Method to improve detection of thin walled polyethylene terephthalate containers for recycling including those containing liquids

摘要

Disclosed herein are methods to improve detection of PET polymer materials within a waste material to be sorted. The methods disclosed allow for municipal solid waste to be separated so that PET polymer materials, including those containing liquids, are separated for recycling, or other purposes. PET polymer materials, such as water bottles which have been disposed of while still containing liquid may now be separated by the enhanced methods disclosed herein.

主权项

1. A method of improving detection of polyethylene terephthalate polymer materials within a stream of materials comprising:
providing a stream of materials; irradiating the stream of materials with near infrared radiation; measuring near infrared radiation emanating from the stream of materials; analyzing the measured near infrared radiation at two or more wavelength regions; determining a ratio of measured near infrared radiation at two regions of wavelengths; comparing the ratio to a preset threshold; adjusting the measured near infrared radiation measurements at one of the wavelength regions according to the results of the comparing step; wherein adjusting the measured near infrared radiation measurements at one of the wavelength regions is adjusting the measured near infrared radiation measurements at one of the wavelength regions to boost the measured near infrared radiation measurements at one of the wavelength regions; processing the adjusted near infrared radiation measurements; identifying at least one polyethylene terephthalate polymer material.