IPEN: Investigación y Desarrollo

IPEN: Investigación y Desarrollo

Recycling plastics sorted — Sciencebase Science Blog

Recycling plastics sorted — Sciencebase Science Blog

Plastics recycling sorted

Plastics recycling sorted

[13 de julio de 2006]

Plastic waste is a mess. Disposal in landfill is the worst option but recycling post-consumer plastic waste presents a technological nightmare given the huge range of polymers used in packaging and products. A rapid, online method of identifying the different plastics in a recycling stream would provide a way to sort them and allow recycling plants to operate far more efficiently and perhaps make plastic recycling commercially viable.

A technique being investigated by Spanish researchers to this end is laser-induced plasma spectroscopy (LIPS). Jesús Anzano, María-Esther Casanova, María-Soledad Bermúdez, and Roberto-Jesús Lasheras of the Laser Analytical Spectroscopy Lab at the University of Zaragoza, in Spain, have now demonstrated that LIPS used in conjunction with a simple statistical correlation method can indeed differentiate between plastics prior to recycling.

Among the most commonly used household and industrial plastics are polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS). The team has developed a compact LIP spectrometer with which they obtained LIP spectra for these polymers in the 200-800 nm range and compared them with library spectra of recycled plastic samples. The researchers have also developed a computer program for data acquisition and data processing that exploits linear and non-parametric (rank) correlations to classify the spectral data.

"The robustness of the technique was demonstrated by the 90-99% reliable identification of almost all analysed plastics," the researchers says, "The technique has excellent potential for on-line, real-time analysis of recycling materials," they say.


Related links:

• Polym Testing, 2006, in press
• Laser Lab, Zaragoza

Article by David Bradley

Miembros del laboratorio láser de la Universidad de Zaragoza

LABORATORIO LÁSER
Universidad de Zaragoza



JESÚS ANZANO LACARTE
JUSTINIANO CASAS GONZÁLEZ,
ROBERTO-JESÚS LASHERAS MOLINA
CRISTINA BELLO GÁLVEZ
SONIA SANGÜESA VILAR
ELIANA GASPAR MORENO
MAYTE BENEDED SERRANO