Mass deacidification processes, paper

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. 

Based on the information available today on the DEZ process, Wei T o process, Koppers process, and VPD process, it is very difficult to judge which process is the best suited to a mass deacidification process. In addition to the limitations of each process which has been discussed, data are lacking to support long-term effects on treated papers. In order to select a viable mass deacidification process, the following parameters have to be considered ... 

All these important parameters must be established for treated papers so that a meaningful evaluation can be made. Before making any decision on selecting an effective mass deacidification process. 

There are some successful new possibilities in the deaddification of paper up to mass deacidification processes by nonpolar solvents (for example the Papersave Process ) whereas no new achievements have been reached in the strengthening of paper, especially not in nonaqueous treatments. The experiences of paper makers are only of limited use in the strengthening of old papers because the papers cannot be changed in structure and compound during restoration or preservation. 

D. N.-S. Hon, Critical Evaluation of Mass Deacidification Processes for Book Preservation, in Historic Textile and Paper Materials III, ACS Symp. Ser. 1989, 410, Chap. 2. 

A. C. Brandt, Mass Deacidification (f Paper - A comparative study of existing processes, BibliothSthque nationale prolibres Biblio-thSque nationale, Paris 1992. 

An ideal mass deacidfication process should preserve book papers in a usable condition. For best results, any mass deacidification developed must meet the following criteria ... 

No reports have been released yet. The effects of the chemical process on paper, covers and inks have not been published. The Koppers process appears to be a unique one with great potential for mass deacidification with success. More testings are required. As with the Wei T o process, the effect of Freon on the ozone layer of the stratosphere is a concern. 

Many libraries have large holdings of books printed on acid paper. Deacidifying books individually is a very time-consuming and expensive process. A process in which large numbers of books could be deacidified at the same time (mass deacidification) is a desirable invention. The problem has... 

The process is designed as an inexpensive mass-production application of vapor-phase deacidification, and it would be inappropriate to apply it indiscriminately without pretesting items where book components other than the paper were considered to be of artistic or historical value. Packs of loose sheets enclosed in archival storage boxes have also been processed, and all the material in the boxes and the boxes themselves were completely deacidified. In cases where an item to be processed is out of the ordinary, one can either draw on past experience or make a processing test on similar material of no value. 

The problem of mass vapor-phase methods for the deacidification of books or textiles has received a great deal of attention in the last few years. Such treatments are best applied to current books in which the paper is still strong. Rebuilding strength into textiles or books by a vapor-phase treatment is eminently desirable. Both problems are discussed in this volume. When solved, the processes will probably be carried out in special plants by chemists rather than by conservators. 

Cyclohexylamine carbonate, morpholine, amines in general and ammonia itself have all been considered as deacidifying treatments. Many are liquids with a significant vapour pressure or are gases, which makes them potentially useful for mass processes. However, all suffer from the problem that the deacidification produced is not permanent and some cause yellowing of the paper. None is currently in favour. 

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