A method and apparatus for replicating industrial oven temperature profiles for paint curing experiments

Abstract

This invention relates to the field of coating curing testing technology, and provides a method and apparatus for replicating the temperature curve of an industrial drying tunnel for coating curing experiments. The method includes: S1, clarifying the requirements of the customer and the target product; S2, collecting data on the drying temperature replication curve of the coating after it has been applied in the customer's industrial drying tunnel; S3, designing the coating formulation and proportion according to the requirements, applying it to laboratory specimens, and sending them to a laboratory oven for drying, with the temperature of the laboratory oven controlled according to the drying temperature replication curve data; S4, determining whether the coating of the dried laboratory specimens meets the customer's requirements, until the coating of the laboratory specimens meets the customer's coating requirements. The coating curing testing method for replicating the temperature curve of an industrial drying tunnel provided by this invention can effectively avoid the problem of significant deviation between the curing effect of laboratory specimens and mass-produced workpieces, and improve the matching degree between coating formulation development, process parameter debugging, and actual production.

Description

Technical Field

[0001] This invention relates to the field of coating curing experimental technology, specifically to a coating curing experimental method and apparatus that replicates the temperature curve of an industrial drying tunnel. Background Technology

[0002] In modern industrial coating, coating curing is a crucial process that determines the final performance of the coating. Core performance indicators such as adhesion, hardness, corrosion resistance, weather resistance, gloss, and mechanical strength depend not only on the coating's formulation but also closely on the temperature-time history (i.e., temperature profile) during the curing process. Currently, continuous curing tunnels are commonly used in large-scale industrial production to cure coated workpieces.

[0003] A typical industrial continuous curing oven is divided into three functional sections along the workpiece conveying direction: a heating zone, a heat preservation and curing zone, and a slow cooling zone. Workpieces continuously pass through the oven at a constant speed via overhead conveyors, roller conveyors, or other transport devices, experiencing a complete thermal process: rapidly heating from room temperature to the curing temperature, holding at the set temperature for a certain time, and then slowly cooling to near room temperature. This forms a continuous dynamic temperature curve with specific heating rates, heat preservation temperatures, heat preservation times, and cooling rates. The temperature curves of industrial ovens vary significantly across different industries and products. Even within the same oven, temperature distribution is uneven at different locations, and different parts of the workpiece will exhibit different actual temperature curves due to differences in heat capacity.

[0004] When developing customized coating products for downstream customers, paint manufacturers typically follow this R&D process: First, the formulation is designed and optimized based on the customer's coating performance requirements (such as hardness, adhesion, salt spray resistance, etc.); then, small-scale coating samples are prepared in the laboratory and coated onto standard test panels; finally, the test panels are placed in a general-purpose electric thermostatic oven in the laboratory for curing. After curing, the various properties of the coating are tested. If the test results meet the customer's requirements, the formulation is considered successfully developed and ready for mass production and delivery to the customer.

[0005] However, in actual production applications, paint manufacturers often encounter a difficult technical problem: paint products that meet all performance standards after curing in a laboratory constant-temperature oven often fail to achieve the expected coating performance and exhibit quality defects when applied to actual production lines and cured in industrial continuous curing tunnels. Specifically, this manifests as problems with coating adhesion, hardness, surface smoothness, corrosion resistance, and color. Summary of the Invention

[0006] To overcome the above-mentioned defects, embodiments of the present invention provide a coating curing experimental method and apparatus for replicating the temperature curve of an industrial drying tunnel, which solves the technical problem in the related art that the coatings produced by coating manufacturers do not meet the requirements of the demanding manufacturers.

[0007] At least one embodiment of the present invention provides a coating curing experimental method for replicating the temperature profile of an industrial drying tunnel, comprising the following steps: S1. Clearly define the coating requirements of the coating customer and the target product to be coated; S2. Collect drying temperature replication curve data of the target product after coating and drying in the industrial drying tunnel of the coating demander. S3. Design the coating formula and proportion according to the coating requirements, apply it to the laboratory specimens and send them to the laboratory oven for drying. The temperature of the laboratory oven is controlled according to the drying temperature replication curve data until the laboratory specimens are dried. S4. Determine whether the coating of the dried laboratory specimens meets the coating requirements of the coating customer. S5. Repeat steps S3 and S4 until the coating of the dried laboratory specimens meets the coating requirements of the coating customer, and obtain the coating formula and proportion corresponding to the coating requirements of the coating customer.

[0008] For example, at least one embodiment of this disclosure provides a coating curing experiment method for replicating the temperature curve of an industrial drying tunnel. In step S2, the drying temperature replication curve data includes a heating section, a curing and heat preservation section, and a cooling section.

[0009] For example, at least one embodiment of this disclosure provides a coating curing experiment method for replicating the temperature curve of an industrial drying tunnel. Step S2 further includes synchronously acquiring the heat flux density curve at the corresponding position in the industrial drying tunnel. In step S3, while controlling the temperature according to the drying temperature replication curve data, the laboratory oven synchronously replicates the heat flux density change curve in the industrial drying tunnel through the built-in heat flux adjustment module, so that the heat exchange rate on the surface of the laboratory specimen is consistent with the industrial production conditions.

[0010] For example, at least one embodiment of this disclosure provides a coating curing experimental method for replicating the temperature curve of an industrial drying tunnel. In step S3, the laboratory specimen is customized according to the target product and is a scaled-down version of the target product.

[0011] At least one embodiment of the present invention also provides a coating curing device that replicates the temperature curve of an industrial drying tunnel, including a curing chamber, a hot air circulation heating unit, a temperature detection unit, a central control unit, a data communication interface, and a temperature processing software module embedded in the central control unit; It also includes an oven temperature tracker, which is used to collect the complete time-series temperature curve of the workpiece as it enters the industrial coating curing oven and stores it as drying temperature replication curve data. The central control unit establishes a direct communication connection with the furnace temperature tracker through the data communication interface, and automatically downloads and parses the drying temperature replication curve data. The temperature processing software module is used to convert the parsed drying temperature replication curve data into real-time heating control parameters. The hot air circulation heating unit is electrically connected to the central control unit. Under the control of the central control unit, it performs full-cycle heating according to real-time heating control parameters, completely simulating the temperature changes of the heating section, curing and heat preservation section and cooling section of the industrial drying tunnel, so as to achieve coating curing.

[0012] For example, at least one embodiment of this disclosure provides a coating curing apparatus that replicates the temperature profile of an industrial drying tunnel, wherein the data communication interface integrates a wired communication interface and a wireless communication module.

[0013] For example, at least one embodiment of this disclosure provides a coating curing device for replicating the temperature curve of an industrial drying tunnel. The temperature detection unit is a multi-point distributed temperature sensor array arranged in the inner cavity of the curing chamber. The multi-point distributed temperature sensor array and the central control unit constitute a real-time closed-loop temperature control system, which can dynamically correct heating deviations and control the temperature curve replication error within ±1℃.

[0014] For example, at least one embodiment of this disclosure provides a coating curing device for replicating the temperature curve of an industrial drying tunnel. The central control unit has a built-in data storage unit that can store at least hundreds of industrial drying tunnel temperature curves of different coating production lines and different process parameters. It supports one-click retrieval and reuse of stored curves, as well as online editing and modification of local parameters.

[0015] For example, at least one embodiment of this disclosure provides a coating curing device for replicating the temperature curve of an industrial drying tunnel. The temperature processing software module has a built-in timing calibration algorithm that adaptively corrects the downloaded temperature curve of the industrial drying tunnel based on the size of the laboratory specimen, the loading amount, and the thermal inertia parameters of the curing chamber.

[0016] For example, at least one embodiment of the coating curing apparatus provided in this disclosure further includes an online curing degree closed-loop feedback system, which consists of a Fourier transform infrared spectroscopy probe, a dielectric constant sensor, and a curing degree analysis module; the Fourier transform infrared spectroscopy probe monitors the changes in the absorption peak intensity of characteristic functional groups in the coating in real time, the dielectric constant sensor monitors the changes in the dielectric constant of the coating in real time, and the curing degree analysis module calculates the real-time curing degree based on the functional group conversion rate and the dielectric constant change rate; when the actual curing degree deviates from the preset curing degree curve, the central control unit automatically increases or decreases the heating power and heating time.

[0017] The present invention provides a coating curing experimental method and apparatus for replicating the temperature curve of an industrial drying tunnel. Compared with the prior art, the coating curing experimental method for replicating the temperature curve of an industrial drying tunnel can effectively avoid the problem of significant deviation between the curing effect of laboratory test pieces and mass-produced workpieces, and improve the matching degree between coating formulation development, process parameter debugging and actual production. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the frame structure of the coating curing device provided in an embodiment of the present invention; In the diagram: Curing chamber-1, hot air circulation heating unit-2, temperature detection unit-3, central control unit-4, data communication interface-5, temperature processing software module-6, oven temperature tracker-7. Detailed Implementation To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0022] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0023] To make the drawings concise and easy to understand, some drawings only show one of the components with the same structure or function, or only one of them is marked. In this article, "one" not only means "only one", but can also mean "more than one", and "several" includes "two" and "more than two".

[0024] Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. It is understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0025] One embodiment of the present invention provides a coating curing experimental method for replicating the temperature profile of an industrial drying tunnel, the specific steps of which are as follows: S1. Clearly define the coating requirements of the coating customer and the target product to which the coating will be applied. The coating customer is an electronic equipment manufacturer. Their requirements for the coating are good insulation, weather resistance, and a certain degree of hardness. The target product is the casing of electronic equipment.

[0026] S2. Data on the drying temperature replication curve of the target product after coating and drying in the industrial drying tunnel at the coating customer's site is collected. Temperature sensors are placed at regular intervals along the conveying path of the electronic equipment casing within the industrial drying tunnel. After multiple measurements and averaging, a complete drying temperature replication curve is obtained. This curve includes the heating phase, the curing and holding phase, and the cooling phase. Specifically, the heating phase rapidly increases the temperature from room temperature (22℃) to 130℃ at a rate of 4℃ per minute; the curing and holding phase maintains the temperature at 130℃ for 25 minutes; and the cooling phase slowly decreases the temperature to 55℃ at a rate of 3℃ per minute.

[0027] S3. The coating formulation and proportioning were designed according to the coating requirements, and the coating was applied to laboratory test specimens, which were then placed in a laboratory oven for drying. The temperature of the laboratory oven was controlled according to the drying temperature replication curve data until the laboratory test specimens were completely dry. Based on the coating requirements of electronic equipment manufacturers, the R&D personnel designed the coating formulation. The coating was evenly applied to laboratory test specimens made of the same material as the electronic equipment casing, and then the test specimens were placed in the laboratory oven. The laboratory oven temperature was controlled according to the collected drying temperature replication curve data. During the heating phase, the oven temperature increased from 22°C to 130°C at a rate of 4°C per minute; during the curing and heat preservation phase, the temperature was maintained at 130°C for 25 minutes; during the cooling phase, the temperature decreased from 130°C to 55°C at a rate of 3°C per minute.

[0028] S4. Determine whether the coating of the dried laboratory specimens meets the coating requirements of the coating customer. Perform performance testing on the coating of the dried laboratory specimens. Measure the insulation resistance of the coating using an insulation resistance tester, evaluate the weather resistance of the coating using an accelerated aging test chamber, and test the hardness of the coating using a hardness tester.

[0029] S5. Repeat steps S3 and S4 until the coating of the dried laboratory specimen meets the coating requirements of the coating customer. After multiple adjustments and tests, the coating performance indicators of the dried laboratory specimen finally meet the coating requirements of the electronic equipment manufacturer, thus obtaining the coating formula and ratio suitable for electronic equipment casing.

[0030] In practical applications, this method of replicating the temperature profile of industrial drying tunnels effectively avoids significant deviations between the curing results of laboratory specimens and mass-produced workpieces, improving the matching degree between coating formulation development, process parameter debugging, and actual production. By accurately collecting temperature profile data from industrial drying tunnels and controlling the temperature in a laboratory oven according to this profile, the laboratory-simulated curing process more closely resembles the actual curing process in production. This allows for more accurate evaluation of coating formulation performance, reduces product quality issues caused by differences between actual production and laboratory testing, and provides coating manufacturers with more reliable R&D and production data.

[0031] The material and surface treatment of laboratory test specimens should be as consistent as possible with the actual product to ensure the validity of the experimental results. When adjusting the coating formulation, the interactions between various performance indicators should be comprehensively considered to avoid improving one performance at the expense of other performances.

[0032] Furthermore, with the continuous development of industrial production technology, the temperature profiles of industrial drying tunnels may change. Paint manufacturers should regularly re-collect and evaluate the temperature profiles of their industrial drying tunnels and update laboratory simulation conditions in a timely manner to ensure that paint formulations always meet the needs of actual production. Simultaneously, for newly developed paint products or new industrial drying tunnels, it is also necessary to re-collect temperature profiles and adjust experimental methods to guarantee product quality and production efficiency.

[0033] In actual production, this experimental method can also be combined with other advanced detection technologies and analytical techniques, such as scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), to analyze the microstructure and composition of the coating, further understand the physical and chemical changes during the coating curing process, and provide more detailed evidence for optimizing the coating formulation. For example, by observing the surface morphology and internal structure of the coating through SEM, the density and uniformity of the coating can be analyzed, thereby better evaluating the performance of the coating formulation.

[0034] This experimental method for replicating the temperature profile of industrial drying tunnels for coating curing has significant practical application value. It provides coating manufacturers with more effective R&D and production tools, improving the quality and performance of coating products and meeting the needs of customers in different industries. The design principle of this method is based on the significant impact of temperature profiles in industrial drying tunnels on coating curing effects. By accurately collecting temperature profile data from industrial drying tunnels and simulating it in a laboratory oven, the laboratory curing process can be made as close as possible to the actual production curing process, thereby reducing coating performance deviations caused by differences between laboratory and actual production environments. The improved scheme effectively avoids deviations between the curing effects of laboratory specimens and mass-produced workpieces, improves the matching degree between coating formulation R&D, process parameter adjustment, and actual production, reduces product quality problems caused by differences between actual production and laboratory testing, and provides coating manufacturers with reliable R&D and production data, exhibiting broad applicability. Furthermore, by further optimizing the experimental method and combining it with other technologies, a deeper understanding of the coating curing process can be achieved, improving product quality control levels.

[0035] As a further technical solution, in step S2, heat flux density sensors are used to collect heat flux density curves at corresponding locations within the industrial drying tunnel. These sensors are arranged around the target product within the industrial drying tunnel, with one sensor placed at regular intervals along the product's conveying path. The sensors monitor and record the heat flux density data at each location in real time, and the average value is calculated after multiple measurements to ensure data accuracy.

[0036] In step S3, the laboratory oven is equipped with an advanced heat flux regulation module. After acquiring the heat flux density curve data from the industrial drying tunnel, this module adjusts the heating element power and ventilation system within the oven to synchronously replicate the heat flux density change curve within the industrial drying tunnel, based on the curve's variations. For example, during the heating phase of the industrial drying tunnel, if the heat flux density gradually increases, the oven's heat flux regulation module will adjust accordingly, ensuring that the heat flux density on the surface of the laboratory specimen also gradually increases in the same trend and manner, thereby guaranteeing that the heat exchange rate on the surface of the laboratory specimen is consistent with industrial production conditions.

[0037] Heat flux density is the amount of heat passing through a unit area per unit time, and it directly affects the curing rate and extent of a coating. Different heat flux densities can cause changes in the temperature gradient and molecular motion within the coating, thus affecting the coating's quality and performance. By accurately collecting the heat flux density curves of industrial drying tunnels and replicating them in a laboratory oven, the simulated curing environment in the laboratory can be made closer to actual production, allowing for a more accurate assessment of the coating's curing effect under real thermal conditions.

[0038] This approach improves the accuracy and reliability of experiments, comprehensively considers the impact of heat flux density on coating curing, and reduces the deviation between experimental results and actual production. It enables more precise selection of coating formulations and process parameters suitable for actual production, reduces R&D costs and production risks, and improves the quality and performance of coating products, making them more compliant with industrial production requirements.

[0039] As a further technical solution, in step S3, the laboratory specimen is customized based on the target product, becoming a scaled-down version of the target product. First, according to the size and shape of the target product, a specimen is fabricated using high-precision processing equipment at a specific scale. During the fabrication process, the dimensional accuracy and surface roughness of the specimen are strictly controlled to ensure a high degree of similarity to the geometric features of the target product. Simultaneously, the material selected for the specimen is the same as or has similar physicochemical properties to the target product, and the same surface treatment processes, such as polishing, degreasing, and phosphating, are performed to ensure that the coating and curing on the specimen are consistent with those on the actual product.

[0040] The shape, size, and surface characteristics of the target product affect the coating thickness, uniformity, and heat transfer during the curing process. Using scaled-down parts as laboratory specimens allows for the maximal reproduction of the coating and curing conditions of the actual product in a laboratory environment, enabling experimental results to more accurately reflect the actual product's condition.

[0041] This enhances the correlation between experimental results and actual production, enabling laboratory experiments during coating R&D to more effectively guide actual production. It allows for more accurate evaluation of the application effects of coating formulations and processes on actual products, reducing R&D errors and production problems caused by differences between test samples and actual products. This improves the efficiency and success rate of coating R&D, contributing to the production of coating products with more stable quality and superior performance.

[0042] As a further technical solution, a thermal time constant matching calibration step is added in step S3. First, the thermal time constants τ1 and τ2 of the target product (e.g., an automobile engine block) and a proportionally scaled-down laboratory specimen are measured separately. During measurement, high-precision temperature sensors are placed at multiple key locations on both the target product and the specimen, and then the same standard thermal excitation source, such as a brief constant-power heating pulse, is applied to them. The temperature change data of the temperature sensors over time is recorded, and the thermal time constant is calculated using heat conduction theory and corresponding mathematical models through a data fitting method.

[0043] Next, using the formula τ = ρcV / hA (where ρ is the material density, c is the specific heat capacity, V is the volume, h is the surface heat transfer coefficient, and A is the heat transfer area), the ratio of thermal time constants k = τ2 / τ1 is calculated. Here, the material density ρ and specific heat capacity c can be obtained from material property handbooks, the volume V is calculated based on the geometric dimensions of the product or specimen, the surface heat transfer coefficient h can be estimated through experimental measurement or empirical formulas, and the heat transfer area A is calculated based on the surface area of ​​the product or specimen.

[0044] Finally, the time axis of the drying temperature replication curve data is nonlinearly stretched or compressed according to the ratio k. For example, if k is less than 1, it means that the thermal response of the laboratory specimen is faster than that of the target product. In this case, the time values ​​on the time axis are multiplied by k to compress the time, thus shortening the time for the laboratory specimen to undergo the same temperature change process in the oven, making it equivalent to the thermal history of the target product in the industrial drying tunnel. If k is greater than 1, the time values ​​on the time axis are divided by k to stretch the time, thus extending the time for the laboratory specimen to undergo the same temperature change process.

[0045] The thermal time constant reflects the rate of thermal response of an object, and it is related to factors such as the object's material properties (e.g., density, specific heat capacity), geometric dimensions (volume, surface area), and surface heat transfer conditions. Objects of different sizes, due to their varying heat capacities and heat transfer characteristics, require different amounts of time to reach the same temperature state under the same thermal environmental changes. By calculating the ratio of thermal time constants and adjusting the time axis, the thermal history of laboratory specimens in an oven can be made consistent with the thermal history of the target product in an industrial drying tunnel, thus more accurately simulating the impact of actual production thermal processes on coating curing.

[0046] By using thermal time constant matching calibration, the thermal behavior of laboratory specimens more closely resembles that of the target product, avoiding experimental result deviations caused by differences in the thermal characteristics of the specimens and the actual product. This allows for more accurate evaluation of the performance of coating formulations under actual production conditions, providing a more reliable basis for coating research and development. It helps develop coating products that better meet actual production needs, reducing increased R&D costs and product quality issues caused by mismatches between experiments and actual production. Simultaneously, it enhances the guiding significance of experimental results for actual production, improving the efficiency of coating R&D and production.

[0047] like Figure 1 As shown, an embodiment of the present invention also proposes a coating curing device that replicates the temperature curve of an industrial drying tunnel. The device includes a curing chamber 1, a hot air circulation heating unit 2, a temperature detection unit 3, a central control unit 4, a data communication interface 5, and a temperature processing software module 6 embedded in the central control unit 4. It is also equipped with an oven temperature tracker 7.

[0048] The furnace temperature tracker 7 enters the industrial coating curing oven along with the workpiece, and collects the complete time-series temperature curve experienced by the workpiece in the industrial oven in real time and stores it as drying temperature replication curve data. For example, in the industrial oven of automotive parts, the furnace temperature tracker 7 moves with the car engine block and records the temperature once every certain time period, such as 1 second, to form a complete temperature change curve.

[0049] The central control unit 4 establishes a direct communication connection with the furnace temperature tracker 7 via the data communication interface 5. The data communication interface 5 integrates a wired communication interface and a wireless communication module, compatible with the data transmission protocols of mainstream furnace temperature trackers on the market. After the furnace temperature tracker 7 completes data acquisition, it can directly download the temperature record file to the central control unit 4 via a wired connection such as a USB interface or a wireless connection such as WiFi, without requiring intermediate processing via a computer.

[0050] The central control unit 4 automatically downloads and parses the drying temperature replication curve data. The temperature processing software module 6 converts the parsed drying temperature replication curve data into real-time heating control parameters. For example, if the curve shows that the temperature needs to rise from 100℃ to 150℃ within a certain period of time, the temperature processing software module 6 will calculate the corresponding heating power, heating time, and other parameters.

[0051] The hot air circulation heating unit 2 is electrically connected to the central control unit 4. Under the control of the central control unit 4, it performs full-cycle heating according to the measured temperature curve. In the heating stage, the hot air circulation heating unit 2 increases the heating power according to the control parameters, so that the temperature inside the curing chamber rises rapidly. In the curing and heat preservation stage, it maintains an appropriate heating power to maintain a stable temperature. In the cooling stage, it reduces the heating power and starts the cooling device, such as a fan, to gradually lower the temperature, thus completely simulating the temperature changes in the heating, curing and heat preservation, and cooling stages of an industrial drying tunnel, and achieving coating curing.

[0052] Temperature detection unit 3 monitors the temperature inside the curing chamber in real time and feeds the data back to central control unit 4. Central control unit 4 performs multi-point closed-loop real-time correction based on the feedback data to ensure that the curve replication error is ≤±1℃.

[0053] This system directly uses oven temperature trackers to measure temperature curves, replacing traditional manual programming. The curing conditions for laboratory samples are highly consistent with those of mass-produced workpieces. For example, in the curing verification of powder coatings, liquid coatings, and anti-corrosion coatings, it can accurately simulate temperature changes in actual production. One-click download of temperature records and automatic parsing and execution eliminate data export and program editing steps, significantly improving R&D and debugging efficiency. For instance, during coating formulation development, researchers can quickly obtain and apply actual oven temperature curve data, accelerating the development process. Multi-point closed-loop real-time correction ensures curve replication error ≤ ±1℃, meeting high-precision curing verification requirements and guaranteeing the consistency and stability of coating curing effects. It can store multiple process curves, adapting to various coating production line oven process simulations. Different coating manufacturers can flexibly use this device for coating curing simulation based on their own oven temperature tracker type and different oven processes.

[0054] The device collects real-time temperature curve data of the industrial drying tunnel using a furnace temperature tracker, transmits the data to the central control unit via a data communication interface, and then converts it into heating control parameters by the temperature processing software module. This parameters control the hot air circulation heating unit to simulate the temperature changes in the industrial drying tunnel, thus achieving coating curing. Simultaneously, feedback from the temperature detection unit ensures the accuracy of temperature control.

[0055] The furnace temperature tracker collects data, the data communication interface transmits data, the central control unit parses and processes the data, the temperature processing software module generates control parameters, the hot air circulation heating unit executes heating, and the temperature detection unit provides feedback on temperature information for correction. This system achieves a 1:1 replication of the actual curing conditions on the production line from a laboratory environment, improving the accuracy of coating formulation development and curing process verification. It is simple and efficient to operate, has high temperature control accuracy, and strong versatility, providing coating manufacturers with a reliable means of simulating coating curing.

[0056] As a further technical solution, the temperature detection unit 3 consists of a multi-point distributed temperature sensor array arranged inside the curing chamber 1. These sensors are evenly distributed at different locations inside the curing chamber 1, such as the top, bottom, and sides, to comprehensively monitor the temperature inside the chamber. They, together with the central control unit 4, form a real-time closed-loop temperature control system. For example, when a temperature sensor at a certain location detects a deviation between the actual temperature and the temperature expected based on the drying temperature replication curve data, this information is quickly fed back to the central control unit 4. The central control unit 4 then adjusts the heating parameters of the hot air circulation heating unit 2 to dynamically correct the heating deviation, ensuring that the temperature curve replication error is always controlled within ±1℃. This high-precision temperature control provides a stable and accurate temperature environment for coating curing, and is particularly suitable for temperature-sensitive coatings, such as some high-performance anti-corrosion coatings.

[0057] The central control unit 4 has a built-in data storage unit capable of storing at least hundreds of industrial oven temperature profiles from different coating production lines with varying process parameters. For example, a coating R&D company may serve clients in multiple industries, such as automobile manufacturing and home appliance production, where the oven temperature profiles for coating production lines differ significantly. This device can effectively store these different profiles. R&D personnel can retrieve the stored profiles with a single click through the user interface and quickly apply them to current coating curing simulation experiments. If the actual requirements do not perfectly match certain local parameters of the stored profiles, online editing and modification are also supported. For instance, for the coating curing of a specific model of home appliance casing, it may be necessary to fine-tune the holding time or heating rate of the original stored oven temperature profile from the home appliance coating production line to achieve the best curing effect.

[0058] The hot air circulation heating unit 2 is connected to the inner cavity of the curing chamber 1. Its structure includes a variable frequency circulating fan, an electric heating element, and a uniform airflow duct structure. The uniform airflow duct structure adopts a symmetrical upper and lower air outlet design. After air is blown out of the duct, it is first heated by the electric heating element, and then circulates within the curing chamber under the action of the variable frequency circulating fan. By adjusting the speed of the variable frequency circulating fan, the flow rate and volume of the hot air can be precisely controlled. This design ensures that the temperature field uniformity deviation within the curing chamber 1 is ≤±2℃, which is highly compatible with the hot air convection environment of industrial curing ovens. For example, when curing liquid coatings, a uniform temperature field ensures that the coating cures evenly on the surface of the specimen, avoiding local over- or under-curing problems, thereby improving the quality and performance of the coating.

[0059] The central control unit 4 is equipped with a human-machine interface, providing operators with a convenient operating experience and comprehensive information display. During operation, the interface displays the current heating temperature in real time, allowing operators to monitor the temperature situation during the curing process. Simultaneously, the progress curve is presented intuitively in graphical or percentage form, making it easy for operators to track the entire curing process. Furthermore, historical temperature data can be accessed at any time, helping operators analyze past experimental data and summarize experience. Operators can also manually pause, resume, and urgently stop heating through this interface. For example, if an abnormal temperature or other unexpected situation is detected during the experiment, the emergency stop button can be pressed immediately to prevent further problems from occurring.

[0060] The inner wall of the curing chamber 1 is made of stainless steel, a material with excellent corrosion resistance and thermal conductivity, ensuring uniform temperature distribution within the chamber. The outer wall is equipped with a multi-layered aluminum silicate fiber sealing insulation layer, with a thickness ≥80mm. This design effectively reduces heat loss, making the temperature inside the chamber more stable. For example, during long-term curing processes, even if the external ambient temperature fluctuates, the internal temperature of the curing chamber 1 remains within a relatively stable range due to the insulation layer, thereby improving temperature control stability and ensuring that the coating curing process is not excessively affected by external ambient temperature.

[0061] The temperature processing software module 6 has file parsing capabilities, supporting the parsing of temperature record files in various formats, including but not limited to CSV, TXT, and DAT formats. In practical applications, the data formats generated by furnace temperature trackers 7 from different manufacturers may vary. This software module can automatically identify the data formats generated by different furnace temperature trackers 7 and complete the parsing. For example, when a temperature record file stored in CSV format is obtained from a furnace temperature tracker of a certain brand, the temperature processing software module 6 can quickly and accurately parse the data and convert it into the format required for subsequent processing, laying the foundation for accurate temperature profile replication.

[0062] This device is widely applicable to the simulation and verification of curing processes for powder coatings, liquid coatings, anti-corrosion coatings, electrophoretic coatings, and adhesives. Taking electrophoretic coatings as an example, the curing process requires extremely high control over temperature and time. This device can accurately simulate the temperature profile of industrial drying tunnels, providing reliable experimental data for optimizing the curing process of electrophoretic coatings. This helps researchers determine the optimal curing conditions and improve the performance and quality of electrophoretic coatings.

[0063] The temperature processing software module 6 incorporates a timing calibration algorithm. In actual operation, the size and loading capacity of the laboratory specimens, as well as the thermal inertia parameters of the curing chamber 1 itself, all affect the replication of the temperature profile. For example, when the laboratory specimens are large or the loading capacity is high, their heat capacity is relatively large, and the heating or cooling process may be slightly slower than expected in an industrial drying oven. In this case, the timing calibration algorithm will adaptively correct the downloaded industrial drying oven temperature profile based on these actual parameters. By adjusting the timing and rate of temperature changes, the curing process is made more consistent with the heat transfer conditions in actual industrial production, further improving the accuracy of the temperature profile replication and ensuring reliable results in coating curing experiments under different conditions.

[0064] As a further technical solution, an online curing degree closed-loop feedback system is also included. This system consists of a Fourier transform infrared spectroscopy (FTIR) probe, a dielectric constant sensor, and a curing degree analysis module. The FTIR probe monitors the changes in the absorption peak intensity of characteristic functional groups in the coating in real time, the dielectric constant sensor monitors the changes in the dielectric constant of the coating in real time, and the curing degree analysis module calculates the real-time curing degree based on the functional group conversion rate and the dielectric constant change rate. When the actual curing degree deviates from the preset curing degree curve, the central control unit 4 automatically increases or decreases the heating power and heating time.

[0065] Fourier transform infrared (FTIR) spectroscopy, positioned close to the coating of the specimen, enables real-time monitoring of changes in the absorption peak intensity of characteristic functional groups within the coating. For example, in epoxy resin coatings, the absorption peak intensity of epoxy groups gradually decreases as the curing reaction progresses. The FTIR probe acquires information on functional group changes through real-time monitoring of these specific absorption peaks and transmits the data to the curing degree analysis module.

[0066] A dielectric constant sensor is also positioned close to the coating to monitor changes in its dielectric constant in real time. During the coating curing process, the dielectric constant of the coating changes accordingly as the polymer network forms and the degree of cross-linking increases. The dielectric constant sensor can sensitively capture these changes and feed the data back to the curing degree analysis module in real time.

[0067] The curing degree analysis module receives characteristic functional group absorption peak intensity data from the FTIR probe and dielectric constant change data from the dielectric constant sensor. Based on a pre-set algorithm, it calculates the real-time curing degree by combining the functional group conversion rate and the dielectric constant change rate. For example, by comparing the currently detected functional group absorption peak intensity with the initial state, the functional group conversion rate is obtained; simultaneously, based on the real-time change in the dielectric constant, the dielectric constant change rate is calculated, and thus the real-time curing degree of the coating is comprehensively calculated.

[0068] The curing degree analysis module compares the calculated real-time curing degree with the preset curing degree curve. When a deviation occurs between the actual curing degree and the preset curing degree curve, a deviation signal is sent to the central control unit 4. The central control unit 4 then responds by automatically increasing or decreasing the heating power and heating time of the hot air circulation heating unit 2. For example, if the actual curing degree is lower than the preset value, the central control unit 4 will appropriately increase the heating power and extend the heating time to accelerate the curing reaction process; conversely, if the actual curing degree is higher than the preset value, it will reduce the heating power or shorten the heating time to avoid over-curing.

[0069] Suppose a curing experiment for a new type of powder coating is underway. The oven temperature tracker 7 collects temperature curve data from the industrial drying tunnel and transmits it to the central control unit 4 via the data communication interface 5. The temperature processing software module 6 converts this data into heating control parameters, controlling the hot air circulation heating unit 2 to simulate the temperature changes in the industrial drying tunnel.

[0070] During the curing process, an FTIR probe monitors in real time the changes in the absorption peak intensity of specific functional groups in the powder coating, such as ester functional groups in polyester powder coatings, while a dielectric constant sensor simultaneously monitors the changes in the coating's dielectric constant. The curing degree analysis module calculates the real-time curing degree based on these two sets of data and compares it with a preset curing degree curve. If, at a certain point in time, the actual curing degree is found to be lower than the preset value, the central control unit 4 automatically increases the heating power of the hot air circulation heating unit 2 and appropriately extends the heating time for that stage. Through this real-time feedback and adjustment mechanism, the curing process of the powder coating is ensured to always proceed according to the preset curing degree curve, improving the stability and consistency of the coating's curing quality.

[0071] Fourier transform infrared spectroscopy utilizes the characteristic that different functional groups have specific absorption peaks in the infrared band. By monitoring changes in the intensity of these absorption peaks, it reflects the consumption or transformation of functional groups, thereby inferring the progress of the curing reaction. The dielectric constant is closely related to the molecular structure and polarization properties of the material. During the curing process of the coating, the dielectric constant changes accordingly with molecular cross-linking and structural changes. Calculating the degree of curing by combining these two parameters provides a more comprehensive and accurate reflection of the coating's curing state. By comparing the actual degree of curing with the preset value in real time and feeding this feedback to the central control unit to adjust heating conditions, a closed-loop control system is formed, enabling precise control of the coating curing process.

[0072] This system enables real-time and precise monitoring and control of the coating curing process, avoiding under- or over-curing issues caused by a mismatch between the temperature profile and actual curing requirements, thus significantly improving coating curing quality. For different types and formulations of coatings, the system can adjust based on real-time curing conditions, enhancing its adaptability to various coating curing processes. In coating development, it can quickly and accurately determine optimal curing process parameters, reducing the number of repeated trials and greatly improving development efficiency.

[0073] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A coating curing experimental method for replicating the temperature profile of an industrial drying tunnel, characterized in that, Includes the following steps: S1. Clearly define the coating requirements of the coating customer and the target product to be coated; S2. Collect drying temperature replication curve data of the target product after coating and drying in the industrial drying tunnel of the coating demander. S3. Design the coating formula and proportion according to the coating requirements, apply it to the laboratory specimens and send them to the laboratory oven for drying. The temperature of the laboratory oven is controlled according to the drying temperature replication curve data until the laboratory specimens are dried. S4. Determine whether the coating of the dried laboratory specimens meets the coating requirements of the coating customer. S5. Repeat steps S3 and S4 until the coating of the dried laboratory specimens meets the coating requirements of the coating customer, and obtain the coating formula and proportion corresponding to the coating requirements of the coating customer.

2. The coating curing experimental method for replicating the temperature profile of an industrial drying tunnel according to claim 1, characterized in that, In step S2, the drying temperature replication curve data includes the heating section, the curing and heat preservation section, and the cooling section.

3. The coating curing experimental method for replicating the temperature curve of an industrial drying tunnel according to claim 2, step S2 further includes synchronously acquiring the heat flux density curve at the corresponding position in the industrial drying tunnel; in step S3, while controlling the temperature according to the drying temperature replication curve data, the laboratory oven synchronously replicates the heat flux density change curve in the industrial drying tunnel through the built-in heat flux adjustment module, so that the heat exchange rate on the surface of the laboratory specimen is consistent with the industrial production conditions.

4. The coating curing experimental method for replicating the temperature profile of an industrial drying tunnel according to claim 1, characterized in that, In step S3, the laboratory specimen is customized based on the target product and is a scaled-down version of the target product.

5. A coating curing device that replicates the temperature profile of an industrial drying tunnel, characterized in that, It includes a curing chamber (1), a hot air circulation heating unit (2), a temperature detection unit (3), a central control unit (4), a data communication interface (5), and a temperature processing software module (6) embedded in the central control unit (4). It also includes a furnace temperature tracker (7), which is used to collect the complete time-series temperature curve experienced by the workpiece in the industrial coating curing oven as it enters the oven and stores it as drying temperature replication curve data. The central control unit (4) establishes a direct communication connection with the furnace temperature tracker (7) through the data communication interface (5) and automatically downloads and parses the drying temperature replication curve data; The temperature processing software module (6) is used to convert the parsed drying temperature replication curve data into real-time heating control parameters. The hot air circulation heating unit (2) is electrically connected to the central control unit (4). Under the control of the central control unit (4), it performs full-cycle heating according to real-time heating control parameters, fully simulating the temperature changes of the heating section, curing and heat preservation section and cooling section of the industrial drying tunnel, so as to achieve coating curing.

6. A coating curing apparatus for replicating the temperature profile of an industrial drying tunnel according to claim 5, characterized in that, The data communication interface (5) integrates a wired communication interface and a wireless communication module.

7. A coating curing apparatus for replicating the temperature profile of an industrial drying tunnel according to claim 5, characterized in that, The temperature detection unit (3) is a multi-point distributed temperature sensor array arranged in the inner cavity of the curing chamber (1). The multi-point distributed temperature sensor array and the central control unit (4) constitute a real-time closed-loop temperature control system, which can dynamically correct heating deviations and control the temperature curve replication error within ±1℃.

8. A coating curing apparatus for replicating the temperature profile of an industrial drying tunnel according to claim 5, characterized in that, The central control unit (4) has a built-in data storage unit that can store at least hundreds of industrial drying tunnel temperature curves for different coating production lines and different process parameters. It supports one-click retrieval and reuse of stored curves as well as online editing and modification of local parameters.

9. A coating curing device for replicating the temperature profile of an industrial drying tunnel according to claim 5, characterized in that, The temperature processing software module (6) has a built-in timing calibration algorithm that adaptively corrects the downloaded industrial drying tunnel temperature curve based on the size of the laboratory specimen, the loading amount, and the thermal inertia parameters of the curing chamber (1).

10. The coating curing apparatus according to claim 6, characterized in that, It also includes an online curing degree closed-loop feedback system, which consists of a Fourier transform infrared spectroscopy probe, a dielectric constant sensor and a curing degree analysis module; the Fourier transform infrared spectroscopy probe monitors the changes in the absorption peak intensity of characteristic functional groups in the coating in real time, the dielectric constant sensor monitors the changes in the dielectric constant of the coating in real time, and the curing degree analysis module calculates the real-time curing degree based on the functional group conversion rate and the dielectric constant change rate; when the actual curing degree deviates from the preset curing degree curve, the central control unit (4) automatically increases or decreases the heating power and heating time.

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