DE102022121248A1 - Method for marking workpieces and printing device - Google Patents

Abstract

The invention relates to a method for marking workpieces (11), which preferably consist at least partially of wood, wood material, plastic or the like, comprising the steps: bringing about a relative movement between a workpiece (11) and a printing device (10), printing on a surface the workpiece (11), in particular a coating material (14), which is provided on at least one surface of the workpiece (11), with a surface decoration and applying an information-containing marking to the surface of the coating material (14), the marking using a fluorescent Medium is applied to the workpiece, as well as a printing device (10) for printing workpieces (11).

Description

Technical area

The invention relates to a method for marking workpieces, which preferably consist at least partially of wood, wood material, plastic or the like, and to a printing device for printing workpieces.

State of the art

Workpieces, for example for furniture or component production, are often marked for simplified identification, for example printed with readable identification features or provided with machine-readable barcodes or transponders (RFID). Such markings can include identification features relating to the workpiece, workpiece features or the like. In addition to requiring a lot of time and money, these types of markings can represent a visual impairment during later use, especially on workpieces whose surfaces are provided with a coating material and/or a decoration. Consequently, such markings are removed from the workpiece after the manufacturing process, which, however, makes it difficult to identify the workpiece at a later point in time and represents additional work.

Presentation of the invention

The invention is based on the object of proposing a method for marking workpieces, which enables simple and cost-effective marking of workpieces and does not impair the visual appearance of the workpieces. It is also an object of the invention to propose a printing device which enables workpieces to be marked easily and cost-effectively.

A method for marking workpieces is defined in claim 1. A printing device for printing workpieces is defined in claim 10. Subclaims relate to specific embodiments.

Because, according to the invention, the marking is applied to the workpiece by the fluorescent medium and visualization of the marking is therefore only possible under UV light, the marking can remain permanently on the surface of the workpiece without visually affecting a workpiece used, for example, as a furniture element to represent.

The marking can in particular include readable information. These can preferably be identification features or workpiece features relating to the workpiece, for example workpiece dimensions, workpiece material, workpiece color, properties of the coating material, adhesives used and/or auxiliary materials, or the like.

By preferably applying the marking to a surface decoration previously printed on the coating material, simple and cost-effective printing and marking of workpieces can be achieved. This also makes it possible to permanently mark the workpiece that has already been printed for later use. However, within the scope of the invention, it is also possible to first apply the fluorescent marking and only then or possibly simultaneously apply a surface decoration.

A further development of the method can provide that the surface decoration is printed on the surface of the workpiece by at least one print head of the printing device and the marking is printed on the surface decoration by at least one further print head.

In this way, both the surface decoration and the marking can be printed onto the coating material by a printing device. At least the at least one print head for printing the surface decoration can be designed as an ink-jet print head or a laser print head.

Preferably, the surface decoration and the marking can be printed by the printing device in two successive printing processes, preferably one continuous processing process.

Preferably, the printing device can be designed as a continuous device, in which a large number of workpieces are conveyed successively in a continuous direction to the printing device and are printed and marked by this.

The relative movement is preferably brought about by a conveyor device, for example a conveyor belt, conveyor belt or a conveyor chain, through which the workpiece is conveyed in a conveying direction relative to the printing device.

Alternatively, the printing device can be designed as a stationary printing device, in which the workpiece is recorded in a stationary manner and the printing device or the print heads are movable relative to the workpiece.

Likewise, the printing device can be set up so that a conveying movement or an adjusting movement can be carried out relative to one another both by the workpiece and by the printing device or the print heads.

In a further advantageous embodiment of the method, it can be provided that the marking is applied to the surface decoration by means of the fluorescent medium as a machine-readable coding, in particular a barcode and/or QR code.

This machine-readable coding enables information to be attached to the coating material easily and in a space-saving manner. Due to the small space requirement, such a marking can also be provided in particular on surfaces of a workpiece that provide a small area, for example narrow surfaces or surfaces with a special geometric configuration.

A further embodiment of the method can provide that before applying the marking and/or after applying the marking, a transparent surface coating, in particular a clear varnish, is applied to the workpiece at least in areas.

The transparent surface coating is preferably applied to the workpiece after printing the surface decoration. The transparent surface coating allows a protective layer to be applied to the surface decoration and/or the marking. In particular, the transparent surface coating can be printed onto the surface of the coating material by a further print head of the printing device. Preferably, the transparent surface coating is printed onto the surface of the workpiece or coating material using a clear varnish.

Advantageously, the method can provide that at least the surface decoration is actively dried after printing and before applying the marking.

The printing device preferably has a drying unit which actively dries at least the surface decoration after printing. The drying unit enables multi-layer printing by the printing device, in particular in one pass of the workpiece relative to the printing device. Drying is preferably carried out by the drying unit after printing the surface decoration and/or after printing the marking and/or after printing the transparent surface coating. Drying can be done by an air flow, heating or the like.

Particularly preferably, in the method, the coating material can be a strip-shaped or web-shaped coating material which is attached to at least one narrow surface and/or wide surface of the preferably plate-shaped workpiece, and the surface decoration and the marking can be printed onto the surface of the coating material by the printing device.

Narrow surfaces of plate-shaped workpieces can be coated with a narrow surface coating material, also known as edge band. Since the marking can also be printed, in particular, on the narrow-surface coating material, the method can also be used to mark plate-shaped workpieces with a small workpiece thickness.

By printing the marking on the surface of the narrow-surface coating material, accessibility to the marking, i.e. reading out the marking, can also be made possible with a large number of plate-shaped workpieces stacked one on top of the other.

A further advantageous embodiment of the method can also provide that the surface decoration and the marking are printed onto the workpiece in one pass of the workpiece to the printing device.

For this purpose, the printing device can preferably be designed both for printing the surface decoration and for printing the marking. In this way, the surface decoration and marking can be printed quickly and cost-effectively. The method also enables easy integration into an existing manufacturing environment, e.g. a production line, for producing the workpieces.

Advantageously, it can also be provided in the method that the marking is detected by a detection device after application and the information contained in the marking is transmitted to a control device, the information being checked by the control device and the workpiece being fed to a further processing step if the test result is positive is or is rejected and if the inspector has a negative result The result is returned or rejected for post-processing.

In this way, the print quality, i.e. the readability, of the applied marking can be checked immediately after printing. Through the recording device and the direct checking of the recorded information, quality assurance of production, especially in real time, can be ensured.

In a further development of the method, the information contained in the identification can be transmitted to a data processing device and stored in a data memory.

This allows the information contained in the identification to be stored centrally. The information can be stored on a central server, for example a manufacturer or supplier.

The data processing device can preferably be integrated into a computer network, such as a LAN (Local Area Network) and/or WAN (Wide Area Network), the Internet or the like. The data processing device can preferably be part of a cloud-based network. Such storage can enable easy access to the information relating to the workpiece.

The task is also achieved by a printing device for printing workpieces, which preferably consist at least partially of wood, wood material, plastic or the like, according to claim 10.

The printing device is preferably designed as a digital printing device, through which a single-color and/or multi-color printing process can be carried out. The printing device can comprise a plurality of print heads, through which the surface decoration and the marking comprising the readable information can be easily printed onto a coating material attached to the workpiece.

Brief description of the drawings

• 1 eine schematische Ansicht einer Ausführungsform einer Druckeinrichtung zum Bedrucken einer Oberfläche eines Werkstücks;
• 2 eine Ablaufdiagramm eines Verfahrens zum Bedrucken und Kennzeichnen des Werkstücks durch die Druckeinrichtung in 1.

Further features and advantages of a device, a use and/or a method result from the following description of embodiments with reference to the accompanying drawings. Of these drawings shows:

• 1 a schematic view of an embodiment of a printing device for printing on a surface of a workpiece;
• 2 a flowchart of a method for printing and marking the workpiece by the printing device in 1 .

Description of embodiments

The same reference numbers listed in different figures designate identical, corresponding, or functionally similar elements.

1 shows a highly schematic view of a printing device 10 for printing workpieces 11. In particular workpieces 11, which are at least partially made of wood, a wood material, plastic, composite material or the like.

The workpieces 11 are preferably plate-shaped workpieces 11, for example solid wood panels, chipboard, fiberboard or the like. Such workpieces 11 can be intended, for example, for furniture or component production.

Surfaces of the workpiece 11, i.e. wide surfaces 12 and/or narrow surfaces 13 of the workpiece 11, can be provided with a coating material 14. In particular, at least one narrow surface 13 is coated with a narrow surface coating material, also referred to as edge material or edge band.

The printing device 10 is designed in particular as a digital printing device with which a single-color printing process and/or multi-color printing process can be carried out. With such a printing device 10, both multi-colored surface decorations, for example a simulated wood grain or the like, as well as individual colors can be printed.

The printing device 10 is in particular set up so that the narrow surface coating material attached to the at least one narrow surface 13 can be printed. Likewise, the printing device 10 can be set up to print on other (coated or uncoated) surfaces of the workpiece 11, i.e. wide surfaces 12 and/or narrow surfaces 13 of the workpiece 11.

To carry out the printing process, it is provided that a relative movement is brought about between the workpiece 11 and the printing device 10. In particular, the workpiece 11 is arranged on a conveyor device 15, for example a conveyor belt, a conveyor belt or a conveyor chain, through which the workpiece 11 is conveyed to the printing device 10 in a conveying direction F during the printing process.

Alternatively or additionally, it can be provided that the printing device 10 comprises an adjusting device, not shown, through which components of the printing device, for example a printing unit or print heads described below, can be moved relative to the workpiece 11, for example by a multi-axis adjusting movement.

The printing device 10 comprises a printing unit 16 for carrying out the printing process and a printing control 17 for controlling the printing unit 16. The printing unit 16 comprises a plurality of print heads 18, 19, 20.

The printing unit 16 comprises a print head 18 or several print heads 18. The print head 18 can be designed as a laser print head. The print head 18 is preferably designed as an ink-jet print head for dispensing printing inks. The printing inks can be UV and/or water-based inks, varnishes and/or paints.

The print head 18 is set up to print a single-color or multi-colored surface decoration onto the coating material 14, in particular onto the narrow surface coating material attached to the narrow surface 13. The surface decoration can represent a simulated wood grain, a single-color or multi-color printed image or the like.

The printing unit 16 includes at least one further print head 19 for delivering a fluorescent medium, preferably a fluorescent ink or an ink that contains a fluorescent component.

The print head 19 is set up to print an identification using the fluorescent medium onto the surface decoration previously printed on the coating material 14, in particular on the narrow-surface coating material.

In particular, the identification is formed as a machine-readable coding, for example a bar code, QR code or the like, by the fluorescent medium. However, the marking is not limited to such machine-readable coding and can also be designed, for example, as numbers, letters, pictograms or the like.

The identification is in particular an identification that contains information relating to the workpiece 11. The marking includes, in particular, readable information, which includes, for example, identification features or workpiece characteristics relating to the workpiece (workpiece dimensions, workpiece material, workpiece color, properties of the coating material, adhesive used and/or auxiliary materials) or the like.

By printing the marking on the previously printed surface decoration, the workpiece 11 can be clearly identified in a simple manner at any time, i.e. for example during a manufacturing process, during a storage process or even during a later product life cycle, for example as a component of a furniture part or the like.

By printing the marking through the fluorescent medium, the marking on the previously printed surface decoration is only visible to the human eye under UV light. The marking therefore does not represent any visual impairment on the workpiece 11, so that it can remain permanently on the printed surface decoration and enables the workpiece 11 to be clearly identified at any time.

The printing unit 16 further comprises at least one further print head 20 for applying a transparent surface coating, preferably a clear varnish. The at least one further print head 20 for applying the transparent surface coating can be part of the printing unit 16 or can be provided separately.

The print head 20 is set up to apply the transparent surface coating, in particular the clear varnish, to the coating material 14 before applying the marking and/or after applying the marking as a protective layer for the surface decoration or the marking.

In addition, the printing device 10 can have a detection device 21, through which the marking applied to the surface decoration can be detected. The detection device 21 can be an optical device, for example a camera device, laser device or the like, through which the marking can be detected, for example using UV light. The detection device 21 can be part of the printing unit 16 or can be provided separately.

The recorded information contained in the identification is transmitted to a control device 17 and stored in a data memory of a data processing device 22.

Preferably, the information contained in the label is recorded by the Control device 17 is checked, whereby the workpiece 11 can be fed to a further processing step or removed from the processing process if the test result is positive, and can be returned for post-processing, for example for re-marking the workpiece, or sorted out if the test result is negative.

In addition, the printing device 10 can have a drying unit, not shown. This allows the surface decoration, the marking and/or the transparent surface coating to be actively dried after printing.

The drying unit enables the drying time to be shortened and thus the multi-layer printing process of the surface decoration and the marking on the coating material 14 to be shortened. The drying unit can be formed by an air flow device or a heating device.

2 shows in a flow chart based on steps S1 to S6 the process steps for printing and marking the workpiece 11 by the in 1 described printing device 10.

In step S1, the workpiece 11 is first provided with the coating material 14 attached thereto, in particular with the narrow surface coating material attached to the narrow surface 13.

In the following method step S2, the relative movement between the workpiece 11 and the printing device 10 is brought about. In particular, the workpiece 11 is conveyed by the conveying device 15 in the conveying direction F to the printing device 10.

In the further method step S3, the surface decoration is printed by the print head 18 onto the coating material 14, in particular onto the narrow surface coating material attached to the narrow surface 13.

In the subsequent method step S4, the marking is printed by the print head 19 onto the previously printed surface decoration.

In method step S5, the transparent surface coating is applied by the print head 20 to the coating material 14, in particular to the narrow surface coating material attached to the narrow surface 13. Alternatively, this step S5 can also take place before method step S4.

The method step S6 provides that the applied identification is detected by the detection device 21 and the detected information is transmitted to the control device 17. The control device 17 checks and/or stores the recorded information.

It will be apparent to those skilled in the art that individual features described in different embodiments can also be implemented in a single embodiment, provided they are not structurally incompatible. Likewise, various features described within a single embodiment may also be provided in multiple embodiments individually or in any suitable subcombination.

Claims (10)

Method for marking workpieces (11), which preferably consist at least partially of wood, wood material, plastic or the like, comprising the steps: bringing about a relative movement between a workpiece (11) and a printing device (10), Printing a surface of the workpiece (11), in particular a coating material (14), which is provided on at least one surface of the workpiece (11), with a surface decoration, and Applying a label containing information to the surface of the coating material (14), the label being applied using a fluorescent medium. Procedure according to Claim 1 , in which the surface decoration is also printed on the surface of the workpiece (11) by at least one print head (18) of the printing device (10) and the marking is printed on the surface decoration by at least one further print head (19). Procedure according to Claim 1 or 2 , in which the marking is also applied to the surface decoration using the fluorescent medium as a machine-readable coding, in particular a barcode and/or QR code. Method according to one of the preceding claims, in which a transparent surface coating, in particular a clear varnish, is also applied to the workpiece (11) at least in areas before applying the marking and/or after applying the marking. Method according to one of the preceding claims, in which at least the surface decoration is actively dried after printing and before applying the marking, preferably the printing device (10) has a drying unit which actively dries at least the surface decoration after printing. Method according to one of the preceding claims, in which the coating material (14) is also a strip-shaped or web-shaped coating material which is attached to at least one narrow surface (13) and/or wide surface of the preferably plate-shaped workpiece (11), and the surface decoration and the marking are printed onto the surface of the coating material by the printing device (10). Method according to one of the preceding claims, in which the surface decoration and the marking are also printed on the workpiece (11) in one pass of the workpiece (11) to the printing device (10). Method according to one of the preceding claims, in which the marking is further detected after application by a detection device (21) and the information contained in the marking is transmitted to a control device (17), the information being checked by the control device (17) and that If the test result is positive, the workpiece (11) is fed to a further processing step or is rejected and, if the test result is negative, it is returned for post-processing or is rejected. Procedure according to Claim 8 , in which the information contained in the identification is also transmitted to a data processing device (22) and stored in a data memory. Printing device (10) for printing workpieces (11), which preferably consist at least partially of wood, wood material, plastic or the like, in particular for carrying out the method according to one of Claims 1 until 9 , with a printing unit (16) for carrying out a printing process on at least one surface of a workpiece (11), in particular at least one narrow surface (13) of the workpiece (11), a conveyor device (15) for bringing about a relative movement between the workpiece (11) and the printing unit (16), and a control device for controlling the printing unit (16), characterized in that the control device is set up to control the printing unit in such a way that it applies a marking containing information to the surface of the workpiece (11) by means of a fluorescent medium. brings up.

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