THE DAGBLADET FULL-SCALE PRINTING TRIALS .4. AN ANALYSIS OF ROLL QUALITY

A series of 27 printing trials was carried out under standardized full -scale production conditions on a modern, four-color, offset press. On e objective was to evaluate the roll-quality characteristics of the di fferent newsprints. Roll hardness and out-of-roundness (OoR) were meas ured and compared for virgin-fiber and deinked newsprint. Static OoR w as found to be an inadequate predictor of dynamic OoR on the press. Th e results of a subsequent study-designed to look at the same issues bu t with controlled handling of the rolls between the mill and the press room-also are presented. Rolls slit from the edge of the jumbo roll sh owed less OoR than rolls cut from the middle. The primary factor affec ting the form of OoR is the way that the clamp truck grips the roll.