THE STRENGTHENING OF EMBRITTLED BOOKS USING GAMMA-RADIATION

The embrittlement of papers, manufactured through processes introduced in the mid-19th century, has caused many millions of books to become fragile, even to the point of being unusable. During the 1980s the Bri tish Library funded a research programme, carried out at the Universit y of Surrey, to develop a technology which could be used to treat brit tle books on a large scale, with the goal of greatly extending their u seful life. The process developed, known as graft co-polymerization, i nvolves three stages: i) application of a cocktail of monomers to the book's pages; ii) equilibration of these monomers throughout the text block; iii) a low, slow dose of gamma-radiation to effect polymerizati on. The work at the University of Surrey studied various combinations of monomers, as well as equilibration times and dose regimes; it also examined the environment necessary to achieve polymerization within th e pages of the book, whilst leaving it in an otherwise original condit ion. In collaboration with the British Library, Nordion International has designed a full-scale book-strengthening plant capable of processi ng between 200,000 and 500,000 books per year, with estimated prices t o customers in the region of pound 8-pound 10 per volume (US $12-16). In order to test the equipment and procedures that would be involved i n such a plant, pilot-scale equipment has been designed and assembled on the premises of Isotron pie, where use is made of a conventional ir radiator. This paper gives details of the graft co-polymerization proc ess, and some results of the pilot-scale work, in terms of both effica cy and controllability. It also discusses the technical and economic f easibility of building and running a full-scale plant.