Labeling device, in particular in a beverage filling machine, comprising an ammeter for evaluating the labels

Abstract

The present invention relates to a labeling device comprising an ammeter by means of which the labels to be attached are evaluated and which is used to react to anomalies with regulating actions during operation in order to ensure the desired labeling result.

Description

[0001] Labeling device, in particular in a beverage filling plant, comprising an ammeter for evaluating the labels

[0002] Field of the invention

[0003] The present invention relates to a labeling device with an ammeter with which the labels to be applied are evaluated

[0004] State of the art

[0005] Labels applied using a labeling device, particularly in beverage bottling plants, can be evaluated for their water absorption, especially when water-based adhesives are used. US 2006 / 124239 A, for example, describes wet-glue labeling, which uses a liquid adhesive to affix the label to the container. Wet adhesives are applied to a label shortly before the label is attached to the object to be labeled (such as a bottle). For optimal label application, the so-called Cobb value (water absorption of the paper) is determined. The Cobb value can be determined, for example, in accordance with DIN 53121 (August 2014).The Cobb value, a measure of water absorption, is used to determine a balance with regard to adhesion and rapid application and secure positioning of the label, as it can be used to determine, for example, relevant process parameters for the amount or type of adhesive to be used.

[0006] However, it has been shown that determining the Cobb value is not always sufficient to ensure consistent labeling quality. Especially when there are fluctuations in the quality of the label material, a preliminary determination of the Cobb value is not sufficient to ensure trouble-free labeling. At the same time, it has been shown that determining the Cobb value is not always sufficient to predict the actual behavior of the labels during application.

[0007] There is therefore a need for a more accurate way to predict the labeling behavior of a label during bonding, especially with a water-based adhesive (applied, for example, by spraying). This method should also be feasible during ongoing operation of a labeling device, thus obtaining measurement results during operation that allow for direct intervention in the labeling process, for example, by adjusting the type or quantity of adhesive.

[0008] Brief description of the invention

[0009] It has surprisingly been found that the aforementioned problems can be solved by performing an ammeter measurement on the labels. The present invention is based on this finding.

[0010] Detailed description of the invention

[0011] Ammeter measurements on labels can be performed, for example, in accordance with the measurement procedure described in GB 403304 A. The information obtained with such a measurement, which, similar to the determination of the Cobb value, is a measure of the label's water penetration behavior, has proven to be a more accurate (but at the same time simpler) way of determining relevant information for labels to be used in the context of the present invention.

[0012] The information obtained by the ammeter measurement allows for more precise control of the labeling process, as it predicts the actual behavior of a label when bonded with a water-based adhesive in a labeling device better than the Cobb value. Ammeter measurement, in particular, allows for a precise and rapid determination of the penetration rate of water (and thus also of water-based adhesives) into the label. This measured value allows for precise control and regulation of the labeling process. In particular, if the quality of the label material changes (which also occurs within a given batch of labels), the labeling process can be quickly adapted to the changing label quality.

[0013] Within the scope of the present invention, the quality of the labeling, in particular the precise and durable positioning of the label, can be ensured by taking into account the measured value of the ammeter measurement.

[0014] For this purpose, for example, an ammeter measurement can be continuously performed on labels during operation of a labeling device. For example, a labeling device can be connected to an ammeter measuring station in such a way that at least one out of every thousand labels, for example three out of every thousand, is diverted from the continuous feed of labels to the labeling device and fed to the ammeter measuring station. The information obtained from the ammeter measurement can then flow back into the control or regulation of the labeling device in order to effect an adaptation of the adhesive quantity or adhesive composition when a change in the measured value of the ammeter measurement is detected. This allows for more precise and better control of the labeling result, even compared to determining the Cobb value.

[0015] Within the scope of the present invention, however, it is of course also possible and preferred in embodiments if, in addition to the ammeter measurement, a determination of the Cobb value also takes place. This can basically be integrated into a labeling device in an analogous manner. In addition to the ammeter measuring station, the labeling device of the present invention can therefore also have a measuring station for determining the Cobb value. Again, for this purpose, a desired number of labels can be diverted from the label feed to the labeling device during ongoing operation and fed to the measuring station for determining the Cobb value. The labeling device of the present invention then likewise has the devices necessary for diverting the labels, so that these labels are then fed to the measuring station for determining the Cobb value, as in the ammeter measurement.The information obtained when determining the Cobb value, which supplements the results of the ammeter measurement, can then be incorporated into the control or regulation of the labeling process.

[0016] Finally, the labeling device can also comprise, in combination with the device for determining the Cobb value or on its own, a device for determining the flexural rigidity of the labels. Again, for this purpose, a desired number of labels can be diverted from the label feed to the labeling device during operation and fed to the measuring station for determining flexural rigidity. The labeling device of the present invention then also comprises the devices necessary for diverting the labels, so that these labels are then fed to the measuring station for determining flexural rigidity, as in the ammeter measurement. The information obtained during the determination of flexural rigidity, which supplements the results of the ammeter measurement, can then be incorporated into the control or regulation of the labeling process.

[0017] As already explained above, the present invention provides the result of the ammeter measurement as a measure for determining the quality of labels (i.e., in particular, their suitability for use in a labeling device using a water-based adhesive, in particular in a high-speed labeling process with spray application of the adhesive). It has been shown that labels are particularly suitable for use in such a process if they exhibit rapid penetration behavior towards water, which can be quantified by the time course of the increase in the measured value during the ammeter measurement.

[0018] In the context of the present invention, it was particularly found that this suitability can be determined not only qualitatively / relatively (a rapid increase in the measured value is better than a slow increase in the measured value), but also quantitatively via the increase in the measured value in the ammeter measurement as defined below.

[0019] For this purpose, the increase in current during the measurement (as described here, measured value at time 0 seconds (start of measurement) is 0 mA) is determined from the start time until a current value of 0.9 mA is reached, with determination of the times necessary to reach currents of 0.1 to 0.9 mA (in steps of 0.1 mA).

[0020] High-quality labels, i.e. those which are suitable for problem-free use in the high-speed labeling processes described above, are characterized by an increase in current strength during the ammeter test, wherein a current strength of 0.7 mA is reached within a period of 30 s or less, preferably 20 s or less, in embodiments approximately 15 s. A preferred course of the increase in current strength is one in which a measured value of 0.1 mA is reached after 15 s or less, preferably 10 s or less, such as approximately 5 s, and a measured value of 0.5 mA is reached after 20 s or less, preferably 15 s or less, such as approximately 10 s.

[0021] It has been shown that with such a current increase profile, labels can demonstrate excellent suitability for use in high-speed labeling devices with spray application of a water-based adhesive (i.e., good adhesion, low tendency to edge or corner lifting or label slippage), regardless of the type of label (printed, metallized, etc.). The present invention thus shows that labels with a very rapid initial current increase to 0.1 mA and a subsequent, still rapid but slowing current increase can be very well used in the labeling processes described here.

[0022] If, in addition to the ammeter measurement, the Cobb value and / or the flexural rigidity of the labels are also determined, the measured values ​​obtained can also be used to evaluate the labels and thus to control or regulate the labeling process.

[0023] It has been shown that, in combination with the results of the ammeter measurement, labels with a flexural rigidity in the range of 0.1 to 0.01 Nmm, preferably in the range of 0.75 to 0.05 Nmm, are particularly suitable for use in high-speed labeling systems. In principle, with regard to flexural rigidity, lower values ​​are advantageous within the scope of the present invention.

[0024] With regard to the Cobb value, determined as indicated here after 60 s, it is preferably in the range of 10 to 80 g / m 2 should be, with values ​​in the upper range being preferred.

[0025] Labels that are particularly preferred and suitable for use in the labeling systems described here therefore preferably have short penetration times against water (ammeter measurement), while at the same time having low values ​​for flexural strength and (relatively) high Cobb values.

[0026] Such labels are therefore particularly suitable for use in labeling systems with spray application of a water-based adhesive and ensure a high-quality labeling process. In principle, the knowledge provided by the present invention regarding target values ​​for penetration behavior (ammeter measurement), flexural rigidity, and Cobb value enables a simple yet highly accurate evaluation of labels, possibly even before their actual use in a labeling process. In particular, with metallized labels, the basic suitability for use in labeling can be tested on test pieces, and modifications can be made if deviations from the target values ​​occur, for example, with regard to label thickness, base material (paper type), number and material of intermediate layers, etc.

[0027] In particular, it can be provided that the invention can also be used for applying the adhesive using a glue roller (conventional labeling) instead of spray application. The labeling device can therefore have a glue roller for applying the adhesive and / or the aforementioned device for spray application (spray nozzles). The labels to be evaluated within the scope of the present invention are labels with at least one paper layer. The labels can be printed, have metallized layers, and can also be multi-layered. Such additional layers can be polymer layers, lacquer layers, intermediate layers to improve the adhesion of the different layers in multi-layer labels, and also protective layers, etc.

[0028] The ammeter measurement, as well as the optional determination of the Cobb value, is performed on the side (paper layer) of the label that is coated with the adhesive and applied to the object to be labeled. In a preferred embodiment, the flexural rigidity of the labels can also be determined as a third parameter. In this particularly preferred embodiment, a total of three parameters are determined on the labels to be used: the ammeter measurement, the determination of the Cobb value, and the determination of the flexural rigidity.

[0029] As already stated above, the adhesive used for labeling is preferably a water-based adhesive that is applied by spraying in the labeling device, either directly onto the label or onto the surface of the object to be labeled. This type of spraying can be achieved using spray nozzles, similar to an inkjet printing process.

[0030] It has been shown that by determining the speed of water penetration into a label using an ammeter and using the information thus obtained during labeling, a high quality of labeling can be achieved for a variety of different labels (simple paper label, printed paper label, metallized paper label).

[0031] The present invention thus also provides a method for quality control of labels, wherein the method comprises an ammeter measurement, optionally in combination with the determination of the Cobb value and / or the determination of the flexural rigidity, on the labels. This quality control also allows the monitoring and control of the labeling process, since the labeling process can be regulated / controlled based on knowledge of the parameters described and determined here (result of the ammeter measurement, Cobb value and / or flexural rigidity). By storing such measurement results in combination with the respective labeling behavior as well as other relevant information about the labeling process (adhesive used, amount of adhesive applied, type of object to be labeled, other parameters such as temperature and humidity, etc.), the labeling process can be monitored and controlled.), a library of information can be created which, when used with appropriate systems, can lead to a self-learning system for controlling and regulating the labeling process. This allows stable labeling processes to be set up more quickly, thus reducing waste when starting up a labeling process.

[0032] The ammeter measurement is used to determine, in particular, the speed at which water penetrates the label. This information is a key factor for the control and regulation of a labeling device in which labels are applied to objects to be labeled using water-based adhesives. As with the labeling device described above, those skilled in the art will understand that the evaluated labels are not used for labeling (they are discarded after each measurement), but that the information obtained from the measurements is considered representative of the remaining labels in a set of labels. These remaining labels are fed into the labeling process, and the information obtained from the measurement is used to control and regulate the labeling process.All preferred embodiments described above with the labeling device according to the invention also apply in an analogous manner to the method described here.

[0033] Measurement methods:

[0034] COBB value: ISO 535:2014

[0035] Bending stiffness: DIN 53121

[0036] Ammeter measurement: Square samples (50 x 50 mm) are cut from labels that have been conditioned for at least 16 hours at 23°C and a relative humidity of 55 + 5%. The first electrode of the ammeter is placed on the sample holder, and 0.2 ml of deionized water is added. The sample is then placed on the water droplet with the non-printed side. The second electrode of the ammeter is then placed on the other side of the sample. The measurement starts when the second electrode makes contact with the sample. Readings are taken at intervals of 0.05 mA (the time elapsed until the respective value is reached in mA).

Claims

Claims Labeling device, in particular in a bottling plant for beverages, comprising an ammeter measuring station for evaluating labels. Labeling device according to claim 1, wherein the label is applied to the object to be labeled using a water-based adhesive. Labeling device according to one of the preceding claims, wherein labels are automatically fed to the ammeter measuring station at defined intervals during ongoing operation. Labeling device according to one of the preceding claims, wherein the labeling device additionally has a measuring station for determining the Cobb value of the labels and / or a measuring station for determining the flexural rigidity of the labels. Labeling device according to claim 4, wherein labels are automatically fed to the measuring station for determining the Cobb value and / or the flexural rigidity at defined intervals during ongoing operation.Labeling device according to one of the preceding claims, wherein the labels are unprinted paper labels, printed paper labels, or metallized paper labels. Labeling device according to one of the preceding claims, wherein the adhesive is applied by spraying, either onto the labels or onto the object to be labeled. Labeling device according to one of the preceding claims, wherein the results of the ammeter measurement and optionally the determination of the Cobb value and / or the determination of the flexural rigidity are used to control or regulate the labeling process, for example by adjusting the composition of the adhesive used. A method for quality control of labels, the method comprising an ammeter measurement on the labels. The method according to claim 9, wherein the method additionally comprises determining the Cobb value and / or the flexural rigidity of the labels.