Research on ink blot evaluation of aged paper before and after restoration

• Published in: Nordic pulp & paper research Vol. 37; no. 2; pp. 320 - 329
• Main Authors: Wang, Qinwen, Xu, Zhi, Fan, Huiming
• Format: Journal Article
• Language: English
• Published: De Gruyter 27.06.2022
• Subjects: deacidification and enhancement; evaluation; graphic quality; paper documents
• ISSN: 0283-2631; 2000-0669
• DOI: 10.1515/npprj-2021-0084

To evaluate the changes in the ink on paper subject to accelerated degradation before and after restoration treatment, an evaluation index describing changes to ink on paper documents before and after deacidification and enhancement by combining subjective and objective evaluations was established to improve the evaluation of the effect of deacidification and enhancement agent on the restoration of paper from the perspective of the ink thereon. According to the test indicators, test and control standard boards were designed and the paper for accelerated degradation was produced. In the experiment, 0.4 mol/L sodium carbonate solution, 6wt% styrene butadiene latex (SBR latex), sodium silicate, and polyamide polyamine epichlorohydrin (PAE) compound solution was applied to the accelerated degradation paper samples, respectively. After treatment, the quality indices such as color density, color difference, handwriting contrast and handwriting line width were measured. And observers were organized to make subjective evaluation on the accelerated degradation samples before and after the treatment. The results showed that the color density of magenta ink sample decreased by 10.61 % and the edges were blurred. The contrast and line width of handwriting after the treatment were decreased slightly. After treatment with 6 wt% SBR latex, the ink density of black increased the most (by 31.62 %) with no clear change in the handwriting contrast and line width. When using sodium silicate and PAE compound solution, the comprehensive effect on the text was much better. The results of subjective evaluation were consistent with the changes of objective indices.