Research of paper/paperboard mechanical characteristics

Abstract

This article deals with paper/paperboard mechani-cal characteristics (fracture force, stresses and strains), printing processes (varnishing, two-side print) and the ef-fect of various surface defects on mechanical properties of aforementioned materials.The research results have indicated that the ob-tained variation character of strain dependences on stresses makes it possible to distinguish two zones: the first -where the paper casting direction slightly affects pa-per/paperboard mechanical characteristics (strains and stresses), and the second zone - where the casting direction has a significant effect on the above-mentioned character-istics. One-side and two-side prints as well as varnishing are found to have a negligible effect on tension characteris-tics. Uneven paper/paperboard surface, breaking away of a coated layer during printing, and the appearance of fibers on a coated layer affect greatly the values of fracture stresses and strains.