Rubbing stability of printed innovative paper substrates containing cereal straw pulp

Abstract

Paper is one of the most important materials for packaging and the demand for this material is constantly increasing. The printing and packaging industries are researching alternative sources of fibre, to produce more environmentally friendly paper without compromising quality. As a packaging material, paper must meet high strength requirements, and it has to exhibit acceptable surface properties to preserve the printing quality. This research had two objectives: to produce paper made from pulp of recycled fibre reinforced with virgin straw fibre and to evaluate the print quality on such papers. Straw pulp used for this purpose was obtained from three cereal crops: wheat, barley, and triticale. The paper produced was printed by using five printing techniques. Rubbing stability was evaluated by the difference in colour and reflectance spectra before and after performing rub tests and a comparison was made for the best interaction of paper and ink determined by the printing technique. For the prints with the highest colour difference after the rub test, the surface of the rub test receptor (uncoated recycled paper) was examined for signs of ink transfer during the test and the areas of transferred ink coverage were calculated on their processed microscopic images.