Characterisation of coated paper structure

Coated paper quality is heavily affected by sheet uniformity, including uniformity of the base sheet and coating in both the planar and through-thickness design. Controlling this uniformity is easier if the sheet uniformity can be qualitatively or quantitatively defined. For this reason Amcor Research and Technology (ART) has developed a series of techniques designed to describe the sheet structure. These include stereo mosaic imaging of sheet surfaces, power spectrum characterisation of sheet surfaces, cross-section pigment characterisation, and coating penetration and coating uniformity characterisation. Examples of the use of these methods are described