Effects of recovered paper quality and deinking process parameters on dirt levels in newsprint

At Abitibi-Consolidated, we developed a standardized measurement and reporting procedure for dirt levels in newsprint. We report two measurements: TAPPI dirt (> 0.04 mm(2)) and "visible dirt," > 0.1 mm(2). The first corresponds to the background "greyness" of the sheet, while the second corresponds to the amount of visible specks. By tracking these numbers, we can observe recovered paper quality trends, the effect of process parameters on dirt levels, and the correlation between dirt levels and customer quality perceptions.