Influence of plasma and radio wave treatment on paper structure

A paper for offset printing was exposed to radio frequency discharge plasma and radio frequency electromagnetic field. Optical response and structural features of paper before and after the treatment have been investigated by several techniques: digital laser speckle photography, laser Stokes polarimetry and attenuated total reflectance (ATR). The changes of statistical distributions of speckle patterns has been observed for plasma treated paper as a result of increase of correlative dimensions of structural heterogeneity of modified paper. It is shown also that the radio wave treatment leads to anisotropy reduction in the paper structure that is more apparent if the magnetic field lines are oriented transversely to the plane of a paper sheet.