The importance of measuring devices in printing cylinder production
von Ansgar Wessendorf,
Quality control is of extreme important in the production of gravure printing cylinders. This is also due to the fact that the cylinder is decisive for the achievable print quality and therefore can hardly be underestimated, especially in the case of high-quality print jobs, particularly for branded products.
Aspects of quality control
As far as quality control is concerned, there are various aspects to be considered. Prior to each process step in cylinder production such as copper plating, chrome plating, grinding and engraving, the appropriate quality controls must be carried out. This not only enables repeatability in the production of the cylinders, but also avoids problems during engraving (e.g. stylus breaking), as well as during printing (e.g. chrome wear, colour changes).
Resource protection through quality control
In addition, the issue of sustainability is becoming increasingly important. The past crisis years have also left their mark on gravure printing. Rising prices for raw material and energy burden the business and stress present producers and buyers of gravure cylinders with difficult decisions. In this context, quality control is even more important in ensuring the efficient use of resources.
Only through precise process control of the gravure cylinders produced the quality of the printing forme and thus also of the printed product can be optimised. This avoids wasting material and thus ensures that resources are used sparingly. Furthermore, this reduces the waste rate in the printing process and thus also the unnecessary consumption of ink and substrate. In summary, the importance of quality control may be characterize as follows: poor quality gravure cylinders cost time, money as well as resources!
Measurement technology for all process steps
For example, the non-destructive measurement of the layer thickness of the electroplated metals (copper, chrome) is indispensable. The thickness of the copper layer can be determined with the Minitest layer thickness gauge (Figure 1), which is equipped with a magnetic-inductive probe. In contrast, the chromium layer is measured with a special probe using the eddy current method. The SD-H3 hardness tester is used for copper hardness testing according to the UCI method, which is particularly important for achieving optimum engraving results (figure 2).
Optimal roughness properties of the cylinder surface is a prerequisite for trouble-free printing and also increases the service life of the cylinders. The PS10 roughness gauge serves this purpose (figure 3).
The correct cylinder circumference is of major importance in achieving the required web tension in the press. For this purpose, Heimann offers the D.Mess circumference measuring device (figure 4).
The quality of the engraved cells is decisive for the subsequent print result. The CheckMaster II measuring microscope is designed to determine deviations of the cells from the required ideal shape (figure 5).
German company Graphische Technik und Handel Heimann GmbH has been a family business for over 45 years. As a supplier to the gravure printing industry, it manufactures high-quality chemicals and consumables and also supplies high-precision measuring equipment for the production of gravure cylinders.