Abstract: A mixture of air, paper stock made from recycled paper, foaming agents and surfactants are injected into a pressurized container. The container has a stock inlet at an end opposite a stock outlet, and three outlets arranged along the top of the container between the stock inlet and the stock outlet. The first top outlet nearest the stock inlet is separated from the second and third outlets by a baffle, and the second and third outlets are separated from the stock outlet by a baffle. Each outlet has a valve which controls flow from that outlet. By adjusting the outlet valves, foam and waste ink is vented from the first and second outlets from the stock inlet, while stock is vented from the third outlet which is closest to the stock outlet. The stock passing through the third outlet is recycled through the container.

Abstract: A mixture of air and paper stock made from recycled paper from which the ink particles have been chemically released is injected into a cylindrical processing vessel. Added surfactants create a foam from the air as it rises through the stock and cause the ink particles to adhere to the air bubbles, resulting in a foam containing a concentrated fraction of the ink particles with some included fibers. The foam rises to the top of the vessel, and carries with it ink particles. Additional air injection ports can be used to increase the amount of foam generated and the amount of ink removed. Flow of stock and foam from the vessel can be controlled by adjusting valves on the stock and foam outlets. Flotation sensors allow the foam head to be maintained at the stock level by controlling the rate foam is withdrawn through the foam outlets.

Abstract: A mixture of air and paper stock made from recycled paper from which the ink particles have been chemically released is injected into a cylindrical processing vessel. Added surfactants create a foam from the air as it rises through the stock and cause the ink particles to adhere to the air bubbles, resulting in a foam containing a concentrated fraction of the ink particles with some included fibers. The foam rises to the top of the vessel, and carries with it ink particles. Additional air injection ports can be used to increase the amount of foam generated and the amount of ink removed. Flow of stock and foam from the vessel can be controlled by adjusting valves on the stock and foam outlets. Flotation sensors allow the foam head to be maintained at the stock level by controlling the rate foam is withdrawn through the foam outlets.