Most plastic films are non-polar polymers with low surface tension, generally 29-30mN/m. In theory, if the surface tension of an object is lower than 33mN/m, known inks and adhesives are both It cannot be firmly attached to it, so corona treatment is required on its surface. The processing principle is to apply high-frequency and high-voltage electricity to the processing equipment, so that it generates high-frequency and high-voltage discharges, and generates small and dense purple-blue sparks. Various ions generated after the ionization of air accelerates and impacts the plastic film in the treatment device under the action of a strong electric field. The chemical bonds of plastic molecules are broken and degraded, increasing the surface roughness and surface area. A large amount of ozone will also be generated during discharge. Ozone is a strong oxidant, which can oxidize plastic molecules and generate more polar groups such as carbonyl groups and peroxides, thereby increasing its surface energy.