Abstract: Multistep recycling processes for preparing recycled plastic materials. The processes feature a sequence of operations selected from the group consisting of preprocessing operations, size reduction operations, gravity concentration operations, color sorting, sorting by thickness, friction, or differential terminal velocity or drag in air, surface to mass control operations, separation processes enhanced by narrow surface to mass distributions, blending operations, and extrusion and compounding operations. Plastic-rich mixtures are subjected to the process, and one or more recycled plastic materials are collected as outputs of the sequence of processes.

Abstract: Techniques for creating recycled plastic materials from waste plastic materials are described. A recycled plastic material contains at least a primary polymer, a secondary polymer, and residual additives. Predetermined properties of the recycled plastic material can be controlled by selecting the types of waste plastic materials used in the recycling feed, determining the types and amounts of recycled plastic material recovered from a separation process and blending the recycled plastic material with other materials.

Abstract: This invention relates to improving the separation efficiency in a triboelectric separator by adding media against which the components of the mixture will charge. As a result, random charging between the components of the mixture is reduced and controlled, and predictable charging is achieved.