Research into the hygienic qualities of paper recovered by mechanical sorting of municipal waste

Abstract

The R 80-plant of Imperial- Krauss-Maffei-Industrieanlagen GmbH, Munich, is a mechanical sorting unit for municipal waste with a capacity of 5 t/hr. It uses a dry process and has been developed to the point at which it is suitable for commercial application. Paper and cardboard are the principal components in municipal waste, having 20–40% weight percentage and 30–60% volume percentage. Some 61% of the available paper and cardboard could be recovered by mechanical sorting of 31 tons of municipal waste in the R 80-plant and were used as ‘raw material’ for paper in conventional paper mills. After the production of different grades of paper a research, subsidized by German state authorities, was made checking the bacteriological contamination of these papers with a view of their range of application, e.g. for packing purposes. These results are encouraging. If certain precautions are taken there is no objection against the commercial use of such papers. The precautions are thermal and/or chemical treatments of the waste paper and a thorough purification of the effluents of the paper mill. There is evidence of a wide range of application for such papers, which will contribute to the progress of recycling valuable materials from waste.