Studies on the Washing of Paper: Part 1: The Influence of Wetting on the Washing Rate.

The rate of wetting and washing of paper was been studied in this article. The papers studied were an Arches artists' paper and a Whatman filter paper. The papers were used as supplied and as artificially discoloured by soaking them in a concentrated aqueous extract of old, discoloured paper. The wetting of the Arches paper was much slower than that of the filter paper; a surfactant accelerated the wetting of the Arches paper but had little effect on the filter paper. For both discoloured papers, the rate of washing was accelerated by the presence of surfactant. The rate of wetting and of washing was increased as the temperature increased. A period of storage at zero degree, relative humidity increased the extent of washing compared with paper previously humidified.