Contact type conduction drying oven

Abstract

The invention discloses a contact type conduction drying oven, and relates to the technical field of drying, the contact type conduction drying oven comprises a box body, the interior of the box body is hollow to form a drying chamber, and one side of the box body is provided with a box door; the image acquisition unit is arranged in the box body and is used for acquiring an image of the surface of an object to be dried in the drying chamber; the heat conduction template array is arranged in the drying chamber and located below an object to be dried, and the heat conduction template array is composed of a plurality of independent and controllable heat conduction template units; the micro-motion mechanism is connected with each heat conduction template unit; and the control system is in communication connection with the image acquisition unit, the micro-motion mechanism and the heat conduction template unit. The device has the function of supplying heat as required based on the ink layer image.

Description

Technical Field

[0001] This invention belongs to the field of drying technology, specifically relating to a contact-type conductive drying oven. Background Technology

[0002] In the field of inkjet printing, it is often necessary to perform rapid and uniform drying and curing treatment on flat objects whose surfaces are coated with ink, paint or other liquid functional materials.

[0003] Traditional drying equipment, such as hot air circulating ovens, infrared ovens, or tunnel ovens, typically uses uniform temperature, airflow, and time settings for the entire drying area. However, the ink coverage and ink layer thickness vary across different areas of the item being dried. Using uniform parameters can lead to thin ink areas becoming overly dry and brittle, resulting in color distortion, while thick ink areas may not cure sufficiently and adhere well, negatively impacting overall print quality.

[0004] Some patents that use image recognition to control the switching of infrared lights or adjust drying time in different zones represent an improvement in control logic, but they can only adjust the energy density reaching the material surface, resulting in energy loss from the surface to the interior.

[0005] This application has the function of providing on-demand heating based on ink layer images. Summary of the Invention

[0006] The purpose of this invention is to provide a contact conduction drying oven to solve the technical problems mentioned in the background art.

[0007] To achieve the above objectives, the specific technical solution of the present invention is as follows: A contact conduction drying oven, comprising: The box has a hollow interior forming a drying chamber, and a door is provided on one side of the box. An image acquisition unit, located inside the chamber, is used to acquire images of the surface of the object to be dried placed in the drying chamber. A thermally conductive template array is disposed in the drying chamber and located below the object to be dried. The thermally conductive template array is composed of multiple independent and controllable thermally conductive template units. A micro-motion mechanism, connected to each of the heat-conducting template units, is used to drive the corresponding heat-conducting template unit to move in the vertical direction, so as to change the distance between it and the back of the object to be dried; The control system is communicatively connected to the image acquisition unit, the micro-motion mechanism, and the heat-conducting template unit. The control system is configured as follows: Based on the image acquired by the image acquisition unit, ink partition identification is performed, and image feature information related to ink layer thickness of each partition is determined; according to the image feature information, the micro-motion mechanism corresponding to each ink partition is controlled to make the corresponding heat-conducting template unit form a heat conduction contact state with the back of the object to be dried, or maintain a close proximity state within 10mm, and the heating parameters of the heat-conducting template unit are controlled.

[0008] Optionally, the drying chamber is provided with a shelf for clamping and fixing the items to be dried. The heat-conducting template array is located below the shelf. The shelf includes a frame and a flexible net that supports and keeps the items to be dried flat. The four sides of the frame are provided with multiple clamping components for clamping the edges of the items to be dried so that they are laid flat on the flexible net.

[0009] Optionally, the step of extracting image features and determining image feature information related to ink layer thickness specifically includes: extracting the average brightness value of the ink zone in the HSV color space, and converting the average brightness value into a relative thickness coefficient K reflecting the ink layer thickness according to a pre-stored brightness-thickness calibration model; the control system is further configured as follows: Receives user input regarding the type of substrate for the item to be dried; Based on the relative thickness coefficient K and the substrate type, the control system generates drying requirement information for each zone. Based on the drying requirements, the target temperature and action time parameters are independently set for each heat-conducting template unit that comes into contact with or is close to the object.

[0010] Optionally, the thermally conductive template unit is embedded with a temperature sensor, and the control system has a built-in or connected material database to obtain the thermal conductivity parameters corresponding to different substrate types.

[0011] Optionally, the micro-motion mechanism is a screw mechanism driven by a stepper motor or a micro linear motor; the surface of the thermally conductive template unit that contacts the object is covered with an integrated partitioned flexible thermally conductive layer, the flexible thermally conductive layer including a high thermal conductivity flexible core area in the middle and a low thermal conductivity flexible insulation ring area surrounding the high thermal conductivity flexible core area; the high thermal conductivity flexible core area is made of vertically high thermal conductivity material, and the low thermal conductivity flexible insulation ring area is made of low thermal conductivity insulation material.

[0012] A method for drying objects in a contact conduction drying oven includes: S1. Acquire an image of the object's surface using the image acquisition unit, and identify multiple ink zones based on color and contour features; S2. For each ink zone, extract its average lightness value in the HSV color space; based on the pre-stored lightness-thickness calibration model, convert the average lightness value into the corresponding relative thickness coefficient K; S3. The control system generates control commands for the micro-motion mechanism and the heat-conducting template unit based on the relative thickness coefficient K of each partition and the substrate type. S4. The micro-motion mechanism drives the corresponding heat-conducting template unit to move according to the control command, so that it forms a preset contact or proximity state with the back of the object; S5. Start the heat-conducting template unit to perform contact conduction heating on the corresponding ink zone using the set heating parameters.

[0013] Optionally, in step S3, the control system calculates the required heat transfer for each zone based on the relative thickness coefficient K and the substrate type using a thermal conduction model, and determines the target temperature and application time for each thermally conductive template unit accordingly. Attached Figure Description

[0014] Figure 1 This is an open structural diagram of the present application; Figure 2 This is a schematic diagram of the control structure of this application; The markings in the diagram are as follows: 1. Box body; 11. Box door; 2. Thermal conductive template array; 21. Thermal conductive template unit; 22. Flexible thermal conductive layer; 3. Shelf; 31. Flexible mesh; 32. Clamping assembly; 4. Micro-motion mechanism. Detailed Implementation

[0015] The following is in conjunction with the appendix Figure 1-2 This application provides a contact-type conductive drying oven. The oven body 1 is in the shape of a vertical cabinet, with a door 11 on the front side equipped with a sealing strip and a glass observation window to ensure the airtightness of the chamber and safe observation. The interior of the oven body 1 forms a drying chamber.

[0016] An industrial camera serving as an image acquisition unit is installed on the upper part of the chamber wall, and a dedicated shelf 3 is provided at the bottom of the chamber. The shelf 3 includes a rectangular aluminum alloy frame 33 and a flexible mesh 31 stretched within the frame, with the frame 33 and the flexible mesh 31 forming a bearing plane. In this embodiment, the flexible mesh 31 is a stainless steel woven wire mesh, used to provide stable mechanical support and ensure that the object to be dried remains flat. Clamping components 32 are provided on the four sides of the frame 33. In this embodiment, the clamping components 32 are stainless steel spring clips, used to clamp the four sides of the object, ensuring that it remains flat and attached to the mesh throughout the drying process.

[0017] Directly below the metal mesh of the shelf 3, a thermally conductive template array 2 is installed. In this embodiment, the array consists of 42 (7x6) independently controllable thermally conductive template units 21. In this embodiment, each unit is an aluminum alloy block with an embedded electric heating wire and a PT100 temperature sensor. A 2mm integrated partitioned flexible thermally conductive layer 22 is bonded to the top surface with thermally conductive adhesive. This flexible thermally conductive layer 22 is a silicone-based integrated hot-pressed structure.

[0018] The central part of the flexible thermal conductive layer 22 is a high thermal conductivity flexible core area, accounting for 80%-85% of the effective contact area of ​​the flexible thermal conductive layer 22. In this embodiment, the high thermal conductivity flexible core area is a spherical alumina composite modified high thermal conductivity silicone with a thermal conductivity of 1.8 W / (m·K), which is the core channel for heat transfer from the thermal conductive template unit 21 to the back of the object. A low thermal conductivity flexible insulation ring area is arranged around the outside of the high thermal conductivity flexible core area, with a ring width of 2.5 mm. In this embodiment, the low thermal conductivity flexible insulation ring area is made of ceramic microsphere modified low thermal conductivity silicone with a thermal conductivity of only 0.25 W / (m·K), which is integrally hot-pressed with the high thermal conductivity flexible core area to suppress the heat of the high thermal conductivity core area from spreading laterally to the edge of the template unit. After testing, the lateral heat diffusion temperature difference within a single template unit is ≤2℃, and the heat transfer temperature difference between adjacent template units is ≤1℃, ensuring the accuracy of ink zone heating on demand.

[0019] Each heat-conducting template unit 21 is connected to a micro-motion mechanism 4 below it. In this embodiment, the micro-motion mechanism 4 is a ball screw mechanism driven by a stepper motor. The moving end of the mechanism is fixedly connected to the heat-conducting template unit 21, which can drive the heat-conducting template unit 21 to rise and fall vertically within the range of 0-50mm, with a repeatability accuracy of ±0.05mm.

[0020] The control system is an embedded main control board, installed in the electrical control compartment of enclosure 1. The industrial camera, all stepper motor drivers, solid-state relays for each heating unit, and temperature sensors are all connected to the main control board. A touchscreen is embedded in the base of enclosure 1, serving as the human-machine interface.

[0021] This application also provides a method for drying objects using a drying oven, taking the example of a user drying a cotton canvas item to be dried.

[0022] Open the box door 11, lay the item flat on the flexible net 31 of the shelf 3, use the clamping components 32 around the edges to clamp the item to make it flat and fixed, and close the box door 11.

[0023] Step S1: The system starts up, and the image acquisition unit (industrial camera) captures a high-resolution image of the front of the item to be dried. The control system runs an image processing algorithm: First, the image is converted from RGB space to HSV color space, and preliminary segmentation is performed according to the preset ink color threshold to distinguish the ink area from the blank substrate area; then, noise is removed and broken areas are connected through morphological processing, and connected component analysis is performed to finally identify several independent "ink zones".

[0024] Step S2: For each ink zone identified in Step S2, the control system extracts the V (brightness) channel values ​​of all pixels within that zone in the HSV space and calculates their average value to obtain the average brightness value V_region for that zone. Subsequently, the control system queries the "brightness-thickness calibration model" pre-stored in memory, inputs V_region into the model, and calculates the "relative ink layer thickness coefficient K_region" corresponding to that zone. Based on the numerical range of K_region, it can be further classified into one of three levels: "thin" (e.g., K < 0.4), "medium" (e.g., 0.4 ≤ K < 0.8), and "thick" (e.g., K ≥ 0.8), or a more precise calculation can be performed using continuous K values.

[0025] In this embodiment, the "pre-stored brightness-thickness calibration model" is obtained through the following calibration process: A digital inkjet standard calibration plate is made, which contains at least 6 solid areas from light to dark. Each area has a known maximum solid ink coverage percentage (e.g., 20%, 40%, 60%, 80%, 100%), and this percentage is defined as the "relative ink layer thickness coefficient K" of the area.

[0026] For each calibration block in the image, its pixels are extracted and converted to the HSV color space. The average value of all pixels in its V (luminance) channel is calculated and denoted as V_calib. V_calib is then fitted with an exponential curve using the least squares method to establish a continuous mapping function from V_calib to K, i.e., the "luminance-thickness calibration model," and burned into the memory of the control system.

[0027] The table below shows the relationship between the ink coverage percentage (K) of key nodes and the average brightness value: Calibrating block number Ink coverage percentage (K) Average lightness value (V_calib, range 0-255) 1 20% (0.2) 210 2 40% (0.4) 165 3 60% (0.6) 120 4 80% (0.8) 80 5 100% (1.0) 45 Step S3: Drying Parameter Calculation and Command Generation. The control system receives the user-input "cotton canvas" substrate type and retrieves the thermal conductivity of the substrate from the built-in material database. For each ink zone, the control system performs simulation calculations using a built-in heat conduction model based on its area, the calculated K_region value, and the substrate's thermal properties. This model considers the thermal resistance (including contact thermal resistance and material thermal resistance) along the entire path of heat transfer from the thermally conductive template unit 21, through the flexible thermally conductive layer 22, the flexible mesh 31, and the object substrate to the ink layer. Through calculation, the model determines the conductive heat Q_req required for effective drying of the zone. In this embodiment, the heat conduction model is a simplified one-dimensional steady-state heat transfer model, and its basic calculation formula is: Q_req = (T_target - T_ambient) * A * t_duration / R_total. The total thermal resistance R_total is determined comprehensively based on the substrate's thermal conductivity and the ink layer information (correlated with the K value).

[0028] Based on the calculated Q_req, the control system further determines the specific control commands to execute heating, mainly including: The micro-motion mechanism control command determines whether the corresponding heat-conducting template unit 21 adopts the "contact" mode or the "approach" mode, and sets its target vertical position (in contact mode, it is lifted to make slight contact with the bottom surface of the flexible mesh 31; in approach mode, it is set with a precise distance, such as 1mm, 2mm, or 3mm, but not exceeding 10mm). For pressure-resistant materials such as cotton canvas, the contact mode is usually used to obtain the maximum heat conduction efficiency.

[0029] The heating command for each heat-conducting template unit 21 independently sets the target temperature T_target and the application time t_duration. The target temperature must ensure sufficient Q_req is provided within the application time, while not exceeding the heat resistance limit of the substrate. The application time is determined based on a combination of the heat transfer rate and the total heat demand.

[0030] In this embodiment, the control system generates drying requirement information, which is specified as: target temperature - processing time. Based on this information and the spatial distribution structure of the ink partitions, the control system maps it to specific thermally conductive template units 21 to generate the final control instruction set.

[0031] To illustrate the influence of different substrates, cotton canvas and medical gauze are used as examples to show typical drying parameters obtained from experimental tests. The thermal conductivity (λ) of cotton canvas and medical gauze are 0.05 W / (m·K) and 0.03 W / (m·K), respectively. The data obtained from the experimental tests are as follows. Ink layer thickness grade Thickness coefficient (K) Target substrate Target temperature (°C) Duration of action (seconds) Work mode Thin 0.3 cotton canvas 52 90 touch Medical gauze 48 120 Approximately 1.3mm middle 0.6 cotton canvas 70 240 touch Medical gauze 62 320 Approximately 1mm thick 0.9 cotton canvas 82 420 touch Medical gauze 67 540 Approximately (0.5mm) In the cotton canvas substrate, for a large dark blue area that is determined to be of the "thick" level (K_region=0.9), the system maps out the 6 heat-conducting template units 21 that are covered below it, and generates instructions for these 6 units: the micro-motion mechanism is lifted to the "contact" position; the heating target temperature is set to 82℃; and the action time is set to 420 seconds (7 minutes).

[0032] For a light yellow area of ​​"medium" level (K_region=0.6), the four heat-conducting template units 21 below it receive the following instructions: the micro-motion mechanism is lifted to the "contact" position; the heating target temperature is set to 70℃; and the action time is set to 240 seconds (4 minutes).

[0033] For the "thin" region (K_region=0.3), the two corresponding heat-conducting template units 21 below receive the instruction: the micro-motion mechanism rises to the "contact" position; preheating is performed at a lower temperature of 52°C for 90 seconds (1 minute and a half) to prevent the temperature of this region from being too low and affecting the overall drying uniformity or to deal with possible trace amounts of ink.

[0034] Step S4: The control system drives the micro-motion mechanism 4 to make each heat-conducting template unit 21 move precisely to the predetermined position (contact or approach) according to the instruction.

[0035] Step S5: Heating Execution. The control system sends commands to the heating circuits of each heat-conducting template unit 21 to initiate heating. Each unit controls its temperature according to its independent T_target, rapidly raising it to the preset temperature and maintaining it at a constant temperature for t_duration. Heat is efficiently and vertically conducted through the highly thermally conductive core area of ​​the flexible thermally conductive layer 22 and the flexible mesh 31 to specific ink zones on the back of the object, achieving on-demand heating.

[0036] Once the preset maximum operating time for all heat-conducting template units 21 is reached, the control system issues a stop command, and all heating units cease operation. Subsequently, the control system controls the micro-motion mechanism 4 to drive the entire heat-conducting template array 2 to descend to its initial reset position, completely disengaging from the shelf 3. The user can then open the door 11, release the clamping assembly 32, and remove the dried items.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A contact-type conductive drying oven, characterized in that, include: The box (1) has a hollow interior forming a drying chamber, and a door (11) is provided on one side of the box (1). An image acquisition unit is installed inside the housing (1) and is used to acquire images of the surface of the object to be dried placed in the drying chamber. A thermally conductive template array (2) is disposed in the drying chamber and located below the object to be dried. The thermally conductive template array (2) is composed of multiple independent and controllable thermally conductive template units (21). The micro-motion mechanism (4) is connected to each of the heat-conducting template units (21) and is used to drive the corresponding heat-conducting template unit (21) to move in the vertical direction so as to change the distance between it and the back of the object to be dried; The control system is communicatively connected to the image acquisition unit, the micro-motion mechanism (4), and the heat-conducting template unit (21). The control system is configured as follows: Based on the image acquired by the image acquisition unit, ink partition identification is performed, and image feature information related to ink layer thickness of each partition is determined; according to the image feature information, the micro-motion mechanism (4) corresponding to each ink partition is controlled to make the corresponding heat-conducting template unit (21) form a heat conduction contact state with the back of the object to be dried, or maintain a close proximity state within 10mm, and the heating parameters of the heat-conducting template unit (21) are controlled.

2. The drying oven according to claim 1, characterized in that, The drying chamber is provided with a shelf (3) for clamping and fixing the items to be dried. The heat-conducting template array (2) is located below the shelf (3). The shelf (3) includes a frame (33) and a flexible net (31) that supports and keeps the items to be dried flat. The four sides of the frame (33) are provided with multiple clamping components (32) for clamping the edges of the items to be dried so that they are laid flat on the flexible net (31).

3. The drying oven according to claim 1, characterized in that, The step of extracting image features and determining image feature information related to ink layer thickness specifically includes: extracting the average brightness value of the ink zone in the HSV color space, and converting the average brightness value into a relative thickness coefficient K reflecting the ink layer thickness according to a pre-stored brightness-thickness calibration model; the control system is further configured as follows: Receives user input regarding the type of substrate for the item to be dried; Based on the relative thickness coefficient K and the substrate type, the control system generates drying requirement information for each zone. Based on the drying requirements, the target temperature and action time parameters are independently set for each heat-conducting template unit (21) that comes into contact with or is close to the object.

4. The drying oven according to claim 1, characterized in that, The thermally conductive template unit (21) is equipped with a temperature sensor, and the control system is equipped with or connected to a material database to obtain thermal conductivity parameters corresponding to different substrate types.

5. The drying oven according to claim 1, characterized in that, The micro-motion mechanism (4) is a screw mechanism driven by a stepper motor or a micro linear motor; the surface of the heat-conducting template unit (21) that contacts the object is covered with an integrated partitioned flexible heat-conducting layer (22), the flexible heat-conducting layer (22) includes a high thermal conductivity flexible core area in the middle and a low thermal conductivity flexible insulation ring area surrounding the high thermal conductivity flexible core area; the high thermal conductivity flexible core area is a vertical high thermal conductivity material, and the low thermal conductivity flexible insulation ring area is a low thermal conductivity insulation material.

6. A method for drying objects using a contact-type conductive drying oven as described in any one of claims 1-5, characterized in that, include: S1. Acquire an image of the object's surface using the image acquisition unit, and identify multiple ink zones based on color and contour features; S2. For each ink zone, extract its average lightness value in the HSV color space; based on the pre-stored lightness-thickness calibration model, convert the average lightness value into the corresponding relative thickness coefficient K; S3. The control system generates control commands for the micro-motion mechanism (4) and the heat-conducting template unit (21) based on the relative thickness coefficient K of each partition and the substrate type. S4. The micro-motion mechanism (4) drives the corresponding heat-conducting template unit (21) to move according to the control command, so that it forms a preset contact or proximity state with the back of the object; S5. Start the heat-conducting template unit (21) to perform contact conduction heating on the corresponding ink partition with the set heating parameters.

7. The method according to claim 6, characterized in that, In step S3, the control system calculates the heat required for each zone based on the relative thickness coefficient K and the substrate type using a heat conduction model, and determines the target temperature and action time of each heat-conducting template unit (21) accordingly.

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