Method for determining locally distributed finishing value of die cutting station
The force distribution of the tool element is measured by sensor components and the finishing value is calculated, which solves the problem of determining the local distribution finishing value of the die-cutting station, and achieves efficient die-cutting effect and productivity improvement.
Patent Information
- Application Number
- CN202410798775.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-06-20
- Filing Date
- 2024-06-20
- Publication Date
- 2024-12-20
AI Technical Summary
The prior art is difficult to accurately determine the local distribution finishing value of the die-cutting station, resulting in poor die-cutting effect, and manual adjustment of the die-cutting force is required during the production process, which increases the workload and production time of the operator.
Through multiple sensor components, measure the force distribution of the tool element, calculate the deviation between the rated force value and the actual force value, and accurately determine the finishing value to adjust the die shear force distribution to achieve local thickness changes of the finishing page.
It significantly improves the accuracy of die-cutting effect, reduces the workload and time of setting up the die-cutting station, saves operating costs and improves productivity.
Smart Images
Figure CN119159640A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for determining a locally distributed finishing value of a die-cutting station. Background Art
[0002] The invention belongs to the technical field of platemaking industry, in particular to the field of so-called post-press processing, in particular to the field of die-cutting or industrial production of flexible sheet-shaped printing materials, i.e. the high-quality and high-productivity production of die-cut products such as labels or folding boxes, preferably made of paper, cardboard, paperboard, plastic or composite materials.
[0003] During the die-cutting process, for example during flatbed die-cutting, it may happen that the die-cutting tool or the tool element of the so-called die-cutting tool (e.g. the die-cutting knife) does not achieve the desired die-cutting effect, for example the product to be die-cut is not completely cut through, which is preferably determined in a die-cutting test before the actual production. The same applies to embossing. In this case, it may be helpful to increase the die-cutting force locally, i.e. in the area of the tool element that did not die-cut correctly. For this purpose, so-called finishing sheets can be produced. According to the conventional method, the machine operator manually applies a strip (or strips) of a certain thickness as a so-called finishing element at the location where the die-cutting force is to be increased locally. The thickness of the finishing sheet can also be changed locally at multiple locations. During the production process, the finishing sheet is placed under the die-cutting tool and the finishing sheet has the die-cutting force increased locally by its adjusted thickness profile, so that a satisfactory product is produced overall.
[0004] EP2327521B1 discloses a method for finishing the tools of a flatbed sheet die-cutting and / or embossing machine, which has at least one die-cutting and / or embossing station, each of which has an upper platen and a lower platen. The pressure distribution during the die-cutting and / or embossing process is measured by a planar (especially film-like) pressure distribution sensor or a so-called measuring pad extending on the tool surface, from which the finishing requirement distribution is calculated and the tool is finished accordingly. EP3153286B1 discloses a similar system.
[0005] DE 10 2015 106 344 B4 discloses a machine-specific finishing of sheets which is derived directly from deformation measurements.
[0006] Therefore, in order to create a suitable finished sheet, ie a finished sheet that can adequately compensate for potential die-cutting errors, it is necessary to be able to determine the finishing values, preferably the thickness values, with sufficient accuracy in order to create the finishing elements of the finished sheet. Summary of the invention
[0007] The object of the present invention is to improve the prior art in such a way that, in particular, locally distributed finishing values (or register values or correction values) can be determined with sufficient accuracy to achieve a satisfactory punching result.
[0008] According to the present invention, the above object is achieved by a method according to a preferred technical solution of the present invention.
[0009] Advantageous and therefore preferred embodiments of the invention can be derived from the alternative embodiments as well as from the description and the drawings.
[0010] The invention proposes a method for determining locally distributed finishing values of a die-cutting station, wherein a sensor field comprising a plurality of sensor elements measures locally distributed values of forces caused by a plurality of tool elements of a manipulated tool, characterized in that a) during the measurement, the tool element (11) W i The number of sensor elements is I, S k The number of is K, where for the indices i and k: 1≤i≤I and 1≤k≤K; b) for each tool element W i Determine the length value LW ik And predetermine the length-dependent rated force value FW i , where the length value LW ik Indicates tool component W i In the sensor element S k The length of the measuring range and the rated force FW i Indicates tool component W i length-dependent rated force; c) for each sensor element S k Calculate the rated force F k , where for multiple tool elements W j Applicable: F k =∑ j (LW jk ×FW j ), where for the index j: 1≤j≤I; d) at each sensor element S k Measure the actual force value FM in the measuring range k ; e) For each value k, the rated force F k and actual force value FM k The comparison is made and based on the determined deviation DF k =F k -FM k Calculation of finishing element ZE k The finishing value ZRW k .
[0011] Advantageous development schemes and effects of the present invention
[0012] The invention advantageously enables the locally distributed finishing values to be determined with sufficient accuracy to achieve a satisfactory die-cutting result. The invention provides for this purpose a combined measuring and calculating method.
[0013] The invention advantageously allows a considerable reduction in the amount of work when setting up a die-cutting station, in particular when setting up a so-called first operation, and thus considerable time savings. The invention thus makes it possible to save costs, in particular costs for operating personnel, and to increase productivity by additional production time at the die-cutting station.
[0014] In the prior art, discrete pressure measuring pads for each measuring field have not hitherto been taken into account for determining the total force acting on this measuring field.
[0015] For large area loads (significantly larger than the discreteness of the measuring pad), this can be interpreted as a pressure distribution.
[0016] In contrast, the present invention is based on the knowledge gained through observation that the cutting blade of a cutting tool or a cutting die generates a very local or partial load, the force per unit length of which is ideally constant over the length of the cutting blade, i.e. the tool element, and has a value adapted to the substrate. The force acting on the measuring element of the measuring pad therefore depends both on this value and on the length of the tool element within the measuring range of the measuring element. If this length is not taken into account, it is not possible to calculate a force measurement, i.e. a setpoint force value. According to the invention, the tool length for each measuring field can be derived from the preliminary phase data and incorporated into the evaluation of the measurement data.
[0017] The invention is also based on the knowledge gained from the observation that if the measured force value in a measuring field deviates downward from the setpoint value, the local (or local) refining requirement ZRW at this point k If the measured force value in a measuring field deviates upward from the setpoint value, the finishing requirement for the surrounding area (e.g. all adjacent measuring fields) is greater than zero. The reasonable size of the environment to be considered for a measuring location can be determined experimentally in advance and then provided as an input value to the method.
[0018] One of the goals of finishing is to achieve the same good punching or embossing results everywhere on the substrate. To this end, the force specific to the tool element must be approximately the same everywhere on the sheet or adjusted by a local variation in the thickness of the finished sheet. The required thickness variation value (change in punching force per unit to be achieved) can be determined experimentally and adjusted to the production method of the finished sheet. This value can also be provided as an input value to the method.
[0019] The calculated finishing requirements can also be additionally subjected to geometric low-pass filtering in order to eliminate high-frequency noise in the finishing requirements. If the calculated finishing requirement value lies between the thickness resolution capabilities of the production method for the finished sheets, it can be rounded up or down. The finishing requirements determined in this way are implemented as locally distributed thickness variations in the finished sheets, preferably automatically, for example by printing the finished sheets with inks of varying thickness.
[0020] The tool element is preferably designed as a knife or as a grooved line or a pressure rubber. Length-dependent setpoint force value FW i A value that depends on the substrate is preferred.
[0021] Expansion scheme of the present invention
[0022] Preferred developments of the present invention (hereinafter referred to as developments) are described below. If not technically excluded, these developments can also be combined with one another.
[0023] One refinement of the invention can be characterized in that for only one value k, the correction value ZRW is used k Create finishing element ZE k , or for multiple values of k using the refinement value ZRW k Create finishing elements ZE separately in the case k , or for each value k using the refinement value ZRW k Create corresponding finishing elements ZE respectively k It is preferred to consider k such values when there is actually a need for finishing.
[0024] One development may be characterized in that, in step e, the finishing value ZRW k is calculated as the local height value or thickness value of the finished sheet, ie the respective finishing element ZE of the finished sheet k This is preferred if the cutting force should be increased locally.
[0025] One development may be characterized in that, in step e, the finishing value ZRW k is calculated as the adjacent height values or thickness values of the finished sheet, ie the respective finishing element ZE of the finished sheet k This is preferred if the punching force should be reduced locally, ie conversely should be increased in the local environment.
[0026] One development can be characterized by combining the calculation of the local height value with the calculation of the adjacent height value for producing the finished sheet.
[0027] One development may be characterized in that previously experimentally determined altitude values or altitude value changes can be predefined and used.
[0028] One development can be characterized in that the finished sheet produced includes all k finishing elements ZE k .
[0029] One development can be characterized by the production of the finished sheets by the additive process.
[0030] One development can be characterized by the printing of finishing sheets.
[0031] One development can be characterized in that the finishing sheet is printed using an inkjet printing method.
[0032] One development can be characterized in that the finishing sheets are produced automatically by locally gluing sections of the finishing tape.
[0033] One development can be characterized in that the finishing sheets are produced manually by locally gluing sections of the finishing tape, wherein the gluing positions are displayed to the operator.
[0034] One development can be characterized in that the finishing sheets are produced manually by locally gluing sections of the finishing tape, wherein the thickness of the adhesive tape is displayed.
[0035] One development concept can be characterized by the production of the finished sheets using the subtractive method.
[0036] One development can be characterized in that the finishing sheet is produced automatically by locally removing layers of the multi-layer finishing sheet.
[0037] One development can be characterized in that steps d and e of the method are carried out iteratively, intermediate finishing sheets being produced and the iteratively measured finishing values ZRW being converted into k are combined and used to produce the final finished sheet. In each additional iteration step, either the previously created intermediate finishing sheet (as the sum of the intermediate finishing sheets created before it) or all the previously created intermediate finishing sheets can be remeasured. Finally, only the final finished sheet is used for production.
[0038] One refinement may be characterized in that in step c, it is applicable only for those portions of the sensor element S which are at least partially located k Tool element W within the measuring range j , that is, the length value LW jk ≠ 0. Therefore, tool components that are not locally functional can be ignored.
[0039] An extended solution may be characterized by the fact that in step c: j=W i All tool components.
[0040] One development may be characterized in that step d includes a sensor element S k The measuring device can be implemented with a measuring foil or measuring pad. It is preferably flexible and can include electronic measuring units arranged in a matrix.
[0041] One development can be characterized in that the measuring foil or the measuring pad is arranged next to the tool. Preferably, the measuring foil or the measuring pad is arranged behind the tool, ie on the rear side of the tool.
[0042] One development can be characterized in that in step b, tool data from the prepress are provided.
[0043] One extended solution may be characterized in that the tool data includes the tool elements W i Type.
[0044] One extended solution may be characterized in that the tool data includes the tool elements W i position and / or angle.
[0045] One embodiment can be characterized in that in step c the setpoint force value F k is calculated as an absolute value.
[0046] One embodiment can be characterized in that in step c the setpoint force value F k are calculated as relative values.
[0047] One embodiment can be characterized in that in step d the actual force value FM k is measured during the measurement time window in which the tool element is expected to be functional.
[0048] A further development can be characterized by measuring the actual force value FM with a predefined time resolution in the measuring time window. k The resolution is preferably chosen to be very fine in order to accurately detect and measure the peak values of the die cutting forces.
[0049] One further development can be characterized in that step d is performed in a measuring station different from the die-cutting station. This has the advantage that production does not need to be interrupted for the measurement.
[0050] One development can be characterized in that the calculations in steps b and e are performed by a digital computer.
[0051] The features and feature combinations disclosed in the above technical field, summary and development sections as well as in the following exemplary embodiments section form further advantageous developments of the invention in any combination with one another. BRIEF DESCRIPTION OF THE DRAWINGS
[0052] Figures 1 to 3 The preferred embodiments and extensions of the present invention are shown. DETAILED DESCRIPTION
[0053] Figure 1 A schematic (longitudinal) cross-sectional view of a preferred machine configuration for carrying out a preferred embodiment of the method according to the invention is shown. Figure 1 In the center is shown a flatbed die-cutter 1 with a processing direction 1a for the sheets and movable upper and lower tools; the die-cutter comprises, one after the other along the processing direction, a feeder 2 for the stacks of printed products to be processed, a feed table 3, a die-cutting station 4, a waste removal station 5, a useful part separation station 6 and a station 7 for removing sample sheets. The sheets 8 to be die-cut are processed individually and automatically, for which purpose the die-cutter comprises a digital computer 17 for controlling the production process or is connected to such a digital computer. The (upper) tool 10 is designed as a die-cutting tool and has a corresponding tool element 11, i.e. a die-cutting element; the lower tool is arranged opposite the upper tool as a matching tool and interacts with it.
[0054] The machine configuration optionally also includes (as shown on the right) a prepress device 15, such as a digital computer, in particular a digital computer with a data memory 16; the prepress device is preferably connected to the computer 17 for data transmission.
[0055] The machine configuration also includes an optional measuring station 20 with a measuring device 21 for automatically measuring local force distribution values during the die-cutting process (shown by way of example at the bottom left) and a device 32 for automatically producing a finished sheet 30 based on the die-cutting forces measured and processed by means of computer technology according to the invention (shown by way of example at the top left); both stations are preferably also connected to the computer 17 for data transmission. In contrast to the illustration, the die-cutting forces can also be measured directly in the flatbed die-cutting machine 1 or its die-cutting station 4; in this case, a separate measuring station 20 is not required.
[0056] The measuring device 21 comprises a sensor field 22 with a plurality of sensor elements 23, which are arranged on a (preferably square) measuring grid, wherein each sensor element 23 is assigned its own measuring range 24. Each measuring range has a size 24a (see Figure 3 ).
[0057] The device 32 for automated production can preferably produce finishing sheets 30, intermediate finishing sheets 30a and / or final finishing sheets 30b. The production can be carried out by producing or applying finishing elements 31: the production can preferably be carried out by applying a liquid or pasty (and hardening or hardenable) finishing material (such as ink); the application can preferably be carried out by applying a self-adhesive finishing tape or a finishing tape section (such as an adhesive tape).
[0058] Therefore, the measurement is preferably carried out in the measuring station 20, while the die-cutting station 4 can be used for actual production. After the measurement is completed, the tool 10 is removed from the measuring station 20. Likewise, the finishing sheet 30 created for the tool 10 is also removed from the device 32. Then, both are placed in the die-cutting station 4 for production without die-cutting errors.
[0059] As shown, the measuring system 20 and the device 32 can be arranged as a common unit, for example, arranged one above the other or directly adjacent to each other. Alternatively, the two units can also be arranged separately, for example, at a certain distance from each other; in this case, the two units are preferably connected to the digital computer 17 via a separate connection.
[0060] Figure 2 A schematic flow chart showing a preferred embodiment of the method of the present invention is shown, wherein the steps are as follows:
[0061] Step 40: Providing a computer, preferably a digital computer 17, which performs the calculations 40a including the comparison.
[0062] Step 41: Providing a (die-cutting) tool 10 with a (die-cutting) tool element 11 (preferably a die-cutting blade) for a future die-cutting task. The provision is preferably carried out in the measuring station 20 or alternatively directly in the die-cutting station 4. Thus, the tool element W i The number I of is also known, where: 1≤i≤I.
[0063] Step 42: Provide digital data of the tool 10, preferably data of the position and angle of all tool elements 11 and their respective length values, as well as data of the setpoint force values. These data are transmitted to a provided computer 17, preferably from a data memory 16 of the prepress stage 15. The provided or predefined values preferably include the length-dependent setpoint force value FW i .
[0064] Step 43: If the punching force is not measured directly in the punching station 4, a measuring device 20 is optionally provided; the measuring device comprises a sensor field 22 with sensor elements 23. The measuring device 20 is preferably connected to a computer 17 provided for data transmission, in particular for transmission of measured values. k The number K of is also known, where: 1≤k≤K.
[0065] Step 44 : Providing digital data of the measuring device 20 , preferably data of the measuring range 24 of the measuring grid, such as the position and the size 24 a of the measuring range 24 .
[0066] Step 51: Determine or calculate the length value LW ik .
[0067] Step 52: For multiple tool components W j , through F k =∑ j (LW jk ×FW j ) Calculate the rated force F k , where the index j applies: 1≤j≤I. The calculation is preferably performed for all tool elements 11 of the tool 10 .
[0068] Step 53: Measure the actual force value FM k In this case, at least one trial die-cut is preferably carried out in the measuring station 20. The substrate used and to be die-cut should have relevant parameters, such as thickness, which match or are at least similar to the substrate used in subsequent production.
[0069] Step 54: For each value of k, set the rated force F k and actual force value FM k Compare (by computational techniques) and determine or calculate the deviation DF k =F k -FM k Here, there are three cases: a) F k >FM k ; b) F k ≈FM k ; or c) F k <FM k In case a, finishing is required in the region of the locally measured sensor element 23; in case b, no finishing is required; in case c, finishing is required in the local environment of the region of the locally measured sensor element 23.
[0070] Step 55: Based on the determined or calculated deviation, the finishing element ZE k Calculate the finishing value ZRW k , for example thickness values. These values can preferably be transmitted to the device 32 and used there to produce the finished sheet 30.
[0071] Figure 3 Six examples of different sensor elements 23 and their measuring ranges 24 are shown, with corresponding linear dimensions 24a, here exemplarily square ranges:
[0072] Top left: Only one tool element 11 is arranged in the area 24, here taking the angle of 0° as an example. Its length LW ik 1 length unit LE (related to the linear dimension 24a). Rated force value FW related to length i 400N / LE. Rated force F k The calculated value of is 400N by way of example. The actual force value FMk The measured value is 400 N. This gives the finishing value ZRW k = 0. No local finishing is required.
[0073] Upper center: Only one tool element 11 is arranged in the area 24, here taking the angle of 0° as an example. Its length LW ik 1 length unit LE (related to the linear dimension 24a). Rated force value FW related to length i 500N / LE. Rated force F k The calculated value of is 500N by way of example. The actual force value FM k The measured value is 500 N. This gives the finishing value ZRW k = 0. No local adjustment is required.
[0074] Top right: Only one tool element 11 is arranged in the region 24, here taking a first angle different from 0° as an example. Its length LW ik 1.25 length units LE (related to linear dimension 24a). Length-dependent rated force FW i 400N / LE. Rated force F k The calculated value of is 500N by way of example. The actual force value FM k The measured value is 500 N. This gives the finishing value ZRW k = 0. No local adjustment is required.
[0075] Lower left: Only one tool element 11 is arranged in the region 24, here taking a first angle different from 0° as an example. Its length LW ik 1.25 length units LE (related to linear dimension 24a). Length-dependent rated force FW i 400N / LE. Rated force F k The calculated value of is 500N by way of example. The actual force value FM k The measured value is 400 N. This gives the finishing value ZRW k >0. Local finishing is necessary. Die cutting force must be increased locally.
[0076] Lower center: Only one tool element 11 is arranged in the region 24, here taking a second angle different from 0° as an example. Its length LW ik 0.4 length unit LE (related to linear dimension 24a). Length-dependent rated force FW i 400N / LE. Rated force F k The calculated value of is 160N for example. The actual force value FM k The measured value is 130 N. This gives the finishing value ZRW k>0. Local finishing is necessary. Die cutting force must be increased locally.
[0077] Bottom right: Two tool elements 11 are arranged in the region 24 , both of which are, by way of example, at an angle different from 0°. Length value LW ik 0.4 length units LE and 1LE respectively (related to linear dimension 24a). Length-dependent rated force FW i They are 400N / LE and 200N / LE respectively. Rated force F k The calculated values of are 160 N and 200 N, ie 360 N in total. The actual force value FM k The measured value is 400 N. This gives the finishing value ZRW k <0. Must be finished in local environment. Die cutting force must be reduced locally.
[0078] It can be seen from these examples that if the discreteness of the sensor field 22, for example the measuring pad, is known, it is possible to calculate from the predefined setpoint values and the tool-specific distribution (number, angle) of the tool elements 11 which tool element lengths LW are expected to be present in which measuring field k. ik Combined with rated force FW i , the expected measuring force value F for each measuring element can be obtained k .
[0079] Optionally, the sensor field 22 which does not contain the tool element 11 can be excluded from the calculation, so that possible noise in the measurement signal does not lead to artifacts in this region.
[0080] List of reference numerals:
[0081] 1 Flatbed die cutting machine
[0082] 1a Processing direction
[0083] 2 Feeder
[0084] 3 Feeding station
[0085] 4 Die-cutting stations
[0086] 5 Waste Removal Station
[0087] 6 Useful part separation station
[0088] 7 Remove the sample sheet.
[0089] 8 pages
[0090] 10 Tools
[0091] 11 Tool components
[0092] 15 Prepress
[0093] 16 Data memory / data
[0094] 17 Digital Computer
[0095] 20 measuring stations
[0096] 21. Measuring device
[0097] 22 Sensor Field
[0098] 23 Sensor element
[0099] 24 Measuring range
[0100] 24a Dimensions of the measuring range
[0101] 30 finishing sheets
[0102] 30a Intermediate finishing sheets
[0103] 30b Final finishing sheet
[0104] 31 Finishing components
[0105] 32 Device for producing finished sheets
[0106] 33 Finishing materials
[0107] 34 Finishing belt
[0108] 40 Provide computers
[0109] 40a Calculation
[0110] 41 Providing a tool having a tool element
[0111] 42 Provide data (tool)
[0112] 43. Providing a measuring device having a sensor element
[0113] 44 Provide data (measuring device)
[0114] 51 Determine the length value
[0115] 52 Calculation of rated force
[0116] 53 Measuring actual force value
[0117] 54 Comparison by computational techniques
[0118] 55 Calculate the finishing value.
Claims
1. A method for determining locally distributed finishing values of a die-cutting station, wherein a sensor field (22) comprising a plurality of sensor elements (23) measures locally distributed values of forces caused by a plurality of tool elements (11) of a manipulated tool (10), characterized in that a) During the measurement, a number of tool elements (11) W is present i and a number K of sensor elements (23) S k , where for subscripts i and k: 1≤i≤I and 1≤k≤K; b) For each tool element (11) W i Calculate the length value LW ik And predetermine the length-dependent rated force value FW i , where the length value LW ik Indicates sensor element (23) S k The measuring range (24) of the tool element (11) W i Length and rated force FW i Indicates tool element (11) W i Length-dependent rated force; c) For each sensor element (23) S k Calculate the rated force F k , where for a plurality of tool elements (23) W j Applicable: F k =∑ j (LW jk ×FW j ), where for subscript j: 1≤j≤I; d) In each sensor element (23) S k The actual force value FM is measured in the measuring range (24) k ; e) For each value of k, set the rated force F k and actual force value FM k The comparison is made and based on the determined deviation DF k =F k -FM k Calculation finishing element (31) ZE k The finishing value ZRW k .
2. The method according to claim 1, characterized in that For only one value k, using the refinement value ZRW k Create finishing element (31) ZE k ; or, for multiple values of k, using the refinement value ZRW k Create finishing components (31) ZE separately in the case of k ; or, for each value k, using the refinement value ZRW k Create finishing components (31) ZE separately in the case of k .
3. The method according to claim 1 or 2, characterized in that: In step e, the finishing value ZRW k is calculated as the local height value of the finishing sheet (30), namely for each finishing element (31) ZE of the finishing sheet (30) k .
4. The method according to claim 1 or 2, characterized in that: In step e, the finishing value ZRW k The adjacent height values of the finishing sheet (30), namely, the finishing elements (31) ZE for the finishing sheet (30), are calculated. k adjacent finishing element (31).
5. The method according to any one of the preceding claims, characterized in that Producing a finishing sheet (30) comprising all k finishing elements (31) ZE k .
6. The method according to claim 5, characterized in that The finished sheet (30) is produced by an additive process.
7. The method according to any one of the preceding claims, characterized in that Steps d and e of the method are carried out iteratively, wherein an intermediate finishing sheet (30a) is produced and the iteratively measured finishing value ZRW is converted to k Combined and used to produce the final finished sheet (30b).
8. The method according to any one of the preceding claims, characterized in that In step c, only those sensors S which are located at least partially on the sensor element (23) are used. k The tool element (11) W in the measuring range (24) j , that is, the length value LW jk Tool element ≠0.
9. The method according to any one of the preceding claims 1 to 7, characterized in that In step c, apply W j =W i All tool elements (11).
10. The method according to any of the preceding claims, characterized in that Step d is performed in a measuring station (20) different from the die-cutting station (4).