Mass deacidification of paper

Abstract

Paper, the carrier of our written heritage, decays within a relatively short period of time mainly due to its acid content and the influence of air pollution. More than 50% of the records of our libraries and archives are already at risk. Mass deacidification allows this problem to be counteracted by significantly slowing down the deterioration of paper and thereby prolonging its life span. An overview of all relevant mass deacidification methods is given. As it was found that the 'papersave' method was the most suitable to meet Swiss requirements, a plant using an optimised version of this method was built and put into service in March 2000. Thanks to this optimisation, not only books and loose sheets but also documents in archival boxes could be mass-deacidified for the first time. Due to the necessity to analyse not only test papers but also original documents, new non-destructive testing methods had to be developed. Findings of basic investigations regarding treatment effects as well as results of routine quality control turned out to be very satisfactory.