Simco/ramic Corporation

William S Drummond

H Parks Squyres

Philip L Hoffman

Casey P Walsh

A plastic container sorter (10) moves labeled plastic containers (14, 20, 48, 54, 58) of various colors and transparencies through an inspection zone (18). A pair of line-scanning color cameras (22, 24) capture respective transmittance and reflectance images of the containers and generate raw transmittance and reflectance image data. The raw container data are digitized, normalized, and binarized to provide accurate transmittance and reflectance container RGB image data and binarized image data for differentiating container image data from background data. Container sorting entails eroding (120) the binarized transmittance image and merging (122) the eroded image with the transmittance image data to yield a transmittance image. The eroded transmittance image is analyzed (124, 126) to determine whether the container is opaque. If the container is opaque, color analysis proceeds by analyzing the reflectance image data. If, however, the container is not opaque, transmittance image data are used to classify the container as green transparent (140), translucent (142), or clear transparent (142). Classified containers are transferred to an ejection conveyor (46). Side discharge of a classified container is effected by an air ejector (64) blast that is timed in response to sensing a particular container adjacent to an appropriate side discharge station (60).

Plastic container sorting system and method

In a preferred embodiment, a sorting apparatus according to the present invention includes a conveyor belt for carrying a stream randomly-arranged articles, at least some of which are post-consumer plastic articles made of PVC and others of which are made of PET. The conveyor belt carries the articles to an irradiation area where they are irradiated with ultraviolet light that induces the post-consumer articles of PVC to emit phosphorescent light that persists after the irradiation ends. The conveyor belt then carries the articles to an inspection zone that is isolated from the ultraviolet light. A video camera is positioned to receive phosphorescent light emitted from post-consumer articles made of PVC. Other articles commonly in the stream of post-consumer plastic articles (e.g., PET) do not emit phosphorescent light and are, therefore, distinguishable from the PVC articles.

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Medford, OR, United States of America

William S Drummond