Volume 17, Number 2
Sep 1993

The German Mass Deacidification Project

Peter Schwerdt, of Battelle Ingenieurtechnik GmbH (formerly Battelle Europa), sent in an English-language brochure on Battelle's project with the German Library (Deutsche Bibliothek): "Mass Deacidification Saves Books and Archivals." It gives graphs of treatment results, photographs of equipment, and facts about the process and chemicals used. They may send copies on request; their fax number is +49 69/79 08-86.

He also sent the following description of the process:

We in fact eliminated the harmful CFC's by an environment-compatible solvent called Hexamethyldisiloxane (HMDO). It is a nontoxic, easy-to-evaporate, clear kind of a silicon oil of low viscosity which is highly inert to all book and archival materials. It leaves no residues in the paper. In our closed cycle process it can be completely recovered and reused.

The MMC itself is also replaced by a different magnesium alkoxide which easily mixes with the HMDO without any free alcohols or co-solvents. With this solution the former side effects of the MMC liquids on inks, colors, glues, plastics, etc., due to the alcohol co-solvents are completely eliminated.

Archival materials can be treated just the same as books to achieve a deacidification without any damaging side effects.

The total treatment time, including pre-drying, impregnation and post-drying, takes less than two hours. Both drying steps work very efficiently and safely with the combined vacuum/microwave technique.

The Leipzig plant is designed for four chambers to achieve a capacity of about 400,000 volumes a year in future. For the beginning the process will be operating with only two chambers with all other components of full size.