High-Speed Automated Optical Sorting of Recovered Paper, 2000 Recycling Symposium Proceedings

Felix A. Hottenstein, Garry R. Kenny, Tom Friberg, Mike Jackson--Recycling of post-consumer waste paper currently requires extensive manual sorting for removal of contaminants and to separate the paper into grades usable by paper mills. This manual sorting results in relatively high processing costs as well as exposure of workers to hazards. This problem has been partially addressed with mechanical separation equipment such as special screens. However, this separation has until now been limited to mechanical properties of the paper such as object dimension and weight. Equipment for automated separation of different paper grades has not been available. This paper presents new technology utilizing optical sensing for the separation of different paper grades from mixed paper. It allows distinguishing various paper grades, for example bright white from non-bright white or colored from white paper, respectively. The paper describes the development, prototype testing and field experience for a full-scale system after one year of operation. Sensor technology, material handling and capacity, system separation performance, and future possibilities will be discussed comprehensively. Economic aspects will be addressed as well as quality issues such as product consistency, and control over supplier quality.