Rub resistance of multilayer prints on papers produced with alternative fiber sources

The packaging industry is a rapidly growing industry all over the world and is in constant development following
the requirements for more environmentally friendly materials to replace plastic and other non-degradable materials.
Paper is a material that can be safely disposed of as a waste or reused as a recycled material. The problem with
paper recycling is that the cellulose fibers get shorter with each cycle and thus the properties of the recycled
paper deteriorate. Therefore, a certain amount of virgin fibers must be added to the paper pulp to maintain the
required quality and strength of the paper used as packaging. Alternative fiber sources, such as rapidly renewable
cereal straw, can replace the use of virgin wood fibers which are in short supply and thereby reduce the concerns
about deforestation. In this research, laboratory paper substrates were produced from admixture of recycled
fibers and virgin cereal straw fibers. The papers produced were printed with three full tone layers of conventional
process inks (cyan, magenta and yellow) printed one on top of the other using three different printing techniques
(offset, gravure, and screen printing). Since the rub resistance of printed paper is one of the most important
factors in determining its suitability for packaging, this study analyzed the rub resistance of multilayer prints on
paper substrates with alternative fiber sources. When used as secondary packaging, paper is subjected to various
circumstances under which prints can be damaged, such as transport, contact with other packaging material, or
handling by the end user. Therefore, the mechanical properties of such prints must be robust and stable in contact
with external influences. The quality of the prints after rub resistance tests was determined through measuring
the spectrophotometric properties and calculating the color differences between the multilayer prints before and
after performed test.