Patent ID: 6578478
Filing Date: 2003-06-17
Classification: B41F

Abstract:
An electrostatic arrangement for a gravure printing unit for polarizing the ink molecules used in the gravure printing unit, comprising:a multi-layer impression roller, a voltage electrode positioned relative to said impression roller such that an air gap is formed therebetween, and a printing plate cylinder positioned close to said impression roller such that a web of a printing material is feedable between said impression roller and said printing plate cylinder, said voltage electrode being an inductor electrode and having a plurality of emission needles which are spaced apart from one another, said plurality of emission needles each having a tip and, when a DC voltage is applied to said voltage electrode, current flows from said tips of said plurality of emission needles, through said air gap, and into said impression roller, and said plate cylinder having dimples to carry the ink molecules, wherein said multi-layer impression roller has an impression roller core, an outermost semiconductor layer, a highly conductive layer underneath said semiconductor layer and an insulating layer underneath said highly conductive layer and adjacent to said impression roller core, said voltage electrode being positioned such that said air gap is located between said voltage electrode and said semiconductor layer of said multi-layer impression roller; and said multi-layer impression roller has a longitudinal length and said voltage electrode extends longitudinally and axially having a length of not greater than about 50% of said length of said multi-layer impression roller.