Millimeter-Wave Imaging for Recycled Paper Classification

Millimeter-wave imaging may be used to assist in the problem of wastepaper recognition during the sorting and recycling process. Currently, there are a variety of techniques, which are used within materials recovery facilities to sort waste paper and card; however, improvements in sorting capability can be realized using a multiple sensors to provide complementary (orthogonal) data. This paper discusses the issues related to the processes, which are currently used for sorting of recycled wastepaper and the phenomenology for millimeter-wave imaging of a wastepaper material. Experimental measurements and images in the millimeter wave band are presented, which support the proposed application.