Method for determining local distribution trim value of die cutting station
By using sensor components to measure waste cleaning power in waste cleaning stations or useful partial separation stations, the problem of difficult to determine the local layout and dressing value during the die cutting process is solved, and accurate dressing value calculation and automation are realized, improving the efficiency of die cutting production and quality.
Patent Information
- Application Number
- CN202410933353.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-07-12
- Filing Date
- 2024-07-12
- Publication Date
- 2025-01-14
AI Technical Summary
During the die-cutting process, it is difficult for the prior art to accurately determine the local layout dressing value, resulting in the die-cutting tool elements not meeting the expected results, and manual evaluation is time-consuming and experience-dependent, affecting production efficiency and product quality.
By setting sensor elements at a cleaning station or a useful partial separation station, the cleaning force is measured to determine the trimming value of the partial layout, and converting it using calculation techniques to generate appropriate trimming sheets to improve the die cutting results.
Accurate measurement and automated calculation of local partial layout trimming values are realized, which significantly reduces the workload of setting up die cutting stations, saves time and costs, and improves productivity and product quality.
Smart Images
Figure CN119304960A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for determining locally distributed trimming values for a die-cutting station.
[0002] The invention belongs to the field of graphic arts industry technology, 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 die-cut products made of paper, cardboard, paperboard, plastic or composite materials. Background Art
[0003] During the die-cutting process, for example in 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 result, 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 is true for embossing. In this case, it may be helpful to increase the die-cutting force locally, that is, in the area of the tool element that punched incorrectly. For this purpose, so-called trimming sheets can be produced. According to the conventional method, the machine operator manually applies one (or more) adhesive strips of a certain thickness as so-called trimming elements at the locations where the local increase in the die-cutting force is required. The thickness of the trimming sheet can also be changed locally in multiple places. During the production process, the trimming sheet is placed under the die-cutting tool and the die-cutting force is increased locally through its adjusted thickness profile, so that an overall satisfactory product is produced.
[0004] EP2327521B1 discloses a method for trimming tools of a die-cutting machine and / or embossing machine. In this case, the pressure distribution is measured by a surface-shaped and in particular film-shaped pressure distribution sensor extending on the tool surface. The pressure distribution sensor is arranged between the protective plate and the movable upper platen within a station of the die-cutting machine and / or embossing machine. The machine also has a waste removal station downstream of this station, but no measurements are performed in this station.
[0005] It is also known to determine the trim value by the machine operator. Here, the operator visually assesses the separation point after a trial stripping. However, the operator must be very experienced to make such an assessment and the process is very time-consuming. Summary of the invention
[0006] The object of the present invention is to provide an alternative method to the prior art which preferably allows the determination of locally distributed trimming values with sufficient accuracy to achieve satisfactory punching results.
[0007] According to the invention, the object is achieved by a method in a preferred technical solution.
[0008] Advantageous and therefore preferred embodiments of the invention are revealed in the alternative embodiments, the description and the drawings.
[0009] According to the invention, a method for determining locally distributed trimming values for a die-cutting station is provided, wherein a sensor field of a plurality of sensor elements measures locally distributed values of forces caused by a plurality of tool elements of a manipulated tool, characterised in that the sensor field measures locally distributed values of stripping forces caused by a plurality of stripping elements of a manipulated stripping tool in a stripping station, a useful part separation station or a measuring station.
[0010] Advantageous design and effects of the present invention
[0011] The invention advantageously enables the locally distributed trimming values to be determined with sufficient accuracy to achieve a satisfactory die-cutting result. The invention provides a combined measuring and calculating method for this purpose. Furthermore, the invention can also be automated.
[0012] The invention has the advantage that the workload can be significantly reduced when setting up a die-cutting station, especially when setting up a so-called first operation, thereby saving a lot of time. The invention can therefore save costs, preferably operating personnel costs, and increase productivity due to the additional production time of the die-cutting station.
[0013] According to the invention, in contrast to the known prior art, the force measurement is not carried out in the die-cutting and / or embossing station or in a separate (die-cutting and / or embossing) measuring station, but in the stripping station, the useful part separation station or in a separate (stripping) measuring station. The forces determined in situ during the stripping or separation process are then used to determine the trimming values and, if necessary, also to carry out a corresponding conversion. The values etc. required for the appropriate conversion can be determined beforehand by experiments and then provided.
[0014] Therefore, the process of producing a new die-cut product (new "job") using a specific die-cutting tool may include the following steps: performing a test die-cutting using the die-cutting tool, clearing the test die-cut sheets or separating the useful parts of the test die-cut sheets, locally / spatially measuring the clearing force (the force when separating the useful parts from the useful parts is also referred to as the clearing force here), converting the clearing force into a trimming value, trimming the trimmed sheets, placing the trimmed sheets under the die-cutting tool and performing productive die-cutting.
[0015] The invention is an alternative to known measuring solutions in die-cutting and / or embossing stations.
[0016] Expansion scheme of the present invention
[0017] Preferred developments of the present invention (developments for short) are described below. These developments can also be combined with one another, unless technically excluded.
[0018] A further development may be characterized in that locally distributed correction values are calculated from the measured values by computational techniques. In order to calculate the correction values from the measured values, the required conversion values etc. may be determined and stored in advance by experiments and then provided.
[0019] An extension may be characterized in that several trimming elements are created using the calculated trimming values.
[0020] One development can be characterized in that the measurement is performed by means of a measuring foil or a measuring pad which comprises the sensor element.
[0021] One development can be characterized in that the measuring foil or the measuring pad is arranged on the stripping tool.
[0022] One development can be characterized in that the measuring foil or the measuring pad is arranged on the rear side of the stripping tool.
[0023] One development may be characterized in that a tool with movable waste removal elements may be used as the waste removal tool. These elements are preferably movable.
[0024] One development can be characterized in that the movable stripping elements are received in respective guides.
[0025] One development can be characterized in that the movable removal element transmits the force to be measured to the sensor element.
[0026] One development can be characterized in that the stripping tool interacts with a counter tool, the stripping opening of which is dimensioned in such a way that no appreciable additional forces are generated when measuring the stripping force.
[0027] One development can be characterized in that the stripping opening is dimensioned so as to have an overdimension.
[0028] An embodiment can be characterized in that the removal force is measured at the separation point between useful part and grid and at the separation point between useful part and useful part.
[0029] One development can be characterized in that a trimmed sheet is produced which includes the trimming element.
[0030] One development can be characterized in that the trimming sheet is produced additively.
[0031] One development can be characterized in that a finishing sheet is printed.
[0032] One development can be characterized in that the trimming sheet is printed using an inkjet printing process.
[0033] One development can be characterized in that the trimmed sheets are produced automatically by locally applying the trimming tape.
[0034] One development can be characterized in that the trimming sheet is produced manually by partially gluing sections of the trimming tape, wherein the gluing locations are indicated.
[0035] One development can be characterized in that the trimmed sheets are produced manually by locally gluing sections of trimming tape, wherein the thickness of the tape is indicated.
[0036] One development can be characterized in that the trimmed sheets can be produced using a subtractive or process method.
[0037] One development can be characterized in that the trimming sheet is produced automatically by partially removing layers of the multi-layer trimming sheet.
[0038] An extended concept can be characterized in that the stripping force is measured within a measuring time window in which the stripping element is expected to be active.
[0039] One development can be characterized in that the removal force is measured within the measuring time window with a predetermined time resolution; for example 500 Hz.
[0040] One development can be characterized in that the calculation is performed using a digital computer.
[0041] The features and feature combinations disclosed in the above technical field, summary and development sections as well as in the following exemplary embodiments section represent further advantageous developments of the invention, and these features and feature combinations can be combined with one another as desired. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Figures 1 to 4 The preferred embodiments and extensions of the present invention are shown. In the figures, corresponding features are indicated by the same reference numerals. For the sake of clarity, repeated reference numerals in the figures are partially omitted. DETAILED DESCRIPTION
[0043] Figure 1 A schematic (longitudinal) cross-sectional view of a preferred machine configuration for carrying out a preferred embodiment of the method of the present invention is shown. Figure 1In the figure, a flatbed die-cutter 1 is shown in the center, which has a processing direction 1a for the sheets and has an upper tool and a movable lower tool; the die-cutter comprises, one after the other along the processing direction, a feeder 2 for stacking the 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 the 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, namely a die-cutting element 11'; the lower tool is arranged opposite the upper tool and interacts with the upper tool as a matching tool 13.
[0044] The machine configuration optionally includes (shown on the right) a prepress device 15 , for example 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.
[0045] According to the invention, a measuring process is preferably carried out in the waste stripping station 5 (or the useful part separation station 6) to obtain measured values, which can be used to generate suitable, i.e. fully compensated trimmed sheets (or calibration sheets), and the measuring process is described in detail below in conjunction with the further figures. Alternatively, the machine configuration can also include an optional separate measuring station 20 with a measuring device 21 for automatically measuring the local force distribution values during the waste stripping process (illustrated exemplarily at the bottom left); the station is preferably connected to a computer 17 for data transmission.
[0046] The machine arrangement comprises a device 32 for automatically producing a trimmed sheet 30 (shown by way of example at the upper left) based on the removal forces measured according to the invention; this station is preferably also connected to a computer 17 for data transmission.
[0047] The device 32 for automatic production can preferably produce a trimmed sheet 30, an intermediate trimmed sheet 30a and / or a final trimmed sheet 30b. The production can be carried out by producing or placing a trimming element 31: the production is preferably carried out by applying a liquid or pasty (hardening or hardenable) trimming material (such as ink); the placement is preferably carried out by applying a self-adhesive trimming tape or a section thereof (such as a tape section). The intermediate trimmed sheet 30a can be produced as an (intermediate) result of a continuous iterative measurement and can be used together in subsequent production. The final trimmed sheet 30b can be produced as a (final) result of a continuous iterative measurement and used in production (the final trimmed sheet represents the sum of the intermediate trimmed sheets).
[0048] After the measurement is completed, the trimmed sheet 30 matching the tool 10 is taken out from the device 32. The trimmed sheet is then placed in the punching station 4 so that production can be carried out without punching errors.
[0049] Before measuring the forces during the stripping process, the sheet 8 to be measured is die-cut. Here, the feed is preferably selected so that the die-cutting knife cuts through approximately 70% of the surface. This feed can be carried out manually, for example in steps of 30 to 50 micrometers. The forces are then measured locally or partially during stripping, i.e. the sheet 8 is moved to the stripping station 5 or the measuring station 20.
[0050] Figure 2 A schematic cross-sectional view of a preferred embodiment is shown. Figure 2 The measuring station 20 shown with the measuring device 21 can be Figure 1 (lower left) shown station; however, preferably, the stripping station 5 performs stripping during the production process and is used as a measuring station 20 itself during interruptions or measuring phases in order to measure the forces during the stripping process with a measuring device 21.
[0051] Figure 2 A tool 10 is shown, in this case a stripping tool 10 ′ with a plurality of tool elements 11 , in this case stripping elements 11 ′. The stripping elements 11 ′ are received in a guide 12 in a movable manner, for example displaceable manner (see direction of movement 12 a; in the example shown, upward and downward). The tool 10 works together with a mating tool 13 (in this case, a lower tool); the mating tool comprises a stripping opening 13 a, which optionally has an oversize 13 b in order to avoid deviations in the forces to be measured. The oversize 13 b is preferably realized at least in the upper region of the stripping opening 13 a. It may be advantageous to provide, for example, a projection 13 c (without oversize or with a slight undersize) in the middle region of the stripping opening 13 a with an oversize, with which the mesh 8 b (or another piece of waste material to be stripped) contacts with its edge. By contact and light clamping, it is possible to prevent the mesh 8 b to be stripped from being carried upwards instead of downwards. When the size of the protrusion 13c is optimized, the mesh 8b will pop up downward.
[0052] Such a stripping tool 10 ′ can also be used to separate useful parts from one another, ie can also serve as a (useful part) separation tool; the same applies to the stripping element 11 ′.
[0053] During the stripping process, the movable stripping element 11 ′ transmits the stripping forces to the sensor elements 23 of the sensor field 22 of the measuring device 21, which are preferably assigned to the stripping element on the rear side. In this case, preferably a measuring range 24 is assigned to each stripping element 11 ′. In this way, the distribution of the stripping forces can be measured locally or locally. The measured values obtained in this way are preferably transmitted and (temporarily) stored in order to further calculate and obtain the required correction values.
[0054] The stripping tool preferably has a measurement grid or local measurement resolution that corresponds to the grid used for placing stripping elements on the stripping tool.
[0055] Figure 3 A schematic cross-sectional view of a preferred embodiment is shown. The useful part 8a is stripped or separated from the adjacent useful part 8a by means of the (lowered) stripping element 11' of the stripping tool 10' and by means of the locally and temporarily lowered mating tool 13. The stripping force occurring in this process is measured by means of the sensor element 23. Thus, if there is no useful part separation station 6, the stripping force between two useful parts can also be measured directly in the stripping station 5.
[0056] Figure 4 A schematic top view of a preferred embodiment is shown. The grid in the figure corresponds to the local (measurement) resolution (or spatial measurement resolution) of the existing sensor element 23, for example 8x8 millimeters. The figure shows, by way of example, a sheet 8 with at least two adjacent useful parts 8a, which are separated from the surrounding grid 8b by a stripping process (at the boundary 9a shown in bold) and from one another (at the central separation line 9b, also shown in bold). The grid is removed after stripping and, if necessary, processed. The separation of the two useful parts 8a from one another is carried out by means of a stripping tool 11 or its stripping element 11 ′, which, by way of example, presses the useful part 8a shown on the right downwards at the separation line 8c. When measuring the stripping force, the useful part 8a shown on the right is pressed downwards at the separation line 8c by, for example, 5 millimeters. Measurements at the separation points of useful part from useful part can be carried out by means of stripping elements specially installed or switched on for this purpose (because: as standard, no separation between useful part and useful part is carried out during stripping); lowering (or removal) of the mating tool can also be carried out at these points / lines.
[0057] If the measurement of the removal forces is carried out in the removal station 5 , preferably all components which are required only for the measurement and which influence the production removal are removed during the production process or, for example, folded or pushed away.
[0058] The process of measuring and trimming can be repeated until the best trim is found. For example, the trim values found each time can be added together.
[0059] List of reference numerals:
[0060] 1 Flatbed die cutter or die cutter (and / or embossing machine)
[0061] 1a Processing direction
[0062] 2 Feeder
[0063] 3 Feeding table
[0064] 4 die-cutting stations and / or embossing stations
[0065] 5 Waste Removal Station
[0066] 6 Useful part separation station
[0067] 7 Take out the sample
[0068] 8 pages
[0069] 8a Useful part
[0070] 8b Grid
[0071] 9a Separation point / separation line
[0072] 9b Separation point / separation line
[0073] 10 Tools
[0074] 10` Waste removal tools
[0075] 11 Tool elements
[0076] 11`Waste removal components
[0077] 12 Guide device
[0078] 12a Mobility / direction of movement
[0079] 13 Matching tool / lower tool
[0080] 13a Stripping opening
[0081] 13b Oversize
[0082] 13c Raised
[0083] 15 Prepress equipment
[0084] 16 data memory / data
[0085] 17 Digital Computer
[0086] 20 measuring stations
[0087] 21. Measuring device
[0088] 22 Sensor Field
[0089] 23 Sensor element
[0090] 24 Measuring range
[0091] 30 Trimming sheets
[0092] 30a Intermediate trimming sheet
[0093] 30b Final trim sheet
[0094] 31 Trimming components
[0095] 32Device for producing trimmed sheets
[0096] 33 Finishing Materials
[0097] 34 Trimming tape.
Claims
1. A method for determining locally distributed trimming 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 The sensor field (22) measures locally distributed values of the stripping forces caused by a plurality of stripping elements (11') of an actuated stripping tool (10') in a stripping station (5), a useful part separation station (6) or a measuring station (20).
2. The method according to claim 1, characterized in that The correction value of the local distribution is calculated from the measured values by means of a computational technique.
3. The method according to claim 2, characterized in that A number of trimming elements (31) are created using the calculated trimming values.
4. The method according to any one of the preceding claims, characterized in that The measurement is performed by means of a measuring foil (22) or a measuring pad (22) which comprises the sensor element (23).
5. The method according to any one of the preceding claims, characterized in that A tool (10) having a movable stripping element (11') is used as a stripping tool (10).
6. The method according to claim 5, characterized in that The movable stripping element (11') transmits the force to be measured to the sensor element (23).
7. The method according to any one of the preceding claims, characterized in that The stripping tool interacts with a mating tool, the stripping opening of which is dimensioned in such a way that no appreciable additional forces are generated when measuring the stripping forces.
8. The method according to claim 7, characterized in that The stripping opening (13a) is dimensioned to have an oversize (13b).
9. The method according to any one of the preceding claims, characterized in that The waste removal force is measured at the separation point (9a) between the useful part and the grid and at the separation point (9b) between the useful part and the useful part.
10. The method according to any of the preceding claims, characterized in that A trimmed sheet (30) including a trimming element (31) is produced.