Used plastics cannot simply be reused in the form they are collected, due to degradation phenomena (primarily oxidation and photooxidation reactions) which occurred during their first life cycle (i.e., previous processing steps and service life). These molecular structure changes combined with the influence of inhomogeneities, residual impurities and physical pre-damage, reduce significantly the thermal and light stability of the recyclates. As a result the recycled plastics cannot satisfy the requirements for an extended product life or they cannot meet the requirements of a new application. Therefore, quality improvement of the recycled plastics becomes the key issue. To achieve upgrading of recycled plastics not only sophisticated cleaning and separation is needed but also material properties have to be optimized. The best way for achieving the quality improvement of the recyclates is firstly to separate effectively the plastics in different categories, to purify the recovered grade from all negative impurities and contaminants and finally, to improve the quality of the recycled material through restabilization.
展开▼
