Effects of Atmospheric Pressure Plasma Activation on Paper and Printability

This work concerns the suitability of atmospheric plasma activation for the modification of paper surfaces and its ability to improve printability. Most papers produced are used for printing applications. Atmospheric plasma processing is the only way to exploit plasma technology in the paper and printing industry, since batch processing is not an option for the large volume production. Industrial corona treatment, as it is referred to in the paper industry, is already used to improve adhesion between paper and polymer films. However, the surface properties of the paper play a key role in printability, and surface modification using plasma treatment could be a way of controlling the surface properties without affecting bulk properties. The surface properties of paper substrates were modified using two kinds of atmospheric plasma equipment; one at the pilot scale and one at the laboratory scale. The surface chemistry changes were measured using XPS and FTIR-ATR. In addition, the surface energy was determined as a function of the contact angle. The topographical changes were measured using AFM. The effects of plasma treatment on printability were evaluated by both the offset and inkjet printing methods. The correlation between surface property changes and printability are presented and discussed. The effects of the treatment time and different work gases (air, N2 and He) are also evaluated. Furthermore, the aging effect of plasma activation on paper is evaluated.