DESCRIPTION


One of the most common problems in gravure printing is related to the “Missing Dots”.
When the ink sited into the engraved cells of the printing cylinder cannot be completely transferred to the substrate to print, being it paper or film, this situation generates the missing of dots on the image. By consequence an important decrease of the printed image quality is there.

ACE is an important actor of the segment since many years, with its well known and qualified ESA Rotostatic system fed with 230V. Two different applications, Top Loading and Direct Charging, to which today adds the new “patented” version ACE ESA 24V, the outstanding and more advanced solution available on the market up to date.

The installation of ACE ESA24V is normally done on those printing units showcasing the problem. Components of the system are a first antistatic low tension and high performance bar to eliminate all the electrostatic charges effecting the substrate to print, which are generated during the run of the material getting in contact with the rollers, all along the press. An electrostatic charging device, perfectly calibrated accordingly with the needs, provides the generation of an homogeneous and intense electrical field between the pressure roller and the printing cylinder, thus creating the polarization of the ink laid in the engraved cells. This effect, facilitates the full transfer of the ink on the substrate to print. A second 24V antistatic bar is then located at printing unit exit, to grant the substrate running to the next printing unit, to be neutral and free from static charges. ACE ESA 24V System offers the advantage of being installed either on new machine and, as retrofitting on existing presses. Thanks to the features of its management software, the system grants high efficiency and contemporarily the operation of maintenance and replacement of the sleeve can be scheduled, thus reducing to the minimum those stoppages generated by the decreasing of the sleeve themselves. With the features described, ACE ESA 24V is the ideal instrument for the increasing of the net output of the rotogravure printing line.

ESA24V can be supplied in both the version Top Loading and Direct Charging. These two versions differ for the technology applied for inflòuencing the pressure roller of each printing unit.

ACE ESA System

New Press

Existing press

Film

Paper

Cardboard

Non Metallic Laminated

Top Loading: TL24 e TL230

⚫️

⚫️

⚫️

⚫️

⚫️

⚫️

Direct Charging: DC50

⚫️

⚫️

⚫️

⚫️

⚫️

⚫️

Direct Charging: DC24 e DC60

⚫️

⚫️

⚫️

⚫️

>

⚫️

Figure 1 shows a full cell for rotogravure and the most typical surface that results from the elimination of excess ink on the cylinder surface. Apart from the increase of the pressure exerted by the printing roller it is difficult for the substrate to come into contact with the ink surface when it is located below the surface of the cylinder.

Figure 2 shows the ink in a cell for rotogravure under the influence of the electric field created by the ACE Rotostatic system. The variation in shape of the ink surface induces part of the ink to rise above the surface of the cylinder in such a way as to ensure a perfect contact with the substrate.