Characterization of post-consumer polyolefin wastes by hyperspectral imaging for quality control in recycling processes

An innovative recycling process to obtain pure polyethylene and polypropylene from household waste

“…Several studies have been carried out also in waste recycling sector, i.e. glass recycling (Bonifazi and Serranti, 2006), compost product quality control (Dall'Ara et al, 2012), characterization of end-of life mobile phones (Palmieri et al, 2014) and characterization of different plastics (Serranti et al, 2011Ulrici et al, 2013;Luciani et al, 2013). Both MDS and HSI were applied to the same PO coming from Romanian and Dutch household waste (HW) to assess and validate the performances of such technologies for PO waste sorting and quality control.…”

Alternative polymer separation technology by centrifugal force in a melted state

“…The same principle applies to optical sorting, which can be automated, and is another way of pre-sorting, whereby an optical light, infrared or Xray source can be used. The absorbed light can be exploited in this way and is reflected differently by the polymers owing to the specific state of electrons which characterize every polymer substance (Arvanitoyannis and Bosnea, 2001;Bodzay et al, 2009;Serranti et al, 2011). With optical methods, polymers can only be sorted by colour, except for black painted materials.…”

“…Standard industrial solutions for polymer waste separation of individual components are: (i) integrated spectral imaging analysis (Bodzay et al, 2009;Serranti et al, 2011); (ii) gravity separation of density-based of polymers; (iii) froth flotation; (iv) electrostatic separation; and (v) magnetic separation (Bakker et al, 2009;Burat et al, 2009;Carvalho et al, 2007;Pongstabodee et al, 2008;Sadat-Shojai and Bakhshandeh, 2011;Takoungsakdakun and Pongstabodee, 2007). The literature also mentions centrifugal force separation (Gent et al, 2009), separation in a melted state and chemical solving (Bakker et al, 2009), which are used rather within laboratory conditions.…”

“…Surveying separation by spectral signs, Gondal and Siddiqui (2007) found that laser-induced breakdown spectroscopy is suitable for detecting PE, PP and ABS molecules. Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy are widely used for detecting the purity of the separated final polymer waste, after the measurement of the spectral signals for pure substances (Fávaro et al, 2013;Giancola et al, 2012;Ramesh et al, 2007;Serranti et al, 2011;Vajna et al, 2012).…”

Upgrading of PVC rich wastes by magnetic density separation and hyperspectral imaging quality control

“…Several studies have been carried out also in waste recycling sector, i.e. glass recycling (Bonifazi and Serranti, 2006), compost product quality control (Dall'Ara et al, 2012), recycled aggregates from concrete characterization of different plastics (Serranti et al, 2011;Bonifazi et al, 2013;Hu et al, 2013;Ulrici et al, 2013).…”