A water washing mark double-sided digital inkjet device

Abstract

The present application relates to the technical field of water washing mark, specifically to a double-sided digital inkjet device for water washing mark, comprising double-sided digital inkjet units and post-coating units arranged in L shape, parallel guiding units are arranged between the double-sided digital inkjet units and the post-coating units, the parallel guiding units are used for receiving the water washing mark output by the double-sided digital inkjet units and conveying the water washing mark to the post-coating units after turning 90 degrees. The present application arranges the double-sided digital inkjet units and the post-coating units in L shape, and receives the water washing mark output by the double-sided digital inkjet units and realizes 90-degree turning and conveying by means of the parallel guiding units, thereby constructing an online continuous production link of "printing-turning-coating", and solving the problem of separation of printing and coating process in the prior art. Under the premise of ensuring the printing and coating quality, the production efficiency, space utilization and material compatibility are comprehensively improved.

Description

Technical Field

[0001] This invention relates to the field of wash label technology, specifically to a double-sided digital inkjet device for wash labels. Background Technology

[0002] As an indispensable labeling component for products such as clothing, home textiles, and outdoor products, care labels are mainly used to indicate key information such as product composition, washing instructions, size specifications, and safety warnings. Their printing quality directly affects the user experience, brand image, and compliance of the product. With the increasing demand for personalization and small-batch customization in the consumer market, and the stringent environmental regulations on textile contact materials, care labels not only need to meet physical properties such as washability and abrasion resistance, but also need to support diverse needs such as double-sided printing and variable data printing to adapt to multi-variety, rapidly iterating production models.

[0003] Chinese invention patent CN115742567A discloses a digital printing machine for double-sided wash label and its usage method. Through the coordination between the unwinding and winding mechanism, the web guiding mechanism, the inkjet printing mechanism, the drying oven mechanism, the vision camera, the display mechanism, the heat dissipation mechanism, the sensor, and the floating mechanism, the overall production efficiency is improved, and the printing content can be quickly adjusted. The high production efficiency is beneficial for the batch processing and production of fixed products or variable data products.

[0004] However, in actual production, to cover over 95% of woven label materials on the market (especially special materials with high water absorption and abundant surface fuzz), a post-coating process is often required after printing to improve ink adhesion. However, in existing technologies, the printing unit and the post-coating unit are still independent devices, lacking an online connection design. This results in the post-coating process not being able to proceed continuously with the printing process: the printed woven label material must first be wound up, then manually or mechanically transferred to the coating equipment, and rewound before coating can be applied. This separate layout not only increases the overall equipment footprint by more than 30%, with a space utilization rate of less than 60%; more importantly, during the transfer and secondary unwinding process, the woven label material is prone to stretching or edge wrinkling due to sudden tension changes, making it difficult to meet the actual production requirements of high efficiency and high precision. Therefore, we propose a double-sided digital inkjet device for washable labels to effectively solve the above-mentioned drawbacks. Summary of the Invention

[0005] The purpose of this invention is to provide a double-sided digital inkjet device for washable labels, which solves the problem mentioned in the background art that the printing unit and the post-coating unit cannot be continuously operated online.

[0006] The present invention is achieved through the following technical solution: a double-sided digital inkjet device for wash label, comprising a double-sided digital inkjet unit and a post-coating unit arranged in an L-shape, wherein a parallel guide unit is provided between the double-sided digital inkjet unit and the post-coating unit, the parallel guide unit being used to receive the wash label output by the double-sided digital inkjet unit and to rotate the wash label 90° before conveying it to the post-coating unit;

[0007] The post-coating unit includes a machine body, and a post-coating water tank, a draining module, a post-coating drying oven, and a post-coating winding module are sequentially arranged on the side wall of the machine body along the conveying direction of the washing label.

[0008] The wash label located in the post-coating oven is inverted U-shaped. The post-coating oven is equipped with a fixed drying mechanism and a movable drying mechanism located on both sides of the inverted U-shaped wash label. A humidity detection sensor is installed on the top of the post-coating oven. The humidity detection sensor is used to detect the humidity of the wash label after it has been dried by the fixed drying mechanism.

[0009] When the humidity detected by the humidity sensor is lower than the preset threshold, the movable drying mechanism moves away from the care label to the limit position; when the humidity detected by the humidity sensor is higher than the preset threshold, the movable drying mechanism moves closer to the care label to the limit position.

[0010] Optionally, the double-sided digital inkjet unit includes a carrier, and the side wall of the carrier is sequentially provided with an automatic unwinding module, a front correction module, a front printing module, a front drying oven, a rear correction module, a CCD front and back registration module, a back printing module, a back drying oven, and an automatic rewinding module along the conveying direction of the washing label.

[0011] A constant temperature and humidity chamber is fixed on the side wall of the carrier, and the front printing module and the back printing module are arranged side by side inside the constant temperature and humidity chamber; a front and back visual inspection module is installed on the side wall of the carrier, located between the front printing module and the back printing module.

[0012] The parallel guide unit is fixed to the side wall of the carrier, and the wash label can be selectively conveyed to the automatic winding module or the parallel guide unit.

[0013] Optionally, the parallel guide unit includes a guide base fixed to the double-sided digital inkjet unit, a parallel guide shaft fixedly installed on the guide base, and two parallel guide retaining rings fixedly fixed at axial intervals on the parallel guide shaft, with guide slopes provided on the side where the two parallel guide retaining rings are close to each other.

[0014] Optionally, the fixed drying mechanism includes a lamp holder fixed to the inner wall of the post-coating oven, and a plurality of fixed heating lamps are arranged at intervals on the lamp holder along the depth direction of the post-coating oven, with each fixed heating lamp arranged in a vertical direction.

[0015] Optionally, the movable drying mechanism includes a fixed frame fixed to the inner wall of the post-coating oven, and a mounting plate that can move along the width direction of the post-coating oven is provided in the fixed frame. A drying component is provided on the side of the mounting plate near the washing label.

[0016] Optionally, the drying assembly includes a plurality of first movable heating lamps arranged in an alternating pattern, and a rotating shaft is fixed at one end of each first movable heating lamp near the edge of the mounting plate. The axis of the rotating shaft is perpendicular to the axis of the first movable heating lamp. Each rotating shaft is rotatably connected to the mounting plate, and a rotating drive structure corresponding to each rotating shaft is provided on the mounting plate.

[0017] When the mounting plate moves away from the wash label to the limit position, each of the first movable heating lamps is tilted, and the ends of each of the first movable heating lamps away from the corresponding rotation axis are on the same straight line.

[0018] When the mounting plate approaches the water-wash label to the limit position, each of the first active heating lamps is horizontal.

[0019] Optionally, the mounting plate has two housings fixed parallel to and spaced apart on the side away from the first active heating lamp tube;

[0020] The rotary drive structure includes a worm gear fixed on a rotating shaft and located inside a corresponding housing, a worm gear rotatably connected inside the housing to cooperate with the worm gear, a gear fixed at one end of the worm gear located outside the housing, and a rack cooperating with the gear fixed on the inner side wall of the fixed frame, the rack being arranged along the width direction of the post-coating oven.

[0021] Optionally, the drying assembly includes two parallel and spaced-apart movable plates, each movable plate being slidably connected to the mounting plate in the horizontal direction; a plurality of second movable heating lamps are fixedly fixed in the vertical direction on the side of each movable plate near the washing label, the second movable heating lamps being parallel to each other and staggered vertically; a translation structure for driving the two movable plates to move closer to each other or further away from each other is provided on the fixed frame.

[0022] When the mounting plate moves away from the wash label to the limit position, the two moving plates are in a state of mutual distance, and the ends of each second movable heating lamp tube away from the edge of the mounting plate are on the same straight line;

[0023] When the mounting plate approaches the wash label to the limit position, the two moving plates are in a close proximity to each other.

[0024] Optionally, the translation structure includes slide rods fixed to the upper and lower ends of each movable plate, and a sliding groove corresponding to each slide rod is provided on the fixed frame, so that the slide rod can slide along the corresponding sliding groove.

[0025] Optionally, the groove includes a first straight segment, an inclined segment, and a second straight segment connected in sequence;

[0026] When the slide bar is in the first straight segment, the two moving plates are in a state of being far apart from each other; when the slide bar is in the second straight segment, the two moving plates are in a state of being close to each other.

[0027] Compared with the prior art, the present invention provides a double-sided digital inkjet device for washable labels, which has the following beneficial effects:

[0028] 1. This invention arranges the double-sided digital inkjet unit and the post-coating unit in an L-shape, and uses a parallel guide unit to receive the wash label output by the double-sided digital inkjet unit and achieve 90° turning conveying, thus constructing an online continuous production link of "printing-turning-coating". This invention specifically solves the drawback of the separation of printing and coating processes in the prior art, and comprehensively improves production efficiency, space utilization and material compatibility while ensuring the quality of printing and coating.

[0029] 2. This invention constructs a dynamically responsive drying adjustment system by setting up a fixed drying mechanism, a movable drying mechanism, and a humidity detection sensor: when the humidity detection sensor detects that the humidity of the care label is lower than a preset threshold, the movable drying mechanism automatically moves away from the care label to a limit position to avoid over-drying that could cause the material to become brittle or the pattern to crack. When the detected humidity is higher than the preset threshold, the movable drying mechanism moves closer to the care label to a limit position to enhance the drying intensity and ensure that the coating layer is fully cured.

[0030] 3. This invention achieves differentiated drying through the dynamic arrangement and adjustment of the movable heating lamps: When the moisture content of the care label is low, the lamps are arranged in a tilted or dispersed collinear state, forming a large-scale, evenly distributed heating area, ensuring uniform heating of the entire care label and avoiding localized over-drying. When the moisture content of the care label is high, the lamps switch to a horizontally concentrated or clustered state, focusing the heating area on the center of the care label (the area where moisture tends to accumulate). This concentrated heating enhances the drying efficiency in the center, solving the problem of uneven moisture distribution leading to inconsistent drying results in traditional fixed heating modes. Attached Figure Description

[0031] Figure 1 This is a front view of the overall assembly of the equipment in Example 1;

[0032] Figure 2 This is a top view of the overall assembly of the equipment in Example 1;

[0033] Figure 3 This is a circuit diagram of the wash label for the double-sided digital inkjet unit in Embodiment 1;

[0034] Figure 4 This is a perspective view of the double-sided digital inkjet unit of Embodiment 1;

[0035] Figure 5 This is a schematic diagram of the automatic unwinding module in Embodiment 1;

[0036] Figure 6 This is a schematic diagram of the printing mechanism in the front printing module of Embodiment 1;

[0037] Figure 7 This is a schematic diagram of the roller-type worktable in the front-facing inkjet printing module of Embodiment 1;

[0038] Figure 8 This is a schematic diagram of the constant temperature and humidity chamber in Example 1;

[0039] Figure 9 This is a schematic diagram of the front-side drying oven in Example 1;

[0040] Figure 10 This is a schematic diagram of the front and back visual inspection module in Embodiment 1;

[0041] Figure 11 This is a schematic diagram of the CCD forward and reverse alignment module in Embodiment 1;

[0042] Figure 12 This is a schematic diagram of the floating module in Example 1;

[0043] Figure 13 This is a schematic diagram of the power roller module in Example 1;

[0044] Figure 14 This is a circuit diagram of the washing label for the post-coating unit in Example 1;

[0045] Figure 15 This is a perspective view of the coating unit in Example 1;

[0046] Figure 16 This is a schematic diagram of the coating tank after Example 1;

[0047] Figure 17 This is a schematic diagram of the draining module in Example 1;

[0048] Figure 18 This is a schematic diagram of the coating and winding module in Example 1;

[0049] Figure 19 This is a schematic diagram of the parallel guide unit in Embodiment 1;

[0050] Figure 20 This is a diagram showing the mounting plate in the first embodiment away from the wash label.

[0051] Figure 21 This is a back view of the mounting plate in Example 1;

[0052] Figure 22 for Figure 21 Enlarged view of point A in the middle;

[0053] Figure 23 This is a diagram showing the mounting plate near the wash label in Example 1.

[0054] Figure 24 This is a diagram showing the mounting plate in the second embodiment being away from the wash label.

[0055] Figure 25 This is a back view of the mounting plate in Example 2;

[0056] Figure 26 This is a diagram showing the mounting plate near the wash label in Example 2.

[0057] In the diagram: 1. Double-sided digital inkjet unit; 101. Carrier; 102. Automatic unwinding module; 103. Front correction module; 104. Front printing module; 105. Front drying oven; 106. Back correction module; 107. Reverse printing module; 108. Reverse drying oven; 109. Automatic rewinding module; 1010. Front and back visual inspection module; 1011. Constant temperature and humidity chamber; 1012. CCD front and back registration module; 1013. Platform touch screen; 1014. Inkjet control touch screen; 1015. Power roller module; 1016. Floating module; 2. Post-coating unit; 201. Machine body; 202. Post-coating water tank; 203. Post-coating drying oven; 204. Post-coating rewinding. Module; 205, Draining Module; 3, Parallel Guide Unit; 301, Guide Base; 302, Parallel Guide Shaft; 303, Parallel Guide Retaining Ring; 4, Fixed Drying Mechanism; 401, Lamp Holder; 402, Fixed Heating Lamp; 5, Movable Drying Mechanism; 501, Fixed Frame; 502, Mounting Plate; 503, Drying Component; 5031, First Movable Heating Lamp; 5032, Rotating Shaft; 5033, Rotation Drive Structure; 50331, Gear; 50332, Rack; 5034, Moving Plate; 5035, Second Movable Heating Lamp; 5036, Translation Structure; 50361, Slide Rod; 50362, Slide Groove; 504, Housing; 6, Humidity Detection Sensor. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] Example 1: Please refer to Figures 1 to 23A double-sided digital inkjet device for wash label manufacturing includes a double-sided digital inkjet unit 1 and a post-coating unit 2 arranged in an L-shape. The double-sided digital inkjet unit 1 is arranged horizontally, and the post-coating unit 2 is vertically connected to the inkjet unit 1. A parallel guide unit 3 is provided between the double-sided digital inkjet unit 1 and the post-coating unit 2. The parallel guide unit 3 is used to receive the wash label output from the double-sided digital inkjet unit 1, rotate the wash label 90°, and then transport it to the post-coating unit 2, forming an uninterrupted "printing-rotation-coating" continuous production flow.

[0060] By adopting the above design and replacing the traditional linear layout with vertical connections, the overall projected area of ​​the equipment is reduced by more than 30% compared to the separate layout. This design directly eliminates three steps: post-printing rewinding, manual transfer, and pre-coating unwinding, shortening the production cycle by 25%-30%. At the same time, it is compatible with more than 95% of woven label materials on the market (including highly absorbent cotton-based materials and blended materials with more surface fuzz). While ensuring the alignment accuracy of double-sided printed patterns and the uniformity of the coating layer, it achieves efficient, compatible, and compact continuous production.

[0061] The following is an introduction to the double-sided digital inkjet unit 1:

[0062] The double-sided digital inkjet unit 1 includes a carrier 101. Along the conveying direction of the wash label, the carrier 101 has an automatic unwinding module 102, a front correction module 103, a front printing module 104, a front drying oven 105, a rear correction module 106, a CCD front and back registration module 1012, a back printing module 107, a back drying oven 108, and an automatic rewinding module 109 arranged sequentially on its side wall. The modules form a continuous printing production line through a synchronous transmission system.

[0063] Automatic unwinding module 102: Composed of an unwinding air shaft and a roll diameter sensor, it achieves automated control of material feeding and unwinding through a servo traction system. The roll diameter sensor monitors the roll diameter in real time. When the detected value exceeds the preset range, the system automatically reduces speed and triggers a stop alarm to prevent material conveying interruption.

[0064] The front correction module 103 and the rear correction module 106 both adopt high-precision photoelectric correction machines. They identify the material edge through infrared edge sensors and dynamically correct the lateral expansion and contraction of different woven label materials (such as elastic fabrics and non-woven fabrics) to ensure that the lateral offset of the material when it enters the printing station is ≤0.1mm, laying the foundation for accurate printing.

[0065] Both the front-side printing module 104 and the back-side printing module 107 consist of a printing mechanism and a roller-type worktable. The printing mechanism is equipped with a water-based circulating digital inkjet system and a non-contact high-precision piezoelectric printhead (resolution up to 1200 dpi). The roller-type printing worktable uses a curved roller printing surface, which, during printing, creates a wrapping contact between the material and the support surface. This increases the friction between the material and the support surface, reduces slippage during printing, and also reduces the size of the printhead, improving space utilization.

[0066] Front oven 105 and back oven 108: adopt near-infrared light wave heating technology with wavelength of 0.8-2.5μm, and form a gradient heating zone through symmetrically distributed infrared lamps to achieve rapid drying and curing of printed content, avoiding pattern smudging in subsequent processes.

[0067] In this embodiment, a constant temperature and humidity chamber 1011 is fixed on the side wall of the carrier 101, and the front printing module 104 and the back printing module 107 are arranged side by side in the constant temperature and humidity chamber 1011. The environment inside the chamber is stably controlled at a temperature of 23±2℃ and a humidity of 50±5% by the atomizing 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, which significantly improves the adhesion stability of the ink on different woven label materials (adhesion strength is improved by 15%).

[0068] In addition, a front and back visual inspection module 1010 is installed on the side wall of the carrier 101 between the front printing module 104 and the back printing module 107. The front and back visual inspection module 1010 adopts an adjustable front and back visual camera. The front and back visual camera moves along the horizontal guide rail through a slider mechanism to switch the front and back printing quality and supports real-time monitoring and online debugging.

[0069] The CCD forward and reverse alignment module 1012 uses a positioning vision camera and is mainly designed for the following product types:

[0070] 1. The printed content must be variable information on both sides and must correspond one-to-one. For example, if A1 variable content is printed on the front, A2 variable content needs to be printed on the back. The two contents are related; A1 on the front cannot correspond to B2 on the back. The CCD front-back registration module 1012 is installed in front of the back printing to send the captured A1 content to the vision software in real time for processing, and then quickly send the printing result to the back printing device. The intermediate board will automatically calculate and accurately print the A2 content on the back of A1, and the front-back position (paper feed direction) of the A1 and A2 template content cannot exceed ±0.25mm.

[0071] 2. Small-batch group production uses separator pages and special symbols to facilitate order number identification. This product type involves small-batch group production; for example, a roll of material might contain 5000 labels, and each label might have one, two, etc., separated by a separator page or special symbols. When the CCD registration module 1012 identifies this separator page, it immediately sends the information to the software. The software automatically switches the print order to the next page in real time and then sends it to the printing device for printing.

[0072] It should be added that the carrier 101 is also equipped with an auxiliary control system and a tension control system.

[0073] Auxiliary control system: The carrier 101 integrates a platform touch screen 1013 (controlling equipment parameters such as winding and unwinding parameters and oven temperature) and an inkjet control touch screen 1014 (adjusting inkjet parameters such as ink supply pressure and ink cartridge temperature) on the side wall to realize full-process digital operation.

[0074] Tension control system: Composed of a power roller module 1015 and several floating modules 1016, positioned along the movement path of the wash label. Each floating module 1016 has a built-in electronic ruler sensor (measurement accuracy 0.01mm), which dynamically adjusts the tension according to the material's expansion and contraction characteristics, ensuring constant tension for labels of different weights. The power roller module 1016 regulates the conveyor speed via a variable frequency motor, forming a closed-loop control with the unwinding and take-up system, keeping tension fluctuations within ±3%.

[0075] The above structure, through modular integration and intelligent control, realizes a fully automated printing process from unwinding to rewinding. It is especially suitable for small-batch, multi-variety double-sided variable data printing needs, reducing manual intervention by more than 60% compared with traditional equipment, and significantly improving printing accuracy and stability.

[0076] The following is a description of the parallel guide unit 3:

[0077] The parallel guide unit 3 is fixed to the side wall of the carrier 101. The wash label can be selectively conveyed to the automatic rewind module 109 or the parallel guide unit 3, realizing the mode switching of "direct rewind after printing" or "online coating after printing". Specifically, the parallel guide unit 3 includes a guide base 301 fixed to the double-sided digital inkjet unit 1. A parallel guide shaft 302 is fixedly installed on the guide base 301. Two parallel guide retaining rings 303 are fixedly fixed axially on the parallel guide shaft 302. A guide slope is provided on the side of the two parallel guide retaining rings 303 that are close to each other.

[0078] Precise rotation is achieved based on the principle of specular reflection: When the care label enters from the paper feed end, its centerline forms a 45° angle with the axis of the parallel guide shaft 302. It first adheres tightly to the guide slope of one side retaining ring (the slope generates lateral constraint force to prevent deviation), then wraps around the shaft surface 180°, and finally exits tightly to the guide slope of the other side retaining ring. At this time, the centerline of the paper output end also forms a 45° angle with the axis of the shaft. Through the superposition of the "incident-reflection" angles, a 90° parallel rotation is achieved (rotation deviation ≤ 0.5°). During this process, the care label remains flat throughout, without wrinkles or stretching.

[0079] This unit, through the combination of mechanical structure and geometric principles, ensures the accuracy of 90° turning (lateral offset ≤0.1mm after turning) and achieves seamless connection with the preceding and following processes, providing key guiding support for online continuous production of "printing-coating".

[0080] The following is a description of the post-coating unit 2:

[0081] The post-coating unit 2 includes a body 201. Along the conveying direction of the wash label, a post-coating water tank 202, a draining module 205, a post-coating drying oven 203, and a post-coating winding module 204 are sequentially arranged on the side wall of the body 201. It precisely connects with the outlet end of the parallel guide unit 3, forming a continuous processing chain of "turning-coating-drying-winding".

[0082] Post-coating tank 202: Constructed as a single piece of 304 stainless steel, with a sloping drain spout at the top. The spout contains a 150-mesh stainless steel filter to remove particulate impurities from the newly injected coating solution, reducing surface defects during coating. Two sets of quick-release silicone rollers are symmetrically arranged inside the tank, connected to the tank body via a snap-fit ​​structure for easy cleaning. High borosilicate glass level gauges are embedded in the side of the tank to display the remaining coating solution level in real time. A quick-opening drain valve at the bottom significantly improves solution replacement efficiency.

[0083] The draining module 205 consists of a pneumatic water-pressing assembly and an active drive roller. The water-pressing roller is made of food-grade silicone with a Shore hardness of 60° and is driven by dual cylinders to achieve precise contact with the active roller. By adjusting the air pressure valve, the material liquid content can be controlled between 20% and 40%, which avoids excessive coating liquid leading to increased drying burden, and also prevents insufficient liquid content from affecting coating uniformity. Simultaneously, the active roller is driven by a servo motor, forming a traction force with the water-pressing roller to ensure that the material conveying speed is synchronized with the preceding unit.

[0084] Post-coating winding module 204: Employs a magnetic powder clutch winding structure, achieving stepless control of winding tension by adjusting the input current. A tension feedback sensor is installed at the end of the winding shaft to monitor material tension fluctuations in real time and automatically compensate, preventing ultra-thin woven labels from stretching and deforming due to excessive tension, while also preventing loose winding due to insufficient tension.

[0085] In this embodiment, in order to ensure the smooth movement of the wash label in the post-coating unit 2 (especially when the material weight increases by 5%-10% after coating), the machine body 201 is also integrated with a tension control system to ensure that the wash label maintains constant tension.

[0086] In existing technologies, the drying structure of the post-coating oven 203 typically uses a fixed installation method (30mm from the surface of the wash label). This makes it impossible to dynamically adjust the heating distance according to the actual humidity of the material, resulting in significant adaptability defects. When the humidity of the drained wash label is too high (e.g., moisture content > 20%), the fixed distance leads to insufficient heat transfer efficiency, incomplete evaporation of moisture from the coating layer, and uneven drying (8%-12% higher moisture content in the center than at the edges), which in turn causes coating adhesion during subsequent winding. Conversely, when the humidity of the wash label is too low (e.g., moisture content < 8%), the excessively close heating distance causes a sudden rise in local temperature (exceeding 80°C), leading to embrittlement of the woven label material (a 15% decrease in tensile strength), charring of the printed pattern edges, and a batch scrap rate as high as 12%. This fixed mode is difficult to adapt to woven label materials with different water absorption rates (e.g., cotton-based materials have a water absorption rate three times that of polyester), severely restricting the stability of drying quality. Therefore, the following design is proposed:

[0087] The wash label located inside the post-coating oven 203 is inverted U-shaped to extend the effective drying time. The post-coating oven 203 is equipped with a fixed drying mechanism 4 and a movable drying mechanism 5 located on either side of the inverted U-shaped wash label. The fixed drying mechanism 4 provides basic heating at a constant distance (30mm from the material surface), while the movable drying mechanism 5 can reciprocate horizontally.

[0088] A humidity detection sensor 6 is installed on the top of the post-coating oven 203. The humidity detection sensor 6 is used to detect the humidity of the wash label after it has been dried by the fixed drying mechanism 4.

[0089] When the humidity detected by the humidity sensor 6 is lower than the preset threshold (e.g., <8%RH), the movable drying mechanism 5 moves away from the care label to a limit position to reduce heat input and prevent over-drying that could cause material embrittlement or pattern cracking. When the humidity detected by the humidity sensor 6 is higher than the preset threshold (e.g., >15%RH), the movable drying mechanism 5 moves closer to the care label to a limit position until it is 15mm away from the material surface, increasing local heating intensity (heat flux increased by 40%) to ensure the coating layer is fully cured.

[0090] In this embodiment, the post-coating oven 203 adopts a dual-unit side-by-side design, with the two ovens arranged in series along the conveying direction, and a set of floating modules in the middle to achieve tension buffering and adjustment. This design not only improves the overall drying efficiency by 25% through segmented drying in two ovens (the first segment focuses on moisture evaporation, and the second segment strengthens coating layer curing), but also avoids material stretching and deformation during long-path conveying through precise tension control, further ensuring the alignment accuracy of double-sided printed patterns and the uniformity of the coating layer.

[0091] The following is a description of the fixed drying mechanism 4:

[0092] The fixed drying mechanism 4 includes a lamp holder 401 fixed to the inner wall of the post-coating oven 203. Several fixed heating lamps 402 are spaced apart on the lamp holder 401 along the depth direction of the post-coating oven 203. Each fixed heating lamp 402 is arranged vertically, forming a uniform heating surface covering the entire width of the material. This structure provides basic heat input at a constant distance (30mm from the material surface), ensuring that the washing label receives preliminary and uniform preheating and drying as it passes through.

[0093] The following is a description of the active drying mechanism 5:

[0094] The movable drying mechanism 5 includes a fixed frame 501 fixed to the inner wall of the post-coating oven 203. A mounting plate 502, movable along the width of the post-coating oven 203, is disposed within the fixed frame 501. A drying assembly 503 is disposed on the side of the mounting plate 502 closest to the washing label. It should be noted that a high-precision electric guide rail or electric telescopic rod can be installed within the fixed frame 501 to drive the mounting plate 502 to achieve linear movement.

[0095] During the research and development process, it was found that when the wash label enters the drying stage after being drained, if the initial humidity is too high (moisture content > 20%), it is easy to form a significant humidity gradient difference due to the following characteristics: Affected by the inverted U-shaped conveying path, the distance between the two sides of the wash label and the drying element is closer than that in the middle, and the air circulation on the sides is better than that in the middle, resulting in heat accumulating faster on the sides; at the same time, the material in the middle forms a slight depression due to tension, and the coating liquid is prone to accumulate here.

[0096] The above factors collectively cause the phenomenon of "drying the sides first and the middle later": the evaporation rate of moisture on the sides is 2-3 times faster than that in the middle. When the sides have reached the drying endpoint (humidity <10%), the humidity in the middle is still as high as 30% or more, resulting in uneven cross-linking and curing of the coating layer. This not only affects the wash resistance (the number of washes in the middle is 40% lower than the standard value), but may also cause the undried areas to stick together due to subsequent winding, causing the batch defect rate to climb to over 15%. To solve this structural drying defect, the dynamic distribution of the heating area needs to be optimized. Therefore, the drying component 503 has been specially designed:

[0097] The drying assembly 503 includes a plurality of first movable heating lamps 5031 arranged in an alternating vertical arrangement. A rotating shaft 5032 is fixed to one end of each first movable heating lamp 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 5031, forming an adjustable-angle heating array. Each rotating shaft 5032 is rotatably connected to the mounting plate 502. A rotation drive structure 5033 is provided on the mounting plate 502, corresponding to each rotating shaft 5032, to drive the rotating shaft 5032 to rotate, thereby causing the first movable heating lamps 5031 to be in an inclined or horizontal state.

[0098] When the mounting plate 502 moves away from the wash label to the limit position, each of the first movable heating lamps 5031 is tilted, and the ends of each first movable heating lamp 5031 away from the corresponding rotation axis 5032 are on the same straight line. The heating area is evenly spread along the width of the material, which can prevent the low-humidity material (humidity < 8% RH) from becoming brittle due to local overheating. When the mounting plate 502 approaches the wash label to the limit position, each of the first movable heating lamps 5031 is horizontal, forming a densely arranged heating band, which specifically strengthens the heating of the middle of the material, controlling the humidity difference between the two sides and the middle of the material to within 3% RH, and solving the problem of "too fast drying on both sides and residual moisture in the middle" under high humidity conditions.

[0099] The following is a description of the rotary drive structure 5033:

[0100] Two housings 504 are fixed parallel to and spaced apart on the side of the mounting plate 502 away from the first active heating lamp 5031 for mounting other components. The rotary drive structure 5033 includes a worm gear fixed on the rotating shaft 5032 and located in the corresponding housing 504. A worm gear that cooperates with the worm gear is rotatably connected inside the housing 504. A gear 50331 located outside the housing 504 is fixed at one end of the worm gear. A rack 50332 that cooperates with the gear 50331 is fixed on the inner side wall of the fixing frame 501. The rack 50332 is 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 gear to rotate. The worm gear transmission causes the rotating shaft to rotate, realizing the linkage adjustment of the lamp angle and position.

[0101] With the above design, when the mounting plate 502 moves away from the wash label to the limit position (50mm from the material surface), the gear and rack drive causes the worm to rotate, thereby driving the lamp tube to rotate around the rotating shaft 5032 to an inclined position (at a 30° angle with the horizontal plane). The free ends of each lamp tube form a continuous straight line, and the heating area is dispersed along the width of the material, which is suitable for the uniform drying of low-humidity materials.

[0102] When the mounting plate 502 approaches the wash label to the limit position (15mm from the material surface), the gear rack reverses its transmission, causing the worm gear to reset and the lamp to rotate to a horizontal position, forming a reinforced heating zone focused on the middle 1 / 3 width area of ​​the material (the heat flux density in the middle is increased by 50% compared to the sides). This design precisely matches the humidity distribution characteristics of "drying the sides first and the middle last": for highly absorbent cotton-based woven labels (moisture content >20%), the drying rate in the middle can be increased by 40%, reducing the humidity difference between the sides and the middle of the material from the traditional 5% or more to less than 1.5%, completely solving the problem of uneven curing of the coating layer caused by localized drying lag.

[0103] This integrated adjustment, which achieves "position movement - angle transformation - thermal field reconstruction" through mechanical linkage, increases the qualified drying rate of high-humidity materials from 82% to 98%, while reducing the edge embrittlement rate caused by over-drying from 5% to 0.8%. It balances the drying rates on both sides and in the middle, while also protecting the drying efficiency and the physical properties of the materials.

[0104] Example 2, please refer to Figures 24 to 26 The difference between this embodiment and Embodiment 1 is that:

[0105] The drying assembly 503 includes two parallel and spaced-apart movable plates 5034, each of which is slidably connected to the mounting plate 502 in a horizontal direction. On the side of each movable plate 5034 near the wash label, a plurality of second movable heating lamps 5035 are fixed vertically at intervals, with the lamps parallel to each other and staggered vertically to form complementary coverage. A translation structure 5036 is provided on the fixed frame 501 for driving the two movable plates 5034 closer together or further apart.

[0106] When the mounting plate 502 moves away from the wash label to the limit position (50mm from the material surface), the two moving plates 5034 are in a state of mutual distance, and the ends of each second movable heating lamp tube 5035 away from the edge of the mounting plate 502 are located on the same straight line, and the heating area is evenly distributed along the full width of the material.

[0107] When the mounting plate 502 approaches the care label to the limit position (15mm from the material surface), the two moving plates 5034 are in a close-to-each-other state. The lamp tubes form a dense heating zone in the middle of the material, specifically addressing the pain point of "drying the sides first and the middle last": for highly absorbent, heavy woven labels (such as cotton-based materials with a moisture content >20%), the increased heating intensity in the middle can shorten the drying time by 35%, reducing the humidity difference between the sides and the middle of the material from 5%-8% in traditional processes to below 1.2%, completely eliminating the coating layer adhesion problem caused by the middle not being completely dry (reducing the defect rate from 12% to 1.5%).

[0108] The following is an introduction to the translation structure 5036:

[0109] The translation structure 5036 includes slide rods 50361 fixed to the upper and lower ends of each movable plate 5034. A groove 50362 corresponding to each slide rod 50361 is provided on the fixed frame 501, allowing the slide rods 50361 to slide along the corresponding groove 50362. In this embodiment, the groove 50362 includes a first straight line segment, an oblique line segment, and a second straight line segment connected in sequence.

[0110] When the slide bar 50361 is located within the first straight segment, the two moving plates 5034 are in a state of distance from each other; when the slide bar 50361 is located within the second straight segment, the two moving plates 5034 are in a state of proximity to each other. The mechanical linkage design of the translation structure 5036 requires no additional driving components; the heating mode switching can be completed solely through the displacement of the mounting plate 502, with a response time of <0.5 seconds. Compared with the electronic control adjustment method, it reduces the number of failure points by 60%, while reducing equipment energy consumption by 18%, thus balancing drying uniformity and operating economy.

[0111] To accommodate the printing needs of different materials, this device is designed with three switchable production process modes, as follows:

[0112] 1. Single-sided printing mode;

[0113] The process is as follows: Automatic unwinding module 102 unwinds → Front correction module 103 calibrates → Front / back printing module (single group enabled) prints → Front and back visual inspection module 1010 inspects → Corresponding side drying oven (front oven 105 or back oven 108) dries → Floating module 1016 controls tension → Automatic winding module 109 winds up.

[0114] This mode is suitable for woven label materials that only require single-sided printing (such as ordinary polyester labels). By using a single set of inkjet printing and directional inspection, it reduces ineffective processes and increases the production efficiency of a single batch by 15%.

[0115] 2. Double-sided printing mode;

[0116] The process is as follows: Automatic unwinding module 102 unwinds → Front correction module 103 calibrates → Front printing module 104 prints → Front visual inspection → Front drying oven 105 dries → Floating module 1016 controls tension → Rear correction module 106 performs secondary calibration → CCD front and back registration module 1012 captures the front reference → Back printing module 107 matches and prints → Back visual inspection → Back drying oven 108 dries → Automatic rewinding module 109 rewinds.

[0117] This mode is designed for materials that require double-sided printing and pattern alignment (such as cotton woven labels with QR codes). By using a positioning vision camera for dynamic matching, it ensures that the alignment error between the front and back patterns is ≤0.2mm, reducing the alignment adjustment time by 40% compared to traditional step-by-step printing.

[0118] 3. Full-process printing-coating mode;

[0119] The process is as follows: Automatic unwinding module 102 unwinds → Front correction module 103 calibrates → Front printing module 104 prints → Front visual inspection → Front drying oven 105 dries → Floating module 1016 controls tension → Rear correction module 106 calibrates → CCD front and back registration module 1012 positions → Reverse printing module 107 prints → Reverse visual inspection → Reverse drying oven 108 dries → Parallel guide unit 3 completes 90° rotation → Rear coating unit 2 coats → Rear coating oven 203 dries → Rear coating rewinding module 204 rewinds.

[0120] This mode integrates printing and coating processes and is suitable for high-end materials that require surface protection treatment (such as water-resistant blended labels). Through the seamless connection of parallel guide unit 3, it avoids secondary material transfer losses, improves coating adhesion by 20% compared to offline processing, and supports continuous production of orders with different lengths from 50 to 1000 meters.

[0121] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0122] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A double-sided digital inkjet device for washable labels, characterized in that: It includes a double-sided digital inkjet unit and a post-coating unit arranged in an L-shape. A parallel guide unit is provided between the double-sided digital inkjet unit and the post-coating unit. The parallel guide unit is used to receive the wash label output by the double-sided digital inkjet unit and rotate the wash label 90° before conveying it to the post-coating unit. The post-coating unit includes a machine body, and a post-coating water tank, a draining module, a post-coating drying oven, and a post-coating winding module are sequentially arranged on the side wall of the machine body along the conveying direction of the washing label. The wash label located in the post-coating oven is inverted U-shaped. The post-coating oven is equipped with a fixed drying mechanism and a movable drying mechanism located on both sides of the inverted U-shaped wash label. A humidity detection sensor is installed on the top of the post-coating oven. The humidity detection sensor is used to detect the humidity of the wash label after it has been dried by the fixed drying mechanism. When the humidity detected by the humidity sensor is lower than the preset threshold, the movable drying mechanism moves away from the care label to the limit position; when the humidity detected by the humidity sensor is higher than the preset threshold, the movable drying mechanism moves closer to the care label to the limit position. The parallel guide unit includes a guide base fixed to a double-sided digital inkjet unit. A parallel guide shaft is fixedly installed on the guide base. Two parallel guide retaining rings are fixedly fixed at axial intervals on the parallel guide shaft. A guide slope is provided on the side of the two parallel guide retaining rings that are close to each other.

2. The double-sided digital inkjet device for washable labels according to claim 1, characterized in that: The double-sided digital inkjet unit includes a carrier, and the side wall of the carrier is sequentially provided with an automatic unwinding module, a front correction module, a front printing module, a front drying oven, a rear correction module, a CCD front and back registration module, a back printing module, a back drying oven, and an automatic rewinding module along the conveying direction of the washing label. A constant temperature and humidity chamber is fixed on the side wall of the carrier, and the front printing module and the back printing module are arranged side by side inside the constant temperature and humidity chamber; a front and back visual inspection module is installed on the side wall of the carrier, located between the front printing module and the back printing module. The parallel guide unit is fixed to the side wall of the carrier, and the wash label can be selectively conveyed to the automatic winding module or the parallel guide unit.

3. The double-sided digital inkjet device for washable labels according to claim 1, characterized in that: The fixed drying mechanism includes a lamp holder fixed to the inner wall of the post-coating oven. Several fixed heating lamps are spaced apart on the lamp holder along the depth direction of the post-coating oven, and each fixed heating lamp is arranged in a vertical direction.

4. The double-sided digital inkjet device for washable labels according to claim 1, characterized in that: The movable drying mechanism includes a fixed frame fixed to the inner wall of the post-coating oven, and a mounting plate that can move along the width direction of the post-coating oven is provided in the fixed frame. A drying component is provided on the side of the mounting plate near the washing label.

5. A double-sided digital inkjet device for washable labels according to claim 4, characterized in that: The drying assembly includes a plurality of first movable heating lamps arranged in an alternating pattern. A rotating shaft is fixed at one end of each first movable heating lamp near the edge of the mounting plate. The axis of the rotating shaft is perpendicular to the axis of the first movable heating lamp. Each rotating shaft is rotatably connected to the mounting plate. A rotating drive structure corresponding to each rotating shaft is provided on the mounting plate. When the mounting plate moves away from the wash label to the limit position, each of the first movable heating lamps is tilted, and the ends of each of the first movable heating lamps away from the corresponding rotation axis are on the same straight line. When the mounting plate approaches the water-wash label to the limit position, each of the first active heating lamps is horizontal.

6. A double-sided digital inkjet device for washable labels according to claim 5, characterized in that: The mounting plate has two housings fixed parallel to and spaced apart on the side away from the first active heating lamp tube; The rotary drive structure includes a worm gear fixed on a rotating shaft and located inside a corresponding housing, a worm gear rotatably connected inside the housing to cooperate with the worm gear, a gear fixed at one end of the worm gear located outside the housing, and a rack cooperating with the gear fixed on the inner side wall of the fixed frame, the rack being arranged along the width direction of the post-coating oven.

7. A double-sided digital inkjet device for washable labels according to claim 4, characterized in that: The drying assembly includes two parallel and spaced-apart movable plates, each of which is slidably connected to the mounting plate in the horizontal direction; a number of second movable heating lamps are fixed in the vertical direction on the side of each movable plate near the washing label, and the second movable heating lamps are parallel to each other and staggered vertically; a translation structure for driving the two movable plates to move closer to each other or further away from each other is provided on the fixed frame. When the mounting plate moves away from the wash label to the limit position, the two moving plates are in a state of mutual distance, and the ends of each second movable heating lamp tube away from the edge of the mounting plate are on the same straight line; When the mounting plate approaches the wash label to the limit position, the two moving plates are in a close proximity to each other.

8. A double-sided digital inkjet device for washable labels according to claim 7, characterized in that: The translation structure includes slide rods fixed to the upper and lower ends of each movable plate, and a sliding groove corresponding to each slide rod is provided on the fixed frame, so that the slide rod can slide along the corresponding sliding groove.

9. A double-sided digital inkjet device for washable labels according to claim 8, characterized in that: The chute comprises a first straight segment, an oblique segment, and a second straight segment connected in sequence. When the slide bar is in the first straight segment, the two moving plates are in a state of being far apart from each other; when the slide bar is in the second straight segment, the two moving plates are in a state of being close to each other.

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