| 摘要 |
<p>Method for cleaning and restoring objects made of biodegradable material comprises placing them in a closed container, establishing a slight vacuum, then impregnating under vacuum with an aq. liquor contg. thermoplastic polymer. The vacuum is broken, contact with the liquor maintained and then the object wiped with water and dried. The impregnant is a soln., dispersion or emulsion, esp. a 5-50 wt.% polyvinyl acetate soln., and the vacuum impregnation is at 400-700 mm for at least 30 min. This is followed by contact for at least 1 hr at normal or slightly elevated (0.1-1 bar) pressure. The method is used to renovate shaped objects made of wood or limestone, clay etc., e.g. old pictures or furniture or items of archaeological interest. The process preserves the characteristics and external appearance of the objects and significantly improves the mechanical strength of objects which have undergone deterioration.</p> |
