The process makes it possible to recover high-value products from commingled plastics. The process, now being pilot-tested in an appliance recycling plant, could unlock many valuable sources of plastic.
Froth flotation allows two or more equivalent-density plastics to be separated with high purity.
The resulting products are of commercial quality and would be priced competitively with virgin materials. The froth flotation technique uses the wetting characteristics of plastic materials as a basis for separating ABS and HIPS plastics. Controlling the chemistry of a solution permits the wetting characteristics to be adjusted selectively. By changing the surface wetting characteristics of equivalent-density plastic materials, small gas bubbles can be attached to one material's surface, reducing its effective density. Because of the lower effective density of the bubble-plastic particles, the plastics will float in an appropriate solution.