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: A method for separating mixtures of solid materials includes incorporating a ferromagnetic particulate material into a mixture of solid materials and, after the incorporating step, separating the mixture of solid materials into at least two groups based on the magnetic and frictional properties of the different components of the mixture of solid materials. The ferromagnetic particulate material can differentially incorporate into or adhere to different components of the mixture of solid materials. The different components of the mixture have different frictional properties and, after the incorporating step, the different components have different magnetic properties.

Abstract: A transportable system for separating materials in a waste stream. An arrangement of separation and grinding devices is mounted on a transportable platform. The devices are configured and arranged to produce three or more product streams from a plastic-rich feed mixture. One of the product streams is a coarse heavy stream, one stream is a ground plastic-rich product stream, and one stream is a ground light material stream. The system can be transported to a waste-goods location, operated to separate waste-goods, and relocated a new location.

Abstract: Methods, systems, and media for use in separating mixtures. A slurry including a separation liquid and one or more particulate media materials is provided. A classification separation is performed on the slurry to produce a classified media having a controlled particle size distribution of the particulate media materials. The classified media is combined with a mixture to be separated to generate a separation mixture. A density separation is performed on the separation mixture. The particle size distribution can be controlled based in part on characteristics of components of a separation system to be used in subsequent density separations.

Abstract: Methods, systems and media for separating polymer mixtures. A mixture including polymeric components is provided. A particulate media is added to the mixture, where the particulate media can selectively mediate a triboelectric charging of the polymer mixture. The media includes a polymeric material having a selected position within an electrostatic charging sequence and a functional additive. The mixture is triboelectrically charged with the media. Two or more components of the polymer mixture are separated according to the triboelectric charge. A portion of the particulate media can be recovered using a recovery process, where the functional additive is selected for compatibility with the recovery process.

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.

Abstract: A differential density alteration (DDA) device to enable the separation and partitioning of particles of one or more selected members of plastics included in a mixture of a plurality of different plastics in which each member of the plurality of different plastics is divided into discrete particles. The DDA device heats the mixture to a temperature for a time that causes the particles of the one or more selected members to alter in such a way that the difference between the apparent density of the particles of the selected one or more members and the apparent density of particles of the other members of the mixture (the differential density), after heating, is different from the differential density before heating, whereby the alteration in differential density produces a differential density alteration (DDA).

Abstract: The present invention provides for discharge (exit) ports for exit fluid flow disposed at or adjacent to one another on one end of a vortex separating body; an inlet port(s) disposed at one end of a separating body having discharge (exit) ports for exit fluid flow disposed at or adjacent to one another at an opposite end of the separating body; increased separation efficiency; solid mass separated per unit energy expended; a body that is predominantly cylindrical in shape that can be made inexpensively from standard sizes of pipe or tubing; a device that is predominantly cylindrical in shape so that the separation (vortex) length of the device can be changed simply by installing or removing sections of pipe or tubing; a device which promotes smooth rotational flow within the vortex region, therefore affecting an efficient separation of particles carried by the transporting fluid therein and reducing the pressure and/or energy required to move the fluid through the device; a device with entrance and especially