Permanence of Paper in Polish Books of the Period 1900-1994
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| Format: | Article |
| Language: | English Slovak |
| ISSN: | ISSN 0034-5806 |
| Online Access: | http://www.viks.sk/chk/res_4_96_214_228.doc |
| Abstract: | Conclusions. This study is devoted to the estimation of the permanence of paper in 1395 Polish books of the period 1900-1994. The following features were selected for the evaluation of the permanence of paper: the folding endurance tested on Schopper apparatus and the pH measurements by a cold extraction method. The durability of the paper was categorized according to the classification of William James Barrow. For multivariate analysis of the measured features over the period 1900-1994, divided into decades, the method of cluster analysis was chosen, with the aim of applying the single linkage method, according to the Lance-Williams formula. In the period 1900-1959 the middle median of double folds varies for the machine direction, between two and three folds, and for the cross direction between one and two folds. In the decades 1960-1969 and 1970-1979 a small increase in double folds in both directions could be observed. The data for double folds on paper in books printed in the period 1980-1994 obviously cannot be considered. The middle median of the pH of paper varies in the period 1900-1969 between 4.60 and 4.99. In the decades 1970-1979 and 1980-1989 the middle median pH of paper is of the 5.06-5.10 level, and for the period 1990-1994 it amounts to 5.25. For the period 1900-1979, in consecutive decades, from 93 to 100% of volumes were made of paper the permanence of which is categorized as first or second class according to W. J. Barrow's classification. Cluster analysis may be used in the investigation of the book paper permanence as a very interesting method of evaluation of the properties of paper, but always in comparison with the consecutive decades of the period 1900-1994. Summaries. The study is devoted to the estimation of the permanence of paper in 1395 Polish books of the period 1900-1994. As features for the evaluation of the permanence of paper, the folding endurance and the pH measurements by a cold extraction method have been chosen. Categorization of the durability of the paper was undertaken according to the classification of William James Barrow 1904-1967. For multivariate analysis of the measured features over the period 1900-1994, divided into decades, the method of cluster analysis was chosen, applying the single linkage method, according to the Lance-Williams formula. For the period 1900-1979 in consecutive decades, from 93 to 100% of volumes were made of paper the permanence of which is categorized as first or second class, according to W. J. Barrow's classification. |
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| ISSN: | ISSN 0034-5806 |
