INFLUENCE OF PLASMA TREATMENT ON PROPERTIES OF WAXED PAPERS

Barrier coatings of fibrous materials are of great interest for the packaging paper producers as increased resistance to oils, grease and other agents with the paper packaging increases the usability of the product. The barrier coatings have to withhold several parameters regarding resistance for the penetration of various agents, runnability on the machines regarding mechanical properties and also printability futures to enhance the packaging. Different sacks, bags and other products are mainly produced by coating the surface of the paper with the appropriate coatings which can be petroleum-based waxes, polymers solutions or pigments. By applying the barrier coatings the surface topography and porosity as well the surface chemistry is changed as the used polymers, waxes and other products which fill the fibrous network of the packaging change the macrostructure and induce different chemical compounds on the surface. These products are mainly printed with flexo technology We have checked the grease resistance with the KIT test (Tappi T 559), dynamic contact angle change, the penetration of liquids and the surface coverage of plasma treated waxed and base papers. Our results indicate improved printability and liquid penetration but also the lowering of grease resistance after plasma treatment. The treatment is possible but further adjustments regarding plasma power and time of treatment are needed to find the optimal parameters for different kind of barrier coated papers.