Quality inspection and discharge of individual products in an automated product processing line

Abstract

The present invention relates to the quality inspection of individual products in an automated product processing line. In order to enable a comparatively simple and reliable quality inspection of individual products in an automated product processing line, a method is proposed comprising the following steps: detecting (41) at least one product property of individual products (3) passing through the product processing line; detecting (42) defective individual products (3) by evaluating the detected product property; marking (43) individual products (3) identified as defective with a marking (7) detectable with the aid of a metal detector (33), in particular a metallic or metal-containing marking; identifying (44) marked individual products (3) with the aid of a metal detector (33); and automatically removing (45) identified individual products (3) from the product processing line.

Description

[0001] The present invention relates to a method and a device for quality inspection of individual products in an automated product processing line, in particular for quality inspection of folding boxes during their production in an automated production line that includes a folding box gluing machine. Furthermore, the invention relates to an automated product processing line or a folding box gluing machine with such a quality inspection device.

[0002] For cost reasons, product processing lines are often fully or partially automated. However, particularly with fully automated lines, visual inspection by the worker is eliminated. To still guarantee the required product quality, quality inspection systems are used to detect defective products. In automated product processing lines with integrated quality monitoring, automated rejection of defective products is also sought to reduce costs. However, automated rejection requires route tracking, which can be used to track a large number of products transported through a product processing line. Such route tracking often cannot be implemented, particularly with processing machines with older control systems, or is not feasible for other reasons.

[0003] Even in cases where individual products are accumulated within the processing line and / or where accumulated individual products are separated again, route tracking is not possible or only possible to a limited extent.

[0004] Various types of folding box gluing machines for producing folding boxes from blanks are known from the state of the art. Various automated processes for quality control of folding boxes during production are also known. These processes regularly check, among other things, the folding (folding accuracy) and the gluing (glue application, skewed gluing, etc.).

[0005] One object of the invention is to enable a comparatively simple and reliable quality inspection of individual products in an automated product processing line, in particular a quality inspection of folding boxes during their production in an automated production line that includes a folder-gluer. In particular, a quality inspection is to be provided in which the automated rejection of defective products is possible without line tracking.

[0006] This object is achieved by a method according to claim 1 or by the subject matter of the further independent claims. Advantageous embodiments of the invention are specified in the subclaims. The advantages and embodiments explained below in connection with the method also apply mutatis mutandis to the device according to the invention, and vice versa.

[0007] The method according to the invention comprises the following steps: detecting at least one product characteristic of individual products passing through the product processing line; detecting defective individual products by evaluating the detected product characteristic; marking individual products identified as defective with a marking detectable by a metal detector, in particular a metallic or metal-containing marking; identifying marked individual products with a metal detector; and automatically removing identified individual products from the product processing line. The device according to the invention comprises devices designed to carry out these method steps.

[0008] The invention enables a comparatively simple and reliable quality inspection of individual products in an automated product processing line based on the testing of product properties as quality characteristics, in particular a quality inspection of folding boxes during their manufacture in a production line that includes a folder-gluer. In particular, a quality inspection is provided in which an automated rejection of defective products is possible without route tracking. In this way, an automated rejection can also be carried out, for example, in folder-gluer machines in which individual folding boxes are accumulated to form an overlapping stream whose overlapping distance (distance from box to box) can be variably adjusted.

[0009] The solution according to the invention can be used in all processing lines in which – in contrast to continuous web systems – individual products are processed and in which no metallic base materials are used or in which the products do not contain metallic components. The solution according to the invention can be used particularly advantageously in the cardboard and corrugated board industry, in particular in the production of folding boxes using folding box gluing machines.

[0010] By identifying and evaluating the current scrap rate early on, rapid interventions can be made in ongoing production to prevent production errors, thereby reducing internal production costs. In addition to clearly marking and rejecting defective goods, precise evaluation and statistical analysis are possible.

[0011] According to preferred embodiments of the invention, the marking comprises applying, applying or inserting a metallic or metal-containing material (e.g. printing ink, varnish, offcuts or adhesive) or a metallic or metal-containing element (e.g. label, staple, nail, in particular tacks) to, onto or into an individual product identified as defective, in particular by spraying, printing, pressure extrusion, labelling, applying or shooting or other suitable marking methods.

[0012] As an alternative to an embodiment of the invention in which an automated selective ejection of individual products occurs, according to another embodiment of the invention, cumulative individual products are ejected during the automated ejection. In other words, even if bundled, stacked, or similar individual products contain only a single defective individual product, the entire bundle, stack, or similar product is ejected. This ensures that only high-quality, defect-free individual products leave the processing line.

[0013] An embodiment of the invention is explained in more detail below with reference to the drawings, in which: Fig. 1 a folding box gluing machine, Fig. 2 a folding box with a marking, Fig. 3 a process flow.

[0014] In the Fig. 1 and 2The folding box gluing machine and the folding box are shown only schematically and only with their essential components.

[0015] Blanks 2 are fed to an exemplary folding box gluing machine 1. The folding box gluing machine 1 comprises a series of stations arranged one after the other and forming an automated production line 10 through which the blanks 2 or the folding boxes 3 produced therefrom are transported in the process direction 4.

[0016] The corrugated board blanks 2 fed to the folding box gluing machine 1 are produced in a previous process (not shown). The corrugated board is printed in a sheet-fed printing press and then punched using a sheet-fed punching machine. The blanks 2 can also be provided with handles, viewing holes, or the like. Another suitable material is, for example, cardboard.

[0017] In an insertion station 11, the punched blanks 2 produced in this way are automatically inserted into the folding box gluing machine with the aid of an insertion robot and fed to a folding and gluing station 12, which forms the core of the production line. There, the blanks 2, which have bottom, lid, and side flaps in a manner known to those skilled in the art, are provided with an adhesive, for which purpose glue nozzles or the like are usually used to apply glue strips. The flaps are then folded or folded over in such a way that they glue together in an overlapping area. The folding boxes 3 thus obtained and laid flat pass through a pressing station 13. This comprises a pressing belt with which pressure is exerted on the shingled web and thus the glue points.

[0018] The folding box gluing machine 1 is designed for the production of e-commerce packaging and includes an additional e-commerce station 14 for applying applications for online commerce, such as hot-melt adhesive, silicone tape, and tear strip. The shingled stream is separated to apply the applications.

[0019] The folding boxes 3 are then stacked in packages at a packing station 15 and strapped with bundle bands for transport. An output station 16 with a palletizing robot completes the production line 10.

[0020] The individual stations are equipped with driven conveyors for transporting the blanks or folding boxes. During their passage through production line 10, the products are accumulated into a shingled stream or, if necessary, separated and re-accumulated. The conveyors and handling equipment required for this are known to those skilled in the art.

[0021] During the production of folding boxes, the following product properties can be monitored, among others: product weight, box dimensions and dimensional deviations, as well as folding accuracy and damage. In particular, gap size differences and crooked gluing can be detected and the shape and folding pattern of the 45° flaps can be monitored. Other product properties that can be monitored include: material defects in the cutting material used, printing errors, the readability of a barcode or QR code, the color density of applied printing inks, and color deviations in the substrate or the applied print (whiteness, CIELAB color space). Other product properties that can be monitored include: the positioning accuracy of the barcode or QR code, the positioning accuracy of labels or prints, the position of hot and cold glue applications, the position of tear threads, or the position of silicone tape in e-commerce applications.The presence of foreign particles can also be monitored. Suitable measuring devices, sensors, detectors, and the like, as well as their mode of operation, are known to those skilled in the art. Therefore, the required control units for these devices, as well as user and communication interfaces, and the like, will not be discussed further.

[0022] Depending on which product property is to be recorded for quality control purposes, an inspection of the products (blanks 2 or folding boxes 3) takes place when the products are separated or when the products are accumulated. Some of the verifiable product properties, such as weight or correct printing, can also be inspected on the blanks 2. An inspection of the glue application takes place before folding, i.e. also on the blanks 2 that are still separated. If necessary, the products are separated for inspection and then accumulated again. Such separation can be achieved by accelerating the products in a transport area to a speed that ensures separation of the flattened products. To detect crooked or incorrect gluing, the fully glued and flattened folding boxes 3 can also be measured in stack form.

[0023] By way of example, a device 20 and a method for quality control based on the testing of proper glue application as a product characteristic are described below. The process sequence is explained in steps 41 to 45 in Fig. 3 shown schematically.

[0024] At suitable inspection points 5 before, during, and / or after one of the production steps outlined above, detection devices 21 are provided for detecting one or more product properties of selected or preferably all individual products passing through the production line 10. These devices may include measuring devices, sensors, detectors, and the like.

[0025] At an inspection point 5, which is located in the production line 10 immediately after the glue application, a suitable detection device 21 is provided, which comprises, for example, a camera 31 for detecting 41 a proper glue application.

[0026] A detection device 22 for detecting 42 defective products by evaluating the product properties detected by the detection device 21 comprises evaluation software, which, in the example described here, is implemented in a central control and processing unit 9 of the folding box gluing machine 1. Measurement values ​​or other detection data acquired during the detection of product properties are transmitted from the detection device 21 to the detection device 22 in the control and processing unit 9.

[0027] The evaluation of the detected product properties in the detection device 22 is carried out, for example, based on a measurement window (target range), whereby the measurement tolerance can be individually adjusted depending on the product, type of corrugated cardboard, and material. If the evaluation of the product property reveals that the product is defective, the detection device 22 sends a corresponding control signal via the control and computing unit 9 to a marking device 23, which is designed to mark 43 products identified as defective with a marking, in particular a metallic or metal-containing marking, detectable with the aid of a metal detector.

[0028] The marking device 23 comprises, for example, a nozzle 32 for spraying a marking 7 with metal-containing printing ink onto a folding box 3 which has been identified as defective. The marking 7 is thus represented as a colour spot, as in Fig. 2illustrated by way of example. The printing ink can contain metallic color pigments to achieve the metal content required for reliable detection. The nozzle 32 is placed at a marking point 6, which is preferably located in the immediate vicinity of the inspection point 5 at which the product property was determined, which is the basis for the marking. Additional detection, recognition, and marking devices can be provided at all stations to check other quality characteristics.

[0029] The folding box 3 marked in this way passes through the production line 10 as described above. At a suitable location on the production line, preferably downstream of all inspection and marking points of the production line, preferably in the outfeed conveyor, there is an identification device 24 comprising a suitable metal detector 33. The identification device 24 is designed to identify 44 the marked folding boxes 3 by detection.

[0030] In this case, a suitable metal detector 33 operating according to the induction principle is designed for detecting ferrous metals and is constructed, for example, in the form of a detector tunnel with transmitter and receiver coils. The ferrous metal-containing printing ink used for the marking 7 is matched to the functionality of the metal detector 33 with regard to its electrical conductivity and / or magnetic permeability. The identification device 24 comprises a suitable evaluation unit with a signal processor for evaluating the measurement results of the metal detector 33.

[0031] At the end of the production line 10, a discharge device 25 is arranged at a suitable location, which is designed for the automated discharge 45 of the folding box stack from the production line in which a marked folding box 3 is located. For this purpose, as soon as a marked folding box 3 is identified, the identification device 24 sends a corresponding discharge signal via the control and computing unit 9 to the discharge device 25. In the example described here, the discharge device 25 is located directly behind the identification device 24 at a common identification and discharge point 7.

[0032] For the purpose of ejection, the ejection device 25 comprises, for example, a mechanical kicker 34 in the case of a bundle ejection of accumulated individual products outlined here.

[0033] Alternatively, the discharge device 25 can also comprise an elevator, a cross conveyor, or a roller table. In the case of selective individual discharge of individual products, the discharge device comprises, for example, a kicker, a flap, or a belt flap. The automatically discharged stacks are manually inspected. Stacks of folding boxes 3 without defective ones are discharged from the discharge station 16 for further use.

[0034] In the example described, all communication takes place using Ethernet interfaces of the participating devices or system components. Preferably, some or all of the participating devices of the device 20 according to the invention are connected via the central control and processing unit 9, both to each other and to the operating software of the folding box gluing machine 1, via a data connection 8. This concerns the detection device 21 for detecting one or more product properties, the recognition device 22 for detecting defective individual products by evaluating the detected product property, the marking device 23 for marking folding boxes identified as defective, the identification device 24 for identifying the marked individual products, and the discharge device 25 for automatically discharging the identified individual products from the production line 10.

[0035] With the aid of the present invention, a comprehensive quality inspection of folding boxes 3 can be performed during the ongoing manufacturing process. For example, compliance with previously defined tolerance values ​​is checked. Defective folding boxes 3 are marked and removed from the process, thus guaranteeing the recipient of the folding boxes 3 a defect-free, high-quality product.

[0036] The device according to the invention is designed to carry out the described method. Preferably, some or all of the devices involved comprise a data processing unit designed to carry out all steps in accordance with the method described here that are related to the processing of data. The data processing units, for example implemented in the central control and computing unit 9 of the folding box gluing machine 1, preferably have a number of functional modules, wherein each functional module is designed to carry out a specific function or a number of specific functions in accordance with the described method. The functional modules can be hardware modules or software modules.In other words, as far as the data processing unit is concerned, the invention can be implemented either in the form of computer hardware or in the form of computer software, or in a combination of hardware and software. As far as the invention is implemented in the form of software, i.e., as a computer program product, all of the described functions are implemented by computer program instructions when the computer program is executed on a computer with a processor. The computer program instructions are implemented in a manner known per se in any programming language and can be provided to the computer in any form, for example, in the form of data packets transmitted over a computer network, or in the form of a computer program product stored on a floppy disk, a CD-ROM, or another data storage medium.

[0037] All features presented in the description, the following claims, and the drawings may be essential to the invention, both individually and in any combination. These features or combinations of features may each constitute an independent invention, the use of which is expressly reserved.

[0038] When specifying a combination of features defining an invention, individual features from the description of an embodiment need not necessarily be combined with one or more or all other features specified in the description of that embodiment; in this respect, each sub-combination of features of one or more embodiments is expressly disclosed.

[0039] Furthermore, physical features of the device can be reformulated to be used as process features, and process features can be reformulated to be used as physical features of the device. Features reformulated in this way are implicitly disclosed. List of reference symbols

[0040] 1Folder-gluer 2Cutting machine 3Folding box 4Process direction 5Inspection point 6Marking point 7Identification and rejection point 8Data connection 9Central control and processing unit 10Production line 11Insertion station 12Folding and gluing station 13Pressing station 14E-commerce station 15Packing station 16Discharge station 20Quality inspection device 21Detection device 22Recognition device 23Marking device 24Identification device 25Discharge device 31Camera 32Nozzle 33Metal detector 34Kicker 41Detection step 42Recognition step 43Marking step 44Identification step 45Discharge step

Claims

1. Method for the quality inspection of individual products in an automated product processing line, in particular for the quality inspection of folding boxes (3) during their production in an automated production line (10) which comprises a folding box gluing machine (1), with the steps of: - detecting (41) at least one product property of individual products (3) which pass through the product processing line, - detecting (42) defective individual products (3) by evaluating the detected product property, - marking (43) individual products (3) which are identified as defective with a marking (7) which is detectable with the aid of a metal detector (33), in particular a metallic or metal-containing marking, - identifying (44) marked individual products (3) with the aid of a metal detector (33), and - automatically discharging (45) identified individual products (3) from the product processing line.

2. Method according to claim 1, wherein the marking (43) comprises applying or applying a metallic or metal-containing material to or on an individual product (3) identified as defective, in particular by spraying, printing or pressure extrusion.

3. Method according to claim 1, wherein the marking (43) comprises applying or introducing a metallic or metal-containing element onto or into an individual product (3) identified as defective, in particular by labelling, applying or shooting.

4. Method according to one of claims 1 to 3, wherein individual products (3) are selectively discharged during the automated discharge (45).

5. Method according to one of claims 1 to 3, wherein during the automated discharge (45) accumulated individual products (3) are discharged.

6. Device (20) for quality testing of individual products in an automated product processing line, in particular for quality testing of folding boxes (3) during their production in an automated production line (10) comprising a folding box gluing machine (1), - with a device (21) for detecting (41) at least one product property of individual products (2, 3) passing through the product processing line, - with a device (22) for detecting (42) defective individual products (2, 3) by evaluating the detected product property, - with a device (23) for marking (43) individual products (2, 3) detected as defective with a marking (7) detectable by means of a metal detector (33), in particular a metallic or metal-containing marking, - with a device (24) for identifying (44) marked individual products (3), wherein this device (24) has a metal detector (33),and - with a device (25) for the automated discharge (45) of identified individual products (3) from the product processing line., 7. Automated product processing line, in particular production line (10) comprising a folding box gluing machine (1), with a device (20) according to claim 6.

8. Folding box gluing machine (1) with a device (20) according to claim 6.

9. A computer program comprising instructions causing the apparatus of claim 6 to perform the method steps of claim 1.

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