ブックタイトルConservation and Restoration of Western Paper

概要

Conservation and Restoration of Western Paper

6. Effectiveness of DeacidificationTreatmentThe deacidification aim is to neutralize theacid present in acidic paper by reducing thehydrolysis of cellulose and to extend the lifeof paper documents. However, deteriorationof paper is not solely caused by theinternal acids but also by a combination ofexternal factors such as enzymes, light, and7, 21, 22heat. Deacidification treatmentstackle the acid in paper which is a majorcause of deterioration but they are notthe solution to all problems. Accordingto the Library of Congress TechnicalSpecifications for Mass Deacidification,deacidification treatment should increase thepermanence of paper by a factor of three. 23Deacidification effectiveness depends greatlyon paper quality, and the more degradedthe paper, the less effective the treatment(Figure 2). Moreover, deacidified paperis just as much in danger to degradationas non-treated paper by other factorsbesides acids. Therefore it can be saidthat deacidification is a treatment whicheffectively slows down the ageing of paper.Deacidification is cost effective when thetreatment occurs before the paper is severelyFigure 2 Efficacy of deacidification on acidic paperdamaged. Moreover, treating other causesof deterioration besides acids can expect alonger lifetime. For example, research showsthat storing a Bookkeeper deacidified paperat 5℃can lengthen its life by 30 times.7. Bookkeeper Mass DeacidificationTechnologyPreservation Technologies Japan (PTJ)started as the Japanese division ofPreservation Technologies L.P. (PTLP) in2007. Since 2008, the company has servedlibraries and archives in Japan with theBookkeeper deacidification process.After the unsatisfactory results with theDEZ process, the Library of Congressintroduced the Bookkeeper process. Thistechnology was developed by PTLP inthe 1980s and the Library of Congressconducted technical tests in 1993-1994. 25The results met every standard set bythe Library and since 1995, PTLP iscontinuously deacidifying 250 thousandvolumes per annum.In Japan, since PTJ set up its Bookkeeperdeacidification plant in Saitama city in 2008,it has deacidified 100 thousand books and67,000 newspapers in the past seven years.Its major customers are university libraries,public libraries, and national institutions.The Bookkeeper deacidifiation treatmentuses magnesium oxide particles dispersedand suspended in a non-aqueous material(a blend of fluorinated materials). Booksor single sheet items are submerged in theliquid. The magnesium oxide that is leftwithin the paper fibers reacts with humidityin the air to transform into magnesium25