Patent ID: 7152742

Claim:
Process for separating polymer fiber material from comminuted carpet pieces, in which said comminuted carpet pieces are fed to a first stirred tank together with an aqueous solution containing separating salt, a first suspension is withdrawn from said first stirred tank and fed to a first mechanical separating stage, a first high-solids phase, a second high-solids phase containing polymer fiber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 separated off in the first mechanical separating stage, the separated second high-solids phase is mixed with a water-containing separation solution in a second stirred tank, and a second suspension is withdrawn from the second stirred tank and fed to a second mechanical separating stage, a third high-solids phase, a polymer fiber material-rich phase, and a liquid phase are separated; off from the second mechanical separating stage, and wherein an acid which is stronger than H 2 CO 3 is introduced into the second stirred tank together with the water-containing separation solution, and the pH of the liquid in the second stirred tank is maintained at 2–6.