|
 |
|||||||
Paper-based collections in the nation's libraries and archives are being threatened by acid contained in the very paper on which they are printed. No fire, flood, tornado or earthquake will ever cause as much damage to the library collections as these harmful acids. In years past, libraries have chosen to microfilm, photocopy, and create digital surrogates to take the place of items already too brittle for patrons to use. Mass deacidification is a chemical process that neutralizes acid in paper and deposits a chemical buffer to prevent further acidification, thereby preventing the materials from becoming brittle. Approximately 60% of Northwestern's paper-based collections are acidic, but not yet brittle. The Library's Preservation Department deacidifies several thousand items annually. Currently, deacidification efforts target the Music and Africana collection, and in FY2005 the Preservation Department treated a total of 6,130 items from both collections. The vendor the Preservation Department currently uses is Preservation Technologies Inc. and the deacidification process is called Bookkeeper.
Every volume and document folder is carefully inspected and the condition is recorded before and after treatment.
The Bookkeeper mass deacidification treatment takes place in vertical cylinders.
During treatment books are placed in a dispersion (PFC-perflurocarbon) in the cylinder and agitated.
