Paper deterioration

Although many mass deacidifications have been developed, it can be stated that none of the technologies offered meets all the criteria. Nevertheless, the DEZ process, Wei T o process, Kopper Process and VPD have demonstrated independently their potential for arresting paper deterioration from acid. To what extent these processes meet the criteria to be used for a practical mass deacidification process is the question that has to be answered. Accordingly, a comparison of the characteristic features of these processes is tabulated in Table I. The evaluation is based on their neutralization chemistry and effectiveness. The engineering design, safety and costs of these processes are not considered in this evaluation. 

The Manufacture and Testing of Durable Book Papers Deterioration... 

While librarians had the physical evidence of paper deterioration before them everyday, there was no lack of scientific study of the paper problem. Vemer Clapp points out that at least 479 investigative reports and articles relating to paper deterioration were produced between 1885 and 1963 (4). If the evidence was available confirming that library materials were deteriorating and would continue to do so at a rapid rate until a better quality paper was used, why were there not more collective protests and actions Clapp concludes, correctly I believe, that it was a combination of economics, chemical knowledge, and communication (4). 

Grove, Lee E. "Paper Deterioration—An Old Story, Coll. Res. Libr. 1964,... 

It was now possible to greatly reduce papers deterioration rate and to restore integrity and strength to those already damaged (1). Barrow s equipment and techniques for doing this have been acquired by more than thirty institutions, worldwide. 

Paper objects may suffer from damage by vermin, insect and microbial attack, theft, fire and flood. However, from a chemist s point of view there are two important mechanisms by which paper deteriorates, both of which may change its hue and make it weaker these mechanisms are acid-catalysed hydrolysis and oxidation. Papers vary a lot in their stability and the worst can become so brittle that they become unusable. Papers made from rags using traditional methods are usually extremely stable, but old papers made from poorly processed wood pulp are often very weak. 

Thallous sulfide paper is prepared by bathing filter paper (S S 589 or Whatman 42) in 0.5 % solution of thallous carbonate or acetate for several minutes. The liquid is allowed to drain off and the paper is dried in a blast of heated air. Thallous sulfide is deposited by placing the paper across a beaker containing ammonium sulfide solution warmed to 80° C. The conversion to thallous sulfide is rapid the paper turns perfectly black on the side exposed to the fumes. Cut into strips, it is ready for immediate use. It is best always to use freshly prepared reagent paper when testing for sulfur. The paper deteriorates on standing because the sulfide is partially oxidized. 

The main cause for paper deterioration in libraries and archives is the acid catalyzed hydrolysis of cellulose, the ingredient that gives permanence to the paper. The aging permanence of paper is closely coimected with the add concentration in the paper. The priority in preservation measures is in most cases the dead-dification of acid paper. Today, more than 70 years after Barrow s pioneering work, mass deacidification of books and archive materials has become a commerdal reality. 

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