A novel process has been found in which the two types of plastic particles having similar specific gravities in a mixture are safely, efficiently, effectively and economically separated after being soaked in a plasticizer for a predetermined amount of time. The recovered and reclaimed particles can be reprocessed without any additional steps other than washing and drying. This novel process is useful in recycling waste plastic materials especially those materials containing polyvinyl chloride.
A method for separating plastic particles by types from a particle mixture of plastics of different types by flotation. The plastic particles are initially processed by a type-dependent change in their wetting behavior in such a manner that the various types can be floated individually out of the particle mixture. This surface treatment of the plastic particles takes place prior to flotation and outside of the flotation device in a physically dry manner by plasma processing of the particle mixture followed by storage for a predetermined time period. Storage results in a material-specific classification wetting behavior.
A method for preparing a mixture of plastics that are incompatible in view of processing in a shaping process, such as by extrusion, characterized by providing an initial mixture of a first part which is essentially composed of uniform material in view of a group of chemical substances, and a second part, separating the first part from the second part, processing the second part to enlarge or modify the surfaces of the constituents of the second part, then recombining the first and second parts into a final mixture, with the second part being essentially uniformly distributed in the first part of the mixture so that an essentially uniform product will occur when processing the mixture in a shaping process. The invention is also directed to a mixture manufactured by this method.
