Corona Treatment of Self-Adhesive Materials
Corona treatment systems are used to increase the surface energy of plastic films and aluminum foils, thereby enhancing their wettability to inks, coatings, and adhesives, ensuring printing and coating quality, and improving lamination stability.
Corona treatment systems for self-adhesive materials are specifically designed to increase the surface energy of plastic films and aluminum foils, enhancing their wettability to inks, coatings, and adhesives, thereby ensuring printing and coating quality and improving lamination stability.
▲ Corona Treatment System Structure
A corona treatment system consists of two tightly integrated components. A corona treatment system has two core components: a power supply assembly (corona generator) and a corona treatment station. The power supply assembly converts standard 50/60 Hz power into single-phase, high-frequency power, typically in the 10 kHz to 30 kHz range, to power the corona treatment station. The corona treatment station consists of electrodes made of ceramic tubes or other materials, insulated treatment rollers, and a support frame. Under the action of a high-potential electrode, discharge occurs through an air gap onto the surface of the passing web, while the treatment roller below the web maintains zero potential. This increases only the material's surface energy, thereby raising its surface tension.
▲ Application of Corona Treatment Systems
The operating principle of a corona treatment system can be summarized as follows: the web passes between a high-voltage electrode and an insulating plate. The high-voltage electricity ionizes the web through the air gap, thereby applying corona treatment to the material. This device is often installed on the equipment of material suppliers, such as plastic film manufacturers and self-adhesive coating plants, to ensure sufficient surface tension and optimal print quality during printing. Examples include injection molding extruders in plastic film manufacturers and coating machines in self-adhesive coating plants. However, because the surface tension or surface energy of a material decreases over time and due to surface friction, some materials may suffer from insufficient surface tension when used on printing presses, affecting ink fastness. Therefore, in recent years, printing presses for thin films have become increasingly equipped with in-line corona devices to ensure surface tension and print quality.