manuscript conservation purchase sheet light

Because mechanical damage affects a great number of paper items in collections, stocks, and estates, its treatment is one of the basic and important challenges in restoration work. Additionally, most of the dangers in connection with reduced strength properties and prior damage result from the reuse of the items that can cause new damage or intensify already existing defects. Poor material quality and/or endogenous cellulose degradation-as in modern papers from the nineteenth and twentieth centuries-as well as cellulose damage by biodeterioration reduce the strength characteristics of papers and worsen mechanical damage when using those papers. Besides the direct influence, sheet borders are exposed to atmospheric influences that could have a negative effect on the strength properties close to the edge of papers. Therefore, damage is most often present around the edges. Different types of damage are caused by local and/or external forces acting on single items. Mechanical damage in form of cracks, cuts, fractures, losses, creases, and deformations very often occur to documents in archives, libraries, and museums. Advantages and limitations are addressed in detail. The paper discusses the applicability and stability of the differently prepared nanocellulose suspensions, also with regard to their mode of application and long-term performance. The results of the treatment depend on the type of nanocellulose, on the paper material, on processing and application techniques. The treatment of mechanical damage and the consolidation of weakened paper areas could be realized by the application of a nanocellulose suspension without an additional adhesive. The paper-nanocellulose composites were characterized with regard to their optical and microscopic integrity and by physical and chemical analyses. The resulting suspensions were applied to historical papers from several centuries with different extents of damage. Concerning material handling and application in conservation steps, different ways to modify the suspensions were tested.

Two different types of nanocelluloses, bacterial cellulose and a mechanically nanofibrillated cellulose based on wood pulp, were tested with regard to their performance in stabilizing fragile papers. Therefore, the present study investigated whether the treatment of historical papers with nanocellulose suspensions is a novel method for paper stabilization. Different types of nanocellulose are interesting as a novel stabilizing materials for paper due to their close structural relation to the paper matrix. The stabilization of such papers is very important because further use of the object can cause additional damage. Historical papers are often locally damaged by exogenous influences and/or have endogenously degraded paper areas.

Manuscript conservation purchase sheet light