Method of recovery of printing ink wastes

Abstract

A method for recovery of printing ink wastes is provided which greatly minimizes pollution problems attendant to the disposal of ink wastes, while permitting formulation of usable ink products from the wastes. The method involves first creating a flowable stream of material including the ink wastes, and directing this stream to a hydroheater (16) along with incoming steam. In the hydroheater (16), the ink wastes are subjected to elevated temperatures and pressures, and intense shear, creating a homogeneous, flowable output. This output may then be dried and powdered, and the powder may be reconstituted as a black ink suitable for commercial printing operations. If desired, the hydroheater (16) output may be treated in a filter press (252) to obtain a filter cake (258), and this cake (258) may be subsequently subdivided and treated with ink carriers to form a processing ink. In a preferred embodiment, dilute printer washup material containing up to 5% by weight residual ink therein may be directly processed in the hydroheater (16); this eliminates the need for preliminary chemical treatment and sludge formation.

Dependencies are inferred from the claim text.