Germany's PTS presents “Reflex absorber – Shielding paper” research project at CEPI's European Paper Week in Brussels

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Germany's PTS presents “Reflex absorber – Shielding paper” research project at CEPI's European Paper Week in Brussels

December 05, 2016 - 22:32

MUNICH, Germany, Dec. 2, 2016 (Press Release) -Again this year, the European Paper Week, one of the largest CEPI events (Confederation of European Paper Industries), took place from 22th to 24th November 2016. The event, at which the most important major corporations in the European paper industry meet, incorporated the Young researchers: European paper industry innovation hub. It was here that ten young researchers from the Denmark, Finland, Germany, the Netherlands, Slovakia and Spain reported about the current topics they are working on. The very exciting projects dealt with innovative topics such as linking biotechnology and nanotechnology with the help of nanocellulose, the circular economy in the paper industry, developing new sources of raw materials and new methods for extracting substances required by the paper industry without requiring large amounts of energy. In addition, research projects were presented on the use of papermaking wastes in high-quality products, on deep-drawing paper as well as on paper equipped with a shielding layer to provide protection from electromagnetic radiation.

Thomas Stocker from PTS presented the “Reflex absorber – Shielding paper” research project. The objective was to develop a special-purpose coating system that is capable of attenuating high-frequency electromagnetic radiation. The functionality was to be produced by means of a coating and not by adding internal fillers to the paper. In order to achieve this function, a reflecting precoat was applied initially and, on top of that, an absorber layer as the top coat. The absorber layer should contain a pigment to absorb the electromagnetic radiation on the one hand and, on the other, it should contain other metal pigments that provide for multiple reflections of the radiation inside the coat, thus intensifying the absorptive function. This structure was able to be implemented within the scope of research project IGF 18055 BR. Silver-coated platy copper pigments exhibited high conductivity values and were thus found to be suitable for the reflecting precoat. They produced attenuation values of approx. -50 dB with a coat weight of 30 g/m². (Barium) ferrites combined with the copper pigment to produce a metal component were identified as the most effective pigments in the absorber layer. The absorber-metal layer was successfully applied to the reflection coating both in the laboratory and on a pilot scale. As a result, excellent attenuation values as low as -55 dB were achieved. The special development was able to be processed (e.g. die cutting, folding) without any problems. With a view to the cost efficiency of the new coating combination, commercial products can be undercut by far in terms of price. For instance, the shielding layer can be produced for approx. € 3/m² plus relevant processing costs, whereas commercial shielding products are available starting at approx. € 20/m².