Method for recovering wasted or old articles from cross-linked plastic, mainly from polyurethane or polyurea

摘要

The invention relates to a process for the recycling of waste or used articles made of crosslinked plastic, in particular polyurethane, involving the following process steps: a) the waste or used articles as raw material are comminuted, for example to give chips or granules, where the size of the comminuted raw material is /= 15 mm, in particular /= 5 mm; b) the comminuted raw material is treated for from 5 to 30 minutes in an apparatus which exerts thermomechanical load, in particular in a compounder, at an apparatus temperature of from 130 to 180 DEG C; c) for re-crosslinking, the degradation product is mixed with a polyfunctional isocyanate at a material temperature of /= 80 DEG C in a mixing apparatus, in particular in a low-temperature compounder, at an apparatus temperature of /= 30 DEG C; d) the reaction mixture is cooled immediately; e) the mixture is finally heated for from 5 to 20 minutes at from 130 DEG to 170 DEG C in a mould at a minimum pressing pressure of 100 bar, during which it is re-crosslinked. a