RECYCLING OF PLASTICS - AUTOMATIC IDENTIFICATION OF POLYMERS BY SPECTROSCOPIC METHODS

In the recycling process of polymers, at least two steps might require an automatic identification tool: the sorting of the plastics, and th e qualification of the regenerated product. We have tested the efficie ncies of reflectance FTMIR and FT Raman with respect to these identifi cation applications. Although it was possible with both techniques to recognize most usual polymers, severe limitations of FTMIR were eviden ced such as a high sensitivity to the surface state, and a weak (noisy ) reflectance signal for CH bonds. On the other hand FT Raman proved t o be a rapid (approximately 1 s per object) and highly selective metho d, giving information even on the mineral fillers present in plastics.