Abstract: Comminuted carpet pieces are fed to a first stirred tank together with an aqueous solution containing separating salt, to form a first suspension, which is fed to a first mechanical separating stage. A first high-solids phase, a second high-solids phase containing polymer fiber material, and a liquid phase are obtained therefrom. The second high-solids phase is mixed with a water-containing separation solution in a stirred tank, to give a second suspension, which is fed to a second mechanical separating stage. A third high-solids phase, a polymer fiber material-rich phase and a liquid phase are withdrawn therefrom. An acid which is stronger than H2CO3 is introduced into the stirred tank together with the water-containing separation solution, and the pH of the liquid in the stirred tank is adjusted to 2–6.

Abstract: Comminuted carpet pieces are fed to a first stirred tank together with an aqueous solution containing separating salt, to form a first suspension, which is fed to a first mechanical separating stage. A first high-solids phase, a second high-solids phase containing polymer fiber material, and a liquid phase are obtained therefrom. The second high-solids phase is mixed with a water-containing separation solution in a stirred tank, to give a second suspension, which is fed to a second mechanical separating stage. A third high-solids phase, a polymer fiber material-rich phase and a liquid phase are withdrawn therefrom. An acid which is stronger than H2CO3 is introduced into the stirred tank together with the water-containing separation solution, and the pH of the liquid in the stirred tank is adjusted to 2-6.

Abstract: Process for separating preshredded carpet materials into as many as three main components of different densities which comprises finely comminuting the carpet materials in the liquid phase. The density of the liquid phase is adjusted to a level between two adjacent densities of the components. Separation of one component from the other components and from the liquid phase in the suspension is effected in a double-cone full-jacketed screw centrifuge. The process is repeated if there are two materials of different densities in the other components fraction. The process is useful for recovering nylon, polyester, or polypropylene from carpet scraps which nylon or polyester can be depolymerized to reusable monomers and which polypropylene can be reprocessed into pellets, non-wovens or fibers.