US Patent 7546803 Letterpress printing machine

A letterpress printing machine is disclosed including a rotary printing cylinder in which a relief printing plate is installed, a substrate surface plate on which a substrate is placed, an ink supply device supplying ink on the relief printing plate, a relief printing plate washing equipment washing the surface of the relief printing plate, and a wiper for a plate. The relief printing plate washing equipment can include a washing liquid supplying unit, an air blasting unit jetting pressurized gas to the relief printing plate, a suction unit sucking the washing liquid scattered by air blasting unit, and a washing liquid recovery unit.