Abstract:
A method of and apparatus for extending the life of fountain solutions used in commercial printing presses comprises withdrawing fountain solution from the dampener recirculation system of a printing press and directing the withdrawn fountain solution through a sediment prefilter, a separation filter, and a post treatment filter. The sediment prefilter preferably comprises a melt blown polypropylene filter; the separation filter preferably comprises a diatomaceous earth filter; and the post treatment filter preferably comprises a zeolite filter.
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.
Abstract:
A roller transfer device for use in sheet fed rotary printing presses of the type employing a one and one half to one delivery system, the transfer device comprising a frame mounted to a drive shaft adjacent the press impression cylinder, and supporting diametrically disposed fabric covered rollers arranged to engage and support a printed sheet during transfer from the impression cylinder to a further processing station within the press.
Abstract:
A system for curing printing plates with controlled radiant energy sources. A conveyor moves a printing plate through a chamber having energy radiators above and below the conveyor. Power to the radiators is controlled for each radiator or to groups of radiators defining radiation zones. Curing time may be controlled by adjusting power to the radiators and adjusting the conveyor speed. Sensors detect a plate as it enters and exits the chamber. Heat sensors may detect chamber or plate temperatures. A color sensor may detect plate color as an indicator of degree of curing. A computer system stores curing scenarios and uses the sensor signals and operator inputs to control power to the radiators and conveyor speed to provide uniform curing of the plate.
Abstract:
A coating apparatus for use in a sheet-fed, offset rotary printing press to selectively apply a protective and/or decorative coating to the wet ink surface of freshly printed sheets and including a coating unit having a pick-up roller for supplying aqueous coating material from a reservoir to the surface of a delivery cylinder mounted on a press delivery drive shaft, the delivery cylinder performing the dual function of a coating applicator roller and a delivery cylinder during coating operations.
Abstract:
A transfer or delivery cylinder for a sheet-fed rotary printing press having an endless chain conveyor carrying gripper bars and grippers and driven by a sprocket wheel concentrically mounted on a drive shaft for pulling freshly printed sheets from the impression cylinder onto the transfer or delivery cylinder for movement to a further processing station within the press, wherein the transfer or delivery cylinder is a right circular cylinder eccentrically mounted to the drive shaft so that upon initial engagement of the freshly printed sheet by the grippers, the leading edge of the cylinder is spaced below the sheet which is thereafter pulled smoothly and uniformly into contact tangentially with the sheet support surface of the transfer or delivery cylinder.