Influence of wheat pulp in printing substrate on the chemical stability of gravure prints

Today, the global emphasis is on the importance and necessity of recycling all types of waste. In the paper industry, the waste paper has been a very important raw material for decades resulting in recycled cellulose fibres. As cellulose fibres become shorter with each recycling cycle, it is necessary to add virgin fibres to the paper pulp to achieve the required quality and stability of the formed paper. Enriching the pulp of recycled fibres with alternative non-wood fibres could be one of the environmentally friendly approaches to paper production. Wheat straw, as a by-product of globally available field crops, has imposed itself as a logical choice of alternative raw material. From the pulp of recycled fibres and from pulp admixture of 70% recycled fibres and 30% wheat fibres, laboratory papers were formed and served as the printing substrates for this study. The possibility of using such papers as printing substrates was assessed based on the chemical stability of the prints produced by the gravure printing technique with two types of inks (conventional and UV). Namely, gravure is the most common technique in printing packaging and the chemical stability of prints is one of the very important requirements in packaging printing.