Plastic Sorting

Recycled Plastic Sorting (PET)

First in Europe and now in the U.S., recycle centers are coming to depend on SWIR-based spectroscopy for sorting plastics in the waste stream, as the images below illustrate. Cost effective SWIR 1024 or 512 element linescan cameras with wavelength sensitivities ranging from 1100 to 2200 nm are mounted onto a spectrograph. While monitoring the sorting conveyor, the spectrograph rapidly identifies the polymer type inherent in the waste and triggers the diversion of the waste into its proper bin.

Near infrared (NIR) spectroscopy identifies and sorts PE-HD, PE-LD, PP, PET, PET-G, PS, PVC, and similar plastics found in automotive, electronic, and household products. The plastics are first ground into little pellets and then sorted using a Sensors Unlimited short wave IR camera system. Of particular value is the ability of short wave IR devices to sort black plastics; this detection and separation process is difficult to accomplish in the visible spectrum.