Gravure printing is widely used for printing magazines, catalogues, stamps, packaging, wallpapers or decorative papers for the furniture industry as well as elaborate artistic publications. The gravure cylinder used for this method consists of a steel core which is coated with copper. To increase the wear resistance, a chrome layer is subsequently applied. For both electroplating processes, given tolerances must be controlled to ensure print quality meets quality standards. Hence, Fischer offers tailor-made instruments for conductivity and coating thickness measurements.
As an engraving material, copper is comparatively “soft”. To increase the hardness, additives are added to the electroplating bath. Conductivity measurement is ideal for measuring hardness as it directly correlates to the conductivity of copper. Fischer offers the SMP350 hand-held instrument and ES40 probe where a suitable frequency can be selected on the instrument for optimal results. For the majority of applications, the copper coating thickness ranges from 150 μm to 2 mm.
Copper or chromium coatings should be deposited within given tolerances for cost effectiveness. The deposited copper coating thickness determines the outer diameter while the given cylinder circumference should correspond to the length of the print image or a multiple of the same. If the chromium coating thickness exceeds given tolerances, the cells will no longer have sufficient capacity for the printing ink. However, if the deposited coating thickness is below tolerance limits, insufficient surface hardness will result. This leads to a reduced number of possible printing processes.
In conclusion, Fischer’s conductivity and coating thickness measuring systems provide valuable information on the inhomogeneity of the thickness of both coatings on the cylinder. This makes the quality control of electroplated chromium and copper coatings on gravure cylinders optimal and effective.
Contact Fischer today to find out how we can help you with your process control requirements!