Polymer tracer detection systems with UV fluorescence spectrometry to improve product reyclability

Abstract

The recycling of materials originating from end-of life products is essential to preserve our raw material resources, which are increasingly expensive and whose extraction is increasingly impactful for the environment. However, certain materials are still not recycled today. In the case of plastics, their recycling includes grinding, which generates complex mixtures. It is not possible to sort these mixtures and reach a high degree of purity with the existing physico-chemical processes. Automated sorting processes using near infrared spectroscopy are limited to dark-colored materials. One option is to add tracers to virgin materials to allow identification and rapid sorting of end-of-life products, using UV fluorescence spectrometry as the identification technique. The optimization of the polymer/tracer/detection system is based on several criteria: the reliability and speed of detection of UV fluorescence tracers added to a polymer matrix with carbon black, the relevance of the environmental impact of the tracers, and the preservation of the mechanical properties of the polymer with the tracers added.