Recycling of cheap packaging waste versus expensive engineering materials

The economical incitement is larger for recycling of expensive engineering materials than for packaging plastics. It should, however, be possible also for municipal waste industry to profit from recycling of packaging waste. At present, municipal waste plants already sell sorted plastics fractions o n the order basis. The degree of mixing of these plastic fractions is the k ey question to be solved in order to obtain a high-quality product. The val ue of recycled HDPE fraction is lowered if it contains impurities of other polymers, e.g. PP, PS or PET because such impurities cause embrittlement. A n addition of an impact modifier to contaminated HDPE was analyzed with res pect to changes in morphology and mechanical properties. Oxidative stabilit y of the polymer matrix decreased as a result of recycling, indicating deco mposition of heat stabilizers, as shown for polyamide 66. The relation betw een expensive/cheap recycled plastics is discussed based on their long-term properties.