Influence of Base Paper Filler Content and Pre-calendering on Metered Film Press Coating - Part II: Paper and Print Quality, 1998 Coating Conference Proceedings

Metered Film Press (MFP) coating has become a common way of upgrading wood-containing grades. To further improve paper and print quality the base paper needs optimization. This study was done on wood-containing base paper produced in full scale. The MFP coating was done on a pilot coater at 1800 m/min. The study showed that base paper properties such as smoothness attained by pre-calendering and filler content (10-20%) have a major influence on paper and print quality. It was found that pre-calendering does not improve surface roughness or gloss significantly. However, the coat weight distribution was improved by pre-calendering as well as by higher filler amounts, which consequently gave positive effects on print quality. Results indicate that pre-calendering can be used to minimize fiber roughening in printing. Increased filler content levels had a positive effect on surface roughness, print gloss, paper gloss and print mottle. The study showed that MFP-coated paper can compete with standard LWC for offset, with optimized coating color formulations, pre-calendering and relatively high filler content levels.