The Design Of Sorting Recycled PET/PVC Plastic Waste Based On Near-infrared Sensor

Recycling of waste plastics is the most reasonable and effective way to reduce environmental pollution, as well as ease resource constraints. The first step of recycling is to sort the abandoned materials into single component, however, these recyclable materials always contain a random mixture of various plastic types, therefore the separation process must be strictly controlled to limit the impurity levels, especially in the textile industry. Among a number of the techiniques for identification of plastics, the near-infrared method is of advanced and interesting nature based on its high speed and performance.This paper describes a system to separate polyethylene terephthalate (PET) and polyvinyl chloride (PVC) postconsumer plastic mixtures. The identification and sorting process of PET and PVC waste mixtures can be achieved by using a near-infrared spectrometer and a control circuit, the remote data communication is realized through the serial port. The entire sorting system can be devided into three parts. The slave machine part using near-infrared sensor and filter to identifie the different NIR absorption peak, and control the air separation unit to sort the two plastic. The host computer part is used to design the interactive interface and complete control parameter settings, and then send those parameters to the terminal machine. The terminal machine distributes those parameters to each slave machine. Above all, the whole setup process is complete.The software design is based on C++, modules'software working analysis are displayed, as well as the software programming process. In host computer, the interface is realized by using MFC programming. Finally, according to experiments results, parameters will be adjusted to achieve reliable operation of the entire separation system.