Operating Instructions POWER TOP Electrostatic Printing Assist Series GNH63

System description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Printing quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 System structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 System components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Identification...

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Electrodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Inspection of the protective resistors - contact protection . . . . . . . .40 Visualization system Eltex Connected Control ECC # . . . . . . . . . .41 7 Trouble-shooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43 7.1 Error messages Visualization system Eltex Connected...

Dear customer, The main function of the electrostatic printing assist ESA in gravure printing is to support the discharge of the ink-filled cells to avoid missing dots. Also, the discharging performance of the cells is improved overall. This means that the printing density can be controlled to a certain extent. The ESA system monitors the charge conditions in the printing units in which this system is installed. The benefits: • Improved printing quality (no missing dots) • Less wear on the impression rollers by reducing the mechanical contact force • Suitable for use in the EX zone in the gas...

1. System description 1.1 Function The electrostatic printing assist ESA utilises the physical fact that electrically charged particles (gravure inks are composed of such particles) are exposed to forces in an electrical field which always shift the particles into areas with higher field strengths. A simple plate condenser (Fig. 1) will help to illustrate this situation. When applying an electrical voltage, the plate condenser generates a homogeneous electrical field between the plates which has a much lower field strength at the edges and outside the plates than between the actual plates. If...

Printing unit Dielectric insulator Impression roller Paper Printing cylinder Filled cell In gravure printing the electrical field is generated in the printing nip between impression roller and impression cylinder. Both the substrate to be printed and the ink are dielectric materials, i.e. insulators. To achieve the desired effect, electrical field strengths of between 3...5 megavolt per meter are required. The electrical field strength is defined as follows: electrical field strength = voltage / distance With a distance of 0.1 mm, which is roughly the thickness of gravure paper, the voltage required...

Now, since ink continually rises into the electrical field when the cells discharge, and since non-polarised paper continually runs through the field space in the printing nip, this means that dielectric insulators are permanently fed into the electrical field. This also means that a low but consistent current has to flow to keep up the proper effect of the ESA system. Other partial currents develop when: • the breakdown strength of the substrate is exceeded, • the impression roller makes direct contact with the impression cylinder. This is why these partial currents dominate the total current...

• Recycled materials and some films have a lower volume resistance and higher roughness depths. Before using materials of this description, first check these for the printability with the ESA printing assist. • Ink conductivity must be below 100 µS/cm. Conductive inks such as metallic inks carry a higher risk of fire in the explosion hazard area and must not be used together with the ESA. • The proper drying of the ink is also important. Inadequately dried inks in connection with double-sided printing and with the nip voltage of the printing assist can cause smudging on the impression roller...

Cable connections

2. Safety The units have been designed, built and tested using state-of-the-art engineering, and have left the factory in a technically and operationally safe condition. If used improperly, the units may nevertheless be hazardous to personnel and may cause injury or damage. Read the operating instructions carefully and observe the safety instructions. 2.1 Identification of risks and hazards Possible risks and hazards resulting from the use of the units are referred to in these operating instructions by the following symbols: Warning! This symbol appearing in the operating instructions refers...

2.4 Technical advance The manufacturer reserves the right to make changes to the technical specifications without prior notice in order to adapt the units to state-ofthe-art engineering. Eltex will provide the latest information on any changes or modifications in the operating instructions on request. 2.5 Proper Use The system ESA GNH63 must only be used for the non-contacting electrostatic printing assist on gravure printing machines. Impression roller electrodes and discharging electrodes are approved solely for use and operation with PCTL/_ _ generator. This ensures that: • the maximum permissible...

• If electrically conductive ink is used to print in a printing unit fitted with ESA, the ESA charging voltage must be disabled in this printing unit and in all following printing units. Discharging must also be switched off resp. moved to the "passive" operating mode (optional). If the passive operating mode is not available, the mains voltage of the generator must also be switched off. • If electrically conductive substrates or substrates coated with conductive material (e.g. metal foil or metal composites) are used in the printing process, the ESA charging voltage must be disabled in these...