Automatic coating circulation and wash-up system for printing presses

Abstract

A coater assembly includes a feed pump and a return pump for circulating a liquid coating material through a doctor reservoir for applying protective or decorative coating material to freshly printed sheets in an offset rotary printing press. A portable console control unit includes circulation and wash-up components for operating the coater in a PURGE/replenishment mode, a COAT mode, a WASH mode and a DRAIN mode. The components for pumping and valving the coating liquid and cleaning liquid are integrated within the portable console unit, which may be remotely located with respect to the press. Cleaning liquid and waste materials are stored internally within the portable console unit. The various operating modes are coordinated by two position, three-port flow control valves which are actuated from one position to the other by electrical solenoids under the control of ON-OFF switches. The ON--OFF switches may be actuated manually, or automatically by a cyclic controller for providing PURGE, COAT, WASH and DRAIN modes. The system may be cleaned without removing the coater or coater parts from the press, and without exposing press personnel to potentially toxic waste materials. The coater assembly may be operated in combination with the plate, blanket or delivery/transfer cylinder.