METHOD FOR SELECTING PAPER FOR MULTICOLOR LITHOGRAPHY ROTARY PRESS

摘要

PROBLEM TO BE SOLVED: To decrease deviation between the printing line printed at the first printing part just after a paster (a joint from paper winding during printing to the next new paper winding) and the printing line printed at the second printing part or thereafter. SOLUTION: A sample sampled from a paper left at 20 deg.C 65%R.H. for at least 4 hr and with a length of 2W in the paper making direction and a width of W is made into twofold so as to make the F face side to the top face at the central part in the paper making direction and is left at 20 deg.C 80%R.H. for at least 4 hr. and in consideration of the direction of deviationΔW in the width direction of the top and bottom papers (when the fold is placed on the top and - in the case when the top paper is deviated right to the bottom paper and + in the case when it is deviated left), the degree of parallelogram P/M of the paper obtd. by the following equation is measured and a paper wherein difference in the degree of parallelogram of a paper for paper winding before and after the paper joint in a multicolor lithography rotary press is within 0.1 is selected. Here, P/M= (ΔW/2W)×100}/(M2-M1) wherein M1: water content (%) at 20 deg.C and 65%R.H. and M2: water content (%) at 20 deg.C and 80%R.H.].