THE DAGBLADET FULL-SCALE PRINTING TRIALS .3. LINTING IN 4-COLOR OFFSET PRINTING

A series of 27 printing trials was carried out under standardized full-scale production conditions on a modern, four-color, offset press. One of the objectives was to evaluate the lin ting characteristics of the 27 different newsprints. The principal aims were to (a) determine the quantity and composition of lint deposits on the offset blankets and (b) identify laboratory methods that could successfully predict the linting resistance of newsprint. Ray cells and fiber fragments from reaction wood constituted a base level in all lint deposits. Some deposits also contained fibers at quantities up to four times that of typical ray-cell linting. However, even lint deposits at this level did not produce significant deterioration in print quality after 100, 000 printing impressions. None of the test methods for predicting linting correlated well with lint deposits removed from the blankets at the end of each print run. However, the GFL and VTT methods demonstrated excellent agreement between results obtained on opposite sides of the paper.