quality is guaranteed, the production efficiency, the space utilization rate and the material compatibility are comprehensively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water washing label, in particular to a water washing label double-sided digital inkjet device. BACKGROUND

[0002] As an indispensable identification component of clothing, home textiles, outdoor products and other products, water washing labels are mainly used to mark key information such as product composition, washing method, size specification, safety warning, etc., and the printing quality directly affects the use experience, brand image and compliance of the product. With the growth of consumer market demand for personalization and small-batch customization, and the strict requirements of environmental protection regulations on textile contact materials, water washing labels not only need to meet the physical properties of water resistance, abrasion resistance, etc., but also need to support diversified needs such as double-sided printing and variable data printing to adapt to the production mode of multi-variety and fast iteration.

[0003] The Chinese invention with publication number CN115742567A provides a front and back water washing label digital printing machine and its use method, which improves the overall production efficiency by cooperating between the take-up and pay-off mechanism, the correction mechanism, the inkjet mechanism, the oven mechanism, the visual camera, the display mechanism, the heat dissipation mechanism, the sensor and the floating mechanism, and can quickly adjust the printing content, with high production efficiency, which is beneficial to batch processing and production of fixed products or variable data products.

[0004] However, in actual production, in order to cover more than 95% of the woven label materials on the market (especially special materials with strong water absorption and more surface fluff), a post-coating process is often added after printing to improve the ink adhesion. However, in the prior art, the printing unit and the post-coating unit are still independent devices, and there is a lack of online connection design between the two, which makes it impossible to continuously perform the post-coating process after the printing process: the woven label material after printing needs to be wound first, then manually transported or mechanically conveyed to the coating device, and then unwound to perform coating treatment. This separate layout not only increases the overall equipment area by more than 30%, and the space utilization rate is less than 60%; more importantly, during the transportation and second unwinding process, the woven label material is prone to stretching or edge wrinkling due to sudden tension changes, which is difficult to meet the actual production needs of high efficiency and high precision. Therefore, we propose a water washing label double-sided digital inkjet device to solve the above problems. SUMMARY

[0005] The present application aims to provide a water washing label double-sided digital inkjet device to solve the problem of the inability of the printing unit and the post-coating unit in the prior art to continuously perform the process online.

[0006] The application is realized by the technical scheme that the water-washing mark double-sided digital inkjet device comprises an L-shaped double-sided digital inkjet unit and a rear coating unit, a parallel guide unit is arranged between the double-sided digital inkjet unit and the rear coating unit, and the parallel guide unit is used for receiving the water-washing mark output by the double-sided digital inkjet unit and conveying the water-washing mark to the rear coating unit after turning the water-washing mark by 90 degrees. The rear coating unit comprises a machine body, a rear coating water tank, a draining module, a rear coating oven and a rear coating winding module are sequentially arranged on the side wall of the machine body along the water-washing mark conveying direction. The water-washing mark in the rear coating oven is in an inverted U shape, and a fixed drying mechanism and a movable drying mechanism are arranged on both sides of the inverted U-shaped water-washing mark in the rear coating oven; a humidity detection sensor is installed on the inner top of the rear coating oven, and the humidity detection sensor is used for detecting the humidity of the water-washing mark dried by the fixed drying mechanism. When the humidity detected by the humidity detection sensor is lower than a preset threshold, the movable drying mechanism moves to a limiting position away from the water-washing mark; when the humidity detected by the humidity detection sensor is higher than the preset threshold, the movable drying mechanism moves to a limiting position close to the water-washing mark.

[0007] Optionally, the double-sided digital inkjet unit comprises a carrier, an automatic unwinding module, a front correction module, a front face printing module, a front oven, a rear correction module, a CCD front and rear positioning module, a reverse face printing module, a reverse face oven and an automatic winding module are sequentially arranged on the side wall of the carrier along the conveying direction of the water-washing mark. A constant temperature and humidity box is fixed on the side wall of the carrier, and the front face printing module and the reverse face printing module are arranged side by side in the constant temperature and humidity box; a front and reverse visual detection module is installed on the side wall of the carrier between the front face printing module and the reverse face printing module. The parallel guide unit is fixed on the side wall of the carrier, and the water-washing mark can be selectively conveyed to the automatic winding module or the parallel guide unit.

[0008] Optionally, the parallel guide unit comprises a guide base fixed on the double-sided digital inkjet unit, a parallel guide shaft is fixedly installed on the guide base, two parallel guide blocking rings are fixedly arranged on the parallel guide shaft in the axial direction, and a guide inclined surface is arranged on one side of each of the two parallel guide blocking rings.

[0009] Optionally, the fixed drying mechanism comprises a lamp holder fixed on the inner side wall of the rear coating oven, a plurality of fixed heating lamp tubes are arranged on the lamp holder in the depth direction of the rear coating oven, and each fixed heating lamp tube is arranged in the vertical direction.

[0010] Optionally, the movable drying mechanism comprises a fixed frame fixed to the inner side wall of the rear coating oven, a mounting plate movably arranged in the fixed frame along the width direction of the rear coating oven, and a drying assembly arranged on the side of the mounting plate close to the washing mark.

[0011] Optionally, the drying assembly comprises a plurality of first movable heating lamp tubes arranged in an up-down staggered manner, a rotating shaft fixed to one end of each first movable heating lamp tube close to the edge of the mounting plate, and the axis of the rotating shaft being perpendicular to the axis of the first movable heating lamp tube; each rotating shaft is rotationally connected to the mounting plate, and a rotating driving structure corresponding to each rotating shaft is arranged on the mounting plate. When the mounting plate is away from the washing mark to the limiting position, each first movable heating lamp tube is in an inclined state, and one end of each first movable heating lamp tube away from the corresponding rotating shaft is located on the same straight line. When the mounting plate is close to the washing mark to the limiting position, each first movable heating lamp tube is in a horizontal state.

[0012] Optionally, two housings are fixed in parallel and at intervals on the side of the mounting plate away from the first movable heating lamp tubes. The rotating driving structure comprises a worm wheel fixed to the rotating shaft and located in the corresponding housing, a worm gear rotationally connected to the worm wheel in the housing, a gear fixed to one end of the worm gear and located outside the housing, and a rack fixed to the inner side wall of the fixed frame and matched with the gear, the rack being arranged along the width direction of the rear coating oven.

[0013] Optionally, the drying assembly comprises two moving plates arranged in parallel and at intervals, each moving plate being slidingly connected to the mounting plate along the horizontal direction; a plurality of second movable heating lamp tubes are fixed in parallel and at intervals on the side of each moving plate close to the washing mark, each second movable heating lamp tube being arranged in an up-down staggered manner; and a translation structure for driving the two moving plates to move close to or away from each other is arranged on the fixed frame. When the mounting plate is away from the washing mark to the limiting position, the two moving plates are in a state of moving away from each other, and one end of each second movable heating lamp tube away from the edge of the mounting plate is located on the same straight line. When the mounting plate is close to the washing mark to the limiting position, the two moving plates are in a state of moving close to each other.

[0014] Optionally, the translation structure comprises a slide rod fixed to the upper and lower ends of each moving plate, and a slide groove corresponding to each slide rod is formed in the fixed frame, and the slide rod can slide along the corresponding slide groove.

[0015] Optionally, the slide groove comprises a first straight line segment, an oblique line segment and a second straight line segment connected in sequence. When the slide bar is located in the first straight segment, the two moving plates are in a state of moving away from each other; when the slide bar is located in the second straight segment, the two moving plates are in a state of moving close to each other.

[0016] Compared with the prior art, the water-washing mark double-sided digital inkjet device has the following beneficial effects: 1. The double-sided digital inkjet unit and the rear coating unit are arranged in an L shape, and the parallel guide unit receives the water-washing mark output by the double-sided digital inkjet unit and realizes 90° turning and conveying, thereby constructing an online continuous production link of "printing-turning-coating", and the disadvantages of separation of printing and coating processes in the prior art are solved, and the production efficiency, space utilization and material compatibility are comprehensively improved under the premise of ensuring the printing and coating quality.

[0017] 2. The fixed drying mechanism, the movable drying mechanism and the humidity detection sensor are arranged to construct a dynamic response drying adjustment system: when the humidity detection sensor detects that the humidity of the water-washing mark is lower than the preset threshold, the movable drying mechanism is automatically moved to the limiting position away from the water-washing mark to avoid material brittleness or pattern cracking caused by excessive drying. When the humidity is detected to be higher than the preset threshold, the movable drying mechanism is moved to the limiting position close to the water-washing mark to enhance the drying intensity to ensure that the coating layer is fully cured.

[0018] 3. The differential drying is realized by dynamic arrangement adjustment of the movable heating lamp tube: when the humidity of the water-washing mark is small, the lamp tube is in a inclined or dispersed collinear state, a large range of uniformly distributed heating area is formed, the whole water-washing mark is evenly heated to avoid local over-drying. When the humidity of the water-washing mark is large, the lamp tube is switched to a horizontal concentrated or close state, the heating area is focused on the middle part (humidity accumulation area) of the water-washing mark, and the middle part drying efficiency is enhanced through intensive heating, thereby solving the problem of different drying effects caused by uneven humidity distribution in the traditional fixed heating mode. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is an overall assembly front view of the equipment of the first embodiment. Figure 2 It is an overall assembly top view of the equipment of the first embodiment. Figure 3 It is a water-washing mark circuit diagram of the double-sided digital inkjet unit of the first embodiment. Figure 4 It is a perspective view of the double-sided digital inkjet unit of the first embodiment. Figure 5 It is a schematic view of the automatic unwinding module of the first embodiment. Figure 6 It is a schematic view of the inkjet mechanism in the front inkjet module of the first embodiment. Figure 7This is a schematic diagram of the roller-type worktable in the front-facing inkjet printing module of Embodiment 1; Figure 8 This is a schematic diagram of the constant temperature and humidity chamber in Example 1; Figure 9 This is a schematic diagram of the front-side drying oven in Example 1; Figure 10 This is a schematic diagram of the front and back visual inspection module in Embodiment 1; Figure 11 This is a schematic diagram of the CCD forward and reverse alignment module in Embodiment 1; Figure 12 This is a schematic diagram of the floating module in Example 1; Figure 13 This is a schematic diagram of the power roller module in Example 1; Figure 14 This is a circuit diagram of the washing label for the post-coating unit in Example 1; Figure 15 This is a perspective view of the coating unit in Example 1; Figure 16 This is a schematic diagram of the coating tank after Example 1; Figure 17 This is a schematic diagram of the draining module in Example 1; Figure 18 This is a schematic diagram of the coating and winding module in Example 1; Figure 19 This is a schematic diagram of the parallel guide unit in Embodiment 1; Figure 20 This is a diagram showing the mounting plate in the first embodiment away from the wash label. Figure 21 This is a back view of the mounting plate in Example 1; Figure 22 for Figure 21 Enlarged view of point A in the middle; Figure 23 This is a diagram showing the mounting plate near the wash label in Example 1. Figure 24 This is a diagram showing the mounting plate in the second embodiment being away from the wash label. Figure 25 This is a back view of the mounting plate in Example 2; Figure 26 This is a diagram showing the mounting plate near the wash label in Example 2.

[0020] In the figure: 1, double-sided digital inkjet unit; 101, carrier; 102, automatic unwinding module; 103, front correction module; 104, front printing module; 105, front oven; 106, rear correction module; 107, reverse printing module; 108, reverse oven; 109, automatic winding module; 1010, front and back visual inspection module; 1011, constant temperature and humidity box; 1012, CCD front and back positioning module; 1013, platform touch screen; 1014, inkjet control touch screen; 1015, power roller module; 1016, floating module; 2, rear coating unit; 201, machine body; 202, rear coating water tank; 203, rear coating oven; 204, rear coating winding module; 205, draining module; 3, parallel guide unit; 301, guide base; 302, parallel guide shaft; 303, parallel guide blocking ring; 4, fixed drying mechanism; 401, lamp holder; 402, fixed heating lamp; 5, movable drying mechanism; 501, fixed frame; 502, mounting plate; 503, drying assembly; 5031, first movable heating lamp; 5032, rotating shaft; 5033, rotating drive structure; 50331, gear; 50332, rack; 5034, moving plate; 5035, second movable heating lamp; 5036, translation structure; 50361, slide rod; 50362, sliding groove; 504, housing; 6, humidity detection sensor. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0022] Embodiment one: please refer to Figures 1 to 23 A water-washed label double-sided digital inkjet device, comprising an L-shaped double-sided digital inkjet unit 1 and a rear coating unit 2, wherein the double-sided digital inkjet unit 1 is arranged in the horizontal direction, and the rear coating unit 2 is vertically connected with the inkjet unit 1 in the vertical direction. A parallel guide unit 3 is arranged between the double-sided digital inkjet unit 1 and the rear coating unit 2, which is used to receive the water-washed label output by the double-sided digital inkjet unit 1, and then convey the water-washed label to the rear coating unit 2 after turning 90°, forming a continuous production flow of "printing-turning-coating" without interruption.

[0023] With the above design, the vertical connection is adopted instead of the traditional linear arrangement, and the overall projection area of the equipment is reduced by more than 30% compared with the separated layout. The design directly cancels the three links of printing, manual transfer and unwinding before coating, shortens the production cycle by 25%-30%, and adapts to more than 95% of the woven label materials on the market (including cotton-based materials with strong water absorption and blended materials with more surface fluff). On the premise of ensuring the alignment accuracy of double-sided printed patterns and the uniformity of the coating layer, efficient, compatible and compact continuous production is realized.

[0024] The following introduces the double-sided digital inkjet unit 1: The double-sided digital inkjet unit 1 includes a carrier 101, and the sidewall of the carrier 101 is sequentially provided with an automatic unwinding module 102, a front deviation correction module 103, a front printing module 104, a front oven 105, a rear deviation correction module 106, a CCD front and rear positioning module 1012, a back printing module 107, a back oven 108 and an automatic winding module 109 along the conveying direction of the water washing label. Each module forms a continuous printing assembly line through a synchronous transmission system.

[0025] The automatic unwinding module 102 is composed of a feeding air expansion shaft and a roll diameter sensor, and realizes automatic control of feeding and unwinding through a servo traction system. The roll diameter sensor monitors the roll diameter in real time, and when the detected value exceeds the preset range, the system automatically slows down and triggers a stop alarm to avoid interruption of material conveying.

[0026] The front deviation correction module 103 and the rear deviation correction module 106: both use high-precision photoelectric deviation correction machines, which identify the material edge through infrared edge sensors and dynamically correct the lateral expansion of different woven label materials (such as elastic fabrics and non-woven fabrics) to ensure that the lateral deviation of the material entering the printing station is ≤0.1mm, laying a foundation for accurate printing.

[0027] The front printing module 104 and the back printing module 107: both are composed of a printing mechanism and a drum-type workbench. The printing mechanism is equipped with a water-based circulating digital inkjet system and a non-contact high-precision piezoelectric nozzle (resolution up to 1200dpi). The drum-type printing workbench adopts a roll-type printing work surface. When printing, the material forms a wrapped contact with the support surface, which can increase the friction between the material and the support surface, reduce the slipping of the material during printing, and also reduce the size of the printing head, providing space utilization.

[0028] The front oven 105 and the back oven 108: adopt near-infrared light wave heating technology with a wavelength of 0.8-2.5μm, and form a gradient heating zone through symmetrically distributed infrared lamp tubes to realize rapid drying and curing of the printed content and avoid pattern smudging in subsequent processes.

[0029] In this embodiment, the side wall of the carrier 101 is fixed with a constant temperature and humidity chamber 1011, and the front and back printing modules 104 and 107 are arranged side by side in the constant temperature and humidity chamber 1011; the environment in the constant temperature and humidity chamber 1011 is stably controlled at a temperature of 23±2℃ and a humidity of 50±5% through the atomization device and air conditioning system in the constant temperature and humidity chamber 1011, so that the surface tension fluctuation of the ink is ≤1mN / m, and the adhesion stability of the ink on different fabric materials is significantly improved (the adhesion strength is improved by 15%).

[0030] In addition, the front and back visual detection module 1010 is installed on the side wall of the carrier 101 between the front and back printing modules 104 and 107, the front and back visual detection module 1010 adopts an adjustable front and back visual camera, and the front and back visual camera moves along the transverse guide rail through a sliding block mechanism to switch the shooting of the front and back printing quality and support real-time monitoring and online debugging.

[0031] The CCD front and back positioning module 1012 adopts a positioning visual camera, and is mainly aimed at the following product types: 1. The content of the printing needs to be variable information on both sides, and needs to be one-to-one corresponding. For example, if A1 variable content is printed on the front, A2 variable content needs to be printed on the back, and the two contents are related and cannot be A1 on the front corresponding to B2 on the back. The CCD front and back positioning module 1012 is installed in front of the back printing to send the shooting of the front A1 content to the visual software for processing in real time, and then quickly send the printing result to the back printing device. The middle board card will automatically calculate and accurately print A2 content on the back of A1, and the edge position of A1 and A2 template content (paper feeding direction) cannot exceed ±0.25mm.

[0032] 2. Small batch production identification and separation page and special symbol to determine the order number content. This product type is small batch production, for example, there are 5000 labels in a roll of material, and there are n styles in the 5000 labels, and one style may have 1, 2, etc. Each style will have a separation page to distinguish or a special symbol. When the CCD front and back positioning module 1012 recognizes this separation page, it will immediately send it to the software for processing, and the software will real-time switch the next page of the printing work order, and then send it to the printing device for printing.

[0033] It should be noted that the carrier 101 is also provided with an auxiliary control system and a tension control system.

[0034] The auxiliary control system: the platform touch screen 1013 (control winding and unwinding parameters, oven temperature and other equipment parameters) and the inkjet control touch screen 1014 (adjust and control ink supply pressure, ink cartridge temperature and other inkjet parameters) are integrated on the side wall of the carrier 101, to realize digital operation of the whole process. Tension control system: composed of power roller module 1015 and several floating modules 1016, arranged on the moving path of the washing tape. The floating module 1016 is built-in with an electronic ruler sensor (measurement accuracy 0.01mm), which can dynamically adjust the tension according to the material stretching characteristics, ensuring that different gram weight tapes maintain constant tension. The power roller module 1016 adjusts the conveying speed through a variable frequency motor, and forms a closed loop control with the unwinding and winding system, so that the tension fluctuation is controlled within ±3%.

[0035] The above structure realizes full-automatic printing process from unwinding to winding through modular integration and intelligent control, especially suitable for small batch, multi-variety double-sided variable data printing requirements, reducing manual intervention by more than 60% compared with traditional equipment, and significantly improving printing accuracy and stability.

[0036] The following describes the parallel guide unit 3: The parallel guide unit 3 is fixed on the side wall of the carrier 101, and the washing tape can be selectively conveyed to the automatic winding module 109 or the parallel guide unit 3, realizing mode switching of "direct winding after printing" or "on-line coating after printing". Specifically, the parallel guide unit 3 includes a guide base 301 fixed on the double-sided digital inkjet unit 1, a parallel guide shaft 302 fixedly installed on the guide base 301, and two parallel guide retaining rings 303 fixedly spaced along the axial direction on the parallel guide shaft 302. A guide inclined surface is arranged on one side of the two parallel guide retaining rings 303.

[0037] Based on the principle of mirror reflection, the washing tape is accurately turned: when the washing tape enters from the paper inlet end, the center line and the axis of the parallel guide shaft 302 form a 45° angle, first tightly adheres to the guide inclined surface of one side retaining ring (the inclined surface generates a lateral restraint force to prevent deviation), and then tightly adheres to the guide inclined surface of the other side retaining ring after winding 180° around the shaft surface. At this time, the center line of the paper outlet end and the axis of the shaft also form a 45° angle, and through the angle superposition of "incident-reflection", 90° parallel turning is realized (turning deviation ≤0.5°). In this process, the washing tape always maintains a flat state without wrinkles or stretching. The unit combines mechanical structure and geometric principles to ensure the accuracy of 90° turning (lateral deviation after turning ≤0.1mm) and realize gapless connection with the previous and subsequent processes, providing key guide support for "printing-coating" online continuous production.

[0038] The following describes the rear coating unit 2: The rear coating unit 2 includes a machine body 201, and a rear coating water tank 202, a draining module 205, a rear coating oven 203 and a rear coating winding module 204 are arranged on the side wall of the machine body 201 in sequence along the conveying direction of the washing tape. Precisely connected with the outlet end of the parallel guide unit 3, forming a continuous processing link of "turning-coating-drying-winding".

[0039] Post-coating water tank 202: The tank body is integrally formed with 304 stainless steel, and the top is provided with an inclined water drain opening. A 150-mesh stainless steel filter screen is built into the opening to filter out particulate impurities in the newly injected coating liquid, reducing surface defects during coating. Two sets of quick detachable silica gel rollers are symmetrically arranged in the tank. The roller shafts are connected to the tank body through a buckle structure, facilitating daily cleaning. The tank body is embedded with a high borosilicate glass liquid level column to display the remaining coating liquid in real time. A quick-opening drain valve is provided at the bottom to greatly improve the efficiency of liquid change. Draining module 205: It is composed of a pneumatic water pressure assembly and a driven roller. The water pressure roller is made of food-grade silica gel with a Shore hardness of 60°. It is precisely attached to the driven roller through double-cylinder driving. By adjusting the air pressure valve, the material liquid rate can be controlled at 20%-40%. This avoids the increase of drying burden caused by excessive coating liquid and prevents the insufficient liquid from affecting the uniformity of the coating. At the same time, the driven roller is driven by a servo motor, forming a traction force with the water pressure roller to ensure that the material conveying speed is synchronized with the previous unit. Post-coating winding module 204: It adopts a magnetic powder clutch type winding structure, which can realize stepless adjustment of winding tension by adjusting the input current. The tension feedback sensor is provided at the end of the winding shaft to monitor the material tension fluctuation in real time and automatically compensate to avoid stretching deformation of the ultra-thin fabric caused by excessive tension, and prevent the fabric from being loose due to insufficient tension.

[0040] In this embodiment, to ensure the smooth movement of the water-washed fabric in the post-coating unit 2 (especially when the material weight increases by 5%-10% after coating), the tension control system is also integrated on the machine body 201 to ensure that the water-washed fabric maintains a constant tension.

[0041] In the prior art, the drying structure of the post-coating oven 203 is usually fixedly installed (30 mm away from the surface of the water-washed fabric), which cannot dynamically adjust the heating distance according to the actual humidity of the material, thus causing significant adaptability defects. When the humidity of the drained water-washed fabric is too large (such as moisture content > 20%), the fixed distance leads to insufficient heat transfer efficiency, incomplete evaporation of the coating layer moisture, and uneven drying (the central moisture content is 8%-12% higher than the edge), which further causes the coating to stick together during subsequent winding. When the humidity of the water-washed fabric is too small (such as moisture content < 8%), the close heating distance causes a sudden temperature rise (more than 80°C) in the local area, leading to the embrittlement of the fabric material (a 15% decrease in breaking strength) and the charring of the printed pattern edge, with a batch rejection rate as high as 12%. This fixed mode is difficult to adapt to fabric materials with different water absorption (such as cotton-based materials with 3 times the water absorption of polyester), which seriously restricts the stability of drying quality. Therefore, the following design is made: The water mark in the rear coating oven 203 is inverted U-shaped, which prolongs the effective drying time. The rear coating oven 203 is provided with a fixed drying mechanism 4 and a movable drying mechanism 5 on the two sides of the inverted U-shaped water mark respectively. Among them, the fixed drying mechanism 4 provides basic heating with a constant distance (30mm from the material surface), and the movable drying mechanism 5 can move back and forth along the horizontal direction.

[0042] A humidity detection sensor 6 is installed on the inner top of the rear coating oven 203, which is used to detect the humidity of the water mark after being dried by the fixed drying mechanism 4; When the humidity detected by the humidity detection sensor 6 is lower than the preset threshold value (such as <8%RH), the movable drying mechanism 5 moves to the limit position away from the water mark, reduces the heat input, and avoids excessive drying to cause material embrittlement or pattern cracking. When the humidity detected by the humidity detection sensor 6 is higher than the preset threshold value (such as >15%RH), the movable drying mechanism 5 moves to the limit position close to the water mark until it is 15mm away from the material surface, and the local heating intensity is enhanced (the heat flux is increased by 40%), so as to ensure that the coating layer is fully cured.

[0043] In this embodiment, the rear coating oven 203 adopts a double-unit side-by-side design, and the two ovens are arranged in series along the conveying direction, and a group of floating modules are used to realize tension buffer adjustment. This design not only improves the overall drying efficiency by 25% through double-oven segmented drying (the first segment focuses on water evaporation, and the second segment enhances coating layer curing), but also avoids material stretching deformation in long-path conveying through precise tension control, further ensuring the alignment accuracy of double-sided printing patterns and the uniformity of the coating layer.

[0044] The fixed drying mechanism 4 is introduced as follows: The fixed drying mechanism 4 includes a lamp holder 401 fixed to the inner side wall of the rear coating oven 203, and a plurality of fixed heating lamp tubes 402 are arranged on the lamp holder 401 along the depth direction of the rear coating oven 203. Each fixed heating lamp tube 402 is arranged in the vertical direction to form a uniform heating surface covering the full width of the material. This structure provides basic heat input with a constant distance (30mm from the material surface), ensuring that the water mark obtains preliminary and uniform preheating and drying when passing through.

[0045] The movable drying mechanism 5 is introduced as follows: The movable drying mechanism 5 includes a fixed frame 501 fixed to the inner side wall of the rear coating oven 203, and a mounting plate 502 is arranged in the fixed frame 501 and can move along the width direction of the rear coating oven 203. The side of the mounting plate 502 close to the water mark is provided with a drying assembly 503. It should be noted that a high-precision electric guide rail or an electric telescopic rod can be arranged in the fixed frame 501 to drive the mounting plate 502 to move linearly.

[0046] In the development process, it is found that if the initial humidity is too large (moisture content > 20%) after the water-washing roll is treated by draining, a significant humidity gradient difference is easily formed due to the following characteristics: due to the inverted U-shaped conveying path, the distance between the edges of the water-washing roll and the drying element is closer than the middle part, and the air flow of the two sides is better than the middle part, resulting in faster heat accumulation on the two sides; at the same time, the middle part of the material forms a slight depression due to tension, and the coating liquid is easy to form a liquid accumulation at this position.

[0047] The above factors jointly cause the phenomenon of "two sides dry first, middle part dry later": the evaporation rate of moisture on the two sides is 2-3 times faster than that in the middle part, when the two sides have reached the drying end point (humidity < 10%), the humidity in the middle part is still as high as 30% or more, causing uneven cross-linking and curing of the coating layer, not only affecting the water washing performance (the middle part is 40% lower than the standard value in terms of washing frequency), but also causing the un-dried areas to stick to each other due to subsequent rolling, making the batch unqualified rate rise to more than 15%. In order to solve this structural drying defect, the dynamic distribution of the heating area needs to be optimized. For this purpose, the drying assembly 503 is specially designed: The drying assembly 503 includes a plurality of first movable heating lamp tubes 5031 arranged in an up-down staggered manner, a rotating shaft 5032 is fixed to one end of each first movable heating lamp tube 5031 near the edge of the mounting plate 502, the axis of the rotating shaft 5032 is perpendicular to the axis of the first movable heating lamp tube 5031, forming an adjustable angle heating array. Each rotating shaft 5032 is rotationally connected to the mounting plate 502, and a rotating drive structure 5033 corresponding to each rotating shaft 5032 is arranged on the mounting plate 502 for driving the rotating shaft 5032 to rotate, so that the first movable heating lamp tube 5031 is in an inclined state or a horizontal state.

[0048] When the mounting plate 502 is away from the water-washing roll to the limiting position, each first movable heating lamp tube 5031 is in an inclined state, and one end of each first movable heating lamp tube 5031 away from the corresponding rotating shaft 5032 is located on the same straight line, and the heating area is evenly spread along the material width direction, which can avoid the brittle of low humidity material (humidity < 8% RH) due to local overheating. When the mounting plate 502 is close to the water-washing roll to the limiting position, each first movable heating lamp tube 5031 is in a horizontal state, forming a dense heating band, which can intensively heat the middle part of the material, and control the humidity difference between the two sides and the middle part of the material within 3% RH, solving the problem of "too fast drying on the two sides and residual water vapor in the middle part" under high humidity conditions.

[0049] The rotating drive structure 5033 is described as follows: Two housings 504 are fixed in parallel and spaced apart from the side of the mounting plate 502 away from the first movable heat-generating lamp tube 5031, for mounting other components. The rotary drive structure 5033 includes a worm gear fixed to the rotary shaft 5032 and located in the corresponding housing 504, a worm shaft rotatably connected in the housing 504 and cooperating with the worm gear, a gear 50331 fixed to one end of the worm shaft and located outside the housing 504, and a rack 50332 fixed to the inner side wall of the fixed frame 501 and cooperating with the gear 50331, the rack 50332 being arranged along the width direction of the rear coating oven 203. When the mounting plate 502 moves along the guide rail, the gear 50331 rolls along the rack 50332, synchronously driving the worm shaft to rotate, and the rotary shaft rotates through the transmission of the worm gear, realizing the linkage adjustment of the angle and position of the lamp tube.

[0050] With the above design, when the mounting plate 502 is away from the water-washing mark to the limiting position (50 mm away from the material surface), the gear-rack transmission makes the worm shaft rotate, thereby driving the lamp tube to rotate around the rotary shaft 5032 to an inclined state (30° angle with the horizontal plane), and the free ends of the lamp tubes form a continuous straight line, and the heating area is dispersed along the width direction of the material, which is suitable for uniform drying of low-humidity materials. When the mounting plate 502 is close to the water-washing mark to the limiting position (15 mm away from the material surface), the gear-rack transmission is reversed to make the worm shaft reset, and the lamp tube rotates to a horizontal state, forming a strengthened heating band focused on the 1 / 3 width area in the middle of the material (the heat flux density in the middle is increased by 50% compared to the two sides). This design precisely matches the humidity distribution characteristics of "drying first on both sides and then on the middle": for cotton-based fabrics with strong water absorption (moisture content > 20%), the drying rate in the middle can be increased by 40%, the humidity difference between the two sides and the middle is reduced from more than 5% to less than 1.5%, and the problem of uneven curing of the coating layer caused by local drying lag is completely solved. This integrated adjustment of "position movement-angle transformation-thermal field reconstruction" through mechanical linkage can improve the drying qualification rate of high-humidity materials from 82% to 98%, and reduce the edge brittleness rate caused by over-drying from 5% to 0.8%, balancing the drying rates on both sides and in the middle, and taking into account the drying efficiency and the protection of the physical properties of the material. Example Two, please refer to Figures 24 to 26 The difference between this embodiment and Example One is: The drying assembly 503 includes two moving plates 5034 arranged in parallel and spaced apart, and each moving plate 5034 is slidably connected to the mounting plate 502 in the horizontal direction. A plurality of second movable heat-generating lamp tubes 5035 are fixed in the vertical direction on one side of each moving plate 5034, and the second movable heat-generating lamp tubes 5035 are arranged in parallel and staggered above and below each other, forming a complementary coverage. The fixed frame 501 is provided with a translation structure 5036 for driving the two moving plates 5034 to move closer to or farther away from each other.

[0051] When the installation plate 502 is away from the water washing mark to the limit position (50 mm away from the material surface), the two moving plates 5034 are in a state of mutual separation, and the second movable heating lamp tube 5035 away from one end of the edge of the installation plate 502 is located on the same straight line, and the heating area is uniformly distributed along the full width of the material.

[0052] When the installation plate 502 is close to the water washing mark to the limit position (15 mm away from the material surface), the two moving plates 5034 are in a state of mutual approach. The lamp tube forms a dense heating band in the middle of the material, which specifically solves the problem of “two sides dry first and middle dry later”: for thick and heavy fabric marks with strong water absorption (such as cotton-based materials with moisture content > 20%), the increase of middle heating intensity can shorten the drying time by 35%, and the humidity difference between the two sides and the middle of the material can be reduced from 5%-8% in traditional process to below 1.2%, completely eliminating the problem of coating layer adhesion caused by the middle not being dry (the unqualified rate is reduced from 12% to 1.5%).

[0053] The translation structure 5036 is introduced as follows: The translation structure 5036 includes a slide rod 50361 fixed to the upper and lower ends of each moving plate 5034, and a slide groove 50362 corresponding to each slide rod 50361 is formed on the fixed frame 501. The slide rod 50361 can slide along the corresponding slide groove 50362. In this embodiment, the slide groove 50362 includes a first straight line segment, an inclined line segment and a second straight line segment connected in sequence.

[0054] When the slide rod 50361 is located in the first straight line segment, the two moving plates 5034 are in a state of mutual separation; when the slide rod 50361 is located in the second straight line segment, the two moving plates 5034 are in a state of mutual approach. The mechanical linkage design of the translation structure 5036 does not require additional driving elements, and the heating mode switching can be completed only by the displacement of the installation plate 502, with a response time < 0.5 seconds, reducing 60% of the fault points compared with the electric control adjustment mode, while reducing the energy consumption of the equipment by 18%, balancing the drying uniformity and operation economy.

[0055] In order to adapt to the printing needs of different materials, the device is designed with three switchable production process modes, as follows: 1. Single-sided printing mode; The process is: automatic unwinding module 102 unwinding → front deviation correction module 103 correction → front / reverse side jet printing module (single group enabled) jet printing → front and back visual detection module 1010 detection → corresponding surface drying oven (front drying oven 105 or back drying oven 108) drying → floating module 1016 tension control → automatic winding module 109 winding. This mode is suitable for label materials that only need single-sided printing (such as ordinary polyester labels). Through single-group jet printing and directional detection, it reduces invalid processes and improves single-batch production efficiency by 15%. 2. Double-sided linkage printing mode; The process is as follows: automatic unwinding module 102 unwinds → front correction module 103 corrects → front jet printing module 104 prints → front visual detection → front oven 105 dries → floating module 1016 controls tension → rear correction module 106 corrects again → CCD front and back positioning module 1012 captures front reference → back jet printing module 107 matches and prints → back visual detection → back oven 108 dries → automatic winding module 109 winds. This mode is suitable for materials that need double-sided printing and have alignment requirements (such as cotton-based labels containing two-dimensional codes). Through dynamic matching of positioning cameras, it ensures that the alignment error of front and back patterns is ≤0.2mm, reducing alignment adjustment time by 40% compared to traditional step-by-step printing. 3. Full-process printing-coating mode; The process is as follows: automatic unwinding module 102 unwinds → front correction module 103 corrects → front jet printing module 104 prints → front visual detection → front oven 105 dries → floating module 1016 controls tension → rear correction module 106 corrects → CCD front and back positioning module 1012 positions → back jet printing module 107 prints → back visual detection → back oven 108 dries → parallel guiding unit 3 completes 90° turning → rear coating unit 2 coats → rear coating oven 203 dries → rear coating winding module 204 rewinds. This mode integrates printing and coating processes and is suitable for high-end materials that need surface protection treatment (such as water-resistant blended labels). Through seamless connection of parallel guiding unit 3, it avoids material transportation loss, improves coating layer adhesion by 20% compared to offline processing, and supports continuous production of different lengths of 50-1000 meters. It should be noted that, in this text, relational terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "includes a" does not exclude the presence of another identical element in the process, method, article or equipment that includes the element.

[0056] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A double-sided digital inkjet printer for washable labels, characterized in that: The double-sided digital inkjet unit and the back coating unit are arranged in an L shape, and a parallel guide unit is arranged between the double-sided digital inkjet unit and the back coating unit, and the parallel guide unit is used for receiving the water washing mark output by the double-sided digital inkjet unit and conveying the water washing mark to the back coating unit after turning the water washing mark by 90 degrees. The back coating unit comprises a machine body, and a back coating water tank, a draining module, a back coating oven and a back coating winding module are sequentially arranged on the side wall of the machine body along the conveying direction of the water washing mark. The water washing mark in the back coating oven is in an inverted U shape, and a fixed drying mechanism and a movable drying mechanism are arranged on both sides of the inverted U-shaped water washing mark in the back coating oven; a humidity detection sensor is installed on the inner top of the back coating oven, and the humidity detection sensor is used for detecting the humidity of the water washing mark dried by the fixed drying mechanism. When the humidity detected by the humidity detection sensor is lower than a preset threshold, the movable drying mechanism moves to a limit position away from the water washing mark; when the humidity detected by the humidity detection sensor is higher than the preset threshold, the movable drying mechanism moves to a limit position close to the water washing mark.

2. A water-based double-sided digital inkjet marking device according to claim 1, characterized in that: The double-sided digital inkjet unit comprises a carrier, and an automatic unwinding module, a front correction module, a front surface printing module, a front surface oven, a rear correction module, a CCD front and rear positioning module, a reverse surface printing module, a reverse surface oven and an automatic winding module are sequentially arranged on the side wall of the carrier along the conveying direction of the water washing mark. A constant temperature and humidity box is fixed on the side wall of the carrier, and the front surface printing module and the reverse surface printing module are arranged side by side in the constant temperature and humidity box; a front and reverse surface visual detection module is installed on the side wall of the carrier between the front surface printing module and the reverse surface printing module. The parallel guide unit is fixed on the side wall of the carrier, and the water washing mark can be selectively conveyed to the automatic winding module or the parallel guide unit.

3. A water-based marking double-sided digital inkjet device according to claim 1, characterized in that: The parallel guide unit comprises a guide base fixed on the double-sided digital inkjet unit, a parallel guide shaft is fixedly installed on the guide base, two parallel guide blocking rings are fixedly arranged on the parallel guide shaft in the axial direction, and a guide inclined surface is arranged on one side of each parallel guide blocking ring.

4. A water-based double-sided digital inkjet marking device according to claim 1, characterized in that: The fixed drying mechanism comprises a lamp holder fixed on the inner side wall of the back coating oven, a plurality of fixed heating lamp tubes are arranged on the lamp holder in the depth direction of the back coating oven, and each fixed heating lamp tube is arranged in the vertical direction.

5. A water-based ink double-sided digital inkjet printing device according to claim 1, characterized in that: The movable drying mechanism comprises a fixed frame fixed on the inner side wall of the back coating oven, an installation plate movably arranged in the width direction of the back coating oven is arranged in the fixed frame, and a drying assembly is arranged on one side of the installation plate close to the water washing mark.

6. A water-based double-sided digital inkjet marking device according to claim 5, characterized in that: The drying assembly comprises a plurality of first movable heating lamp tubes arranged in an up-down staggered manner, a rotating shaft is fixed on one end of each first movable heating lamp tube close to the edge of the installation plate, the axis of the rotating shaft is perpendicular to the axis of the first movable heating lamp tube, each rotating shaft is rotatably connected to the installation plate, and a rotating driving structure corresponding to each rotating shaft is arranged on the installation plate. When the installation plate moves away from the water washing mark to the limit position, each first movable heating lamp tube is in an inclined state, and one end of each first movable heating lamp tube away from the corresponding rotating shaft is located on the same straight line. When the mounting plate is close to the water washing mark to the limiting position, each first movable heating lamp pipe is in horizontal state.

7. A water-based double-sided digital inkjet marking device according to claim 6, characterized in that: Two housings are fixed in parallel and at intervals on the side of the mounting plate away from the first movable heating lamp pipes; The rotating driving structure comprises a worm wheel fixed on the rotating shaft and located in the corresponding housing, a worm gear matched with the worm wheel is rotationally connected in the housing, a gear located outside the housing is fixed on one end of the worm gear, a rack matched with the gear is fixed on the inner side wall of the fixed frame, and the rack is arranged along the width direction of the rear coating oven.

8. A water-based double-sided digital inkjet marking device according to claim 5, characterized in that: The drying assembly comprises two moving plates arranged in parallel and at intervals, each moving plate is slidingly connected to the mounting plate in the horizontal direction, a plurality of second movable heating lamp pipes are fixed in the vertical direction on the side of each moving plate close to the water washing mark, each second movable heating lamp pipe is parallel to each other and distributed in an upper and lower staggered manner, and a translation structure for driving the two moving plates to approach or move away from each other is arranged on the fixed frame. When the mounting plate is away from the water washing mark to the limiting position, the two moving plates are in a state of moving away from each other, and one end of each second movable heating lamp pipe away from the edge of the mounting plate is located on the same straight line. When the mounting plate is close to the water washing mark to the limiting position, the two moving plates are in a state of approaching each other.

9. A water-based double-sided digital inkjet marking device according to claim 8, characterized in that: The translation structure comprises slide rods fixed on the upper and lower ends of each moving plate, and a slide groove corresponding to each slide rod is formed in the fixed frame, and the slide rod can slide along the corresponding slide groove.

10. A water-based double-sided digital inkjet marking device according to claim 9, characterized in that: The slide groove comprises a first straight line segment, an oblique line segment and a second straight line segment connected in sequence. When the slide rod is located in the first straight line segment, the two moving plates are in a state of moving away from each other; when the slide rod is located in the second straight line segment, the two moving plates are in a state of approaching each other.

Images