Device for testing the curing state of KTL-coated components

Abstract

Device for testing the degree of crosslinking of a coating hardened by a crosslinking process (2) on components (3, 11) in a production line, wherein a fluorescence wavelength of the coating emitted under UV light depends on the degree of crosslinking, the device comprising a) a UV light source (6) for illuminating the coating on at least one of the components (3, 11), b) a digital camera system (5) for recording at least one image of the coating illuminated by the UV light source (6), c) an image processing program (9) for evaluating the image data of the recorded image(s) on the basis of a predefined rating scale for the degree of crosslinking of the coating, which has at least one classification into adequate crosslinking and inadequate crosslinking, on the basis of which the evaluation is carried out, d) an output unit (8) and / or a control unit (10) for controlling at least one of the following actions based on the evaluation obtained from the image processing program (9): i) Rejecting components (3, 11) from the production line which, according to the evaluation, exhibit inadequate crosslinking of the coating, whereby the rejected components (niO) can be discarded or subjected to re-crosslinking for the coating, ii) Setting at least one parameter for the crosslinking process to cure the coating.

Description

[0001] The invention relates to a device for testing the degree of cross-linking of a coating hardened by a cross-linking process on components in a production line, wherein the coating is preferably a cathodic dip coating (KTL coating).

[0002] In the context of printing ink curing, DE 10 2011 121 689 A1 refers to a substrate processing method based on the sheet principle in conjunction with an additional curing degree control field applied to the printed sheet.

[0003] In industrial manufacturing, components are frequently coated with a paint. A paint is applied to the component and then cured, typically undergoing a crosslinking process. The crosslinking of the coatings is usually checked destructively on selected individual or statistically selected components.

[0004] Such offline inspection is also time-consuming. The delayed detection of potential coating curing defects is disadvantageous, especially when components are coated on a production line.

[0005] The conditions for the cross-linking of a coating, such as time and temperature, are determined using empirically established parameters. Variations in geometry between different components, e.g., regarding weight and surface area, are often disregarded.

[0006] For a coating to cure, a specific component temperature is required for a specific time. Different component geometries and masses, even with identical oven parameters, particularly temperature and time, result in different surface temperatures due to their varying masses and surface areas. This can lead to variations in the curing state. Furthermore, different positions and loads within the oven also cause deviations. Individual temperature adjustment is not currently practical.

[0007] A commonly used coating process is cathodic dip coating (e-coating). During the cross-linking of e-coatings, as well as other coatings, the frequency of the fluorescence radiation emitted under UV light changes.

[0008] The object of the present invention was therefore to provide a device for testing the degree of cross-linking of a coating hardened by a cross-linking process on components, with which the disadvantages described above can be overcome. In particular, the object was to provide a device with which a non-destructive and automatic test of the degree of cross-linking of the coating can be carried out. It should also be possible to perform the test online and in real time. Furthermore, the device should also enable automatic control of the cross-linking process for the coating.

[0009] The solution to the problem is based, among other things, on the finding that during the crosslinking of coatings, especially e-coatings, the frequency of the fluorescence radiation emitted under UV light irradiation changes depending on the degree of crosslinking. This change in the frequency of the fluorescence radiation emitted under UV light irradiation as a function of the degree of crosslinking, a corresponding method, and related examples are described in detail in DE 10 2020 203 343 A1, to which reference is hereby made.

[0010] A device based on this effect was developed to control the degree of cross-linking of coatings on components. UV is the abbreviation for ultraviolet.

[0011] The invention thus relates to a device for testing the degree of cross-linking of a coating hardened by a cross-linking process on components in a production line, wherein a fluorescence wavelength of the coating emitted under UV light depends on the degree of cross-linking, and wherein the device comprises a) a UV light source for illuminating the coating on at least one of the components, b) a digital camera system for recording at least one image of the coating illuminated by the UV light source, c) an image processing program for evaluating the image data of the recorded image(s) on the basis of a predefined rating scale for the degree of cross-linking of the coating, which has at least one classification into adequate cross-linking and inadequate cross-linking, on the basis of which the evaluation is carried out, d) an output unit and / or a control unit for controlling at least one of the following actions based on the evaluation obtained from the image processing program: i) Removing components from the production line which, according to the evaluation, exhibit inadequate crosslinking of the coating, whereby the removed components can be discarded or subjected to re-crosslinking for the coating, ii) Setting at least one parameter for the crosslinking process to cure the coating.

[0012] The device according to the invention can be used for quality control and / or process control of the coating process.

[0013] The advantages of the device according to the invention are in particular: - Non-destructive testing of the degree of hardening instead of destructive testing - if necessary, testing of the entire series of coated components and not just a part of them - Online monitoring and logging of the curing level in real time is possible instead of the currently common time-consuming offline monitoring. - Online tracking of the curing process for process optimization and reduction of waste - Online process monitoring, control and adjustment (closed loop) possible - Minimizing the error rate caused by faulty curing - Variable process control is possible depending on the component geometry.

[0014] The device according to the invention for testing the degree of cross-linking of a coating hardened by a cross-linking process on components in a production line is described in detail below.

[0015] A production line is a production system in which several processing stations are linked together to manufacture a product according to the line principle. In this context, the production line specifically includes the application of the coating to the components, the curing of the applied coating, and, if applicable, further processing of the coated components.

[0016] The coating is a crosslinkable coating in which the fluorescence wavelength emitted by the coating under UV light depends on the degree of crosslinking. It is further preferred that the change in the fluorescence wavelength emitted under UV light is in the visible range. The crosslinking process hardens or cures the coating.

[0017] The coating is generally an organic coating. Preferably, the organic coating is an electrophoretically deposited coating, in particular a cathodic dip coating (e-coating). The coating can also be, for example, a powder coating. As already explained, an e-coating is applied by cathodic dip coating (e-coating), a process generally known to those skilled in the art. The coating can also be applied by other means, such as spraying.

[0018] The crosslinking of the applied coating, in particular a cathodic dip coating (KTL coating), can be carried out in the usual way, e.g. by UV irradiation or heating, e.g. in an oven, with thermal crosslinking being preferred. The crosslinking temperature depends on the coating used. For example, the crosslinking of KTL coatings can take place at a temperature in the range of 180 to 210 °C.

[0019] The coating applied to the component contains binders, in particular organic binders, whose cross-linking leads to the hardening of the coating. Examples of binders in the coating, especially in e-coatings, are epoxy resins, in particular epoxy resin amine adducts, or blocked isocyanates.

[0020] The device according to the invention comprises a) a UV light source for illuminating the coating on at least one of the components. Industrially suitable UV lamps can be used as the UV light source. One or more UV lamps can be used as the UV light source. The UV light source or UV lamp preferably emits UV light with a wavelength in the range of 315 to 380 nm.

[0021] The device according to the invention further comprises b) a digital camera system for capturing at least one image of the coating illuminated by the UV light source. The digital camera system can comprise one or more digital cameras. Industrial-grade digital cameras can be used.

[0022] It is understood that the digital camera is sensitive to the wavelength range in which the coating's fluorescence wavelength, dependent on the degree of cross-linking, lies when emitted under UV light. As mentioned, it is preferable that the coating's fluorescence wavelength, and especially its changes, be visible in the visible range. The visible range lies in a wavelength range of approximately 380 nm to 780 nm.

[0023] The digital camera(s) of the digital camera system are preferably used for image recognition and are adapted to the color spectrum of UV light.

[0024] The device according to the invention or its digital camera system can be configured to take at least one image of a single coated component or a partial area of ​​the coated component or at least one image of a plurality of coated components for testing the degree of cross-linking of the coating.

[0025] The inspection can therefore be performed on individual coated components. All coated components produced in the production line can be inspected sequentially, or only selected coated components can be inspected. It is also possible to capture an image of multiple coated components, for example, all components on a rack or several components arranged sequentially on a conveyor. The image data of the multiple components in the capture can then be analyzed separately by the image processing program.

[0026] The device according to the invention further comprises c) an image processing program for evaluating the image data of the recorded image(s) based on a predefined rating scale for the degree of cross-linking of the coating, which has at least one classification into adequate cross-linking and inadequate cross-linking, on the basis of which the evaluation is carried out. Adequate cross-linking can be designated as "OK" (iO) and inadequate cross-linking as "not OK" (niO).

[0027] The resulting evaluation is output by the image processing program, in particular to the output unit and / or the control unit.

[0028] The image processing program is software installed on a computing unit, such as a computer. It is created using an industrial-grade image processing library, which then evaluates the image data received from the digital camera system based on a predefined rating scale.

[0029] In a preferred embodiment of the device according to the invention, the image processing program for evaluating the image data is based on an AI system (AI = Artificial Intelligence). The evaluation with an AI system can, for example, be based on machine learning or deep learning based on neural networks.

[0030] The image data from the captured image(s) is evaluated in the image processing program based on a predefined rating scale for the degree of cross-linking of the coating, which includes at least one classification into adequate and inadequate cross-linking. The predefined rating scale thus has at least two levels representing adequate and inadequate cross-linking. These levels can be defined as needed.

[0031] The predefined rating scale can also include more than two levels, e.g., three or more. For example, a rating scale with three levels could include level 1 for a degree of cross-linking below 85% (inadequate cross-linking), level 2 for a degree of cross-linking between 85% and 95%, and level 3 for a degree of cross-linking above 95% (adequate cross-linking). This allows for a more precise assessment of the cross-linking state of a coating, providing additional information that enables, for example, a more detailed evaluation of the cross-linking process and adjustment of its parameters. The actual values ​​for the levels, however, naturally depend on the type of coating and the desired degree of cross-linking.

[0032] The levels of the predefined rating scale can also include a level for an "overburned" coating condition. An overburned coating is one in which the crosslinking process has occurred for too long and / or at too high a temperature, causing the already adequately crosslinked coating to thermally degrade. These degradation processes can be detected by a change in the fluorescence wavelength emitted by the coating under UV light.

[0033] In one embodiment, the evaluation of the image data from the captured image(s) can include an instruction, determined by analysis using the rating scale, to maintain or modify at least one parameter relevant to the meshing process. For this purpose, it may be advantageous if the rating scale comprises several levels, e.g., at least three, or more than three levels.

[0034] The rating scale can alternatively or additionally include a classification of the coating's degree of cross-linking depending on at least two sub-areas of the coating. This allows for a location-dependent assessment of the coating's degree of cross-linking. For example, two different areas of the coating can be evaluated based on the rating scale.

[0035] This method allows for the determination of whether the different areas under investigation exhibit the same or different levels of crosslinking. This can be used, for example, to achieve a more precise evaluation of the average crosslinking degree of the coating. It can also be useful if the evaluation of the image data from the captured image(s) is intended to include instructions, derived from analysis using the rating scale, for maintaining or modifying at least one parameter relevant to the crosslinking process.

[0036] When an image of several coated components is captured, the image processing program can evaluate the respective components separately using the predefined rating scale.

[0037] The predefined evaluation scale is created, in particular, using reference coatings, especially reference e-coatings, where the degree of cross-linking is known. It is understood that the reference coating is the coating whose degree of cross-linking is to be investigated in the production line using the device according to the invention.

[0038] Images of reference coatings, illuminated with a UV light source and with a known degree of crosslinking, are captured using a digital camera system to obtain image data of the reference coatings. This image data of the reference coatings with known degrees of crosslinking is then used to create a predefined evaluation scale, which is provided to the image processing program.

[0039] The reference coatings can be applied to the components that are later to be tested using the device according to the invention. However, it is generally sufficient for the reference coatings to be applied to any substrate. Simple planar bodies are suitable as substrates, e.g., a metal substrate such as a sheet. Alternatively, it is preferred to take the images of the reference coating under the same or similar conditions as those that will later be present during the testing of the degree of cross-linking in the production line using the device according to the invention, e.g., with regard to the UV light source, distance to the UV light source, room brightness, etc.

[0040] The degree of cross-linking of the reference coatings can be determined using established analytical methods that involve the destruction of the sample under test. Examples of suitable methods include differential scanning calorimetry (DSC), MEK testing, thermogravimetry (TG), and infrared (IR) analysis. In DSC testing, for example, the amount of heat released or absorbed by a sample during heating, cooling, or an isothermal process is determined, which provides information about the degree of cross-linking.

[0041] It is understood that at least one reference coating with the corresponding degree of crosslinking must be available for each level of the predefined rating scale. It may be advantageous to take images of several reference coatings for each level to increase accuracy. The required number may depend, for example, on the specific level and the desired accuracy. For example, 1 to 30, preferably 2 to 25, and more preferably 3 to 20 reference coatings can be tested for each level of the predefined rating scale.

[0042] The device according to the invention further comprises d) an output unit and / or a control unit for controlling at least one of the following measures based on the evaluation obtained from the image processing program: i) Removing components from the production line which, according to the evaluation, exhibit inadequate crosslinking of the coating, whereby the removed components can be discarded or subjected to re-crosslinking for the coating, ii) Setting at least one parameter for the crosslinking process to cure the coating.

[0043] In one variant, the device has an output unit for controlling at least one of the aforementioned measures i) and / or ii) based on the evaluation received from the image processing program. The output unit can be a conventional output device, e.g., a screen. The evaluation can be displayed on the output unit in the form of information and / or instructions that an operator can implement. The information / instructions can, for example, state that the coating on the respective component does not exhibit adequate crosslinking and that the component must be discarded or subjected to re-crosslinking, or that the degree of crosslinking is still within the tolerance range, but a parameter of the crosslinking process, e.g., the temperature, should be changed.

[0044] In a preferred embodiment, the device includes a control unit for controlling the aforementioned at least one measure i) and / or ii) based on the evaluation obtained from the image processing program.

[0045] The control unit has at least one input for receiving the evaluation determined by the image processing program and at least one output for outputting actuator signals. The actuator signals can be used to set one or more parameters of the meshing process, e.g., temperature or duration, and / or to control corresponding devices, such as robots, which, for example, remove selected components from the production line and transport them for disposal or re-meshing. The control unit can be based on one or more microprocessors or microcontrollers, which are installed, for example, in a computing unit such as a computer. The control unit can have an output unit as a human-machine interface. The control unit can, for example, be a programmable logic controller (PLC). The image processing program or...Parts of it may be integrated into the control unit.

[0046] It is particularly preferred that the device according to the invention includes the aforementioned control unit, as this enables fully automatic operation in real time. Generally, it is advantageous for the device to also include the output unit in addition to the control unit. This allows for monitoring of the automatic operation.

[0047] Measure i) involves removing components from the production line that, according to the evaluation, exhibit inadequate coating crosslinking. The removed components can be discarded or subjected to re-crosslinking for the coating.

[0048] The removal of components and their transport for disposal or re-networking can be carried out by operating personnel or, preferably, by appropriate equipment such as robots or conveyor systems. This equipment can be controlled by the control unit.

[0049] Measure ii) involves setting at least one parameter for the crosslinking process to cure the coating. The parameters to be set could include, for example, the temperature, the duration, or the positioning of the component(s) during the crosslinking of the coating(s). This can be done by operating personnel. Preferably, such a setting is made by the control unit.

[0050] The image processing program can provide a corresponding evaluation based on the rating scale level determined for the respective component. For example, if a level indicating insufficient meshing is identified, the evaluation can include an instruction to change a parameter of the meshing process, such as temperature and / or duration. If the predefined rating scale has multiple levels that allow for a more precise determination of the meshing degree, correspondingly more precise instructions are possible. It is particularly advantageous for the image processing program to be based on an AI system. This enables self-learning optimization of the predefined rating scale or the instructions for adjusting at least one parameter.

[0051] By adjusting the parameters of the crosslinking process, a control loop is established in which the results of the coating crosslinking obtained using the device according to the invention can be used to adjust the parameters of the crosslinking process. Such process control is very advantageous because it enables continuous optimization of the crosslinking process.

[0052] This is advantageous even for crosslinking processes that are relatively reliable and therefore not very error-prone, such as e-coating. Even in such reliable crosslinking processes, the industrial process is usually carried out with a safety margin, for example, with a duration 5 minutes longer than actually required, in order to minimize rejects. The device according to the invention enables better process control. As a result, the safety margin can be reduced, meaning that the crosslinking parameters, such as the duration, can be controlled more precisely. This saves energy and makes the coating process more environmentally friendly.

[0053] In a preferred embodiment of the device according to the invention, the UV light source and / or the digital camera system are mounted on a mounting device. The respective mounting device can be fixed in place. Alternatively, and preferably, the respective mounting device can allow positioning of the UV light source and / or the digital camera system. The respective mounting device can comprise one or more degrees of freedom, e.g., at least two or at least four degrees of freedom. It is preferred that the respective mounting device comprises up to six degrees of freedom. The mounting device can, for example, be a robot arm.

[0054] In a preferred embodiment of the device according to the invention, the control unit is configured to control the positioning of the UV light source and / or the digital camera system in relation to the component(s) for illumination and / or image capture.

[0055] The aforementioned configuration of the control unit is preferably based on image data obtained from the evaluation of calibration images using an image processing program. The calibration images are generated using a digital camera system by illuminating coated components with the UV light source and capturing the images. The positioning of the component relative to the digital camera system and / or the UV light source can be varied. The image processing program used can be the program for evaluating the image data of the captured image(s) based on a predefined rating scale for the degree of cross-linking of the coating.

[0056] The device according to the invention is configured in particular for quality control and / or process control. It is preferred that the device is configured for online monitoring of the degree of cross-linking of the coating in real time or for online process monitoring, control and adjustment of the production line (closed loop).

[0057] In a preferred embodiment of the device according to the invention, the UV light source and the digital camera system are arranged in a chamber through which the coated components are passed for image acquisition. The chamber is preferably located directly at the outlet of the device for carrying out the crosslinking process, e.g., a crosslinking oven. The chamber can be arranged, for example, offline or inline with the device for carrying out the crosslinking process. In this way, the degree of crosslinking achieved can be determined very quickly, and correspondingly, any necessary adjustments to the parameters of the crosslinking process can be made quickly. The device for carrying out the crosslinking process is also referred to here as a curing unit or a curing unit for crosslinking the coating.

[0058] The device is thus configured in a preferred embodiment to perform the testing of the degree of crosslinking at the end of the process, preferably immediately at the end of the process for crosslinking the coating.

[0059] The chambered setup necessitates the protection of operating personnel, for example, from UV light. Furthermore, the cleanliness of the components' environment can be better controlled. Additionally, the chambered setup allows for easier adjustment of defined lighting conditions for image acquisition. For instance, it is advantageous to photograph coated components in a darkened or semi-dark room. This simplifies precise illumination of the component.

[0060] The device according to the invention further preferably comprises a conveying unit and / or a holder for the coated components. This enables the components to be transported in the desired direction. It can, for example, serve to bring a component to be tested into the appropriate position relative to the UV light source and digital camera system and to transport the component further after the image has been captured.

[0061] The components to be coated can be made of any common material, such as metal or plastic. Components made of metal or metallized plastic are preferred, with metal components being particularly preferred.

[0062] The components to be coated can have any geometry, e.g., planar or complex. Preferably, the components have a complex geometry. In a preferred embodiment, the component to be coated is a vehicle component, and in particular a brake component. Suitable components are, for example, a brake caliper housing or a brake caliper bracket, especially for automotive disc brakes. However, it should be noted that the device according to the invention is independent of the shape and application of the components and can therefore be applied to all coated components, especially e-coated components.

[0063] The invention is further explained below with reference to schematic drawings, which are not intended to limit the scope of the invention. The drawings show: Fig. 1 schematically a semi-automatic workstation for production-accompanying tests in a production line with the device according to the invention Fig. 2 schematically a fully automatic quality control with singulation of components in a production line with the device according to the invention. Fig. 3 schematically a fully automatic quality control without singulation of the components in a production line with the device according to the invention. Fig. 4 schematically a fully automatic testing system for controlling the curing process in a production line with the device according to the invention.

[0064] In Fig. Figure 1 schematically shows a semi-automatic workstation for production-related testing in a production line with the device according to the invention. This is an offline testing station.

[0065] A component is coated in a coating unit 1. The coating is preferably an e-coating (e-coating). The coated component 3 is then cured in a crosslinking process, in particular by heating. The curing unit for crosslinking the coating 2 can, for example, be an oven (not shown) to obtain a cured coating. The components with the cured coating are then fed to the device according to the invention for testing the degree of crosslinking of the cured coating, preferably by means of a conveying unit 4, e.g., a conveyor belt, or a component holder.

[0066] The device comprises a digital camera system 5, a UV light source 6, an output unit 8, and a computer unit 9, into which an image processing program is integrated. The digital camera system 5 is preferably a 2D camera. The UV light source 6 is usually a UV lamp that emits, for example, UV light with a wavelength in the range of 315–380 nm.

[0067] The digital camera system 5 and the UV light source 6 are preferably installed in a chamber (not shown) in which the coatings are inspected. The digital camera system can also be mounted on the side of the chamber so that it can capture images inside the chamber. The chamber should not be very bright for inspection; preferably, it is darkened. The chamber is preferably equipped with a safety device (glare shield) to protect operating personnel 7 from UV light.

[0068] The UV light source 6 and the digital camera system 5 should be adjustable in as many as four degrees of freedom as possible. For this purpose, the UV light source 6 and the digital camera system 5 are each mounted on a support structure, e.g., a robot arm (not shown). The UV light source 6 and the digital camera system 5 are positioned appropriately relative to the component(s) for illumination and image capture. The positioning shown in the figure is purely schematic.

[0069] In the chamber, all or selected components with a hardened coating can be inspected consecutively. For this purpose, each component with the hardened coating is illuminated by the UV light source 6, and at least one image of the illuminated coating is captured with the digital camera system 5. The resulting image data is sent to the image processing program in the computer unit 9 for evaluation of the coating's degree of crosslinking based on the predefined rating scale. The evaluation includes at least one classification into adequate crosslinking (iO = OK) and inadequate crosslinking (niO = not OK). The evaluation is displayed on the output unit 8. For example, it indicates that the coating is niO and the component must be rejected or subjected to re-crosslinking.

[0070] The operating personnel 7 can then carry out the instructions received at the output unit 8. In this way, non-destructive and rapid measurement error detection and validation of the test can be performed.

[0071] Fig. Figure 2 schematically shows a fully automated quality control system with singulation of components in a production line using the device according to the invention. Fig. 2. Apart from the differences noted below, the same information applies as for... Fig. 1, so that reference is made to this.

[0072] The computer unit 10 includes both an image processing program and a control unit. The image data, obtained by capturing at least one image of the component with the hardened coating illuminated by the UV light source 6 using the digital camera system 5, is provided to the image processing program with preset target values ​​according to the predefined evaluation scale. If the evaluation reveals an inadequate cross-linking (i.e., cross-linking niO), this information is transmitted to the control unit. The control unit then activates appropriate actuators, such as robot arms or other conveyor systems, causing the components with improper coating to be automatically removed from the production line. All components in the production line can be inspected, enabling fully automated monitoring of the coating's curing degree.

[0073] Fig. Figure 3 schematically shows a fully automated quality control system without singulation of components in a production line using the device according to the invention. Fig. 3. Apart from the differences noted below, the same information applies as for... Fig. 2, so that reference is made to this.

[0074] Unlike the Fig. 2. A picture of a plurality of coated components 11 is taken with the digital camera system 5. The plurality of components 11 can, for example, be attached to a frame. The plurality of components is shown in the Fig. Figure 3 shows only the front view. The image processing program in the computer unit 10 is configured to simultaneously capture and evaluate different component geometries. The evaluation is sent to the control unit in the computer unit 10. This allows racks containing multiple components 11 with insufficiently cured components (NIO) to be removed from the production line by the control unit and, if necessary, post-cured. After post-curing, the components 11 can be reintroduced into the production line and subjected again to a test of the degree of curing using the device according to the invention.

[0075] Fig. Figure 4 schematically shows a fully automated testing system for controlling the curing process in a production line with the device according to the invention. Fig. Apart from the differences noted below, the same information applies to section 4 as to... Fig. 3, so that reference is made to this.

[0076] During the production line according to Fig. 4 The test station or chamber for testing the degree of cross-linking is located directly next to the curing unit 2 (oven). The UV light source 6 is thermally stable to protect it from the heat of the curing unit. The UV light source 6 can illuminate the majority of coated components 11, which are, for example, located on a rack. The digital camera system 5 is also thermally stable or located outside the chamber. The digital camera system 5 can capture an image of the entire illuminated majority of coated components 11.

[0077] Connected to the digital camera system 5 is the image processing program in the computer unit 10, which is designed to simultaneously capture and evaluate different component geometries. The image data obtained from the digital camera system 5 is used to evaluate the current degree of cross-linking on the coatings. The evaluation from the image processing program is sent to the control unit in the computer unit 10. This allows, as in Fig. 3 racks with a plurality of components 11 with insufficiently cured components (niO) are removed from the production line using the control unit and, if necessary, re-cured and reintroduced into the production line after re-crosslinking.

[0078] Additionally, the image data analysis in the image processing program of computer unit 10 provides information for setting at least one parameter for the crosslinking process used to cure the coating. This information is then sent to the control unit, which may modify at least one parameter for the crosslinking process, such as the oven temperature or the dwell time of the components in the curing unit. The dwell time can be controlled, for example, by modifying the transport speed of the components through the oven. Thus, the oven temperature and / or the transport process within the oven can be controlled to achieve ideal crosslinking. This can reduce both energy consumption and the reject rate. Reference symbol list: 1 coating unit for coating one component 2 Curing units for crosslinking the coating / Oven 3 coated component 4 conveying units 5 Digital camera system 6 UV light source 7 operating personnel 8 output units 9 computer unit with image processing program 10 computer unit with image processing program and control unit 11. Majority of coated components

Claims

[1] Device for testing the degree of crosslinking of a coating hardened by a crosslinking process (2) on components (3, 11) in a production line, wherein a fluorescence wavelength of the coating emitted under UV light depends on the degree of crosslinking, the device comprising a) a UV light source (6) for illuminating the coating on at least one of the components (3, 11), b) a digital camera system (5) for recording at least one image of the coating illuminated by the UV light source (6), c) an image processing program (9) for evaluating the image data of the recorded image(s) on the basis of a predefined rating scale for the degree of crosslinking of the coating, which has at least one classification into adequate crosslinking and inadequate crosslinking, on the basis of which the evaluation is carried out, d) an output unit (8) and / or a control unit (10) for controlling at least one of the following actions based on the evaluation obtained from the image processing program (9): i) Rejecting components (3, 11) from the production line which, according to the evaluation, exhibit inadequate crosslinking of the coating, whereby the rejected components (niO) can be discarded or subjected to re-crosslinking for the coating, ii) Setting at least one parameter for the crosslinking process to cure the coating. [2] Device according to claim 1, wherein the UV light source (6) is attached to a mounting device and / or the digital camera system (5) is attached to a mounting device, wherein the respective mounting device is either fixed or allows positioning of the UV light source (6) and / or the digital camera system (5), wherein the respective mounting device comprises up to 6 degrees of freedom. [3] Device according to a preceding claim, wherein the control unit (10) is configured to control the positioning of the UV light source (6) and / or the digital camera system (5) in relation to the component(s) (3, 11) for illumination and / or image capture. [4] Device according to claim 3, wherein the configuration is based on image data obtained from the evaluation of calibration images using an image processing program (9), wherein the calibration images are generated using the digital camera system (5) by illuminating and recording coated components (3, 11) with the UV light source (6), wherein the positioning of the component (3, 11) in relation to the digital camera system (5) and / or to the UV light source (6) can be varied. [5] Device according to a preceding claim, wherein the rating scale has a classification of the degree of crosslinking in several, namely at least two levels or more than two levels and / or the rating scale has a classification of the degree of crosslinking depending on at least two sub-areas of the coating, wherein the evaluation of the image data of the recorded image(s) includes an instruction determined by analysis on the basis of the rating scale to maintain or change at least one parameter that is relevant for the crosslinking process (2). [6] Device according to a preceding claim, configured for quality control and / or process control, namely for - Online monitoring of the coating's cross-linking level in real time or - Online process monitoring, control and adjustment of the production line (closed loop). [7] Device according to a preceding claim, wherein the UV light source (6) and the digital camera system (5) are arranged in a chamber through which the coated components (3, 11) are passed for image acquisition, which is arranged either offline or inline, directly at the output of the device for carrying out the crosslinking process (2). [8] Device according to a preceding claim, further comprising a conveying unit (4) and / or holder for the coated components (3,11). [9] Device according to a preceding claim, which is configured to take at least one image of a single component (3) and in particular a partial area of ​​the component (3) or at least one image of a plurality of components (11) for testing the degree of crosslinking of the coating. [10] Device according to a preceding claim, which is configured to perform the verification of the degree of crosslinking at the end of the process for crosslinking the coating. [11] Device according to a preceding claim, wherein the coating is a KTL coating and / or wherein the change in the fluorescence wavelength emitted under UV light is visible. [12] Device according to a preceding claim, wherein the component (3, 11) is a vehicle component or a brake component, such as a brake caliper housing or a brake holder, in particular for motor vehicle disc brakes. [13] Device according to a preceding claim, wherein the UV light source (6) is at least a UV lamp with a wavelength in the range of 315 nm to 380 nm. [14] Device according to a preceding claim, wherein the digital camera system (5) is a camera for spatial image recognition. [15] Device according to a preceding claim, wherein the image processing program (9) for evaluating the image data is based on an AI system.

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