Separation of physically co-mingled plastics using a supercritical fluid to facilitate recycling

摘要

The present invention provides a method for selectively separating co- mingled materials of different densities by selective density flotation of the materials in a fluid in the vicinity of its critical point. The extermely high compressibility of a fluid in the vicinity of its critical point allows continuous variations over the maximum density range to be accomplished using minimal changes in temperature and pressure. Materials exhibiting similar densities can thus be separated by adjusting the fluid density to a point between the two materials.