Subject: Thermaline cryogenic drying
Has anybody heard of "Thermaline", cryogenic drying method for water damaged rare and valuable books and document, also adopted for parchment and leather? This method is briefly described in NEDCC technical leaflets, in the section dedicated to disaster recovery. Is it an evolution of freeze drying? How does it work exactly? **** Moderator's comments: Please see <URL:http://www.documentreprocessors.com/> for information on the process. We used it here for our last flood (see <URL:http://www-sul.stanford.edu/staff/flood/> for some background on that event), with very great success. (There's a chance this URL is limited to Stanford access; if so, I assume someone will let me know, and I'll make the resources available somewhere else) The process is in essence vacuum freeze-drying, but with the temperature kept very close to the triple point so there is (possibly) a very brief liquid phase, and drying under restraint (to a higher moisture content than the bone-dry endpoint of ordinary vacuum freeze-drying) to reduce planar distortion, and as a result significantly reduce the amount of rebinding needed. The cost appears to be high, but when you factor in reduced rebinding costs it can be quite competitive. Walter Henry Preservation Dept Stanford University Libraries Barbara Cattaneo *** Conservation DistList Instance 14:55 Distributed: Thursday, April 19, 2001 Message Id: cdl-14-55-028 ***Received on Tuesday, 17 April, 2001