| Summary: | 碩士 === 中興大學 === 森林學系所 === 95 === Summary
Three kinds of material, plastics, wood and paper, have been adopted in this study for paper-based cultural relics’ protection. The permanence and performance of these materials in the protection of aged relics are our main concerns and have been well discussed. Furthermore, some laboratory-made alkaline handsheets were used to carry out the deacidification of acidic paper in this study. The effects of deacidification on paper relics’ permanence were also evaluated.
The experimental results were summarized as follows:
1. After outdoor aging, the plastic board made mainly from PVC and film became yellow and embrittled easily. Instead, the A, C acrylic boards and polyester films still retained good strength and transparency; they also had longer service life and better weather-durability. So, they are more suitable as protective materials for paper-based cultural relics.
2. Eight wooden boards were stacked with filter paper and woodfree printing paper for three hundred days. They all induced negative effects on papers, especially Cryptomeria japonica, Chamaecyparis formosensis and Chamecyparis obtusa. The above-mentioned three wooden materials caused the papers to severe foxing. Among the eight, Picea mariana caused the least change in the color difference of papers. Furthermore, when a metal wire was put between the paper and wooden materials, however the paper still became yellow even though the paper did not have direct contact with the wooden materials.
3. After the accelerated aging with high temperature and humidity, the scale of the color reversion and reduction in strength of acidic sized paper were more serious than that of alkaline sized paper. Color reversion became a rapid and unavoidable problem for the paper containing mechanical pulp. The load of CaCO3 in alkaline paper would act as acid-neutralizer and gradually decrease degradation during the aging of paper. Local-made fine papers are still not as good as imported acid-free papers. The higher content of lignin in local-made fine papers makes them unjustified to meet the definition of acid-free paper.
4. The addition of AKD decreases the strength and lowers the pH value of paper. Strength improvement can be achieved by adding the cationic starch, cationic retention aid-flocculants, and the pH value can be lifted by loading of alkaline filler. The property of alkaline paper, with addition of 0.1% AKD, 0.5% cationic starch, 0.5% cationic retention aid-flocculants and 5% CaCO3, was found to be the best in our study. Besides, the pH value of acidic papers could be increased, by pressing treatment with laboratory-made alkaline paper, to the extent of imported acid-free papers. By increasing the amounts of alkaline filler or the pressing pressures, it could decrease the pressing time and increase the pH value of acidic paper effectively.
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