Laser marking of containers

Abstract

The invention relates to, inter alia, a method for marking containers (12). The method involves laser marking a laser marking (36) on a container (12) by means of a laser marking system (10) in such a way that a surface of the laser marking (36) has at least one predetermined structuring (38), generated by the laser marking system (10), preferably in order to create an optical effect via the at least one predetermined structuring (38).

Description

[0001] DESCRIPTION

[0002] Laser marking of containers

[0003] Technical area

[0004] The invention relates to a method for labeling containers. The invention further relates to a container. The invention also relates to a device for labeling containers.

[0005] Technical background

[0006] Traditionally, containers, such as beverage containers, are labeled using conventional labeling processes. This serves, on the one hand, to identify and differentiate the product from competitors, and, on the other hand, to mark ingredients and comply with legal requirements. Additional information, such as the expiration date, can be applied using a laser unit, for example. For container decorations that do not require labels, combinations of different technologies (e.g., embossing, printing, laser marking) can be used.

[0007] A disadvantage of the current state of the art can be, for example, that the processes are comparatively complex, e.g., direct printing, and thus sometimes result in high costs. The decoration cannot be easily customized, which is problematic for small batches and fully customized containers (batch size 1). Furthermore, the conventional decoration may have a lack of legibility and contrast. Furthermore, there may be little flexibility with regard to the visual impression, for example, with laser marking. Overall, this may result in little or no differentiation opportunities or differentiation from the competition.

[0008] The invention is based on the object of creating an improved technology for marking containers, which preferably enables particularly good readability and particularly good contrast of the marking.

[0009] Summary of the invention

[0010] The object is achieved by the features of the independent claims. Advantageous further developments are specified in the dependent claims and the description. One aspect of the present disclosure relates to a method for marking containers (e.g., for use in a container treatment plant). The method comprises laser marking a laser mark onto a container (or its container surface) using a laser marking system (e.g., a laser pulse marking system) such that a surface of the laser mark has at least one predetermined (e.g., micro- and / or nano-) structuring generated by the laser marking system, preferably for effecting an optical (e.g., reflection) effect through the at least one predetermined structuring.

[0011] The laser marking system can therefore advantageously laser mark a desired laser marking (laser-marked decoration), e.g. with graphics, logo and / or lettering, and additionally create targeted optical effects of the laser marking or decoration through the predetermined structuring(s) of the surface. This can advantageously be used to adjust and improve readability and contrast in desired areas (=where the predetermined structuring(s) is / are). Further potential for improving readability and contrast lies in the targeted combination of different structurings, which can, for example, be adjacent to one another. Overall, this can advantageously enable greater freedom for individual design of the decoration and thus, for example, improved opportunities for differentiation from the competition.

[0012] In one embodiment, the at least one predetermined structuring comprises a plurality of predetermined structurings that differ structurally from one another (e.g., are differently recessed or raised), preferably for effecting different optical effects (e.g., reflections) through the plurality of predetermined structurings. This advantageously allows the potential to improve readability and contrast through the targeted combination of different structurings to be utilized, with the different structurings, for example, generating combinations of different reflections of incident light (e.g., a combination of retroreflection, diffuse reflection, and / or regular reflection).

[0013] In a further exemplary embodiment, the plurality of predetermined structures directly adjoin one another, or a first of the plurality of predetermined structures surrounds a second of the plurality of predetermined structures (e.g. partially or completely), preferably adjacent to the second predetermined structure. Advantageously, this can significantly improve readability and contrast, since the optically produced effect changes abruptly at a boundary between the predetermined structures. In one embodiment, the at least one predetermined structure each has a plurality of structures, which preferably have at least one of the following: a regular or irregular arrangement; arranged next to one another in a grid, a pattern, or a line; adjoin one another; are structurally identical or structurally different; and are microscale or nanoscale.

[0014] This allows a wide variety of optical effects to be achieved, particularly those aimed at different reflection behavior when incident light is applied.

[0015] In a further embodiment, the multiple structures comprise multiple (e.g., microscale or nanoscale) honeycomb structures, multiple (e.g., microscale or nanoscale) corner reflector structures, multiple (e.g., microscale or nanoscale) lens reflector structures, multiple (e.g., microscale or nanoscale) irregular structures, multiple caterpillar-like structures, multiple interlocking or meandering structures, and / or at least one planar surface structure that is essentially planar at the microscale or nanoscale. This advantageously allows targeted sections with predominantly retroreflection, diffuse reflection, and / or regular reflection to be created.

[0016] In one embodiment, the multiple structures are each at least partially raised, preferably foamed, and / or at least partially recessed, preferably embossed. This advantageously allows for the creation of very targeted combinations of structures that can be used to achieve very specific optical effects to improve readability and contrast.

[0017] In a further embodiment, the at least one predetermined structure comprises a retroreflector structure designed to cause retroreflection of incident light. Retroreflection can thus advantageously be achieved as the desired optical effect in order to use it specifically in the laser marking to increase readability and contrast, particularly in combination with an adjacent regular reflector structure and / or a diffuse reflector structure.

[0018] In one embodiment, the retroreflector structuring comprises at least one of: a plurality of (e.g., ablated) (e.g., microscale or nanoscale) honeycomb structures; a plurality of (e.g., ablated) (e.g., microscale or nanoscale) corner reflector structures, preferably each having three reflector surfaces arranged at an angle to one another, which are arranged as a triple mirror; and a plurality of (e.g., foamed) (e.g., microscale or nanoscale) lens reflector structures, preferably in a circular shape, in a rod shape, or in a (e.g., curved or intertwined or meandering or wavy) bead shape.

[0019] Advantageously, the honeycomb structures, corner reflector structures and / or incident light can essentially reflect as retroreflectors and thus achieve a desired optical effect in this area of ​​the laser marking.

[0020] In a further embodiment, the at least one predetermined structure comprises a regular reflector structure designed to effect regular reflection of incident light. This advantageously allows regular reflection to be achieved as the desired optical effect in order to use it specifically in the laser marking to increase readability and contrast, particularly in combination with an adjacent retroreflector structure and / or a diffuse reflector structure.

[0021] In one embodiment, the regular reflector structure comprises at least one planar surface structure that is essentially planar at the microscale or nanoscale. Advantageously, the planar surface structure can reflect incident light essentially regularly or directly, thus achieving a desired optical effect in this area of ​​the laser marking.

[0022] In a further embodiment, the at least one predetermined structuring comprises a diffuse reflector structuring designed to cause diffuse reflection of incident light. Optionally, the diffuse reflector structuring can comprise a plurality of (e.g., microscale or nanoscale) irregular structures arranged in a distributed manner, preferably resulting in an irregular, microscale, or nanoscale roughened surface. Diffuse reflection can thus advantageously be achieved as the desired optical effect in order to use it specifically in the laser marking to increase readability and contrast, particularly in combination with an adjacent retroreflector structuring and / or a regular reflector structuring.

[0023] Preferably, the retroreflector structuring, the regular reflector structuring, and / or the diffuse reflector structuring directly adjoin one another. This advantageously enables particularly good readability or particularly good contrast. In one embodiment, the at least one structuring is created during laser marking by at least one of: a laser beam angle of incidence on the container specifically specified for the respective predetermined structuring or a combination of different laser beam angles of incidence on the container specifically specified for the respective predetermined structuring; a laser beam intensity specifically specified for the respective predetermined structuring or a combination of different laser beam intensities specifically specified for the respective predetermined structuring;a laser beam wavelength specifically specified for the respective predetermined structuring or a combination of different laser beam wavelengths specifically specified for the respective predetermined structuring; a laser beam pulse duration specifically specified for the respective predetermined structuring or a combination of different laser beam pulse durations specifically specified for the respective predetermined structuring (particularly preferred: a combination of nanosecond pulses and picosecond pulses or a combination of picosecond pulses and femtosecond pulses); a spatial laser beam pulse spacing specifically specified for the respective predetermined structuring or a combination of different spatial laser beam pulse spacings specifically specified for the respective predetermined structuring;a temporal laser beam pulse interval specifically specified for the respective predetermined structuring or a combination of different temporal laser beam pulse intervals specifically specified for the respective predetermined structuring; and a focus diameter specifically specified for the respective predetermined structuring or a combination of different focus diameters specifically specified for the respective predetermined structuring.

[0024] Advantageously, this allows a separate parameter set for the laser marking system to be specified for each predetermined pattern, allowing the predetermined pattern to be created reliably and repeatably. In particular, using a combination of nanosecond, picosecond, and / or femtosecond pulses and / or by specifically adjusting the laser beam incidence angle, functional optical surfaces can be efficiently produced with high precision.

[0025] In a further embodiment, the method further comprises producing or treating, preferably coating, the container prior to laser marking such that, at least in the area in which the laser marking and / or the at least one predetermined structuring is laser-marked, irreversibly thermochromic pigments or laser additives are introduced, which react with a color change and / or a shading effect during laser marking. Advantageously, in this way, the desired optical effect caused by the predetermined structuring can be further enhanced, refined, or differentiated by the color change or shading effect, for example, in or adjacent to the predetermined structuring.

[0026] In one embodiment, the method further comprises (e.g., camera-assisted) detection of the laser marking and / or the at least one predetermined structuring after laser marking by means of a preferably camera-assisted inspection device, and adjusting the operation of the laser marking system and / or a container conveyor as a function of the detected laser marking and / or the detected at least one predetermined structuring by means of a control device. Advantageously, the applied laser markings can be monitored in this way. Furthermore, there is the possibility of adjusting (e.g., closed-loop or open-loop control) certain operating parameters of the device, e.g., the container conveyor or the laser marking system.

[0027] A further aspect of the present disclosure relates to a (e.g., beverage) container, preferably a bottle or can, wherein the container has a laser marking produced or laser-marked by a method as disclosed herein. It is understood that the container can achieve the same advantages as those already described with reference to the method.

[0028] A further aspect of the present disclosure relates to a device for marking containers for a container processing plant. The device comprises a container conveyor for transporting the containers, preferably upright, and a laser marking system for laser marking the containers transported by the container conveyor. The device further comprises a control device configured to operate the device to carry out a method as disclosed herein. Advantageously, the same advantages that have already been explained with reference to the method can be achieved by means of the device.

[0029] Preferably, the device can be incorporated into a container processing system for manufacturing, cleaning, coating, testing, filling, sealing, equipping, and / or packaging containers for pasty or liquid media, preferably beverages or liquid foodstuffs. For example, the containers can be designed as bottles, cans, tubes, canisters, cartons, flasks, etc.

[0030] Preferably, the term "control device" can refer to electronics (e.g., implemented as a driver circuit or with microprocessor(s) and data memory) which, depending on its design, can perform control tasks and / or regulation tasks and / or processing tasks. Even if the term "control" is used herein, it can also appropriately include or mean "regulation" or "control with feedback" and / or "processing".

[0031] The previously described preferred embodiments and features of the invention can be combined with one another as desired.

[0032] Short description of the characters

[0033] Further details and advantages of the invention are described below with reference to the accompanying drawings. They show:

[0034] Figure 1 is a schematic representation of an exemplary device for marking containers;

[0035] Figures 2 - 4 schematic side views of containers with exemplary laser markings;

[0036] Figure 5 is a schematic plan view of a portion of a predetermined structuring;

[0037] Figure 6 is a schematic sectional view of the predetermined structuring of Figure 5;

[0038] Figure 7 is a schematic plan view of a portion of a predetermined structuring;

[0039] Figure 8 is a schematic sectional view of the predetermined structuring of Figure 7;

[0040] Figure 9 is a schematic plan view of a portion of a predetermined structuring;

[0041] Figure 10 is a schematic sectional view of the predetermined structuring of Figure 9; Figure 11 is a schematic plan view of a portion of a predetermined structuring;

[0042] Figure 12 is a schematic sectional view of the predetermined structuring of Figure 11;

[0043] Figure 13 is a schematic plan view of a portion of a predetermined structuring;

[0044] Figure 14 is a schematic sectional view of the predetermined structuring of Figure 13;

[0045] Figure 15 is a schematic plan view of a portion of a predetermined structuring; and

[0046] Figure 16 is a schematic sectional view of the predetermined structuring of Figure 15.

[0047] The embodiments shown in the figures correspond at least partially, so that similar or identical parts are provided with the same reference numerals and for their explanation reference is also made to the description of the other embodiments or figures in order to avoid repetition.

[0048] Detailed description of exemplary embodiments

[0049] Figure 1 shows a device 8 for marking container 12.

[0050] The device 8 comprises a laser marking system 10. Preferably, the device 8 may further comprise a container conveyor 30. Optionally, the device 8 may comprise an inspection device 34.

[0051] The laser marking system 10 can laser mark containers 12 or apply a laser marking 36 to the containers 12. The laser marking system 10 can also be referred to as a laser marking system, laser coding system, or laser inscription system. Preferably, the laser marking system 10 can be a CO2 laser marking system, a fiber laser marking system, or a UV laser marking system. For example, the laser marking system 10 can be a pulsed laser marking system.

[0052] The laser marking system 10 can preferably comprise a laser source 14 and a marking head 16. The laser source 14 can be embodied, for example, as a laser tube. The laser tube can be sealed. The laser tube can be filled with a gas, e.g., containing CO2, or a gas mixture, e.g., a CO2-N2-He gas mixture. Electrodes can also be arranged in the laser tube. A supply unit can be connected to the electrodes (not shown in Figure 1). The supply unit can supply the laser source 14 with electrical energy. By means of a high-frequency voltage, for example, molecules, e.g., CO2 molecules, in the laser tube can be excited to oscillate and thus emit a laser beam. The laser source 14 can also be referred to as an oscillator.

[0053] The laser beam generated by the laser source 14 can be guided or directed to the marking head 16 directly or via mirrors. It is possible, for example, to arrange a so-called telescope between the laser source 14 and the marking head 16 to expand the laser beam.

[0054] The marking head 16 can preferably have two movable mirrors 18 and 22 and two drives 20 and 24. The marking head 16 can further have a focusing device 26. The marking head 16 can also be referred to as a coding head, marking head, or writing head.

[0055] The first drive 20 can rotate the first mirror 18 about a first axis (e.g., x-axis). The first mirror 18 can also be referred to, for example, as a movable scanner mirror, e.g., an X-scanner mirror. The second drive 24 can rotate the second mirror 22 about a second axis (e.g., y-axis). The second mirror 22 can also be referred to, for example, as a movable scanner mirror, e.g., a Y-scanner mirror. The first axis and the second axis can preferably run perpendicular to each other.

[0056] The mirrors 18, 22, moved by the drives 20, 24, can direct the laser beam according to the desired laser marking 36. The laser beam can thus move, for example, in a writing manner across the surface of the container 12. Preferably, the laser beam can move across the surface of the container 12 within a marking field assigned to the respective marking head 16.

[0057] Before the laser beam hits the surface of the container 12, it can be focused using a focusing device 26. The focusing device 26 can, for example, comprise a focusing lens. The focusing lens can also be referred to as a condenser lens. The focusing lens can, for example, be an F-theta lens. Depending on the configuration, the focusing lens can be arranged inside or outside the marking head 16. The focusing device 26 can also, for example, comprise a protective screen to protect the focusing lens.

[0058] It is possible for the laser marking system 10 to have a plurality of marking heads 16. The plurality of marking heads 16 can, for example, be arranged side by side and / or one above the other. For example, two, three, or more marking heads 16 can be included.

[0059] Each marking head 16 can be connected to its own laser source 14, which can emit a laser beam to the respective marking head 16. Accordingly, the laser marking system 10 can have multiple laser sources 14.

[0060] It is also possible for multiple marking heads 16 to receive their respective laser beams from the same laser source 14. For example, a beam splitter can be arranged between the laser source 14 and multiple marking heads 16. The beam splitter can, for example, split a laser beam received from the laser source 14 into multiple laser beams and direct them to the multiple marking heads 16.

[0061] For example, the marking heads 16 can generate or enable different laser beam incidence angles on the container 12 and / or different spatial laser beam pulse spacings on the container 12. It is also possible for a single marking head 16 to generate or enable different laser beam incidence angles on the container 12 and / or different spatial laser beam pulse spacings on the container 12.

[0062] If multiple laser sources 14 are included, they can, for example, be of identical construction. However, it is also possible for the laser sources 14 to be at least partially different in order to achieve different effects (e.g., color effects, haptic effects, surface structures) when laser marking the containers 12.

[0063] For example, the laser sources 14 can generate laser beams with different laser beam intensities, different laser beam wavelengths, and / or laser beam pulse durations. It is also possible for a single laser source 14 to be configured to generate laser beams with different laser beam intensities, different laser beam wavelengths, and / or laser beam pulse durations.

[0064] The container conveyor 30 can transport the containers 12 in one transport direction (see arrow in Figure 1). For example, the container conveyor 30 can be a rotary container conveyor (container conveyor carousel). Alternatively, the container conveyor 30 can be a linear container conveyor, for example.

[0065] The container conveyor 30 can support the containers 12 during transport, preferably at the bottom, periphery, and / or mouth. The container conveyor 30 can have container holders 32 for supporting the containers 12. The container holders 32 can preferably hold the containers 12 in base handling or neck handling.

[0066] It is possible that the container conveyor 30 does not have separate container holders 32 and, for example, the containers 12 are simply supported on a preferably revolving conveyor element (e.g., belt, strap, chains or plates) of the container conveyor 30.

[0067] For example, the container holders 32 can each support a container 12. The container holders 32 can each have, for example, a container plate (e.g., a container turntable), a centering bell, a container clamp, and / or an inflation device. For example, a container 12 can be fixed between a container plate and a centering bell. An optional, additional inflation device can provide additional stability, e.g., when the containers 12 are labeled before filling.

[0068] Preferably, the container conveyor 30 can be configured to rotate the transported containers 12 each about its own vertical axis. Preferably, the container holders 32 can be rotatable about their respective vertical axes to rotate the containers 12.

[0069] During laser marking, the container conveyor 30 preferably moves the containers 12 in the transport direction past the laser marking system 10. Optionally, the containers 12 can be rotated by the container conveyor 30 about their own vertical axis during laser marking. Alternatively, the containers 12 can remain stationary, for example, during laser marking.

[0070] Optionally, the device 8 can further comprise the preferably camera-supported inspection device 34. The inspection device 60 can detect the laser markings 36 and / or predetermined structuring(s) 38 applied to the containers 12 by the laser marking system 10 and, for example, check or evaluate them with regard to quality, dimensions, etc. Depending on the evaluation, operation of the device 8 can be adjusted, e.g., by means of a control device. For example, a container transport speed of the container conveyor 30 or a container rotation speed of the container conveyor 30 can be reduced if it is detected that the applied laser markings 36 and / or predetermined structuring 38 are incomplete, or a warning can be issued to a user via an output device.

[0071] The laser marking 36 applied by the laser marking system 10 can, for example, comprise a decoration (e.g., a decorative surface), at least one character and / or a character string, preferably a single-line or multi-line string.

[0072] It is possible that during laser marking using the laser marking system 10, irreversible thermochromic pigments or laser additives in or on the container 12 may react with a color change and / or a shading effect. For example, the pigments or laser additives can be incorporated into the container material during the manufacture of the container 12. Alternatively, the container 12 can be coated externally with a coating comprising the irreversible thermochromic pigments or laser additives prior to laser marking.

[0073] Specifically, chromophoric, irreversible thermochromic pigments, laser additives, or similar substances can be applied to the containers 12 or incorporated into the container wall. This preparation can be carried out, for example, during container manufacture or separately, e.g., by coating, spraying, dipping, etc. Introduction directly into the container base material is also conceivable. In the case of PET containers, this can be done, for example, in the same way as the introduction of scavengers or permeation inhibitors, e.g., using monolayer or multilayer technology. The pigments, laser additives, or similar substances can be characterized by being wavelength- and / or thermosensitive. This means that they can react to certain wavelengths, energy doses, or irradiation durations, etc. in a predictable manner with a color change or shading effects (grayscale). A mixture of different substances with different sensitivities orSensitivity ranges can enable a wide spectrum of colors and effects. Monochrome effects can also be sufficient in principle. This may be the case, for example, when only an increase in contrast and thus increased legibility of logos, fonts, or codes that are molded into the container surface (e.g., in stretch blow molding or similar) is required.

[0074] A special feature of the present disclosure is that a surface of the laser marking 36 of the container 12 has at least one predetermined structuring 38, which is / was generated by the laser marking or by means of the laser marking system 10, as shown purely schematically in Figures 2 to 4. Purely by way of example, the surface of the laser marking 36 of the container 12 in Figure 2 has three predetermined structurings 38. The surface of the laser marking 36 of the container 12 in Figure 3 has two predetermined structurings 38. The surface of the laser marking 36 of the container 12 in Figure 4 likewise has two predetermined structurings 38.

[0075] The structuring 38 is preferably a microstructuring, a nanostructuring, or a combined micro-nanostructuring. The structuring 38 can be a functional structuring for producing an optical effect. The at least one structuring 38 can preferably comprise a retroreflector structuring 38A, 38B, 38E, and / or 38F (see Figures 5 to 8 and Figures 13 to 16), a regular reflector structuring 38C (see Figures 9 and 10), and / or a diffuse reflector structuring 38D (see Figures 11 and 12).

[0076] If several predetermined structures 38 are included, these can preferably differ structurally from one another. Thus, the structures 38 can preferably produce different optical effects.

[0077] The plurality of predetermined structures 38 can be directly adjacent to one another and, for example, surround one another. However, it is also possible for the structures 38 to be arranged at a distance from one another. Preferably, the structures 38 do not overlap one another.

[0078] Each structuring 38 can have several structures 40.

[0079] The structures 40 of a respective structuring 38 can be arranged regularly or irregularly. The structures 40 of a respective structuring 38 can be arranged next to one another in a grid, a pattern, or a line. The structures 40 of a respective structuring 38 can be adjacent to one another. The structures 40 of a respective structuring 38 can be structurally identical or structurally different. The structures 40 of a respective structuring 38 can be microscale or nanoscale.

[0080] The plurality of structures 40 may each be raised, preferably foamed, or recessed, preferably abraded, or a combination thereof.

[0081] Preferably, the multiple structures 40 can be raised differently from one another, preferably foamed to varying degrees, and / or recessed differently, preferably ablated to varying degrees, for different structurings 38. In general, the structures 40 or the structurings 38 can be created by an operation (parameter set) of the laser marking system 10 that is specific to the respective structuring 38. In this case, the laser marking system 10 can be operated by a control device depending on the particular structuring 38 to be created.

[0082] Specifically for the respective structuring 38, for example, a laser beam angle of incidence on the container 12, a combination of different laser beam angles of incidence on the container 12, a laser beam intensity or a combination of different laser beam intensities and / or a laser beam wavelength or a combination of different laser beam wavelengths can be specified.

[0083] A laser beam pulse duration or a combination of different laser beam pulse durations, a spatial laser beam pulse spacing or a combination of different spatial laser beam pulse spacings and / or a temporal laser beam pulse interval or a combination of different temporal laser beam pulse intervals can also be specified specifically for the respective structuring 38.

[0084] A focus diameter (focus spot) or a combination of different focus diameters (focus spots) can also be specified specifically for the respective predetermined structuring 38.

[0085] Figures 5 to 8 show a retroreflector structure 38A and a retroreflector structure 38B.

[0086] The retroreflector structure 38A, 38B can cause what is known as retroreflection of incident light. During retroreflection, light can be largely reflected in the direction of incidence, i.e., the direction from which the light originated, largely independent of the direction of incidence or the angle of incidence with respect to the orientation of the retroreflector structure 38A, 38B.

[0087] As shown in Figures 5 and 6, the retroreflector structure 38A may include a plurality of honeycomb or corner reflector structures 40A. Each honeycomb or corner reflector structure 40A may be configured for retroreflection.

[0088] The corner reflector structures 40A can preferably be arranged regularly, e.g., adjacent to one another in a grid or pattern. The corner reflector structures 40A can, for example, be adjacent to one another or spaced apart from one another. The corner reflector structures 40A can preferably be structurally identical. The corner reflector structures 40A can preferably be microscale or nanoscale.

[0089] The corner reflector structures 40A can be formed as depressions in the surface, preferably created by material removal caused by the laser marking system 10.

[0090] Each honeycomb or corner reflector structure 40A can have a plurality of reflector surfaces arranged at an angle to one another. Particularly preferably, each honeycomb or corner reflector structure 40A has three reflector surfaces arranged at an angle to one another, which are arranged as a so-called triple mirror.

[0091] To create the angle reflector structure 40A, laser beams or laser beam pulses can strike the surface of the container 12 at different angles of incidence. For example, a different angle of incidence of the respective laser beam or laser beam pulse can be specified for each reflector surface of an angle reflector structure 40A and generated accordingly by the laser marking system 10. For example, for an angle reflector structure 40A with three reflector surfaces arranged at an angle to one another, which are arranged as a so-called triple mirror, three laser beams, three laser beam pulses, or three laser beam pulse bursts, each with different angles of incidence, can be generated by the laser marking system 10 and strike the surface of the container 12 to create the angle reflector structure 40A.

[0092] As shown in Figures 7 and 8, the retroreflector structure 38B may include a plurality of lens reflector structures 40B. Each lens reflector structure 40B may be configured for retroreflection.

[0093] The lens reflector structures 40B can preferably be arranged regularly, e.g., adjacent to one another in a grid or pattern. The lens reflector structures 40B can, for example, be adjacent to one another or spaced apart from one another. The lens reflector structures 40B can preferably be structurally identical. The lens reflector structures 40B can preferably be microscale or nanoscale.

[0094] The lens reflector structures 40B can be formed as elevations in the surface, preferably produced by foaming the (e.g., plastic) material caused by the laser marking system 10.

[0095] Each lens reflector structure 40B can have an optical lens shape in cross-section. The lens shape can, for example, have an ovoid shape or an approximately spherical shape. To create the lens reflector structure 40B, laser beams or laser beam pulses can strike the surface of the container 12 at the same angle of incidence, with a comparatively short irradiation time / pulse duration and / or a comparatively low laser beam intensity being selected.

[0096] Figures 9 and 10 show a regular reflector structure 38C. The regular reflector structure 38C can also be referred to as a direct reflector structure.

[0097] The regular reflector structure 38C can cause a so-called regular or direct reflection of incident light. With regular or direct reflection, incident light can be reflected at a certain angle, but not back in the direction from which the light originated. Thus, the angle of incidence and the angle of reflection relative to the normal to the incidence can preferably be equal.

[0098] The regular reflector structuring 38C may have at least one planar surface structure 40C. The planar surface structure 40C may be substantially planar at the microscale or nanoscale.

[0099] The planar surface structure 40C can preferably be formed as an extended depression in the surface, preferably created by material removal caused by the laser marking system 10. The extended depression can preferably have a micro- or nanoscale substantially planar bottom.

[0100] To create the flat surface structure 40C, for example, a laser beam from the laser marking system 10 can be guided continuously and line by line across the surface of the container 12. Adjacent lines can preferably overlap. Alternatively, for example, a plurality of laser pulses from the laser marking system 10 can strike the surface of the container 12 one after the other and adjacent to one another. Adjacent laser pulse impact points can preferably overlap with one another.

[0101] Figures 11 and 12 show a diffuse reflector structure 38D.

[0102] The 38D diffuse reflector structure can cause what is known as diffuse reflection of incident light. Diffuse reflection can cause incident light to be reflected in various directions, resulting in scattered light.

[0103] The diffuse reflector structure 38D can have a plurality of irregular structures 40D, resulting in a microscale or nanoscale irregularly roughened surface. The irregular structures 40D can preferably be arranged irregularly next to one another. The irregular structures 40D can, for example, be adjacent to one another or spaced apart from one another. The irregular structures 40D are structurally different. The irregular structures 40D can preferably be microscale or nanoscale.

[0104] The irregular structures 40D can be formed as depressions in the surface, preferably generated by material removal caused by the laser marking system 10. Alternatively or additionally, the irregular structures 40D can be formed as elevations in the surface, preferably generated by foaming of the (e.g., plastic) material caused by the laser marking system 10.

[0105] To create the irregular structures 40D, laser beams or laser beam pulses can strike the surface of the container 12, for example, with different angles of incidence, different intensities, different distances and / or different pulse durations, etc.

[0106] Figures 13 to 16 show a retroreflector structure 38E and a retroreflector structure 38F, which in turn can cause a so-called retroreflection of incident light.

[0107] The retroreflector structure 38E, 38F can comprise a plurality of caterpillar-shaped lens reflector structures 40E and 40F, respectively. The caterpillar-shaped lens reflector structures 40E, 40F can be, for example, elongated or rod-shaped (see Figures 13 and 14) or curved, wavy, intertwined, and / or meander-shaped (see Figures 15 and 16). Each lens reflector structure 40E, 40F can be configured for retroreflection.

[0108] The lens reflector structures 40E, 40F can preferably be arranged regularly, e.g., adjacent to one another in a grid or pattern and / or intertwined with one another. The lens reflector structures 40E, 40F can, for example, be arranged in single rows or multiple rows. The lens reflector structures 40E, 40F can, for example, be adjacent to one another or spaced apart from one another. The lens reflector structures 40E, 40F can preferably be structurally identical. The lens reflector structures 40E, 40F can preferably be microscale or nanoscale.

[0109] The lens reflector structures 40E, 40F can preferably be formed as elevations in the surface, preferably created by foaming the (e.g., plastic) material caused by the laser marking system 10. Each lens reflector structure 40E, 40F can have an optical lens shape in cross-section. The lens shape can, for example, have an ovoid shape or an approximately spherical shape.

[0110] To create the lens reflector structures 40E, 40F, laser beams can, for example, strike the surface of the container 12 at the same angle of incidence and be moved across the surfaces along a desired path. Preferably, a comparatively short irradiation time / pulse duration and / or a comparatively low laser beam intensity can be selected.

[0111] The invention is not limited to the preferred embodiments described above. Rather, a multitude of variants and modifications are possible which also make use of the inventive concept and therefore fall within the scope of protection. In particular, the invention also claims protection for the subject matter and features of the subclaims, independent of the claims referred to. In particular, the individual features of independent claim 1 are each disclosed independently of one another. In addition, the features of the subclaims are also disclosed independently of all features of independent claim 1. All ranges referred to herein are to be understood as disclosed in such a way that, as it were, all values ​​falling within the respective range are individually disclosed, e.g., also as preferred, narrower outer limits of the respective range.

[0112] List of reference symbols

[0113] 8 Device for marking containers

[0114] 10 Laser marking system

[0115] 12 containers

[0116] 14 Laser source

[0117] 16 Marking head

[0118] 18 first mirror

[0119] 20 first drive

[0120] 22 second mirror

[0121] 24 second drive

[0122] 26 Focusing device

[0123] 30 container conveyors

[0124] 32 Container holder

[0125] 34 Inspection facility

[0126] 36 Laser marking

[0127] 38 predetermined structuring

[0128] 38A Retroreflector structuring

[0129] 38B Retroreflector structuring

[0130] 38C Regular reflector structuring

[0131] 38D diffuse reflector structuring

[0132] 38E Retroreflector structuring

[0133] 38F retroreflector structuring

[0134] 40 Structure

[0135] 40A corner reflector structure

[0136] 40B lens reflector structure

[0137] 40C flat surface structure

[0138] 40D irregular structure

[0139] 40E lens reflector structure

[0140] 40F lens reflector structure

Claims

CLAIMS 1. A method for marking containers (12), the method comprising: Laser marking a laser marking (36) on a container (12) by means of a laser marking system (10) such that a surface of the laser marking (36) has at least one predetermined structuring (38) generated by the laser marking system (10), preferably for effecting an optical effect by means of the at least one predetermined structuring (38).

2. The method according to claim 1, wherein: the at least one predetermined structuring (38) has a plurality of predetermined structurings (38) which are structurally different from one another, preferably for effecting different optical effects by the plurality of predetermined structurings (38).

3. The method according to claim 2, wherein: the plurality of predetermined structures (38) are directly adjacent to one another; or a first of the plurality of predetermined structures (38) surrounds a second of the plurality of predetermined structures (38), preferably adjacent to the second predetermined structure (38).

4. Method according to one of the preceding claims, wherein: the at least one predetermined structuring (38) each has a plurality of structures (40) which preferably have at least one of: being regularly arranged; being arranged next to one another in a grid, a pattern or a line; being adjacent to one another; being structurally identical; and being microscale or nanoscale.

5. The method according to any one of the preceding claims, wherein: the plurality of structures (40) comprise a plurality of honeycomb structures, a plurality of corner reflector structures (40A), a plurality of lens reflector structures (40B), a plurality of irregular Structures (40D), a plurality of caterpillar-like structures (40E, 40F), a plurality of interlocking or meander-like structures (40F), and / or at least one planar surface structure (40C) which is essentially planar on a microscale or nanoscale; and / or the plurality of structures (40) are each at least partially raised, preferably foamed, and / or at least partially recessed, preferably ablated.

6. The method according to any one of the preceding claims, wherein: the at least one predetermined structuring (38) comprises a retroreflector structuring (38A, 38B) configured to cause retroreflection of incident light.

7. The method according to claim 6, wherein: the retroreflector structure (38A, 38B) comprises at least one of: a plurality of honeycomb structures; a plurality of corner reflector structures (40A), preferably each having three reflector surfaces arranged at an angle to one another, which are arranged as a triple mirror; and a plurality of lens reflector structures (40B, 40E, 40F), preferably in a circular shape, a rod shape, or a bead shape.

8. The method according to any one of the preceding claims, wherein: the at least one predetermined structuring (38) comprises a regular reflector structuring (38C) configured to effect regular reflection of incident light.

9. The method according to claim 8, wherein: the regular reflector structuring (38C) has at least one planar surface structure (40C) which is substantially planar on a microscale or nanoscale.

10. The method according to any one of the preceding claims, wherein: the at least one predetermined structuring (38) comprises a diffuse reflector structuring (38D) designed to cause diffuse reflection of incident light, and optionally the diffuse reflector structuring (38D) comprises a plurality of irregular structures (40D) arranged in a distributed manner, so that preferably an irregular, microscale or nanoscale roughened surface is obtained.

11. The method according to any one of the preceding claims, wherein: the at least one structuring (38) is produced during laser marking by at least one of: a laser beam angle of incidence on the container (12) that is specifically predetermined for the respective predetermined structuring (38) or a combination of different laser beam angles of incidence on the container (12) that is specifically predetermined for the respective predetermined structuring (38); a laser beam intensity that is specifically predetermined for the respective predetermined structuring (38) or a combination of different laser beam intensities that is specifically predetermined for the respective predetermined structuring (38); a laser beam wavelength that is specifically predetermined for the respective predetermined structuring (38) or a combination of different laser beam wavelengths that is specifically predetermined for the respective predetermined structuring (38);a laser beam pulse duration specifically predetermined for the respective predetermined structuring (38) or a combination of different laser beam pulse durations specifically predetermined for the respective predetermined structuring; a spatial laser beam pulse spacing specifically predetermined for the respective predetermined structuring (38) or a combination of different spatial laser beam pulse spacings specifically predetermined for the respective predetermined structuring (38); a focus diameter specifically predetermined for the respective predetermined structuring (38) or a combination of different focus diameters specifically predetermined for the respective predetermined structuring (38);and a temporal laser beam pulse interval specifically predetermined for the respective predetermined structuring (38) or a combination of different temporal laser beam pulse intervals specifically predetermined for the respective predetermined structuring (38); 12. Method according to one of the preceding claims, further comprising: Producing or treating, preferably coating, the container (12) before laser marking in such a way that at least in the area in which the laser marking (36) and / or the at least one predetermined structuring (38) is laser marked, irreversibly thermochromic pigments or laser additives are introduced, which react during laser marking with a color change and / or a shading effect.

13. Method according to one of the preceding claims, further comprising: Detecting the laser marking (36) and / or the at least one predetermined structuring (38) after the laser marking by means of a preferably camera-supported inspection device (34), and Adapting an operation of the laser marking system (10) and / or a container conveyor (30) as a function of the detected laser marking (36) and / or the detected at least one predetermined structuring (38) by means of a control device.

14. Container (12), preferably a bottle or can, wherein the container (12) has a laser marking (36) produced by a method according to one of claims 1 to 12.

15. A device (8) for marking containers (12) for a container treatment plant, comprising: a container conveyor (30) for transporting the containers (12), preferably upright; a laser marking system (10) for laser marking the containers (12) transported by the container conveyor (30); and a control device configured to operate the device (8) to carry out a method according to one of claims 1 to 13.

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