Process for disintegration and pure-sorted separation of recyclable different plastics of composite structural parts

摘要

A process is provided for disintegration and pure-sorted separation of different plastics of composite structural parts to be recycled, which parts consist of a support composed of thicker-walled hard plastic, an intermediate layer applied with firm adhesion to this support and composed of foam material, and a flexible foil adhering firmly to the outside of the intermediate layer and made thinner-walled than the support. The composite structural parts are first comminuted into approximately cuboid particles preferably of a granulation of approximately 20 mm and comprising still different plastics. Subsequently, the particles formed are disintegrated in a dry manner into their individual materials, and these are then separated in a pure-sorted manner. For this purpose, the less break-resistant foam material of the particles is selectively comminuted mechanically by an impact stressing of the particles to form substantially smaller crumbs than the remaining pieces of particles of more break-resistant plastic. The smaller foam crumbs are screened off from the coarser remaining particle pieces. These two operations are advantageously carried out in a batchwise operated hammer mill with an integrated screen plate. To produce cuboid particles, the composite structural parts are first cut into narrow strips in a twin- shaft cutter, and these are subsequently chopped into short parts in a knife mill. Where three-component structural parts are concerned, the initially remaining mixture of thick-walled hard-plastic fragments and of thin-walled foil chips is separated in a pure-sorted manner by a vertical low-turbulence wind sifter.