纸张印刷墨斑检测方法初探

Studies on Print Mottle of Printing Paper

关键词:  新闻纸  铜版纸  单面涂布白纸板  印刷墨斑  主观判定  客观判定

Key Words:color offset newsprint  art paper  single coated paper  print mottle  subjective evaluation  objective quantitative assessment

摘要:使用IGT印刷适性仪，对新闻纸、单面涂布白纸板和铜版纸的印刷墨斑变化规律及检测方法进行探讨。实验结果表明，由于试样本身质量的差异，新闻纸优化的印刷条件中除油墨量0.10 mL相同外，印刷压力和速度均不相同；涂布白纸板（F）和铜版纸E优化的印刷条件为：油墨量0.20 mL、印刷压力325 N、速度0.4 m/s；涂布白纸板（H）优化的印刷条件为：油墨量0.05 mL、印刷压力525 N、速度0.3 m/s，光谱法与主观判定结果一致性较好。实验结果也表明，两种主观判定结果的一致性较好；3种客观判定方法中，光谱法和PTS法判定结果较稳定，与主观判定的一致性也较好，经进一步完善，可望作为评价纸张印刷墨斑的新方法。

Abstract:This paper evaluates the print mottle in the prints of different kinds of paper such as color offset newsprint, art paper and single coated paper. Results showed that the optimized conditions for the two kinds of newsprint A & B are different except for the ink amount of 0.1 mL. The optimized conditions of the single coated paper F and art paper E are as follows: ink amount 0.2 mL, printing pressure 325 N, printing speed 0.4 m/s. There exists inconsistent correlation between objective quantitative assessment of mottling and subjective evaluation for F, however there is good correlation for E. The optimized conditions of the single coated paper H are as follows: ink amount 0.05 mL, printing pressure 525 N, printing speed 0.3 m/s. Results show that there exists consistent correlation between 2 groups and 4 groups subjective evaluation of mottling. Among the three digital analysis methods, power spectrum analysis correlates the most closely with the visual results, then the PTS method. And the grey value method correlates the least. So the power spectrum analysis and the PTS method are expected to be a new method for evaluation of the print mottle.