Development of Mass Deacidification Processes

If new paper is torn the fibers slide apart without breaking. This can be sho wn with pictures from a scanning electron microscope of the angles of cracks of aged and non-aged paper after a strain-to-stress measurement (Fig. 13.5). The fibers of the new paper only slid apart whereas in the aged paper they broke. This means that the fiber-fiber bonds in new paper and the individual fibers in aged paper are the mechanically weaker points. 

There are many statements in literature about different deacidification systems and agents, its advantages, use and also comparative examinations [10-15]. In the treatment a long-term add protection (exogenous influences) is to be achieved and therefore an additional alkaline buffer is deposited in the paper [17-23]. In the follovdng the most important methods are introduced. 

On the one hand the deacidification systems can be divided into single sheet methods and mass deaddijication methods. On the other hand the methods can differ in the polarity of the solvents used. Polar solvents have a swelling effect on cellulose, or rather paper, and can dissolve some of the colors and inks and therefore mostly nonpolar solvents are used in mass deacidification systems. Single sheet methods with water as a treatment medium are the classical methods. 

Mass preservation is designed to meet the needs of national and major research Hbraries and archive groups. With a mean collection deterioration rate of 4.7 % [24] and Hmited resources, a treatment based on painstaking manual work is inconsistent with the need. Further, greater emphasis has been placed on nonaqueous and gas-phase deaddification techniques to compensate for some of the intrinsic Hmitations of aqueous methods. 

Nonaqueous deacidification systems contain a deacidification agent and an organic solvent that serves as the carrier. The solvents offer the advantage of rapid penetration and drying. The latter is particularly important in minimizing the 

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