5th Section Paper in Archives and Libraries
| Hlavní autori: | , , |
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| Médium: | Článok |
| Jazyk: | angličtina slovenčina |
| On-line prístup: | http://www.viks.sk/chk/wpp1_2003.doc |
| Abstrakt: | SUMMARIES. To elucidate the preservation degree of the samples of printing paper from 53 degraded books stored at the Latvian National Library (LNL), a major state book repository in Latvia, were taken. The following characteristics were determined and analysed: brightness; paper surface pH; pH of aqueous extracts (20 °C, 100 °C); lignin content; acid-insoluble ash; tearing resistance and index; breaking length, etc. For printing paper samples, the pH indices are considerably below 7 (3.5÷6.0). For 60 % of samples, lignin content is above 10 %. The most typical quantity of fillers is 14-20 % (acid-insoluble ash). Breaking length ranges from 265 m to 3665 m. Tearing index ranges from 1.62 mN.m2/g to 7.19 mN.m2/g. A comparative analysis has shown that the investigated characteristics are, on the average, by 30÷70 % below the standards (normative values) for more than a half of paper samples. Keywords: printing paper, aging, preservation, lignin, physicochemical and mechanical properties CONCLUSION. The quantitative characteristics of the basic properties of the printing paper produced in the first half of the 20th century and aged in natural conditions reflect the current condition of this paper. They are the basis for the assessment of the condition of the printing paper in Latvia's libraries and archives. A comparative analysis has shown that for more than a half of printing paper, the quantitative characteristics are, on the average, by 30-70 % lower than the standard (normative) values. It is advisable to perform restoration works for eliminating the elevated acidity firstly for print paper with a pH below 5.0. Of great importance is the quantitative determination of mass for books stored in LNL, produced in the first half of the 20th century, which require restoration. Taking into account the necessity to perform the restoration work gradually, firstly for eliminating the elevated acidity, practically for all books printed in the corresponding time, it is expedient to determine the sequence of these books' restoration. It should be pointed out that the chosen printing papers aged in natural conditions are of great importance for solving the practical tasks of restoration, as well as in the theoretical aspect to investigate the chemical and physicochemical changes on different levels of the wood fibre structure, ranging from the molecular and supramolecular fibrillar formations to the fibre (cell) wall level. |
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| ISBN: | ISBN 80-227-1942-0 |
