Device for the electrostatic application of material particles entrained in a stream of gas to an advancing, flat substrate

摘要

A device for the electrostatic application of particles entrained in a stream of gas to a non-conductive, flat substrate, typically a web or sheets of paper. The particles are electrically neutral in the stream. A charging electrode is located below the substrate in the area where the gas stream impinges on the substrate. The substrate is advancing lengthwise, and a counterelectrode is located below the substrate in the direction of advance from the charging electrode. Preferably the direction and velocity of the gas stream near the substrate and direction and velocity of the substrate itself are approximately equal. Also in the preferred form, a grounded collecting pan is located beneath the electrodes.