Book, preservation

Critical Evaluation of Mass Deacidification Processes for Book Preservation... 

Four mass deacidification processes for book preservation namely, the Library of Congress diethyl zine process, Wei T o nonaqueous process, Kopper s "Book Keeper" process, and Langwell interleaf vapor phase process, are critically evaluated, based on their chemical characteristics and effectiveness on deacidification. 

Why are the cave paintings of thousands of years old in better condition than modern papers Why do many early books printed in the 15th century show no signs of serious deterioration How can we preserve our accumulated knowledge Are the current technologies on book preservation effective Are the current practice on book preservation acceptable ... 

Moreover, recently Book Preservation Associates and Lithco have announced new mass deacidification methods. These processes should be considered if data are available. 

Accordingly, a complete book preservation program should consider (a) complete deacidification (b) improving fold endurance, tear and tensile strength of paper and (c) inhibiting oxidation. 

Book Preservation Technologies. Congress of the United States Office of Technology Assessment. Washington DC 20510-8025 OTA-0-376, 1986. 

One major problem is that DEZ ignites spontaneously on contact with air. Therefore, this treatment must be carried out in a chamber filled mainly with N2(g), where the amount of O2 present can be rigorously controlled. The pressure in the chamber must be maintained well below one atmosphere both to lower the boiling point of DEZ and to remove excess moisture from the book s pages. Several major DEZ fires have slowed its implementation as a book preservative. 

Book Preservation Associates (BPA) was formed in 1988 as a wholly owned subsidiary of ETO Sterilization, a processor of spices, medical products and cosmetics. In the BPA process books or other library materials are placed in closed boxes in a vacuum chamber. The pressure is reduced and the books are exposed to ammonia for 6 h. The chamber is then purged and evacuated. Ethylene oxide is introduced and the materials are held for 12 h at nearly atmospheric pressure. The chamber is alternately purged and evacuated up to 25 times before treated materials are removed. The total cycle time is 24 h [31]. Books are placed in an aeration room for two days to permit off-gasing of the ethylene oxide before being returned to H-braries. 

This is a Hquid, nonaqueous process that employs a perfluorocarbon carrier to deposit a submicron dispersion of magnesium oxide. No alcohol is involved and a surfactant is employed to keep the neutralization agent evenly distributed in the fluorocarbon solvent The technique was developed by Koppers Chemical Company in 1981, who transferred the rights of the process to Richard Spatz in 1987. Book Preservation Technologies, in which Spatz is a prindpal, continues the development of the method. 

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. 

M. Howe, The Book Preservation Associates Process, Mid-Atlantic Regional Archives Conference, New Brunswick, N. J., May 19,... 

U. S. Congress, Office of Technology Assessment, Book Preservation Technologies, OTA-0-375, Government Printing Office, Washington, D. C., 1988. 

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