Method for Fast Quality Evaluation of Deep‐drawn Paperboard Packaging Components

Abstract

The visual and mechanical quality of paperboard packaging components formed by deep drawing closely corresponds to the wrinkle distribution within the material wall section. Assessing this quality of paperboard packaging components currently relies on very slow or even subjective methods. Therefore, counting the number of wrinkles and measuring the mean distance between wrinkles proved to be a sensitive strategy for the evaluation of quality levels in deep drawing formed paperboard containers like cups or trays. A method introduced by Hauptmann proposes the measurement of the distances between 10 wrinkles in machine direction and 10 wrinkles in cross direction for each sample. However, this method is unsatisfactory because it can only observe a small part of each sample and is subject to deviation through the individual judgement of the person carrying out the survey. Further methods, as well as their respective application range, are listed in Table . Hence, it is desirable to automate the wrinkle survey to be carried out without operator influences to the measurement. This paper introduces such an automated measuring method. The given method relies on recording the sample surface topography through laser‐distance measurement. An evaluation algorithm, which enables the detection of wrinkles in the topographic data, is proposed. Furthermore, it is shown that the method yields feasible results and is capable of generating reliable quality information in considerably reduced time frames.

Analysis of Dominant Process Parameters in Deep-Drawing of Paperboard

“…The samples exhibited strong curvatures at the bottom, which impeded true measurements. Furthermore, the wrinkles were just beginning to form between 2 mm to 4 mm (Müller et al 2017). Therefore, in this experiment, the wrinkle structures at the low drawing heights did not exist or were very delicate and often below the detection threshold of the measuring method.…”

“…For other geometries, a more complex manipulation was necessary. The limitations concerned with the measuring device are described in detail in Müller et al (2017).…”

“…For this purpose, the sample was mounted on a rotary plate and scanned by a triangulation laser. The profile of the laser measurement was then evaluated for wrinkles, as described in the work of Müller et al (2017).…”

“…This work aims to experimentally identify those parameters and model the general wrinkle-forming behavior accordingly. For this purpose an experimental study that links The method described in Müller et al (2017) was used to obtain the wrinkle distributions for a multitude of samples. The process parameters of the sample productions had various applied blankholder forces, matrix temperatures, and forming punch temperatures.…”

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The application of the wrinkle measuring method described in Müller et al (2017) and the subsequent evaluation algorithm of a range of deepdrawn samples were used to determine the influences and interdependencies of blankholder force, tool temperatures, and drawing height on the formation of wrinkles in paperboard. The main influences were identified and quantitatively evaluated.

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