Sorting and sepn. of plastic waste and into its component types - by marking with a suitable dye during mfr. and combined measurement of fluorescent wavelength and lifetime

摘要

The plastic is marked, during the course of its prodn., with a dye, the colour and specific fluorescence lifetime of which are measured to allow sepn. of plastic waste mixts.. (I) is a multiplex fluorescence dye having the same absorption and emission wavelengths with differing quantum yields and fluorescence lifetimes and is e.g. coumarin or flavine, pref. formed from dyes that absorb and fluoresce in the far UV visible and/or the near IR regions. USE/ADVANTAGE - The process is useful for the sorting and sepn. of plastic waste into its different types. The process is rapid, requires small quantities of dye additive and by a combined measurement of fluorescence wavelength and lifetime allows differentiation of a greater number of marked plastic types than prior art.