Polyethylene terephthalate recovery from waste - using hydrocyclones and pref. aq. ethylene glycol as separating liq., extruding and polycondensing

摘要

Ethylene glycol is used as separating liq. in polyethylene terephthalate recovery from mixts., using at least one hydrocyclone and a separating liq. The glycol pref. contains up to 50 wt.% water, w.r.t. glycol and water mixt. The ethylene glycol-contg. recovered polyethylene terephthalate particles are extruded, polycondensed and processed to fibres or filaments. Ethylene glycol residues adhering to the polyethylene terephthalate do not disturb further processing. The ethylene glycol is released in subsequent condensn. and also takes up dissolved impurities. Polyethylene terephthalate waste, e.g. from polyethylene terephthalate bottles contg. also polyethylene and paper, is recovered and used as fibre raw material.