Bottle sorter, optical

Optical sensors can be used to separate plashes based on either color or transparency. This technique is used to separate bottles by color because clear PET has more value than colored PET. Developed from the coffee bean separators that are used to eliminate unripe green beans from the mix, these computer-controlled systems can rapidly differentiate between the various hues of the plastic regrind. The color of each piece of plastic is quickly established using a type of CCD camera and is either allowed to flow downward or is ejected with a puff of air into the reject or collection pile. Satake [77], for example, produces equipment that is specifically designed to separate plastics by color but their main business is still from the agricultural industry. Satake s ScanMaster IE, SE, and DE Optical Sorters are used to differentiate the colors of HDPE and PET materials in recycling operations. 

---