Method and system for radiation drying of substrate coatings

Abstract

The invention relates to a method and a corresponding system for the radiation drying of substrate coatings such as printed layers and paint layers in a coating system (12), comprising: - at least one irradiation unit (18) for irradiating the substrate coating (16) by means of UV radiation, - a computer-implemented computing unit (22) to which specification data (24) relating to the substrate coating (16) can be transmitted via a data-transmission device (26), - and a comparison module (34) of the computing unit (22) which is designed and programmed to compare the specification data (24) with reference data (30) stored in a database (28), and to provide a setting value for the irradiation unit (18) as a result of the comparison.

Description

[0001] Method and system for radiation drying of substrate coatings

[0002] Description

[0003] The invention relates to a method for radiation drying of substrate coatings such as printing and varnish layers and a corresponding system.

[0004] DE102010038802A1 discloses a device for UV irradiation of objects for the purpose of curing coatings. This device is equipped with several UV lamp modules, each comprising an LED array arranged flatly on a carrier. In current use, the power specifications for such lamp modules are set to the maximum value according to the "more is better" approach in order not to jeopardize the drying result. For such safety reasons, potential energy savings are not utilized.

[0005] Based on this, the invention is based on the object of further developing the methods and systems known in the prior art and of achieving energy savings and an extension of the service life of the irradiation units used while complying with the quality requirements.

[0006] To solve this problem, the combination of features specified in patent claims 1 and 9 is proposed. Advantageous embodiments and further developments of the invention emerge from the dependent claims. The invention is based on the idea of ​​evaluating dependencies in paint and varnish drying using data technology and deriving setting specifications for the dryers from this. Accordingly, the invention proposes the following steps with regard to a method:

[0007] Applying a substrate coating in a coating system, in particular a printing machine, to a substrate, irradiating the substrate coating with UV radiation by means of an irradiation unit, whereby the substrate coating is chemically crosslinked and cured,

[0008] Transmitting specification data of the substrate coating to a computing unit,

[0009] Comparing the specification data with reference data stored in a database using a comparison module of the computing unit, and

[0010] Providing a setting value for the irradiation unit as a result of the comparison by the comparison module.

[0011] In this way, it is possible to reduce the operating current of the irradiation unit to the required level and to achieve energy savings, also in the sense of extending the service life.

[0012] Advantageously, the setting value includes at least one element from the group of radiation output per irradiation unit, print format-dependent edge zone shutdown, print subject-dependent switching, cooling capacity for water or air cooling, and nitrogen feed into the irradiation area. Thus, process optimization can be achieved while taking the relevant operating parameters into account.

[0013] A further advantageous embodiment provides that the specification data is entered automatically by a system control or manually by an operator, so that a flexible user interface is realized.

[0014] A further improvement provides that the specification data define at least one property of the substrate and / or the substrate coating, in particular color shade, color sequence, varnish, layer thickness and type.

[0015] It is also advantageous if the reference data is stored in the database by forming reference data clusters, whereby a setting value is determined or calculated back from each of the reference data clusters.

[0016] In this context, it is also advantageous if the transmitted specification data are assigned to the reference data clusters by comparing at least one property of the substrate and / or the substrate coating and the corresponding setting value is determined.

[0017] For continuous drying, it is advantageous if a setting value is provided for each of several irradiation units acting successively on the substrate coating, in particular depending on the sequence of a multi-layer substrate coating.

[0018] To provide feedback based on actual operating results, it is advantageous if the quality of the radiation drying is recorded via a measuring system or user input and used to correct the setting value. With regard to a radiation drying system, the object mentioned above is achieved by the following combination of features: at least one irradiation unit for irradiating the substrate coating with UV radiation, whereby the substrate coating is chemically crosslinked and cured by the UV radiation; a computer-implemented processing unit to which specification data of the substrate coating can be transmitted via a data transmission device; a comparison module of the processing unit, which is designed and programmed to compare the specification data with reference data stored in a database and to provide a setting value for the irradiation unit as the result of the comparison.

[0019] In this way, the advantages mentioned above with regard to a method can be achieved in an analogous manner.

[0020] In order to enable intelligent process optimization using AI technologies, it is proposed that the computing unit comprises an artificial neural network implemented on a computer.

[0021] In this context, it is further advantageous if the artificial neural network is designed and programmed to have at least one of the following features:

[0022] - Verification of data in the sense of a plausibility check,

[0023] - Assignment of verified data to existing data sets,

[0024] - Comparison of user-specific and user-general data records.

[0025] A further improvement provides that the artificial neural network is trained and programmed to self-learningly correct settings for the setting value according to user feedback and / or measured values ​​of the drying quality.

[0026] The invention will be explained in more detail below using an exemplary embodiment shown schematically in the drawing. In the drawings:

[0027] Fig. 1 shows a system for UV radiation drying of prints in a printing press in a diagrammatic representation;

[0028] Fig. 2 is a flowchart of print job processing.

[0029] The system 10 for UV radiation drying shown in Fig. 1 can be used in a printing machine 12, which is only symbolically indicated, in order to dry printing layers 16 applied to a substrate or printing material 14 by means of UV radiation, whereby a chemical crosslinking and hardening of the liquid applied printing ink occurs.

[0030] For this purpose, the system 12 comprises a plurality of irradiation units 18 for emitting electromagnetic radiation in the UV range, a control unit 20 for controlling the irradiation units 18, a computer-implemented computing unit 22 for processing specification data 24 of a print job, and a data transmission device 26 between the control unit 20 and the computing unit 22.

[0031] As illustrated in Fig. 1, the system layout can be divided into three work areas: setup, processing, and production. Processing involves the use of artificial intelligence (Kl) to optimize the print job and system control. The job or specification data 24 can be automatically entered into the control unit 20 in the Job Definition Format (JDF), which has become established as the industry standard for the graphics industry. Manual input by a user via a human-machine interface (HMI) is also possible. Examples of possible specification data 24 include information regarding printing ink, coating, format, and substrate.

[0032] According to the invention, the specification data 24 can be fed into a database 28 in a cloud environment via the data transmission device 26, for example, via an internet connection. The database 28 also contains reference data 30 from previously processed print jobs, which are summarized in reference data clusters 32 according to given data patterns. For example, color values ​​with the same drying property requirements can be used to form clusters.

[0033] In order to qualify and evaluate the data stored in the cloud database 28, the computing unit 22 comprises a comparison module 34, which provides at least one setting value for the irradiation units 18 as a result of a comparison carried out between specification data 24 and reference data 30.

[0034] According to the invention, an artificial neural network 36 is provided to verify data for plausibility purposes, to assign it to existing data sets, and to compare the data sets on a user-specific and user-superordinate basis. A feedback branch 38 of the data transmission device 36 enables the determined setting value(s) to be fed into the control unit 20. The setting values ​​can include, for example, radiation output per irradiation unit, print format-dependent edge zone deactivation, print subject-dependent switching, cooling output for water or air cooling, and / or nitrogen feed into the irradiation area.

[0035] The control unit 20 is coupled to the irradiation units 18 via a setting branch 40 in order to control them according to the setting values.

[0036] The irradiation units 18 can be equipped with UV lamps or an array of UV LEDs, whose irradiance or radiation output can be regulated and which, depending on the print format, can be easily switched off in unused areas, e.g., edge zones. Such units are available from the applicant under the trademarks BLK, MBS, Modulux, LUV, and Ledcure NX.

[0037] At least one UV unit 18 is expediently assigned to each printing unit of the printing press 12, wherein the printing material is transported successively through the printing units at a given transport speed.

[0038] A feedback line 42 provides the ability to assess the drying quality achieved during operation. This can be achieved by the user conducting a test and, in a particularly simple embodiment, submitting an evaluation. Further methods include connecting a measuring system 44 for metrological product testing, e.g., using a UV analyzer (dose measurement), FTIR measurement (double bond conversion), or similar. The feedback and any changes to the settings are then transmitted to the cloud database 28 and processed in the computing unit 22. The neural network 36 can also be configured to self-learningly correct the setting values ​​based on the feedback.

[0039] Fig. 2 provides a self-explanatory illustration of a possible process flow for processing a print job with UV curing. This involves reading or entering the required process parameters, such as:

[0040] • Substrate: plastic (optical properties), paper (absorbent, non-absorbent),

[0041] • Colour: shade, reactivity (dose), layer thickness,

[0042] • Paint: Matt, Glossy, Reactivity (dose), Layer thickness.

[0043] The relationships for UV drying are then determined using relevant process parameters with Kl tools, from which specifications for the power setting and optionally the inerting per irradiation unit are derived.

[0044] This creates an assistance system to help the user with the aim of saving energy and extending the service life of the irradiation units.

[0045] The energy saving is calculated from the reduction

[0046] • the performance per dryer,

[0047] • the format switch-off (edge ​​zones),

[0048] • the subject-dependent switching (option),

[0049] • water cooling (for water-cooled systems),

[0050] • air cooling (for air-cooled systems),

[0051] • nitrogen in inert systems. The extension of the service life, particularly of the UV LEDs in the irradiation units 18, is based on reducing the operating current. This lowers the operating temperature, which has a positive effect on the service life of an LED.

Claims

Patent claims 1 . A process for the radiation drying of substrate coatings such as printing and varnish layers, comprising: - applying a substrate coating (16) in a coating system (12), in particular a printing machine, to a substrate (14), - irradiating the substrate coating (16) with UV radiation by means of an irradiation unit (18), whereby the substrate coating (16) is chemically crosslinked and cured, - transmitting specification data (24) of the substrate coating (16) to a computing unit (22), - comparing the specification data (24) with reference data (30) stored in a database (28) by means of a comparison module (34) of the computing unit (22), and - Providing a setting value for the irradiation unit (18) as a result of the comparison by the comparison module (34).

2. Method according to claim 1, characterized in that the setting value comprises at least one element from the group radiation power per irradiation unit (18), print format-dependent edge zone switch-off, print subject-dependent switching, cooling power for water or air cooling, nitrogen feed into the irradiation area.

3. Method according to claim 1 or 2, characterized in that the specification data (24) are entered automatically by a system control or manually by an operator.

4. Method according to one of claims 1 to 3, characterized in that the specification data (24) define at least one property of the substrate (14) and / or the substrate coating (16), in particular color tone, color sequence, varnish, layer thickness and type.

5. Method according to one of claims 1 to 4, characterized in that the reference data (30) are stored in the database (28) to form reference data clusters (32), and in that a setting value is determined from each of the reference data clusters (32).

6. Method according to claim 5, characterized in that the transmitted specification data (24) are assigned to the reference data clusters (32) by comparing at least one property of the substrate (14) and / or the substrate coating (16) and the corresponding setting value is determined.

7. Method according to one of claims 1 to 6, characterized in that for a plurality of irradiation units (18) acting successively on the substrate coating (16), a setting value is provided in each case, in particular depending on the sequence of a multi-layer substrate coating (16).

8. Method according to one of claims 1 to 7, characterized in that the quality of the radiation drying is detected via a measuring system (44) or a user input and is used to correct the setting value.

9. System for radiation drying of substrate coatings such as printing and varnish layers in a coating plant (12), comprising: - at least one irradiation unit (18) for irradiating the substrate coating (16) by means of UV radiation, wherein the substrate coating (16) is chemically crosslinked and cured by the UV radiation, - a computer-implemented computing unit (22) to which specification data (24) of the substrate coating (16) can be transmitted via a data transmission device (26), - a comparison module (34) of the computing unit (22), which is designed and programmed to compare the specification data (24) with reference data (30) stored in a database (28) and to provide a setting value for the irradiation unit (18) as a result of the comparison.

10. System according to claim 9, characterized in that the computing unit (22) comprises an artificial neural network (36) implemented on a computer.

11. System according to claim 9 or 10, characterized in that the artificial neural network (36) is designed and programmed to have at least one of the following features: - Verification of data in the sense of a plausibility check, - Assignment of verified data to existing data sets, - Comparison of data records user-specific and across users.

12. System according to one of claims 9 to 11, characterized in that the artificial neural network (36) is designed to and is programmed to self-learningly correct setting values ​​based on user feedback and / or drying quality measurements.

Images