WO2024104565A1

WO2024104565A1 - Label feeding system with visual control of the feeding with external reference

Info

Publication number: WO2024104565A1
Application number: PCT/EP2022/081917
Authority: WO
Inventors: Cristian ANDREATO; Nicolas Chomel
Original assignee: Sidel Participations
Priority date: 2022-11-15
Filing date: 2022-11-15
Publication date: 2024-05-23

Abstract

A label feeding system (15) for a labelling machine (1) comprising: - a feed roller (11) for longitudinally feeding a web (4) of labelling material along a path (P), the web (4) comprising a plurality of longitudinally joined labels (2), each of which comprises a reference region (R); - a frame (8) supporting the feed roller (11), the feed roller (11) being configured for longitudinally feeding the web (4) by rotating with respect to the frame (8) with an angular speed; - a fixed reference member (16) which is fixed to the frame (8); - an optical sensor (17) defining a detection station (D) along the path (P), the sensor (17) being configured for detecting, wit h a detection frequency, at least one linear distance ( D1, D2) between the fixed reference member (16) and the reference region (R) of the label (2) being positioned in the station (D); - an automatic control device (18) configured for automatically controlling the detection frequency, to set the detection frequency preferably to the production speed of the machine (1); wherein the control device (18) is configured for automatically controlling an angular speed and/or an inclination of the feed roller (11) with respect to the frame (8), bas ed on said at least one distance.

Description

LABEL FEEDING SYSTEM WITH VISUAL CONTROL OF THE FEEDING WITH EXTERNAL REFERENCE TECHNICAL FIELD The present invention relates to a label feeding system for a labelling machine, and to a labelling machine for labelling containers, comprising the label feeding system. BACKGROUND ART In the field of packaging pourable products by means of containers, it is known to label the containers by means of labelling machines. The labelling machine typically comprises a web feeding system for feeding a web of labelling material, which comprises a feed roller and a cutting unit for separating sequentially the labels from the web, downstream of the feed roller. The labelling machine comprises also a transfer drum which sequentially receives the separated labels from the cutting unit, and applies sequentially the labels to respective containers, while the containers are conveyed by a conveyor. Typically, the cutting unit comprises a cutting roller, and the cutting frequency corresponds to the production speed of the labelling machine. However, the actual longitudinal length of the labels being fed can be different from the nominal value. Therefore, corrections of the feeding speed are required, to adapt the feeding speed to the actual length. Typically, the actual length can be obtained by a mark reader reading a mark of each label which is fed through a detection station, and by calculating the distance between subsequent marks based on the amount of the web being fed. This solution allows for having a low amount of computational efforts required by the automatic control device of the machine to automatically control the feeding, but the accuracy of this solution can be improved. DISCLOSURE OF INVENTION A feeding system according to present description or according to any of the appended system claims provides an accurate solution for the automatic control of the label feeding within a labelling machine. A labelling machine according to present description or according to any of the appended machine claims comprises a system according to any of the appended system claims or a system according to present description. In the following detailed description, respective embodiments of a label feeding system according to present description and of a labelling machine according to present description will be described. For simplicity, the embodiment of the system will be named “system”, while the embodiment of the machine will be named “machine”. BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description will be made with reference to the appended drawings, in which: Figure 1 is a view of the layout of the machine; Figure 2 is a view of the layout of a part of the machine; Figure 3 shows a sector of the web which is fed by means of the system; Figure 4A and 4B shows one label to explain the meaning of a longitudinal geometrical entity which is involved in the automatic control of the feeding; Figure 5A and 5B shows one label to explain the meaning of a transversal geometrical entity which is involved in the automatic control of the feeding; Figure 6A and 6B shows one label to explain the meaning of a transversal geometrical entity which is involved in the automatic control of the feeding, according to a further alternative solution with respect to Figures 5A and 5B. DETAILED DESCRIPTION OF THE INVENTION The machine 1 is configured for labelling containers 2. The container 2 can be configured for containing a pourable product. The container 2 can be a bottle or a flacon or a jar or a can or any other kind of container. The pourable product can be a food product, or a product for personal care, or a product for home care. For example the pourable product can be tea, milk, water, beer, juice or a pulp. The machine comprises the system 15. The machine 1 comprises a conveyor 6 for conveying the containers 2. The machine 1 is configured so that the containers 2 are sequentially labelled while being conveyed by the conveyor 6. The conveyor 6 can be a carousel which can rotate around an axis X of the carousel, to convey the containers 2. The system 15 comprises a feed roller 11 for longitudinally feeding a web 4 of labelling material along a path P. The web 4 comprises a plurality of longitudinally joined labels 3, each of which comprises a reference region R. Some joined labels 3 are shown in Figure 3, with the respective reference regions R. The system 15 comprises a frame 8 supporting the feed roller 11. The feed roller 11 is configured for longitudinally feeding the web 4 by rotating with respect to the frame 8 with an angular speed. The rotation of the feed roller 11 is around an axis W of the feed roller 11. The system 15 comprises a reel 5 of web which is supported by a shaft 10. The feeding of the web 4 corresponds to the unwinding of the web 4 off the reel 5. The system 15 comprises a fixed reference member 16 which is fixed to the frame 8, as shown also in Figures 3, 4A, 4B, 5A, 5B, 6A, 6B. The system 15 comprises an optical sensor 17 defining a detection station D along the path P. The sensor 17 is configured for detecting, with a detection frequency, at least one linear distance between the fixed reference member 16 and the reference region R of the label 2 being positioned in the station D. Therefore, for each label 2 that is positioned in the detection station D, the optical sensor 17 detects said at least one distance. The frame 18 supports the sensor 17. Each label 3 corresponds to a respective web portion, and the reference region R of each label corresponds to a specific aesthetical pattern which is positioned in the respective web portion. An example of the reference region R is shown in Figures 3, 4A, 4B, 5A, 5B, 6A and 6B. The optical sensor 17 works with the detection frequency. The sensor device 17 comprises a camera or fotocamera which is configured for acquiring images of the portion of the web which is positioned in the detection station D, at least with said detection frequency. The camera or fotocamera is a smart camera or a smart fotocamera. The system 15 comprises an automatic control device 18, which is configured for automatically controlling the detection frequency, to set the detection frequency to the production speed of the machine 1. The detection station D is positioned downstream of the feed roller 11, along the feed path P and with respect to the feeding direction F. The feeding direction F is indicated in Figure 3. Alternatively, the detection station D can be positioned upstream of the feed roller 11. The machine 1 comprises a separation unit 13 for sequentially separating the labels from the web 4. The separation unit 13 is positioned downstream of the feed roller 11, along the path P and with respect to the feeding direction F. The separation unit 13 is configured for working with a separation frequency. The control device 18 is configured for automatically controlling the separation frequency, to set the separation frequency to the production speed of the machine 1. The frame 18 supports the separation unit 13. The separation unit 13 is a cutting unit which is configured for separating the labels by cutting sequentially the web. The cutting unit can comprise a cutting roller carrying a blade, and configured for cutting the web by rotating with an angular speed corresponding to the production speed. The cutting unit defines a cutting station C. The machine 1 comprises a transfer drum 14 for sequentially receiving the separated labels from the cutting unit 13 and sequentially applying the labels on respective containers 2. Alternatively, the transfer drum 14 receives the web from the feed roller 11 and sequentially applies the labels 2 on respective containers 3. In this case, the cutting unit 13 will be configured for cutting sequentially the web while the web is transported by the drum 14. The control device 18 is configured for automatically controlling an angular speed and/or an inclination of the feed roller 11 with respect to the frame 8, based on said at least one distance. In this way, the system 15 allows for carrying out a method for the automatic adaptation of the feeding to the actual geometrical features of the labels 3, which is accurate, robust and cheaper. This method is less expensive in terms of computational analysis, because the reference 16 is not an image reference, but an external reference which becomes an image reference only after the detection. Also, this method is robust with respect to possible accidental movements or not accidental movements of the sensor device 17 which can occur between different production runs, as the reference 16 can remain in the same position. The use of a camera or fotocamera, moreover, provides an increase of the accuracy. The fixed reference member 16 comprises a physical body, for example a bar or a rod or a flange or a bracket. The reference member 16 is positioned, in the detection station D, at the opposite side of the path P with respect to the sensor 17. In this way it is reduced the risk of interference between the presence of the reference member 16 and the detection of the reference region R, which shall be detected to detect the at least one distance between the reference region R and the reference member 16. Alternatively, the reference member 16 can be positioned on the same side of the path P with respect to the sensor 17. In this case, the accuracy of detection of the reference member 16 is improved, in particular in case of web having a certain level of transparency. The system 15 comprises a fixed-light lighting device which is configured to illuminate the detection station D. The at least one distance comprises a longitudinal distance D1 between the reference region R and the fixed reference member 16, along a longitudinal direction L which is parallel to the feed path P. The longitudinal direction L is indicated in Figure 3. The control device 18 is configured for automatically obtaining, based on said longitudinal distance D1, a quantity which is correlated to the actual longitudinal length of the label 2, and for automatically adjusting said angular speed based on said quantity. In this way the feeding speed can be automatically adapted based on the actual longitudinal length of the labels, with an accurate, robust and cheap method. The control device 18 is configured for automatically increasing said angular speed if the quantity indicates an actual length being greater than a nominal value, and for automatically decreasing said angular speed if the quantity indicated an actual length being lower than the nominal value. In this way, if the labels 3 are shorter, the feeding speed is decreased to have a correct separation activity with the nominal production speed, while, if the labels 3 are longer, the feeding speed is increased to have a correct separation activity with the nominal production speed. In Figures 4A and 4B, DN indicates the nominal value of the longitudinal distance, while D1 indicates a value of the longitudinal distance which is not equal to the nominal value DN of the longitudinal distance. The longitudinal distance is considered positive when the reference region R is in a more advanced position than the reference member 16, with respect to the feeding direction F. In Figures 4A and 4B, the value of the longitudinal distance is therefore positive. The control device 18 is configured for automatically increasing said angular speed if the longitudinal distance D1 is lower than a nominal value DN of the longitudinal distance, and for automatically decreasing said angular speed if the longitudinal distance is greater than the nominal value DN of the longitudinal distance. In this way the feeding can be effectively and automatically adapted to the actual longitudinal length of the labels 2 based on the longitudinal distance. The at least one distance can comprise a transversal distance D2 between the reference region R and the fixed reference member 16, along a transversal direction T which is orthogonal to the feed path P. The transversal direction T is indicated in Figure 3. The reference member 16 comprises a visually detectable mark or tag 19, which is positioned on an outer surface of the physical body and which can be detected by the sensor device 17. The transversal distance D2 is between the tag and the reference region R. In Figures 5A and 5B, DN indicates the nominal value of the transversal distance, while D2 indicates a value of the transversal distance which is not equal to the nominal value DN of the transversal distance. The control device 18 is configured for automatically adjusting said inclination of the feed roller 11 based on said transversal distance. The feeding system 15 can comprise an aligning roller 12 which is configured for acting on the web 4, along the path P, for influencing the inclination of the web 4 with respect to the frame 8.The control device 18 is configured for automatically adjusting the inclination of the aligning roller 12 with respect to the frame 18, based on said transversal distance. The aligning roller 12 is positioned, along the path P, between the feed roller 11 and the transfer drum 14, or between the feed roller 11 and the cutting unit 13. The frame 18 supports the aligning roller 12. The tag 19 makes more accurate the detection of the transversal distance. The reference region of each label can be considered to comprise alternatively or in addition, a respective sector 4a of an edge of the web. The transversal distance, in this case, is with respect to said sector 4a. For example, the transversal distance can be between the sector 4a and the tag 19. In this way, the accuracy of detection of the transversal distance is improved. The control device 18 is configured for automatically increasing said detection frequency in case the reference region R is missing for more than a preestablished number of labels 3. In this case, the frequency with which the camera or fotocamera is acquiring images is increased to search again the reference region R. In this case, the control device 18 can be configured for automatically increasing the detection frequency and simultaneously decreasing the angular speed of the feed roller, to make the search operation easier. The control device 18 can comprise at least one control unit or more than one control unit, and all the connections or communications elements which are require by the control unit 18 to carry out the steps described above. Each control unit is programmable. Present invention provides a label feeding system with visual automatic control of the web feeding, according to which an external reference is used to improve the robustness and the accuracy of the control, and to make the control very cheap from a computational analysis point of view.

Claims

CLAIMS 1. A label feeding system (15) for a labelling machine (1) comprising: - a feed roller (11) for longitudinally feeding a web (4) of labelling material along a path (P), the web (4) comprising a plurality of longitudinally joined labels (2), each of which comprises a reference region (R); - a frame (8) supporting the feed roller (11), the feed roller (11) being configured for longitudinally feeding the web (4) by rotating with respect to the frame (8) with an angular speed; - a fixed reference member (16) which is fixed to the frame (8); - an optical sensor (17) defining a detection station (D) along the path (P), the sensor (17) being configured for detecting, with a detection frequency, at least one linear distance (D1, D2) between the fixed reference member (16) and the reference region (R) of the label (2) being positioned in the station (D); - an automatic control device (18) configured for automatically controlling the detection frequency, to set the detection frequency preferably to the production speed of the machine (1); wherein the control device (18) is configured for automatically controlling an angular speed and/or an inclination of the feed roller (11) with respect to the frame (8), based on said at least one distance.

2. System (15) according to claim 1, wherein: said at least one distance comprises a longitudinal distance (D1) between the reference region (R) and the fixed reference member (16), along a longitudinal direction (L) which is parallel to the feed path (P); the control device (18) is configured for automatically obtaining, based on said longitudinal distance (D1), a quantity which is correlated to the actual longitudinal length of the label (2), and for automatically adjusting said angular speed based on said quantity.

3. System (15) according to claim 2, wherein: the control device (18) is configured for automatically increasing said angular speed if the quantity indicates an actual length being greater than a nominal value and for automatically decreasing said angular speed if the quantity indicated an actual length being lower than the nominal value.

4. System (15) according to claim 3, wherein: said longitudinal distance is positive when the reference region (R) is in a more advanced position than the reference member (16), with respect to the feeding direction (F); the control device (18) is configured for automatically increasing said angular speed if the longitudinal distance (D1) is lower than a nominal value (DN) of the longitudinal distance, and for automatically decreasing said angular speed if the longitudinal distance is greater than the nominal value (DN) of the longitudinal distance.

5. System (15) according to any of the previous Claims, wherein each label (3) comprises a respective web portion, and the reference region (R) of each label corresponds to a specific aesthetical pattern which is positioned in the respective web portion.

6. System (15) according to any of the previous claim, wherein the fixed reference member (16) comprises a physical body, for example a bar or a rod or a flange or a bracket.

7. System (15) according to any of the previous claims, comprising a fixed-light lighting device which is configured to illuminate the detection station (D).

8. System (15) according to any one of the foregoing claims, wherein the at least one distance comprises a transversal distance (D2) between the reference region (R) and the fixed reference member (16), along a transversal direction (T) which is orthogonal to the feed path (P).

9. System (15) according to Claims 6 and 8, wherein the reference member (16) includes a visually detectable mark or tag (19) which is positioned on an outer surface of the body, and which can be detected by the sensor device (17); said transversal distance (D2) being between the tag (19) and the reference region (R).

10. System (15) according to Claim 8 or 9, wherein the control device (18) is configured for automatically adjusting said inclination based on said transversal distance.

11. System (15) according to any of Claims from 8 to 10, comprising an aligning roller (12) which is configured for acting on the web (4), along the path (P), for influencing the inclination of the web (4) with respect to the frame (8),the control device (18) being configured for automatically adjusting the inclination of the aligning roller (12) with respect to the frame (8) based on said transversal distance, the frame (8) supporting the aligning roller (12).

12. System (15) according to any of Claims from 8 to 11, wherein each label (3) corresponds to a respective web portion, and the reference region of each label comprises a respective sector (4a) of an edge of the web, the transversal distance being with respect to said sector (4a).

13. System (15) according to any of the previous Claims, wherein the detection station (D) is positioned upstream or downstream of the feed roller (11), along the feed path (P) and with respect to the feeding direction (F).

14. System (15) according to any of the previous Claims, wherein the sensor device (17) comprises a camera or fotocamera which is configured for acquiring, at least with said detection frequency, images of the portion of the web which is positioned in the detection station, the camera or fotocamera being preferably a smart camera or a smart fotocamera.

15. Feeding system (15) according to Claim 14, wherein the control device (18) is configured for automatically increasing said detection frequency in case the reference region (R) is missing for more than a preestablished number of labels (3).

16. Feeding system (15) according to Claim 14, wherein the control device (18) is configured for automatically increasing said detection frequency in case the reference region (R) is missing for more than a preestablished number of labels (3), and/or simultaneously decreasing said angular speed.

17. System (15) according to any of the previous Claims, wherein the reference member (16) is positioned, in the detection station (D), at the opposite side of the path (P) with respect to the sensor (17) or at the same side of the path (P) with respect to the sensor (17).

18. System (15) according to any of the previous Claims, comprising a separation unit (13) for sequentially separating the labels from the web (4), downstream of the feed roller (11), the separation unit (13) being configured for working with a separation frequency, the detection station (D) being positioned, along the path (P) and with respect to the feeding direction (F), upstream of the separation unit (13); wherein the control device (18) is configured for automatically controlling the separation frequency, to set the separation frequency to the production speed of the machine (1).

19. Feeding system (15) according to Claim 18, wherein the separation unit (13) is a cutting unit which is configured for separating the labels by cutting sequentially the web.

20. Labelling machine (1) for labelling containers (2), comprising: - a feeding system (15) according to any of the previous Claims; - a conveyor (6) for conveying containers (2), the machine being configured so that the containers are sequentially labelled while being conveyed by the conveyor (6).

21. Labelling machine (1) according to Claim 20, wherein: - the feeding system (15) is according to Claim 19; - the labelling machine (1) comprises a transfer drum (14) for sequentially receiving the separated labels from the cutting unit (13) and sequentially applying the labels on respective containers (2).

22. Labelling machine (1) according to Claim 20, wherein: - the feeding system (15) is according to Claim 19; - the labelling machine (1) comprises a transfer drum (14) for receiving the web from the feed roller (11) and sequentially applying the labels (2) on respective containers (3), the cutting unit (13) being configured for cutting sequentially the web while the web is transported by the drum (14).