A corona treatment system primarily consists of a generator, a high-voltage transformer, and a treatment machine. The generator provides energy, while the high-voltage transformer converts alternating current (AC) into a high voltage suitable for treatment. The core of the treatment machine is a capacitor. The material to be treated is placed between two electrodes. As the voltage gradually increases, a corona phenomenon occurs, causing surface oxidation and breaking chemical bonds. This process produces hydroxyl groups, carbon groups, and peroxide bonds, roughening the film's surface and helping to reduce surface contamination.
During corona treatment, the film is typically placed between two rollers and treated with a bipolar substance, with the electrodes maintained at a distance of several centimeters. The effectiveness of corona treatment is affected by treatment time, temperature, and humidity. As treatment time decreases, rising temperatures and changing humidity may affect the film's surface energy and lubricity. To ensure smooth film winding, the corona treatment process must avoid the formation of lumps and an increase in surface energy.
Corona treatment is widely used on various film types, particularly polypropylene and low-surface-energy plastics. When the air gap is set to 5 mm and the voltage is adjusted to 560 kHz, the corona discharge can be effectively controlled to ensure the best treatment effect.