Method for controlling a folding box machine for quality assurance

Abstract

A method controls a folding box machine having a plurality of machining stations and a plurality of control devices for controlling the quality of folding boxes. Each control device controls different quality features of each folding box, and each control device transmits the result of the control to a control unit. Target values are stored in the control unit in order to classify the control results into results which meet the quality standard and results which do not meet the quality standard, and a folding box is discharged depending on an evaluation. The method advantageously reduces waste.

Claims

1. A method for controlling a folding box machine having a plurality of processing stations and a plurality of control devices with detection devices to control a quality of folding boxes, which comprises the steps of: using a respective control device to control different quality features of a respective folding box; reporting, via the respective control device, a result of a control operation to a control unit; storing target values for classifying control results into results of the target values being met or not met in the control unit; activating an ejection device via the control unit to eject the respective folding box in dependence on an evaluation of a classification of all the control results; generating a combination of defects as a digital string from binary values based on the classification of all the control results for the respective folding box, wherein each binary value corresponds to a control result of the different quality features; and storing a detection limit for a respective digital string in the control unit, wherein the detection limit indicates how often a certain combination of defects belonging to the respective digital string may occur until the respective folding box is to be ejected.

2. The method for controlling the folding box machine according to claim 1, wherein the quality features are a quality of a printed image, the quality of an embossment, the quality of a Braille lettering, a presence of a code, a window, a glue line, and/or dimensions of the respective folding box.

3. The method for controlling the folding box machine according to claim 1, wherein the folding box machine is a folding box gluing machine.

4. A computer program for running on a control unit connected to a plurality of control devices, the computer program performing the method according to claim 1.

5. A non-transitory computer-readable data carrier storing computer executable instructions to be executed by a control unit connected to a plurality of control devices, the computer executable instructions performing a method for controlling a folding box machine having a plurality of processing stations and the plurality of control devices with detection devices to control a quality of folding boxes, the method comprises the steps of: using a respective control device to control different quality features of a respective folding box; reporting, via the respective control device, a result of a control operation to the control unit; storing target values for classifying control results into results of the target values being met or not met in the control unit; activating an ejection device via the control unit to eject the respective folding box in dependence on an evaluation of a classification of all the control results; generating a combination of defects as a digital string from binary values based on the classification of all the control results for the respective folding box, wherein each binary value corresponds to a control result of the different quality features; and storing a detection limit for a respective digital string in the control unit, wherein the detection limit indicates how often a certain combination of defects belonging to the respective digital string may occur until the respective folding box is to be ejected.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The present invention is explained in more detail with reference to the enclosed figure. For sake of clarity of the figure, the representation not to scale.

(2) FIG. 1 schematically shows a folding box gluing machine which is controlled in accordance with the present invention.

DESCRIPTION OF THE INVENTION

(3) FIG. 1 shows a folding box gluing machine 100 according to an inventive embodiment. If seen in the transport direction T of the folding boxes, it comprises, for example, the following processing stations: a feeder 1, an alignment station 4, a control device 17 for two-dimensional error control, a braille embossing device 18, followed by braille embossing control device 19, a pre-folding station 6, a set-up folding box station 30, a folding station 7, a further control device 20, an ejection module 31, a transfer station 15 and a collecting and pressing device 16. The processing stations and their order should be considered as only exemplary. Likewise, the arrangement and number of control devices 17, 19, 20 is only exemplary. If a higher number of quality features is to be examined, a significantly higher number of control devices can be used. It is also possible that one control device controls several quality features. The control station 17 is connected to a control unit 32 to transmit data of defective boxes to this control unit. An evaluation of the control results is carried out in the control unit 32. Depending thereon, the control transmits signals to ejection unit 31 to eject these defective boxes. In the braille embossing control device 19, the braille embossments are examined as to their height, area and volume, i.e. they are examined topographically f defects. Furthermore, the position of the braille embossment with respect to the box edge and the completeness and correctness of the embossment is analyzed. The data are then either shown on a display so as to allow an operator to carry out respective corrections manually, or are transferred via the control 32 to the respective station to allow an automated adjustment or ejection. In the further control device 20, further box features can be examined, for example the quality of the folds. The result of the control is fed back to the control 32.

(4) The working principle of the control method and the quality control is explained in more detail in the following.

(5) An arbitrary number of quality features or quality criteria is assigned to each box in a predetermined order. Each quality criterion can have a value of 1 or 0, i.e. good or bad. An un-transmitted signal is evaluated like 0. The number of quality criteria make up a digital string which can also be termed box ticket or Folding Box Quality Format.

(6) The following describes in more detail an example with three quality criteria: code on adhesive tab, box rotation>2 and braille lettering present.

(7) The digital string can have the following values: 000 Code wrong, box rotation>2, braille lettering missing 001 Code wrong, box rotation>2, braille lettering correct 010 Code wrong, box rotation<2, braille lettering missing 100 Code correct, box rotation>2, braille lettering missing 011 code wrong, box rotation<2, braille lettering correct 101 code correct, box rotation>2, braille lettering correct 110 code correct, box rotation<2, braille lettering missing 111 code correct, box rotation<2, braille lettering correct

(8) It is conceivable that all boxes having 111 reach the transport stage.

(9) Moreover, boxes identified by 101 can be used in case the box rotation of>2 and a resulting slant adhesion can be accepted.

(10) In view of above-mentioned AQL, boxes identified by 101 could reach the transport stage with a predetermined percentage and be ejected as soon as the maximum number of defects has been reached.

(11) Alternatively, the boxes identified by 101 are merely marked to allow their collection as second quality, or they are assigned to another transport area by a suitable sorting system.

(12) The determination whether a box is to be ejected for a certain string, i.e. in case of a certain combination of defects, can be also be given depending on the product to be produced. For example, in case of a pharmaceutical folding box, an ejection can always be made if the quality of imprinted text, braille lettering or code is insufficient, independently from the further quality features. On the other hand, in case of cosmetic packaging, more importance can be placed on the optical appearance and quality features like ornamental embossments, metallization, color or the like.

(13) By a control method as described, the following advantages can be obtained: Sorting according to different quality criteria, first choice, second choice, third choice, is possible AQL can be met Continuous evaluation of AQL, as a moving average, in lots of 1,000 boxes, etc. Variable design of the quality criteria depending on the customer segment (pharma, cosmetics, food, non-food, confectionery, . . . ) or depending on the customer And overall a reduction of waste, i.e. of maculature.