Corona treatment rollers for plastic film industry
In the production and conversion of plastic film, corona treatment is essential to increase the surface energy of the material and ensure proper adhesion in downstream processes such as printing, laminating, metallizing or bonding.
It is a high-voltage electrical process that generates a controlled discharge between an electrode and a roller coated with dielectric material, over which the film to be treated runs: the quality and uniformity of this coating directly determine the effectiveness and repeatability of the treatment.
Precisely because of the delicacy of the process, which must guarantee an even discharge distribution, consistent dielectric strength and dimensional stability over time, the choice of the roller and the silicone coating it carries is a critical technical element, not a simple consumable component.
Silicone for corona treatment: purity, thickness and technical specifications
The key-feature for the corona treatment rollers are:
- Compound purity: a silicone free of foreign fillers and contaminants reduces the risk of irregular discharge ignition points and the resulting defects (pin-holes, localized burns) on the film surface.
- Calibrated thickness: coating thickness must remain constant across the entire length of the roller, since even minimal variations affect dielectric strength and therefore the uniformity of the treatment.
- Certifiable regulatory compliance: the silicone compound can be certified with a declaration of conformity to the FDA and MOCA positive lists and to the REACH regulation, ensuring traceability and safety of the materials used.
- Guaranteed electrical insulation: dielectric strength between 20 and 28 kV/mm, able to withstand electrical discharges up to 50 kV/mm, for reliable insulation even under the most demanding operating conditions.
- Guaranteed resistance to ozone and heat: compounds formulated to provide certified resistance to the ozone generated by the process and to thermal stress, preserving performance over time without premature degradation.
- Surface free of imperfections: guaranteed finish free of surface defects, an essential condition for an even discharge distribution.
- Tight dimensional tolerances: concentricity, cylindricity and coating thickness must fall within very narrow ranges, since any deviation results in an uneven discharge and inconsistent treatment across the film.
Our solutions, ground directly on the roller or on a dedicated form, achieve dimensional and concentricity tolerances significantly tighter than the extruded sleeves available on the market: the result is a more uniform electrical discharge, consistent corona treatment across the full width of the film, and a longer, more predictable coating service life. Choosing A.Piovan means choosing a partner that combines technical expertise, manufacturing precision and industrial reliability, for a corona treatment process truly equal to the most advanced production requirements of the plastic film industry.
