Plastic pallet having optical code

Abstract

The invention relates to a plastic load carrier having an individual identifier which is optically readable, wherein the surface of the load carrier has a field which is generated by means of a hot-stamping process and which is in optical contrast to the load-carrier material, and wherein surface portions of the hot-stamped field are removed in such a way that these surface portions form an optical, machine-readable code. The invention also relates to a method for producing a load carrier of this kind.

Description

[0001] "Plastic pallet with optical code"

[0002] Description:

[0003] The invention relates to a load carrier made of plastic, in particular a plastic pallet, which has an individual marking, i.e. is individually coded.

[0004] For traceability reasons and for the automatic control of goods flows, it is common practice to individually code load carriers such as pallets. Depending on the materials used, this can be achieved by printing, for example, on pallets made of wood or cellulose materials.

[0005] For generic pallets made of plastic material, for example, RFID chips are used as information carriers. These contain an identification code that is unique to each plastic pallet. The RFID chips can be optimally protected inside the pallets, for example in a pallet base, because they do not need to be read optically, but rather using radio waves that easily penetrate the pallet material. Mechanical damage to the information carriers is virtually impossible. A second advantage of RFID chips is that a large number of pallets can be read practically simultaneously. For example, a truck with a large number of pallets can drive through a reading barrier or gate, and during the passage, all of the pallets on the truck are detected by an antenna system in the barrier or gate.

[0006] Optically readable identification codes such as barcodes or QR codes can be compromised by abrasion or contamination, rendering them unreadable—or at least less easy to read. The reading process takes time because the pallet must be aligned so that its code can be optically scanned. Furthermore, typical scanners only allow the scanning of a single code at a time, so a larger number of pallets requires a correspondingly larger number of separate reading processes and the associated time expenditure.

[0007] In practice, however, there are often requirements to individually optically code a pallet, e.g. if a company works exclusively with optical readers.

[0008] Printing processes that require a custom-made stamp with the respective individual code information for each pallet are not suitable for individual pallet coding for economic reasons, as this would require a large number of different stamps. The same applies to embossing processes, for example, to create a three-dimensional structure in the pallet surface, where recessed areas of this structure could then be filled with ink.

[0009] However, printing using a printing process that economically enables individual printing of the respective pallet in order to create an optically readable code such as a barcode or a QR code is not very wear-resistant, especially not very abrasion-resistant, for the generic plastic pallets.

[0010] Depending on the design of the laser process, lasering changes the surface of the plastic pallet to a lighter or darker color compared to the surrounding, non-lasered plastic material. Depending on the color of the pallet material, a comparatively weak contrast between the lasered areas and the surrounding plastic material can make the code difficult to read. Furthermore, the lasered surface areas are less abrasion-resistant due to the altered and damaged surface structure of the plastic. After the lasered surface portions have been abrasioned, the optical contrast between the underlying plastic material and the surrounding material becomes so low that optical reading of the code is significantly more difficult and associated with corresponding uncertainty.

[0011] The addition of special pigments to the plastic material, which would result in a strong contrast during lasering, is, firstly, economically disadvantageous when considering the small volume of the surface layer in the area to be lasered that must be penetrated by the laser relative to the total volume of the charge carrier, which would be present everywhere with the unused pigments. Secondly, the lasered surface areas are poorly abrasion-resistant due to the altered and damaged surface structure of the plastic, so that the above-described problem of difficult and unreliable code detection arises at the latest when surface portions of the optical code have been removed by abrasion.

[0012] A cost-effective way to apply individual codes to plastic load carriers is to print the codes on labels and stick them onto the pallets. However, there is a fundamental problem with the durability of stickers on load carriers, especially when they are made of a material such as polyethylene ("PE"). While such materials generally allow for bonding, this is only possible under defined, almost laboratory-like conditions. Under the conditions prevailing in practice for applying stickers, the durability of stickers is usually insufficient given the mechanical and thermal stresses to which the load carriers are exposed.

[0013] Given that many load carriers in a load carrier pool are used by several different companies, the load carriers can advantageously have both RFID chips and an optical code for their identification. Sorting the load carriers, which would otherwise be necessary to provide certain companies with only those load carriers that are optically coded, can thus be eliminated, which is economically advantageous. In this case of dual coding, it must be ensured that the information contained in the respective coding of the RFID chip and the optical code is identical. The provision of information carriers previously provided with an optically readable code, such asthe stickers mentioned, is therefore logistically difficult because, firstly, information carriers must be provided whose information content corresponds exactly to the information content of the RFID chips, and secondly, when attaching the information carriers to the load carrier, it must be ensured that the assignment of the RFID chips used on a specific load carrier corresponds to the stickers with the same information content used on the same load carrier.

[0014] The invention is based on the object of improving a generic load carrier such that it has a personalized, preferably permanent, optical marking while being economically producible. Furthermore, the invention is based on the object of specifying a method for producing such a load carrier.

[0015] This object is achieved by a load carrier according to claim 1 and by a method according to claim 20.

[0016] According to the invention, the individual marking is optically readable. The load carrier has at least one field on its surface, created using a hot-stamping process, which is designed to visually contrast with the underlying load carrier material, in particular the pallet material. Surface portions of the hot-stamped field are removed in such a way that these surface portions form at least one optical, machine-readable code.

[0017] In other words, the invention proposes first preparing the charge carrier for individual coding by first creating a field on the outside of the charge carrier using a hot embossing process, which field contrasts, in particular, optically with the charge carrier material. The optical contrast can, for example, preferably consist of a difference in brightness such that a light hot-embossed field is created on a dark charge carrier material, or vice versa. The optical contrast can, even with approximately identical brightness values, preferably consist of a difference in color, for which contrasting colors are used. For example, complementary colors can be used, for example by creating a green hot-embossed field on a red charge carrier material. In particular, the optical contrast can also be achieved by a combination of both different brightness values ​​and different colors.

[0018] In the hot stamping process, which can be used to create long-lasting logos or lettering on plastic components, color pigments are transferred from a transfer film to and into the surface of the load carrier using pressure and heat. For example, a heated stamping die can be used. The surface melts over a very thin layer, creating a strong bond between the load carrier material and the color pigments, resulting in a highly durable, abrasion-resistant optical marking. However, this marking only exists in the form predetermined by the stamping die and therefore does not yet contain any individual identification for the respective load carrier.

[0019] For the purposes of the present invention, anything that can be used in the hot stamping process and has the desired property of optically contrasting with the charge carrier material, so that a correspondingly optically contrasting field can be generated on the surface of the charge carrier, is referred to as a color pigment. For example, particles can be used as color pigments. In one embodiment, the color pigments can change their color during the hot stamping process due to the effects of pressure and / or temperature. In another embodiment, they can be temperature-stable in such a way that they retain their color during the hot stamping process, such as mineral or metallic particles.

[0020] Since the hot-stamped field can be standardized and, for example, always the same size, the required embossing stamp can be used economically without changes to all load carriers that are to be individually optically coded.

[0021] The individual coding is achieved by removing portions of the hot-stamped field, revealing the underlying charge carrier material, which visually contrasts with the hot-stamped field. This creates an optical marking that is easily visible and can be easily read by machines, and is robust and durable against thermal and mechanical stress. The surface of the charge carrier, and in particular the hot-stamped field, therefore represents a marking carrier that bears the optically readable code.

[0022] In a first embodiment considered advantageous, the surface portions of the hot-stamped field are removed by mechanical processing. This can be done, for example, using a milling cutter. Given the thin layer thickness in which the color pigments contrasting with the charge carrier material are located in the hot-stamped field, and the easy mechanical machinability of the plastic material, high processing speeds are achieved during the milling process. The creation of an optically readable code by mechanically removing the corresponding surface portions is therefore possible within a short time. Furthermore, a long service life of the milling tool used is ensured, compared, for example, to milling metal workpieces.

[0023] In a second embodiment considered advantageous, the surface portions forming the code are designed as lasered surfaces. The surface portions removed from the hot-stamped field are thus designed as laser surfaces. A laser process is used to create the desired optical code in the hot-stamped field. Depending on the design of the laser used, the surface portions of the hot-stamped field that are irradiated by the laser are burned. Since the layer thickness in which the hot-stamped color pigments are located is very thin, this layer and the pigments it contains can be removed easily and at high speed by lasering.Separate, unconnected surface areas can be processed very quickly using the laser, without having to remove a mechanical tool from the hot-stamped area and then reposition it at a new location, as is required with a milling head. Instead, the laser can create separate optical regions within the hot-stamped area simply by switching it on and off, or by deflecting or interrupting its beam path. The high processing speed not only ensures very rapid work progress but also protects the charge carrier material from adverse thermal effects, so that the laser can be used to process a single charge carrier without any problems.

[0024] Preferably, the surface portions form an optical, machine-readable code designed as a barcode. Alternatively or additionally, the surface portions form an optical, machine-readable code designed as a QR code. This means that the field contains a barcode and / or a QR code. The surface portions either form the code(s) themselves or their negatives. These code types are robust, easy-to-read, space-saving codes, making them suitable for load carriers of different sizes and for a variety of applications.

[0025] In one embodiment, the load carrier is at least dual-coded in such a way that, in addition to the at least one optical, machine-readable code, it has an information carrier containing a non-optical, machine-readable code. The load carrier therefore has two different identification carriers. The second identification carrier can, for example, be an RFID chip whose code can be read wirelessly using radio waves. The two codes preferably have at least overlapping or, more preferably, identical information content. Thus, depending on the respective operational specifications, different reading devices can be used to read the different identification carriers in order to obtain the same information and to be able to clearly identify the plastic pallet.

[0026] In this case of dual coding, the charge carrier can first be provided with the non-optical code, thus individually marking the charge carrier before the optical code is generated. If both codes have the same content—which is considered an advantageous embodiment—the non-optical code can be automatically read before surface portions are removed from the hot-stamped field, thus individually optically encoding the charge carrier.

[0027] In this case, the automatically read non-optical code can be processed automatically to program the tool that removes the surface portions from the hot-stamped field, ensuring the content identity of the two codes contained in the two different marking carriers. The possibility of automatically reading RFID chips within a very short time, as mentioned above, enables a virtually delay-free processing sequence when the initially non-optically coded load carrier is brought to the processing station, where the RFID chip is automatically read and its code is transmitted to the control system of the processing tool, which removes surface portions from the hot-stamped field.

[0028] In an advantageous embodiment, the charge carrier behind the field has, at least in some areas, a different charge carrier material, referred to as a special material, than the base material from which the rest of the charge carrier is made. For example, particularly economical color pigments can be used which do not contrast sufficiently strongly with the base material, while the desired optical contrast with the special material is provided. The base material and the special material can be chemically related to ensure a good bond. For example, they can be practically identical and only differ from one another in terms of their color. The area with the special material can, for example, be created by a plastic plate which is introduced into the mold cavity of an injection mold at a suitable point before the base material is injected into the mold cavity.

[0029] The field preferably extends at an angle, in particular at a right angle, to a support plane in which at least one base surface of the load carrier is arranged. The base surface is formed by an underside of the load carrier. The support plane idealizes a surface of a floor on which the load carrier stands or lies. The field borders the support plane or is spaced from the support plane. Due to the described angle of the field relative to the support plane, the at least one code can be read particularly reliably from one side, and the possibility of reading it is not influenced by a charge state.

[0030] The load carrier preferably has a load-receiving section, a runner section, and / or a block section. The load-receiving section is spaced from the support plane. The load-receiving section forms, in particular, a preferably flat loading surface facing away from the support plane. The runner section borders the support plane and forms at least part of the floor surface. The runner section is, in particular, spaced from the load-receiving section. The block section connects the runner section to the load-receiving section and is, in particular, cuboid-shaped. The load carrier is, in particular, designed similarly to a wooden pallet, preferably a Euro pallet, wherein the at least one runner section corresponds to one of the runners, the at least one block section corresponds to one of the blocks, and the load-receiving section corresponds to the part formed above the blocks.Particularly preferably, the load carrier according to the invention, corresponding to the Euro pallet, has at least four, in particular nine, block sections and two or three skid sections, which are each spaced apart from one another in at least one direction parallel to the support plane.

[0031] The at least one block section preferably has the field on its surface. The field is preferably rectangular. The extension of the field in a direction parallel to the support plane is particularly preferably greater than an extension of the field in a direction perpendicular to the support plane. The RFID chip is in particular arranged within the same block section.

[0032] The field is in particular designed to be spaced apart from both the loading surface and the support plane. Preferably, the field is arranged substantially centrally or centrally on a side surface of the block section and is particularly preferably intersected by a central plane extending parallel to the support plane and centrally between the support plane and the loading surface. In an advantageous embodiment of the invention, the field is arranged between a first parallel plane parallel to the support plane, which is arranged between the support plane and the load-receiving section, and the support plane, and / or the skid section is arranged between the support plane and a second parallel plane parallel to the support plane, which extends between the field and the support plane. This design of the field ensures its accessibility for optical readout particularly reliably.The loading surface preferably extends parallel to the support plane and is designed as a closed surface or as the enveloping surface of an interrupted surface. The loading surface is located, in particular, in a loading plane. In a first preferred embodiment of the invention, the loading plane does not intersect the load carrier, which in this case is designed, in particular, as a plastic pallet. In a second preferred embodiment of the invention, the loading plane intersects the load carrier in such a way that side walls of the load carrier, which surround a loading space, extend above the loading plane. In this case, the load carrier is designed, in particular, as a pallet box.

[0033] The surface on which the field is arranged is preferably formed by an outer wall of the load carrier, in particular of the block section, formed by the charge carrier material. Particularly preferably, a reinforcing wall extending at an angle, in particular at right angles, to the outer wall is adjacent to the outer wall, with a wall connection region opposite the field. This means, in particular, that if the reinforcing wall were to be imaginarily extended, the field would be intersected by it. The reinforcing wall is, in particular, a rib and / or strut within the load carrier or the block section, which makes it more stable. The arrangement of the reinforcing wall behind the field leads to an advantageous design of the field in that deformation of the surface caused by the hot stamping process is effectively counteracted by the reinforcing wall.

[0034] Preferably, the field is at least partially, in particular completely, enclosed by a protruding rib. The rib protrudes in that, extending from the at least substantially flat field, it forms a raised structure that is preferably substantially linear and / or bead-shaped. The rib reduces the risk of mechanical impact on the field during use of the load carrier and thus increases the reliability of the at least one code.

[0035] The field is preferably recessed relative to a first part of the surface surrounding the field. Particularly preferably, the first part of the surface is recessed relative to a second part of the surface surrounding the first part. The first and in particular also the second part of the surface are formed in particular by the block section. This particularly two-stage recess of the field provides even better protection against unintentional impairment by conventional mechanical influences on charge carriers. Within the first part of the surface, embossed symbols are preferably formed next to the field in order to be able to identify the charge carrier.

[0036] In a plan view, the load carrier is preferably at least substantially square or rectangular. The load carrier has a first extension in a width direction and a second extension in a longitudinal direction perpendicular to the width direction. The second extension preferably exceeds the first extension. The field particularly preferably extends at an angle, in particular perpendicular, to the width direction. This position of the field makes it particularly practical to integrate the reading of the at least one code into existing logistics systems, in which load carriers are typically moved in their longitudinal direction.

[0037] The load carrier preferably has a further field on its surface, produced using a hot-stamping process, which is designed to visually contrast with the underlying load carrier material, in particular pallet material, and wherein surface portions of the hot-stamped field are removed in such a way that these surface portions form at least one optical, machine-readable code. The load carrier therefore has at least two coded, in particular identical, fields. These fields are designed to be spaced apart from one another in order to facilitate identification of the load carrier. In particular, the two fields are designed to face away from one another, i.e., are formed on sections of the surface facing away from one another. In particular, at least two of the block elements each have a field.Particularly preferably, these two block elements are diagonally spaced from each other with respect to the basic shape of the load carrier, so that a vertical central axis perpendicular to the support plane runs between them.

[0038] The method according to the invention serves to produce a charge carrier as described above. The method comprises the following steps: A charge carrier is provided. Color pigments are introduced into the surface of the charge carrier using a hot-stamping process, creating a field that optically contrasts with the underlying charge carrier material. Surface portions are removed from the hot-stamped field in such a way that the underlying charge carrier material is visible, and these surface portions form an optical, machine-readable code.

[0039] Preferably, the surface portions are removed from the field using a laser. The surface portions are particularly preferably configured as a barcode and / or a QR code. Preferably, the load carrier is initially non-optically coded, for example, using an RFID chip, and then the optically readable code is generated. The non-optical code is automatically read before surface portions are removed from the hot-stamped field. The non-optical code is used to control the tool, which removes the surface portions from the hot-stamped field in such a way that the optically readable code has the same content or overlaps with the non-optical code. The procedure can also be reversed; in any case, the second coding in the method preferably depends on the first code. Further details and advantages can be found in the schematically illustrated figures described below; they show:

[0040] Fig. 1 shows a load carrier according to the invention designed as a plastic pallet in a first perspective view from above,

[0041] Fig. 2 shows the load carrier according to Fig. 1 in a side view,

[0042] Fig. 3 shows the load carrier according to Fig. 1 in a second perspective view from below,

[0043] Fig. 4 shows a block section of the load carrier according to Fig. 1 in a detailed view from the side,

[0044] Fig. 5 shows the block section according to Fig. 4 in a detailed view from below.

[0045] 1 to 5 illustrate an exemplary plastic load carrier 2 according to the invention, which is designed as a plastic pallet. The load carrier 2 essentially comprises a load-receiving section 26 forming a loading surface 16, nine block sections 24 below it, and three skid sections 22 connecting three block sections 24 each, which skid sections 22 adjoin a support plane AE with their underside floor surfaces 12. The loading surface 16 extends essentially rectangularly, with a second extension in a longitudinal direction LR being greater than a first extension in a width direction BR.

[0046] Two diagonally opposite block sections 24 each have a field 6 produced by a hot stamping process on their surfaces 4 (the position of the second field, not visible due to perspective, is indicated in Fig. 3). This field is designed to visually contrast with the charge carrier material behind it. Surface portions of the hot-stamped fields 6 are removed by laser in such a way that these surface portions form, on the one hand, a machine-readable code designed as a barcode 8 and, on the other hand, a machine-readable code designed as a QR code 10. The two block sections 24, each with a field 6, are arranged opposite one another in such a way that a vertical axis VA, perpendicular to the support plane AE, runs centrally between them.

[0047] 2 and 4, it becomes clear how the fields 6, described in the singular below, are each precisely arranged. The field 6 is surrounded by a substantially rectangular rib 30 and is recessed relative to a first part 34 of the surface 4, which in turn is recessed relative to a second part 44 of the surface 4 surrounding the first part 34. The field 6 is arranged between a first parallel plane PE1 parallel to the support plane AE, which is arranged between the support plane AE and the load receiving section 26, and the support plane AE, and the skid section 22 is arranged between the support plane AE and a second parallel plane PE2 parallel to the support plane AE, which extends between the field 6 and the support plane AE.

[0048] Fig. 5 illustrates that the surface 4, on which the field 6 is formed, is formed by an outer wall 18 of the block section 24. Adjacent to the outer wall 18 is a reinforcing wall 20 with a wall connection region 28 opposite the field 6. List of reference symbols:

[0049] 2 load carriers

[0050] 4 Surface

[0051] 6 field

[0052] 8 Barcode

[0053] 10 QR code

[0054] 12 floor area

[0055] 16 loading area

[0056] 18 Outer wall

[0057] 20 Reinforcing wall

[0058] 22 Skid section

[0059] 24 block section

[0060] 26 Load receiving section

[0061] 28 Wall connection area

[0062] 30 ribs

[0063] 34 first part of the surface

[0064] 44 second part of the surface

[0065] AE Uprising Level

[0066] BR latitude direction

[0067] LR longitudinal direction

[0068] PE1 first parallel plane

[0069] PE2 second parallel plane

[0070] VA vertical axis

Claims

Claims: 1 . Load carrier (2) made of plastic, in particular a plastic pallet, with an individual marking, characterized in that the marking is optically readable, wherein the load carrier (2) has on its surface (4) at least one field (6) produced by a hot stamping process, which is designed to be optically contrasting with the load carrier material behind it, in particular pallet material, and wherein surface portions of the hot stamped field (6) are removed in such a way that these surface portions form at least one optical, machine-readable code (8, 10).

2. Load carrier according to claim 1, characterized in that the surface portions forming the code (8, 10) are designed as lasered surfaces.

3. Load carrier according to claim 1 or 2, characterized in that the surface portions form an optical, machine-readable code designed as a barcode (8).

4. Load carrier according to one of claims 1 to 3, characterized in that the surface portions form an optical, machine-readable code designed as a QR code (10).

5. Load carrier according to one of the preceding claims, characterized in that the hot-stamped field (6) and the underlying Contrast the charge carrier material, especially have contrasting colors.

6. Charge carrier according to one of the preceding claims, characterized in that the hot-stamped field (6) and the charge carrier material behind it have contrasting brightness values.

7. Load carrier according to one of the preceding claims, characterized in that the load carrier (2) is at least dual-coded in such a way that, in addition to the at least one optical, machine-readable code (8, 10), it has an information carrier which contains a non-optical, machine-readable code.

8. A charge carrier according to claim 7, characterized in that the two optical and non-optical codes (8, 10) have the same content.

9. Load carrier according to one of the preceding claims, characterized in that the load carrier (2) behind the hot-stamped field (6) has in some areas a different pallet material, referred to as special material, than the pallet material referred to as base material, from which the rest of the load carrier (2) consists.

10. Load carrier according to one of the preceding claims, characterized in that that the field (6) extends at an angle, in particular at right angles, to a support plane (AE) in which at least one bottom surface (12) of the load carrier (2) is arranged.

11. Load carrier according to one of the preceding claims, characterized by a load receiving section (26) spaced from a support plane (AE), which in particular forms a loading surface (16) facing away from the support plane (AE), in particular a flat loading surface (16), at least one skid section (22) adjacent to the support plane (AE) and at least one block section (24) connecting the skid section (22) to the load receiving section (26) and having the field (6) on its surface (4).

12. Load carrier according to one of the preceding claims, characterized in that the field (6) is arranged between a first parallel plane (PE1) parallel to a support plane (AE), which is arranged between the support plane (AE) and the load receiving section (26), and the support plane (AE) and / or the skid section (22) is arranged between the support plane (AE) and a second parallel plane (PE2) parallel to the support plane (AE) and extends between the field (6) and the support plane (AE).

13. Charge carrier according to one of the preceding claims, characterized in that the surface (4) on which the field (6) is arranged is formed by an outer wall (18) of the charge carrier (2) formed by the charge carrier material which is adjoined by a reinforcing wall (20) extending at an angle, in particular at right angles, to the outer wall (18) with a wall connection region (28) opposite the field (6).

14. Load carrier according to one of the preceding claims, characterized in that the field (6) is at least partially, in particular completely, bordered by a projecting rib (30).

15. A charge carrier according to one of the preceding claims, characterized in that the field (6) is recessed relative to a first part (34) of the surface (4) surrounding the field (6).

16. A charge carrier according to claim 15, characterized in that the first part (34) of the surface (4) surrounding the field (6) is recessed relative to a second part (44) of the surface (4) surrounding the first part (34).

17. Load carrier according to one of the preceding claims, characterized by a plan view of at least substantially rectangular configuration with a first extension in a width direction (BR) and a second extension, which exceeds the first extension, in a longitudinal direction (LR), wherein the field (6) extends flatly, preferably at an angle, particularly preferably at a right angle, to the width direction (BR).

18. Load carrier according to one of the preceding claims, characterized in that the load carrier (2) has on its surface (4) a further field (6) produced by the hot stamping process, which is designed to be optically contrasting with the load carrier material behind it, in particular pallet material, and wherein surface portions of the hot stamped field (6) are removed in such a way that these surface portions form at least one optical, machine-readable code (8, 10).

19. Load carrier according to claim 18, characterized in that the load carrier (2) has the two fields (6) on sections of the surface (4) facing away from each other, in particular on two block elements (24), between which a vertical center axis (VA) runs at right angles to the support plane (AE).

20. A method for producing a load carrier (2) according to one of the preceding claims, comprising the following method steps: • a load carrier (2) is provided, • color pigments are introduced into the surface (4) of the charge carrier (2) by means of a hot stamping process and a field (6) is created which optically contrasts with the charge carrier material behind it, • Surface portions are removed from the hot-stamped field (6) in such a way that the underlying charge carrier material is visible and these surface portions form an optical, machine-readable code (8, 10). 21 . Method according to claim 20, characterized in that that the surface portions of the field (6) are removed by means of a laser.

22. Method according to claim 20 or 21, characterized in that the surface portions are designed as a barcode (8) and / or as a QR code (10).

23. Method according to one of claims 20 to 22, characterized in that the charge carrier (2) is first non-optically coded and then the optically readable code (8, 10) is generated, wherein the non-optical code is automatically read out before surface portions are removed from the hot-stamped field (6), and wherein the non-optical code is used to control the tool which removes the surface portions from the hot-stamped field (6) in such a way that the optically readable code (8, 10) has the same content as the non-optical code.

Images