Adjustment of packaging production machine for containing liquid food product

Abstract

A control device (230) operates a machine (2) for producing a package (10) for containing a liquid food product. The machine is operated to move the inner tool (21) radially projecting from the rotatable member (22) to the processing position (II), the outer tool (25) is arranged to surround an end of the inner tool (21) in the processing position (II), and the outer tool (25) is operated to provide a top portion on an end of the packaging body (11) arranged on the inner tool (21). The control device (230) executes a monitoring program by determining at least one parameter value indicative of a lateral force on the inner tool (21) in the processing position (II) when the outer tool (25) is arranged around the end of the inner tool (21), and by selectively adjusting the relative position of the inner tool (21) and the outer tool (25) based on the parameter value.

Description

Technical Field

[0001] The present disclosure relates to the production of packages for containing liquid food products and, more particularly, to a technique for controlling a machine for producing such packages. Background Art

[0002] In the food industry it is common practice to package liquid foods in packages made from paper-based laminates comprising a core layer of paper or paperboard and one or more barrier layers, such as plastic barrier layers.

[0003] One common type of package is manufactured by forming a tubular blank ("sleeve") of the above-mentioned paper-based laminate material and sealing one end of the sleeve with a top plastic material. Traditionally, the top is formed directly on the end of the sleeve by injection molding. The top includes a neck portion defining a pouring spout, which is sealed by a lid and / or foil. The lid and / or foil may be provided by injection molding or in a separate assembly step. The package is then transported to a subsequent filling station where it is filled with liquid product through the opposite open end of the package. After filling, the open end of the package is folded over and sealed. Applicant manufactures packaging materials under the trademark Tetra Sell ​​these types of packages.

[0004] An example of such a top molding operation is shown in WO2007 / 106006, where a sleeve is placed on the arms of a mandrel wheel, which is then rotated to place the sleeve on an injection molding device. While the sleeve is held on the arms, the injection molding device is placed around one end of the sleeve and operated to mold a top onto the end.

[0005] Industrial production and packaging of liquid foods is automated and involves advanced process control of machinery to enable high-volume production. Safe and reliable operation is extremely important, as operational failures and the resulting production stoppages can have a profound impact on production costs and product quality. For example, it is critical to avoid operational failures that could damage machinery or cause the rejection of large-volume production packages.

[0006] The top forming operation is susceptible to operator errors, as incorrectly connecting the top to the sleeve can result in a package prone to leaking liquid food or even an unsealed package. Such a package needs to be rejected. An incorrect connection can also cause corresponding problems in downstream production, such as the need to clean up leaked food in the filling station.

[0007] This problem generally arises when producing packages for containing liquid food products, whenever it is necessary to provide a top portion over the main body portion. Summary of the invention

[0008] It is an object to at least partially overcome one or more of the above-mentioned limitations of the prior art.

[0009] One such object is to provide a technique for improving the top portion molding performance on the body portion in the production of a package for containing liquid food.

[0010] One or more of these objects, as well as further objects that may emerge from the following description, are achieved at least in part by a computer-implemented method for operating a machine to produce packages for containing liquid food products, a computer-readable medium and a control device according to the independent claims, embodiments of which are defined by the dependent claims.

[0011] A first aspect relates to a computer-implemented method for operating a machine to produce a package for containing a liquid food. The machine includes an internal tool and an external tool. The internal tool extends radially from a rotatable member, the rotatable member being operable to move the internal tool from a loading position to a processing position, in which the external tool is operable to be arranged around the end of the internal tool, the method comprising a production program, the production program comprising: operating the rotatable member to arrange the internal tool in the loading position; arranging the package body on the internal tool in the loading position; operating the rotatable member to move the internal tool together with the package body from the loading position to the processing position; arranging the external tool to surround the end of the internal tool, thereby surrounding the end of the package body; and operating the external tool to provide a top portion on the end of the package body, thereby producing the package. The method also includes a monitoring program, the monitoring program comprising: when the external tool is arranged to surround the end of the internal tool, determining at least one parameter value indicating a lateral force on the internal tool in the processing position based on a measurement signal; and selectively adjusting the relative position between the internal tool and the external tool based on at least one parameter value.

[0012] Through a monitoring program, the method of the first aspect provides a technique for quantifying and correcting the misalignment between the internal tool and the external tool, which may lead to insufficient machine performance in terms of the quality of the final packaging. For example, misalignment may occur due to control errors of the rotatable member and / or the external tool, positional offset of the internal tool and / or the external tool, mechanical deformation of the internal tool and / or the external tool, etc. The monitoring program can be performed separately from the production program or during the production program. If performed before production, the packaging body may or may not be arranged to surround the internal tool during the monitoring program. If performed during the production program, the actual performance of the machine can be evaluated when the external tool is operated to set the top part on the main body part. Therefore, the method can take corrective measures during ongoing production to prevent production that may have been stopped due to misalignment between the internal and external tools.

[0013] The parameter value may be any measured value that is proportional to or otherwise representative of the lateral force on the internal tool. For example, the parameter value may be a lateral force value from a force sensor, a torque value from a torque sensor, a power value or a drive current value for a drive unit of a rotatable member, a strain value from a strain sensor, etc.

[0014] The inner tool radially extends from the rotatable member and thus has a longitudinal extension from the rotatable member to the distal end, which is the end surrounded by the outer tool in the treatment position. As used herein, transverse force refers to the total force component acting on the inner tool and perpendicular to the longitudinal extension of the inner tool.

[0015] As used herein, the term "selectively adjust" means adjusting the relative position between the inner tool and the outer tool in order to satisfy a predefined criterion, the criterion being based on at least one parameter value.

[0016] As used herein, "liquid food" means any food that is non-solid, semi-liquid or pourable at room temperature, including beverages such as water, juice, wine, beer, soda, as well as dairy products, sauces, oils, creams, custards, soups, pastes, etc., and solid foods in liquids, such as beans, fruits, tomatoes, stews, etc.

[0017] As used herein, "package" refers to any package or container suitable for holding a liquid food, including but not limited to containers made of paperboard or paper-based laminate materials, and containers made of or comprising plastic materials.

[0018] A second aspect relates to a computer-readable medium comprising program instructions which, when executed by a processor circuit, are configured to cause the processor circuit to perform the method of the first aspect or any embodiment thereof.

[0019] A third aspect relates to a control device configured to perform the method of the first aspect or any embodiment thereof, the control device comprising a signal interface configured to receive the measurement signal and provide a control signal for operating the machine.

[0020] The second and third aspects share technical advantages with the first aspect.

[0021] Still other objects, features, embodiments, aspects and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of a sequence of processing stations in an exemplary production line for manufacturing packages containing liquid food.

[0023] Figure 2A Is Figure 1 Side view of an exemplary package produced by the top forming station in the production line of Figure 2B yes Figure 2A Cross-section of the shoulder portion of the package

[0024] Figure 3 is a side view of a top forming station according to a detailed example.

[0025] Figure 4A yes Figure 3 Cross-sectional view of the inner tool misaligned relative to the outer tool in the top molding station, Figure 4B The forces acting on the internal tool and its drive mechanism due to misalignment are shown.

[0026] Figure 5 is a flow chart of an exemplary production procedure for operating a top forming station.

[0027] Figure 6-7 is a flow chart of an exemplary monitoring procedure associated with a top forming station.

[0028] Figure 8 is used for Figure 7 Illustration of exemplary thresholds for a monitoring program.

[0029] Figures 9A-9B is a graph of measurement data obtained during operation of the top forming station. DETAILED DESCRIPTION

[0030] Embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all, embodiments are shown. Indeed, the subject matter of the present disclosure may be embodied in many different forms and should not be construed as limited to the embodiments described herein; rather, these embodiments are provided so that this disclosure may satisfy applicable legal requirements.

[0031] Where possible, any advantage, feature, function, equipment and / or operation aspect of any embodiment described and / or envisioned herein may be included in any other embodiment described and / or envisioned herein, and / or vice versa. In addition, where possible, any term expressed in singular form herein is also meant to include plural form and / or vice versa, unless otherwise explicitly stated. Therefore, the term "one (a)" and / or "an" should represent "at least one" or "one or more", even if the phrase "one or more" or "at least one" is also used herein. The terms "multiple", "plural" and "plural" are intended to imply that two or more elements are provided. The term "and / or" includes any and all combinations of one or more related listed elements. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first element may be referred to as the second element, and similarly, the second element may be referred to as the first element without departing from the scope of the present disclosure.

[0032] For the sake of brevity and / or clarity, well-known functions or constructions may not be described in detail. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs.

[0033] Like reference numerals refer to like elements throughout.

[0034] Figure 1 An exemplary production line for producing sealed packages containing liquid food is schematically shown. The production line includes a series of stations 1-4. The sleeve forming station 1 is configured to reshape the sheet into a packaging body ("sleeve"). The packaging body can be a cylindrical packaging body. The sheet can be made of a paper-based laminate as discussed in the background section. The top forming station 2 is configured to provide a top portion on an open end of the sleeve. The top portion thus completely or partially closes the open end of the sleeve. For example, the top portion can define an access opening. When the package leaves the top forming station 2, the access opening may or may not be covered by a film (foil) or a lid. In the example described below, the top forming station 2 is configured to provide a top portion by injection molding. After the top forming station 2, the package has an open end opposite to the end provided with the top portion. The production line may include a capping station 3, which is configured to attach a lid on the above-mentioned access opening. The filling station 4 is configured to fill the liquid food into the package through the open end of the package, and then seal the open end to form a final package containing the liquid food. The filling station 4 may also be configured to sterilize the packages prior to the filling operation.

[0035] Although Figure 1Not shown, any of the stations 1-4 can be repeated to operate in parallel, thereby increasing the throughput of the production line. Each station 1-4 may include one or more machines for performing the processing operations of the station. It is also conceivable that more than one station is implemented by a single machine.

[0036] In the description, the primary name "package" will be used throughout. It will be understood, of course, that this name also covers all the different stages or states that an intermediate package goes through on its way to becoming a final package. The term "final package" is used here to refer to the product filled, sealed and finally formed package.

[0037] Figure 2A Is Figure 1 10 is a side view of a package 10 produced by a top forming station 2 in a bottle. Package 10 is bottle-shaped and may have any cross section, including but not limited to circular, square, rectangular, triangular, polygonal, etc. Package 10 is inverted upside down. Package 10 includes the above-mentioned sleeve 11 and a top portion ("top") 12, and the top merges with the sleeve end 11A. The opposite sleeve end 11B is open and provides a filling opening for filling a liquid product into the package 10. In the illustrated example, the top 12 includes a neck portion ("neck") 12A, which defines an access opening or pouring spout 12B. As described above, the access opening 12B can be sealed by a film or foil (not shown). Alternatively, a lid (not shown) can be attached to the neck 12A to close the access opening 12B, and then the liquid product is filled into the package 10. For example, one or more threads on the lid can engage with the thread 12C on the neck 12A.

[0038] In some embodiments, the top portion 12 is made of plastic material and formed by injection molding. Through injection molding, the top portion 12 is connected to the sleeve end portion 11A along its circumference. Figure 2B yes Figure 2A A cross-sectional view of a portion of the interface between the top 12 and the sleeve 11 within the dashed circle 13. As shown, the top 12 includes a thickened head 14 or "bead" shaped to surround and attach to the circumferential sleeve end 11A. It should be recognized that the strength of the joint between the top 12 and the sleeve 11 depends on the shape and thickness of the bead 14 along the sleeve end 11A. If the joint is too weak at one or more points on the sleeve end 11A, the joint may break when the consumer attempts to open the package by removing the above-mentioned film and / or unscrewing the lid. If the formation of the joint is not well controlled, holes or cracks may even be formed along the joint, causing the liquid food to leak from the package. If a leak occurs in the filling station 4, the production line may need to be shut down for cleaning, resulting in expensive production stops. In addition, if a weak joint in the final package breaks, for example, when the final package is distributed to retailers or consumers, food safety may be compromised.

[0039] Figure 3 is a side view of a top forming station or machine 2 according to a non-limiting example. The top forming station 2 comprises a loading device 200, a processing device 210 and an unloading device 220. The loading device 200 is arranged to receive an incoming sleeve 11, as indicated by arrow A1, and to arrange the sleeve 11 on the processing device 210. The processing device 210 is configured to convert the sleeve 11 into a package 10. The unloading device 220 is arranged to remove the package 10 from the processing device 210 and provide it to downstream processing, as indicated by arrow A4.

[0040] Figure 3 Also included is a control device 230, which is arranged to control the operation of the top forming station 2. The control device 230 may be part of the station 2 or not. The control device 230 may be implemented by hardware or a combination of software and hardware. In the illustrated example, the control device 230 includes a processor circuit 231, a computer memory 232 and a signal interface 233. The processor circuit 231 may include, for example, one or more of a CPU ("central processing unit"), a DSP ("digital signal processor"), a microprocessor, a microcontroller, an ASIC ("application specific integrated circuit"), a combination of discrete analog and / or digital components, or some other programmable logic device (e.g., an FPGA ("field programmable gate array")). A control program including computer instructions (program instructions) may be stored in the memory 232 and executed by the processor circuit 231 to perform the methods and procedures described below. The control program may be provided to the control device 230 on a computer readable medium, which may be a tangible (non-transitory) product (e.g., a magnetic medium, an optical disk, a read-only memory, a flash memory, etc.) or a propagation signal. The signal interface 233 can be configured in accordance with conventional practice to receive input signals and provide output signals. In the illustrated example, the control device 230 is also connected to a feedback device 234 that is configured to generate audible and / or visual feedback to an operator of the station 2. For example, the feedback device 234 can include one or more of a display, an indicator light, a speaker, an alarm, etc.

[0041] The operation of the loading and unloading devices 200, 220 is controlled by control signals denoted by C2 and C4 from the control device 230. The loading and unloading devices 200, 220 may be configured in a number of different ways to perform their respective functions and will not be described in detail. Examples may be found in the above mentioned WO2007 / 106006.

[0042] The handling device 210 includes an elongated arm 21 attached to or otherwise combined with a rotatable member 22 (also referred to as a wheel or spindle wheel). Each arm 21 forms or includes an internal tool, which is also referred to as a spindle. For simplicity, no distinction is made between arms and internal tools hereinafter. The elongated arms 21 extend radially from the wheel 22 and are equidistantly distributed around the wheel 22. In the illustrated example with four arms 21, each arm is arranged at right angles to its adjacent arm. A drive unit 23 is connected to the wheel 22 and is operable to rotate the wheel 22, as indicated by arrow A2. The drive unit 23 can be an electric motor capable of precise angular positioning, such as a servo motor or a stepper motor. The drive unit 23 is operated by a control signal C1 from a control device 230. Specifically, the drive unit 23 is operable to intermittently rotate or index the wheel 22, thereby rotating or indexing the arm 21 to four different angular positions. The drive unit 23 stops at the corresponding angular positions. These positions are Figure 3 denoted by Roman numerals within a dotted circle. Position I is the loading position, in which the arm 21 is aligned with the loading device 200. Position II is the processing position, in which the arm 21 is aligned with the top forming device 24. Position III is the unloading position, in which the arm 21 is aligned with the unloading device 220. Position IV is the intermediate rest position.

[0043] Providing four arms 21 can meet the high throughput of the station 2 because it can perform three operations simultaneously: loading the sleeve 11 onto the arm 21 at the loading device 200, processing the sleeve 11 on the arm 21 at the top forming device 24, and unloading the package 10 from the arm 21 at the unloading device 220. However, any number (n) of arms 21 can be provided on the wheel 22, n≥1.

[0044] The arm 21 extends from the wheel 22 to a common plane which forms a plane of rotation of the arm 21. Depending on the implementation, the plane of rotation may be vertical or horizontal.

[0045] The top forming device 24 comprises an external tool 25 which is movable relative to the arm 21 when the arm 21 is in position II. In the example shown, the external tool 25 is linearly movable between a rest position and an operating position, as indicated by a double-headed arrow A3. In the rest position, the external tool 25 is spaced apart from the arm 21. In the operating position, the external tool 25 is arranged around the distal end of the arm 21, thereby around the end 11A ( Figure 2A ). The actuator 26 is connected to the external tool 25 and is operable to impart movement thereto. It should be emphasized that Figure 3This is merely an illustrative example. The external tool 25 may be movable in further directions relative to the operative position. Furthermore, the external tool 25 may consist of components that are individually movable to meet in the operative position. In its operative position, the external tool 25 is operable to provide the top 12 on the sleeve end 11A. The top forming operation of the device 24 is controlled by one or more control signals indicated by C3 from the control device 230.

[0046] As described above, the top 12 can be formed on the sleeve 11 by injection molding. In this embodiment, the external tool 25 is an injection molding device. In the operating position of the external tool 25, the sleeve end 11A ( Figure 2A ) is surrounded by an external tool 25 so that the sleeve end 11A is engaged between the end of the arm 21 and the external tool 25 during injection molding.

[0047] In more detail, when the outer tool 25 is arranged to surround the end of the inner tool 21 and the end of the package body, a small gap is then formed, which extends between the outer tool 25 and the end of the inner tool 21 and the end of the package body. Operating the outer tool 25 to provide the top portion 12 on the end of the package body (sleeve) 11 generally includes: injecting plastic material or any other suitable material in the gap. The injection molded part formed by the gap then becomes the top 12 of the package. The technology of injection molding the plastic top 12 on the sleeve 11 is previously known and will not be described in detail here.

[0048] Figure 5 is a flow chart of a procedure 100 for operating the top forming station 2 to produce a package 10 starting from a sleeve 11. The production procedure 100 can be implemented by a control device 230, which is operated to provide appropriate control signals C1-C4 through its signal interface 233. As mentioned above, the corresponding arm is or includes an inner tool 21, which cooperates with the outer tool 25 during the top forming operation. In step 101, the wheel 22 is operated to arrange the inner tool 21 in a loading position. Figure 3 In step 101, the drive unit 23 is operated to rotate the wheel 22 to a predefined angular position corresponding to the position I. In step 102, the sleeve 11 is arranged on the internal tool 21 when the internal tool 21 is in the loading position. Figure 3 In step 102, the loading device 200 is operated to push or otherwise slide the sleeve 11 onto the internal tool 21 in position I. In step 103, the wheel 22 is operated to move the internal tool 21 and the sleeve 11 thereon from the loading position to the processing position, which is at a predetermined angular position of the wheel 22. Figure 3In step 103, the drive unit 23 is operated to rotate the wheel 22 to swing the inner tool 21 from position I to position II. In step 104, the outer tool 25 is arranged around the end of the inner tool 21 and thus around the sleeve end 11A. Figure 3 In step 104, the actuator 26 is operated to move the outer tool 25 toward the inner tool 21 and into the operating position. In step 105, the outer tool 25 is operated to provide the top 12 on the sleeve end 11A, thereby producing the package 10. As described above, step 105 may include operating the outer tool 25 to perform injection molding to form the shaped top 12 on the sleeve end 11A. In step 106, the wheel 22 is operated to move the inner tool 21 together with the package 10 thereon from the processing position to the unloading position, which is at a predetermined angular position of the wheel 22. Figure 3 In step 106, the drive unit 23 is operated to rotate the wheel 22 to swing the inner tool 21 from position II to position III. In step 107, the package 10 is removed from the inner tool 21 when the inner tool 21 is in the unloading position. Figure 3 In step 107, the unloading device 220 is operated to pull or otherwise slide the package 10 out of the internal tool 21 in position III. Figure 3 In the context of , step 107 is followed by a step (not shown) of operating the wheel 22 to move the internal tool 21 from position III to position IV. It can be noted that position IV can be omitted, depending on the number of arms 21 and their mutual arrangement.

[0049] The production procedure 100 is then repeated to produce a series of packages 10. It will be appreciated that the procedure 100 may be performed for each arm 21 in the processing device 201, and preferably such that steps 102, 104-105 and 107 are performed simultaneously for different arms 21, i.e., a sleeve 11 is loaded on one arm 21 in position I, a top 12 is formed on a sleeve 11 on another arm 21 in position II, and a package 10 is unloaded from another arm 21 in position III.

[0050] Applicants have appreciated that the relative arrangement of the inner and outer tools 21, 25 during the top forming operation is critical to the quality of the package 10. If the inner tool 21 is poorly aligned with the outer tool 25 during the top forming operation, the top 12 may be formed with an undesirable appearance / thickness and / or an inadequate connection to the sleeve 11. Figure 4AAn example of such a misalignment is shown and is a cross-sectional view of the inner tool 21 and the outer tool 25 during a top forming operation. The inner tool 21 carrying the sleeve 11 has been arranged in position II and the outer tool 25 has been arranged in its operating position. Thereby, the end of the inner tool 21 and the sleeve end 11A are received in the top forming cavity 25B of the outer tool 25. In the illustrated example, the inner tool 21 is slightly tilted in the rotation plane relative to the outer tool 25, as shown by the angle α between the axis of symmetry 25A of the outer tool 25 and the longitudinal axis 21A of the inner tool 21. The applicant has appreciated that if the misalignment can be detected and quantified, it can be compensated for, thereby improving the performance of the station 2. Figure 4A In the example of , compensation may involve modifying the predetermined angular position of the wheel 22 at position II to reduce the angle α. After extensive experimentation, the applicant has found that the lateral forces acting on the internal tool 21 can be analyzed to detect misalignment. Figure 4A In the example of FIG. 4 , the inclination of the inner tool 21 relative to the outer tool 25 increases the lateral force LF on the inner tool 21 when the inner tool 21 is pressed against the wall of the cavity 25B.

[0051] Based on these insights and extensive experiments, the applicant has conceived a monitoring procedure for detecting and compensating for misalignment between the inner tool 21 and the outer tool 25 in the top forming station 2. The monitoring procedure involves the step of determining at least one parameter value based on the measurement signal, which parameter value is indicative of the lateral force on the inner tool 21 in position II while the outer tool 25 is arranged around the end of the inner tool 25. The monitoring procedure also includes the step of selectively adjusting the relative position between the inner tool 21 and the outer tool 25 based on the at least one parameter value. Reference will be made below to Figure 6 -9 further illustrates and explains the monitoring procedure.

[0052] The measurement signal can be provided in many different ways. Figure 3 As shown, one or more sensors 26 may be arranged in the station 2 to generate a measurement signal S1 indicative of the lateral force LF. The respective sensor 26 may be, for example, a force sensor, a strain sensor or a torque sensor. The respective sensor 26 may be associated with a drive unit 23 (as shown), an internal tool 21, a wheel 22 or an external tool 25. In some embodiments, the measurement signal S1 is generated by the drive unit 23 and may represent the torque required to keep the wheel 22 in a fixed angular position (i.e., position II). Figure 4BThe situation in which the drive unit 23 generates a torque T around the rotation axis of the wheel 22 to withstand the lateral force LF acting on the end of the internal tool 23 is shown. The torque T can be given by the instantaneous drive power or drive current of the drive unit 23 or a dedicated torque sensor in the drive unit 23 or derived from the instantaneous drive power or drive current of the drive unit 23 or a dedicated torque sensor in the drive unit 23. There are commercially available motors that are configured to provide a measurement signal representing the current torque. Examples of such motors include servomotors from Rockwell Automation, such as model MPL-B420P-M, and servomotors from Wittenstein, such as model TPM050x-031P-6.

[0053] At least one parameter value may indicate the magnitude and direction of the lateral force. For example, opposite directions may be assigned positive and negative signs. Figure 4B In the example of , the sign of the torque T may indicate whether the lateral force (LF) is in a clockwise or counterclockwise direction.

[0054] Figure 6 An example of a monitoring procedure 200 is shown in the flowchart of FIG. The control device 230 may execute the monitoring procedure 200 based on the measurement signal S1 received through the signal interface 233 and any other input signals that may be required. In step 201, the control device 230 waits until the external tool 25 is in its operating position relative to the internal tool 21 before continuing with step 202. For example, in step 201, the control device 23 may wait until the output signal (not shown) of the drive unit 23 confirms that the internal tool is in position II and the output signal (not shown) of the actuator 26 confirms that the external tool 25 is in the operating position. Alternatively, the control device 230 may wait for a predefined period of time in step 201. In step 202, the measurement signal S1 is processed to determine at least one parameter value. In some embodiments, a plurality of parameter values ​​indicating a lateral force are determined in step 202. In step 203, the at least one parameter value is evaluated according to an acceptance criterion (e.g., a threshold value as described below). The acceptance criterion is met when the at least one parameter value indicates that the misalignment between the internal tool 21 and the external tool 25 is sufficiently small (or absent). If the acceptance condition is met, the process 200 returns to step 201. Otherwise, the control device 230 performs step 204, in which the relative position between the inner tool 21 and the outer tool 25 is adjusted based on at least one parameter value. Step 204 may involve adjusting the position of the inner tool 21, the outer tool 25, or both. Specifically, the adjustment is made to reduce the misalignment, thereby reducing the lateral force acting on the inner tool 21. The adjustment may be given by a mathematical function or a lookup table that relates the adjustment to the parameter value. The adjustment may take into account not only the magnitude of the lateral force, but also its direction.

[0055] exist Figure 4A-4B In the example, at least one parameter value indicates a lateral force LF in the rotation plane of the arm 21. For such a parameter value, the relative position between the internal tool 21 and the external tool 25 is adjusted only in this rotation plane. The internal tool 21 can be adjusted to reduce the angle α by changing the rotation angle of the wheel 22. The external tool 25 can be adjusted by moving the position of the external tool 25 laterally (i.e., in the lateral direction along the symmetry line 25A) and / or by tilting the external tool 25. In some embodiments, the relative position between the internal tool 21 and the external tool 25 is adjusted only by changing the rotation angle of the wheel 22. This adjustment operation is simple and eliminates the complexity of moving the external tool 25. Figure 4A-4B In the example of FIG. 4 , the wheel 22 may be turned counterclockwise to decrease the angle α.

[0056] If the lateral force is measured in a geometrical plane other than the plane of rotation, it is contemplated that the adjustment in step 204 may be made in that geometrical plane, provided that the station 2 includes appropriate structure for such adjustment. However, it is presently considered most important to make the adjustment in the plane of rotation.

[0057] In some embodiments, the monitoring process 200 is performed simultaneously with the production process 100, and is specifically performed during the top forming operation ( Figure 3 104-105 in ). The monitoring program 200 is thus able to detect and compensate for alignment errors that occur during production. This minimizes the risk of producing a large number of defective packages. In some embodiments, the monitoring program 200 is performed as a preliminary check before starting the production program 100. The preliminary check is intended to correct any existing misalignment between the internal tool and the external tool. During the preliminary check, the station 2 can be operated to produce a limited number of packages 10. Alternatively, the preliminary check can be performed with a sleeve on the internal tool, but the external tool is not operated to provide a top on the sleeve. In another alternative, the preliminary check can be performed without a sleeve on the internal tool, and, subsequently, there is no need to operate the external tool to provide a top.

[0058] Figure 7 is a flow chart of another example of the monitoring program 200 . Figure 7 The example in FIG. 1 assumes that there is more than one internal tool 21 on the wheel 22, such as Figure 3As shown. The procedure 200 includes two evaluations of the need for compensation; a slow evaluation and a fast evaluation. The slow evaluation is performed after one full rotation of the wheel 22 and is based on a set of parameter values ​​obtained for all internal tools 21 during one full rotation. When the set of parameter values ​​indicates that there is a certain misalignment between the internal tool and the external tool, the position of the wheel and / or the external tool is adjusted to reduce the misalignment. All internal tools are collectively adjusted, for example to reduce the average misalignment of all internal tools or to reduce the maximum misalignment among the internal tools. The slow evaluation is therefore used to evaluate the entire processing device 210 and, if it is considered necessary, to find an adjustment that is acceptable for all internal tools. If each internal tool is evaluated and adjusted separately, there is a risk of runaway compensation, i.e., the adjustment of one internal tool leads to the need to adjust the next internal tool, and so on, because all internal tools are fixedly arranged on a common wheel. Runaway compensation can be avoided by the slow evaluation.

[0059] On the other hand, the fast evaluation is performed for each internal tool 21 individually, but is more suitable than the slow evaluation for detecting larger misalignments to mitigate the risk of uncontrolled compensation. When the parameter value indicates a sufficiently large misalignment, an adjustment is made. The fast evaluation is used to detect misalignments that may cause poor performance or even mechanical damage to the internal tool or other tools. The fast evaluation is based on the understanding that if there is a large misalignment between one internal tool and the external tool, all internal tools on the wheel 22 may have this misalignment.

[0060] Figure 7 The procedure in includes steps 201 and 202, which are related to Figure 6 . Thus, the process 200 waits until the external tool is arranged to surround the end of the internal tool (step 201), and at least one parameter value PV is determined (step 202). The process 200 then continues with step 203A to perform a quick assessment, in which a representative amplitude value PVR2 of PV is determined and compared to a threshold value TH2. If PVR2 exceeds TH2, the process 200 continues to step 204A, in which an adjustment is made to offset the misalignment represented by PV. If multiple parameter values ​​are determined in step 202, PVR2 can be the average, median, modal value, maximum value, minimum value, etc. of the multiple parameter values. If a single parameter value is determined in step 202, PRV2 can be set to the magnitude of the parameter value. In some embodiments, step 204A includes an adjustment value to be applied by the computing control device when aligning the next internal tool and external tool (see Figure 3103-104 in step 204A). For example, the adjustment value may change the predetermined angular position of the wheel 22 to place the next internal tool in position II. After step 204A, the process 200 continues to monitor the next internal tool on the wheel (step 205). If PRV2 does not exceed TH2 in step 203A, the process continues to step 203B to check whether the parameter values ​​for all internal tools (i.e., one full rotation of the wheel) have been determined. If not, the process 200 continues to monitor the next internal tool (step 205).

[0061] When all internal tools have been monitored, step 203B proceeds to step 203C to perform a consistency check on the set of parameter values ​​(designated [PV]) of the internal tools determined in step 202 during one full rotation of the wheel. The consistency check in step 203C looks for inconsistent directions within [PV]. As described above, the parameter values ​​can represent both the magnitude and direction of the lateral force. For example, if [PV] contains parameter values ​​of different signs, step 203C can identify an inconsistency, meaning that the corresponding lateral forces are in opposite directions. In order to identify an inconsistency, step 203C can also require that the magnitude of the parameter value exceeds a threshold, i.e., the inconsistent lateral forces have a related magnitude. If step 230C identifies an inconsistency, the program 200 proceeds to step 206, which causes the control device to generate an alarm, such as by a feedback device (see Figure 3 Alternatively or additionally, step 206 may cause the control device to stop the operation of the top forming station. The motivation for the consistency check of step 203C is that the direction of the lateral force should be the same for all internal tools, since they are fixedly arranged on the wheel. If the direction is different, a mechanical error may have occurred, for example, one or more internal tools are bent or deformed in other forms.

[0062] If no inconsistency is found in step 203C, the program proceeds to step 203D to perform a slow evaluation, where a representative value PVR1 of [PV] is determined and compared to a threshold value TH1. PRV1 can be given as the mean, median, modal value, maximum, minimum, etc. of the parameter values ​​in [PV]. The calculation of PRV1 is based on the magnitude of the parameter values ​​and, optionally, also on their signs. As can be appreciated from the above discussion, TH1 is less than TH2. If PVR1 exceeds TH1, the program 200 proceeds to step 203E, where an appropriate adjustment is estimated based on [PV], and proceeds to step 204B, where the relative position is adjusted accordingly. For example, an appropriate adjustment can be estimated based on PRV1 or another representative value of [PV] by using a lookup table or a mathematical function. In some embodiments, step 203E generates an adjustment value, such as an angular change, which is applied by the control device when aligning the next internal tool and external tool (see Figure 3 After step 204B, process 200 continues to monitor the next internal tool on the wheel (step 205).

[0063] Figure 8 TH1 and TH2 on the lateral force LF scale are shown. The scale extends from zero (0) to a maximum value MAX. As shown, TH1 and TH2 divide the scale into three force ranges. The range between TH1 and TH2 results in a slow adjustment according to steps 203E and 204B. The range between TH2 and MAX results in a fast adjustment according to step 204A. The range between 0 and TH1 does not result in an adjustment. It can be noted that Figure 8 Assume that the lateral force is given by a positive number (i.e., magnitude). It is currently believed that, at least for the Rockwell Automation and Wittenstein motors exemplified above, adequate performance can be achieved by setting TH1 to 10%-40% of MAX and TH2 to 60%-90% of MAX. In some embodiments, TH1 is set to 20%-30% of MAX and TH2 is set to 70%-80% of MAX.

[0064] exist Figure 7 In the example of , the adjustment to be made is determined based on the lateral force acting on the current internal tool that is engaged with the external tool, and then the adjustment is applied to the next internal tool that will be aligned with the external tool. It is conceivable that the adjustment is applied to the current internal tool to achieve an instant correction of the current internal tool. However, if the end of the current internal tool is locked within the external tool, such an instant correction may not be possible. In addition, the instant correction may cause unstable position control of the internal tool and the external tool.

[0065] It can be noted that Figure 7 The monitoring procedure in can be modified by omitting any of the consistency checks, fast assessments, and slow assessments, depending on the perceived risk and desired monitoring performance of the specific top forming station.

[0066] Figures 9A-9B Included for illustration Figure 3 The utility of the slow compensation of the processing device 201 in Fig.9A, signal 80 represents the angular position of the wheel 22, giving indexed angular values ​​between 0° and 90°. When the angular value increases from 0° to 90°, the wheel 22 rotates a quarter of a turn, whereupon the angular value is reset to 0°. The time period P1 represents the time during which the wheel 22 is stationary, in this case approximately 1.6 seconds. During P1, the top forming operation occurs. The time period P2 represents the duration of one full rotation of the wheel 22 and therefore corresponds to four top forming operations, one for each internal tool 21 on the wheel 22. One full rotation of the wheel 22 is also denoted as a "full production cycle" FPC. Signal 81 represents the execution state of the software code executed on the control device 230 at each time step. The execution state corresponds to a subset of the software code. The numbering of the execution states is arbitrary and is merely used to indicate the time at which the corresponding execution state occurs over time. Reference numeral S represents a data sample, which corresponds to Figure 6-7 Step 202 in the example, thereby generating parameter values. In the example shown, five parameter values ​​are obtained for each time period P1. By sampling more than one parameter value for each time period P1, the influence of false data samples can be reduced. Reference numeral E1 denotes a parameter value corresponding to Figure 7 203A and 203B in the embodiment of the present invention, and if fast compensation is enabled, step 204A is optionally performed. Fig.9A E1 is indicated only once in FIG. 2 , but it should be understood that each data sample S is followed by E1. Reference numeral E2 denotes a set of execution states corresponding to steps 203D, 203E and 204B. Therefore, E2 results in slow compensation. Reference numeral E2' denotes a set of execution states corresponding to step 203D, i.e., without any slow compensation.

[0067] Steering Fig. 9B , signal 82 represents the torque of the drive unit 23 (here the servo motor), and Fig.9A In this example, the lateral force is given by the torque. Therefore, the parameter value is the torque value. Fig. 9B In FIG. 1 , data sampling occurs within a time period ΔS during the corresponding top forming operation. During ΔS, the torque value is relatively stable because the wheel 22 is stationary. The peaks at the beginning and end of the time period P1 represent the torque of the drive unit 23 when the wheel 22 accelerates and decelerates. For clarity, Fig. 9B The top of the diagram lists consecutive complete production cycles from FPC1 to FPC5. The dashed horizontal lines indicate the positions of TH1 and TH2 on the torque scale. Fig. 9BAs shown, the torque value during the top forming operation is less than TH2, so the fast compensation is not initiated. In FPC1, the torque value is greater than TH1, resulting in a slow compensation (E2) for the upcoming FPC2. In FPC2, the torque value is reduced due to the slow compensation. However, the torque value is still greater than TH1, resulting in another slow compensation (E2) for the upcoming FPC3. This is also repeated for the upcoming FPC4, which reduces the torque value in FPC4 below TH1 and causes the control device to avoid slow compensation (E2') for the upcoming FPC5. Therefore, in FPC5, the torque value is approximately the same as the torque value in FPC4.

[0068] It can be seen that these figures, especially Figure 7 , illustrating the Figure 5Some embodiments of a monitoring program related to a top forming machine or station operated in a production program 100 in the present invention. The top forming machine includes a plurality of internal tools arranged to extend radially from a rotatable member, and the production program is repeated for each of the plurality of internal tools. In one embodiment, the monitoring program includes: determining (step 202) at least one parameter value of a corresponding internal tool in the plurality of tools while the external tool is arranged to surround the end of the corresponding internal tool, thereby evaluating (steps 203C, 203D, 203E) a result data set [PV] of parameter values ​​estimated for the plurality of internal tools, and selectively changing (step 204B) the rotation angle of the rotatable member based on the evaluation. In one embodiment, the rotation angle of the rotatable member is changed for the production program to be repeated. In other words, the rotation angle is changed when the next internal tool is to be aligned with the external tool. In one embodiment, [PV] associates each parameter value with the direction of a lateral force in the rotation plane, and the evaluation includes: evaluating (step 203C) [PV] to detect inconsistent directions, and generating (step 206) an alarm signal when inconsistent directions are detected. In one embodiment, the evaluation includes: evaluating (step 203D) [PV] related to a threshold value TH1, and upon detecting that a representative value PVR1 of [PV] exceeds TH1, determining (step 203E) an angle adjustment value of the rotatable member based on [PV], the rotation angle of the rotatable member being changed according to the angle adjustment value. In one embodiment, the angle adjustment value is determined (step 203E) based on PVR1. In one embodiment, PVR1 is a mean value, a median, a modal value, a maximum value, or a minimum value. In one embodiment, the monitoring program also includes: during each production program, evaluating (step 203A) at least one parameter value of each internal tool relative to another threshold value TH2 exceeding TH1, and upon detecting that a representative value PVR2 of at least one parameter value exceeds TH2, changing (step 204A) the rotation angle of the rotatable member. In one embodiment, the rotation angle is changed based on PVR2 exceeding TH2.

[0069] The present disclosure is not limited to using injection molding to provide a top on the sleeve. For example, an external tool can be configured to perform other types of molding, such as blow molding, compression molding or thermoforming. In a variant, the external tool is configured to attach a ready-made top or a part thereof to the sleeve, such as by bonding, melting, mechanical attachment, etc. In another variant, the external tool is configured to shape the portion of the sleeve into a top or a part thereof. Examples of this molding can be found in WO2010 / 085182 and DE102005048821.

[0070] In addition, the sleeve can be made of or include other materials (such as cardboard or plastic materials) other than the paper-based laminate material. The top can be made of any suitable material or combination of materials. In addition, the technology disclosed herein can be applied to the production of packaging that is not bottle-shaped. The monitoring technology described herein is also applicable to machines configured to produce packaging for containing liquid foods by providing a bottom portion at the end of the sleeve. Therefore, any reference to "top portion" herein can be replaced by "bottom portion" or the more general term "end portion".

Claims

1. A computer-implemented method for operating a machine (2) for producing a package (10) for containing a liquid food, wherein the machine (2) comprises an internal tool (21) and an external tool (25), wherein the internal tool (21) radially extends from a rotatable member (22), the rotatable member (22) being operable to move the internal tool (21) from a loading position (I) to a processing position (II), in which the external tool (25) is operable to be arranged around an end of the internal tool (21), the method comprising a production program (100), the production program (100) comprising: operating (101) the rotatable member (22) to arrange the internal tool (21) in the loading position; placing (102) a packaging body (11) on the inner tool (21) in the loading position (I); operating (103) the rotatable member (22) to move the inner tool (21) together with the packaging body (11) from the loading position (I) to the processing position (II); arranging (104) the outer tool (25) to surround the end of the inner tool (21) and thereby surround the end of the packaging body (11); as well as operating (105) the outer tool (25) to provide a top portion (12) on the end of the package body (11), thereby producing the package (10), The method further comprises a monitoring procedure (200), wherein the monitoring procedure (200) comprises: determining (202) at least one parameter value (PV) indicative of a lateral force (LF) on the inner tool (21) in the processing position (II) based on a measurement signal (S1), when the outer tool (25) is arranged around the end of the inner tool (21); and A relative position between the inner tool (21) and the outer tool (25) is selectively adjusted (204) based on the at least one parameter value (PV).

2. The method according to claim 1, wherein: The measurement signal (S1) is generated when the packaging body (11) is located on the inner tool (21) in the processing position (II) and the outer tool (25) is operated to provide the top part (12) on the end of the packaging body (11).

3. The method according to claim 1 or 2, wherein: The measurement signal (S1) is indicative of the lateral force (LF) and is obtained from an electric motor (23) connected to the rotatable member (22) and operable to rotate the rotatable member (22) or from a sensor (S1) associated with the machine (2).

4. A method according to any one of the preceding claims, wherein: The at least one parameter value (PV) is indicative of the lateral force (LF) in a rotation plane of the inner tool (21), and wherein the rotation angle of the rotatable member (22) is varied to adjust the relative position between the inner tool (21) and the outer tool (22).

5. The method according to claim 4, wherein: The machine (2) comprises a plurality of internal tools (21) arranged to radially extend from the rotatable member (22), wherein the production procedure (100) is repeated for each internal tool (21) of the plurality of internal tools, and wherein the monitoring procedure (200) comprises: determining (202) at least one parameter value (PV) of the corresponding internal tool (21) while the external tool (25) is arranged to surround the end of the corresponding internal tool (21) of the plurality of tools; evaluating (203C, 203D, 203E) a result data set ([PV]) of the parameter values ​​estimated for the plurality of internal tools; and selectively changing (204B) the rotation angle of the rotatable member (22) based on the evaluation (203C, 203D, 203E).

6. The method according to claim 5, wherein the rotation angle of the rotatable member (22) is varied with respect to subsequent repetitions of the production procedure (100).

7. The method according to claim 5 or 6, wherein: The result data set ([PV]) associates each of the parameter values ​​with a direction of the lateral force (LF) in the rotation plane, and wherein the evaluation (203C, 203D, 203E) comprises evaluating (203C) the result data set ([PV]) to detect inconsistent directions and generating (206) an alarm signal when the inconsistent direction is detected.

8. The method according to any one of claims 5 to 7, wherein the evaluating (203C, 203D, 203E) comprises: The result data set ([PV]) is evaluated (203D) relative to a threshold value (TH1) and, upon detecting that a representative value (PVR1) of the result data set ([PV]) exceeds the threshold value (TH1), an angle adjustment value of the rotatable member (22) is determined (203E) based on the result data set ([PV]), wherein the rotation angle of the rotatable member (22) is changed according to the angle adjustment value.

9. The method according to claim 8, wherein the angle adjustment value is determined (203E) based on the representative value (PVR1).

10. The method according to claim 8 or 9, wherein the representative value (PVR1) is a mean value, a median value, a modal value, a maximum value or a minimum value.

11. The method according to any one of claims 8 to 10, wherein the monitoring program (200) further comprises: During each production sequence (100), at least one parameter value (PV) of the corresponding internal tool (21) is evaluated (203A) relative to a further threshold value (TH2) exceeding the threshold value (TH1), and upon detecting that a representative value (PVR2) of the at least one parameter value (PV) exceeds the further threshold value (TH2), the rotation angle of the rotatable member (22) is changed (204A).

12. Method according to claim 11, wherein the rotation angle of the rotatable member (22) is changed based on the representative value (PVR2) exceeding the further threshold value (TH2).

13. Method according to any one of the preceding claims, wherein the package (10) is shaped like a bottle.

14. A computer readable medium comprising program instructions which, when executed by a processor circuit (231), are configured to cause the processor circuit (231) to perform the method according to any one of claims 1-13.

15. A control device configured to perform the method according to any one of claims 1 to 13, the control device comprising a signal interface (233), the signal interface (233) being configured to receive the measurement signal (S1) and to provide a control signal (C1-C4) for operating the machine (2).

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