Glossy coated paper is used as one of the highest quality paper products such as photographic-quality paper and high grade container boxes. However, once the surface is scratched, the resultant traces of the scratch are remarkable and detrimental to its glossy surface finish. Such scratches arise when the coated paper is subject to scratching actions in various contact situations such as a coating process, paper cutting process, and offset printing.
The objective of this research is to investigate the surface deformation properties during scratching. Two different kinds of commercial coated paper samples (ink jet-type and offset printing-type) were prepared for comparative study. The shape of scratches that arise on paper surfaces in scratch tests were determined by using a laser scanning microscope (LSM) to evaluate the deformation mechanisms.
The scratches were typically classified into two types ; “plastic deformation” and “fracture”. The two types are different and independent, but often involved in one scratch. The cross-sectional deformation area and the onset load of crack generation were measured, and then the relationship between them was discussed. Consequently, the characteristics of scratches were influenced by the surface properties. Namely, low plastic deformation and high fracture toughness were suggested to be required for high scratch resistance.