Patent ID: 6644196
Filing Date: 2003-11-11
Classification: B41F

Abstract:
A printing unit comprising:a metering roll and a form roll configured to enable a transfer of an ink having rheological properties from the metering roll to the form roll across a first nip defined between the metering and form rolls, the metering roll having an electrically conductive ceramic layer and the form roll having an electrically conductive rubber layer; a first electrode electrically connected to the metering roll; a second electrode electrically connected to the form roll; a plate cylinder configured to enable a transfer of the ink from the form roll to the plate cylinder across a second nip defined between the form roll and the plate cylinder; a first voltage source electrically connected to the first and second electrodes to apply an electrical field at the first nip and to increase a viscosity of the ink as the electrical field increases; and a second voltage source configured to apply an electric field at the second nip and being electrically connected to the form roll and the plate cylinder.