Method and device for producing labels
An inline die-cutting inspection method using a light source and camera within the label manufacturing device addresses the inefficiencies of external die-cutting tests, ensuring continuous and cost-effective quality control.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ALL4LABELS GRP GMBH
- Filing Date
- 2025-10-27
- Publication Date
- 2026-05-21
AI Technical Summary
Existing label production methods require die-cutting tests to be performed outside the printing press, leading to machine downtime and increased costs due to material handling and subjective quality assessment.
Implement an inline die-cutting inspection process within the label manufacturing device using a light source and camera to capture and evaluate radiographic images of the carrier web, allowing continuous and objective quality control without stopping the machine.
Ensures consistent die-cutting quality with reduced downtime and costs by enabling automatic, objective, and efficient detection of die-cutting defects during the production process.
Smart Images
Figure EP2025080919_21052026_PF_FP_ABST
Abstract
Description
[0001] AII4Labels Group GmbH October 24, 2025
[0002] 1
[0003] Method and apparatus for the production of labels
[0004] The present invention relates to a method and a device for producing labels according to the independent claims.
[0005] The production of labels, for example in printing presses, is generally known from the prior art. In label production, a composite material (face material, adhesive, backing) is typically printed (using various printing processes). After printing, the face material is die-cut accordingly, and the grid (excess material) is removed from the backing web. Only the final labels remain on the backing web. The execution of so-called "die-cutting tests" to check the die-cutting result is also familiar to those skilled in the art. However, according to the prior art, these die-cutting tests are performed outside the printing press, requiring the printing press to be stopped, the material web to be cut at the rewinder, and samples to be unwound, removed, and examined.This is usually done by laying the substrate flat and brushing it completely with test ink, then letting it soak in for a few seconds before removing the ink with a cloth. The quality of the die-cutting can then be assessed based on how well the ink adheres to the substrate.
[0006] The present invention is based on the objective of further developing a method and a device for the production of labels in such a way that a satisfactory die-cutting result can be guaranteed continuously and without the effort and associated costs described above.
[0007] This problem is solved by a label manufacturing process that involves die-cutting labels from a label material, in other words, face stock, which is adhered to a backing web. A backing web is a carrier strip to which the label material adheres. During die-cutting, the label material is cut to create labels, while the backing web should remain intact. Before die-cutting, the backing web, or rather the material applied to it, can be printed at the locations where the labels will be printed.
[0008] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0009] 2
[0010] The process includes automatic die-cutting control within a label manufacturing device. The die-cutting control is therefore not performed outside the label manufacturing device, but within the device itself.
[0011] The die-cutting inspection involves shining a light through the carrier web after the die-cutting process to capture an image of the carrier web under illumination. The carrier web can include the labels or the die-cut label material.
[0012] In particular, the carrier web is illuminated by a light source, especially a light strip, which preferably extends at least along the entire width of the carrier web. It can preferably be arranged such that it is essentially perpendicular to the longitudinal direction of the carrier web and thus parallel to its width. Most preferably, this is an LED light strip. The carrier web is preferably non-transparent. Alternatively, it can be transparent.
[0013] The illumination image is preferably captured using a recording device, in particular a sensor, most preferably a camera. At least one illumination image is preferably captured at regular intervals, most preferably continuously. By illuminating the carrier web and capturing a transmission image, continuous die-cutting inspection can be ensured, thus guaranteeing consistent die-cutting quality. In other words, the die-cutting inspection takes place during the label manufacturing process, i.e., "inline." This allows for simple and comprehensive inspection of all manufactured products.
[0014] The receiving device for the radiographic image and the radiographer for illuminating the carrier track are preferably arranged on opposite sides of the carrier track, so that the radiographer can illuminate the carrier track in the direction of the receiving device. Preferably, the radiographer is positioned below the carrier track and the receiving device above the carrier track.
[0015] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0016] 3
[0017] In particular, the automatic die-cutting inspection takes place after a die-cutting grid has been removed, i.e., after a so-called grid removal process, and preferably before the carrier web is wound up. This allows the carrier web, along with the label or label material on it, to be X-rayed. Stopping the label-making machine is therefore unnecessary. Compared to the prior art, the present method is thus far more cost- and time-efficient, as it avoids machine downtime and waste.
[0018] Advantageously, the labels are separated from the carrier web before die-cutting inspection, allowing the carrier web to be inspected without labels and enabling better detection of potential die-cutting lines. The labels can then be reapplied to the carrier web. Preferably, the labels are reapplied to their original positions. Precise repositioning can be achieved primarily by lengthening or shortening the web paths. In other words, the labels are repositioned.
[0019] During die-cut inspection, the carrier web, either with or without the label material, is guided around a raised section of transparent material, and both the carrier web and the raised section are illuminated. The raised section can be a projection, such as an edge or a wave. The raised section can have a curve with a radius between 1 mm and 40 mm, preferably between 2.5 mm and 30 mm, and most preferably between 5 mm and 20 mm. The raised section comprises, preferably consists of, a transparent, and more preferably prismatic, material, so that the carrier web can be illuminated from behind the raised section. In particular, the raised section is illuminated from behind. The curvature of the carrier material enlarges the perforations accordingly, allowing light to penetrate the material more easily and be detected as a defect, i.e., a die-cutting error.
[0020] By using different illuminance levels and wavelengths, a contrast range adapted to the respective substrate material can be achieved, resulting in the best possible image quality.
[0021] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0022] 4
[0023] The ability to detect the radiographic result is enabled. Monochromatic light is preferably used, as this allows for higher contrast and thus better image quality. The wavelength is preferably selected depending on the material of the carrier film. For example, a wavelength between 400 nm and 500 nm, preferably 455 nm, is used. This can be particularly advantageous if the carrier film is made of polyethylene, as it hardly absorbs or scatters light in this region of the spectrum.
[0024] Preferably, the method includes an evaluation of the radiographic image. Most preferably, the radiographic image is captured as a grayscale image. It therefore contains no color and is not a black and white image, but rather contains shades of gray, which allow for particularly accurate conclusions to be drawn about the fluorescence intensity. Preferably, the evaluation of the radiographic image includes image processing. This includes, in particular, the ability to adjust the contrast and brightness of the images to enable a more precise evaluation of the die-cutting result. Additionally, the images are recorded for subsequent evaluation (e.g., by quality assurance) and the data is archived for specific orders.
[0025] Preferably, the light transmission can be inferred from the gray values, as these are correlated. A lighter gray value corresponds to higher light transmission. Thus, in the backlight image, a carrier web appears darkest at the areas where the labels are typically printed, while the rest of the web exhibits a medium gray value.
[0026] The method includes, in particular, the detection of a die-cutting defect based on the light transmission of the radiograph. A die-cutting defect is a puncture in the substrate material. A die-cutting defect can be detected if the light transmission in at least one area of the radiograph exceeds a predefined value. Typically, in the case of a die-cutting defect, the punch penetrated too deeply into the substrate; in other words, the substrate was damaged, allowing more light to pass through at the affected point. Therefore, the corresponding
[0027] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0028] 5
[0029] Light transmission is increased at the relevant point. If the corresponding light transmission exceeds a predefined value, a corresponding die-cutting defect can be detected. Preferably, the increased light transmission in the area of the die-cutting defect can be defined in comparison to the average light transmission of the carrier web.
[0030] The threshold for increased light transmission can be defined in comparison to an average light transmission, for example, across the entire width compared to the radiograph. The aforementioned threshold can be reached when the light transmission is at least 130%, preferably at least 150%, of the average light transmission of the radiograph. Alternatively, the predefined value can be defined as an absolute value. In this way, a very bright area exceeding an absolutely defined light transmission threshold can be identified as a die-cutting error. The absolute value can be defined as a grayscale value, with areas exhibiting lighter grayscale values being identified as exceedances and thus as die-cutting errors.
[0031] Preferably, the evaluation is computer-implemented and based on predefined thresholds, as described above. Furthermore, a neural network, or in other cases a computer-aided program, can be used to evaluate the radiographic image. This program can be trained, in particular, on previously manually evaluated radiographic images. The automatic evaluation is thus not subjective, as is typical in the prior art, but objective. In the ink test described above, the result depends on the quantity, application, and exposure time of the ink, as well as on the subjective assessment of the individual testers. The evaluation is therefore objective and consistent.
[0032] The captured image can be visualized by a camera. The neural network is primarily a self-learning algorithm that can be linked to image evaluation. The neural network is trained to recognize which die-cutting image still yields an acceptable die-cutting result, thus ensuring consistent reliability.
[0033] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0034] 6
[0035] Furthermore, defective die-cuts can be identified and preferably logged. This allows documentation of when and how many defective die-cuts occurred.
[0036] Furthermore, areas of the carrier web with defective die-cuts can be electronically marked and thus preferably tracked, ideally in a roll map. This allows the current location of the defective die-cuts to be determined.
[0037] In a further step, the process can include issuing a warning if die-cutting errors occur repeatedly over a predefined length of the carrier web. The warning can be visual and / or audible, for example. Issuing the warning prevents further die-cutting errors and allows for appropriate adjustments to the printing parameters without generating excessive material wear. For example, it can be predefined that only a predefined number of die-cutting errors are permitted over a predefined length of the carrier web. For instance, it can be defined that if three die-cutting errors occur over a maximum of three repeat revolutions, a corresponding warning is issued.
[0038] Furthermore, the process can include displaying the X-ray image, for example, on a screen. This serves for manual verification. If, for instance, a die-cutting error is detected and / or a warning is issued, it can thus be manually checked whether this corresponds to the actual situation. The present process is not designed to determine label or grid remnants, but rather to detect die-cutting lines in the substrate. Therefore, the process does not include a step for detecting label or grid remnants on the substrate.
[0039] Overall, the present invention allows for automatic, reliable, and objective die-cutting control, which is far less time-consuming and costly, as it can take place during the production of the labels.
[0040] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0041] 7
[0042] In a further aspect, the invention relates to a device for producing labels, wherein the device comprises a die-cutting unit for die-cutting labels from a label material adhering to a carrier web. The device also includes a die-cutting control unit for automatic die-cutting control within the device. The die-cutting control unit comprises a transparency unit for illuminating the carrier web and a receiving unit for receiving the transparency image. In particular, the device is configured to carry out a method described above.
[0043] As described above, the transmission medium can be a light source, especially a light bar, and the recording medium a camera. Furthermore, the device can include an evaluation unit for evaluating the transmission image, preferably a neural network. The transmission medium and the recording medium are arranged, in particular, on opposite sides of the carrier track and preferably behind a grating unit and in front of a winding unit of the device.
[0044] They show in a purely schematic representation
[0045] Figure 1: a process diagram of a method for manufacturing labels, Figure 2: a device for manufacturing labels,
[0046] Figure 3: a perspective view of part of the device of Figure 2, Figure 4: another perspective view of part of the device of Figure 3;
[0047] Figure 5: a radiographic image, and
[0048] Figure 6: a perspective view of a backlit carrier track.
[0049] Figure 1 shows a process diagram of a process 100 for the production of labels. The process 100 comprises the die-cutting 101 of labels 30 from a label material adhering to a carrier web 31.
[0050] Before the die-cutting control 103 takes place, the labels can be separated from the carrier web 31 102. Thus, the automatic die-cutting control 103, which
[0051] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0052] 8
[0053] within a device 10 for the production of labels, referring to the labelless carrier web or the carrier web with die-cut label material.
[0054] The carrier track 31 is X-rayed 104 and thus a radiographic image 32 is taken 105. An evaluation 106 of the radiographic image 32 is carried out, which includes in particular image processing 107.
[0055] Furthermore, the procedure 100 can include the detection 108 of a defective punch based on the light transmission of the radiographic image. A neural network 109 can be used for the evaluation 106. A warning 110 can be issued, for example, if repeated defective punches have been detected. The radiographic image 32 can also be output 111, for example, for manual inspection.
[0056] Figure 2 schematically shows a device 10 for producing labels 30, comprising a die-cutting unit 11 and a die-cutting inspection unit 12. The die-cutting inspection unit includes a transparency unit 13, namely a light source 14, and a recording unit 15, namely a camera 16. The device 10 further includes an evaluation unit 17, which is configured to evaluate a corresponding transparency image and assess it for die-cutting defects. The device 10 also includes a screener 18 and a rewinder 19. The transparency unit 13 and the recording unit 15 are preferably arranged between the screener 18 and the rewinder 19.
[0057] Figure 3 shows a perspective view of part of the device 10 of Figure 2. Specifically, a carrier web 31 with attached die-cut label material and thus corresponding printed and die-cut labels 30 is shown in an area between the grid removal unit 18 and in front of the rewinding unit 19 of the device 10. Figure 3 shows the light-transmitting element 13, which is designed as a light bar, illuminating the carrier web 31 from below.
[0058] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0059] 9
[0060] Figure 4 also shows in perspective view how a recording device 15, namely a camera 16, is arranged on the opposite side of the X-ray device 13 in order to take an X-ray image.
[0061] Figure 5 shows a radiograph 32 in which the labels 30 are depicted with the darkest gray value due to their printing. The rest of the carrier web 31 has a medium gray value. A clearly visible increased light transmission 33 is evident along part of the contour of the labels 30 shown on the left in Figure 5, which leads to the detection of a die-cutting error.
[0062] Figure 6 shows a backlit carrier web 31. Here, a label-free carrier web 31 is backlit. The labels 30 were previously applied. The carrier web 31 is guided around a raised area 20, here a rounded edge 21. Behind this is a backlighting device 13, here a light source 14. Light 14a can thus pass through the raised area 20 and then the carrier web 31, and then reach the recording device 15, here a camera 16.
[0063] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0064] 10
[0065] Reference sign
[0066] 100 methods for making labels
[0067] 101 Die-cutting labels from a carrier web
[0068] 102 Separating the labels from the backing web
[0069] 103 Automatic die-cutting control within a label manufacturing device
[0070] 104 X-raying the carrier track
[0071] 105 Taking a radiographic image
[0072] 106 Evaluation of the X-ray image
[0073] 107 Image processing of the X-ray image
[0074] 108 Detecting a miscut
[0075] 109 Using a neural network to evaluate the fluoroscopy image
[0076] 110 Issue of a warning
[0077] 111 Edition of the X-ray image
[0078] 10 Device for making labels
[0079] 11 punching units
[0080] 12 Punch control unit
[0081] 13 X-ray equipment
[0082] 14 Light source
[0083] 14a Light
[0084] 15 recording devices
[0085] 16 cameras
[0086] 17 evaluation units
[0087] 18 grating unit
[0088] 19 winding unit
[0089] 20 Highlighting
[0090] 21 edge
[0091] 30 labels
[0092] 31 Carrier track
[0093] RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025
[0094] 11
[0095] 2. X-ray image 3. Increased light transmission 4. Defective die-cut
[0096] RGTH A241089W009902PT
Claims
AII4Labels Group GmbH October 24, 2025 12 Claims 1. Method (100) for the production of labels (30), wherein the method (100) comprises die-cutting (101) labels (30) from a label material adhering to a carrier web (31), characterized by the fact that the method (100) comprises an automatic die-cutting control (103) within a device (10) for the production of the labels (30), wherein the automatic punch control (103) comprises a scanning (104) of the carrier web (31) and a recording (105) of a scanning image (32).
2. Method (100) according to claim 1, characterized by the fact that Before the die-cutting inspection (103) the labels (30) are separated from the carrier web (31) (102) so that the carrier web (31) is scanned without labels.
3. Method according to claim 1 or 2, characterized by the fact that the carrier web (31) is guided around a highlight made of transparent material during the punch control (103), the carrier track (31) is illuminated from the side of the highlighting.
3. Method (100) according to any one of the preceding claims, characterized by the fact that the procedure (100) includes an evaluation (106) of the radiographic image (32).
4. Method (100) according to any one of the preceding claims, characterized by the fact that RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025 13 the radiographic image (32) is captured as a greyscale image.
5. Method (100) according to any one of the preceding claims, characterized by the fact that the method (100) includes the detection (108) of a defective punching (34) based on the light transmission of the radiographic image.
6. Method (100) according to claim 5, A defective punch (34) is detected if the light transmittance in at least one area of the radiograph (32) exceeds a predefined value.
7. Method (100) according to any one of claims 2 to 6, characterized by the fact that the procedure (100) includes the use (109) of a neural network for the evaluation (106) of the radiographic image (32).
8. Method (100) according to any one of claims 5 to 7, characterized by the fact that the procedure (100) includes an output (110) of a warning, if defective punching (34) occurs repeatedly over a predefined length of the carrier track (31).
9. Method (100) according to any one of the preceding claims, characterized by the fact that the procedure (100) includes an output (111) of the radiographic image (32).
10. Device (10) for the production of labels, wherein the device (10) comprises a punching unit (11) for punching labels (30) from a label material adhering to a carrier web (31), characterized in that the device (10) comprises a punch control unit (12) for automatic punch control within the device (10), RGTH A241089W009902PT AII4Labels Group GmbH October 24, 2025 14 wherein the punch control unit (12) comprises a fluorescence transmittance (13) for fluorescence transmittance of the carrier web (32) and a receiving means (15) for receiving a fluorescence transmittance (32).
11. Device (10) according to claim 10, characterized by the fact that the X-ray medium (13) is a light source and the recording medium (15) is a camera.
12. Device (10) according to claim 10 or 11, characterized by the fact that the device (10) comprises an evaluation unit (17) for evaluating the radiographic image (32).
13. Device (10) according to one of claims 10 to 12, characterized by the fact that the X-ray transmission medium (13) and the receiving medium (15) are arranged behind a grating unit (18) and in front of a winding unit (19) of the device (10).
14. Device (10) according to one of claims 10 to 13, characterized by the fact that the device (10) is designed to carry out a method (100) according to one of claims 1 to 9. RGTH A241089W009902PT