Zhejiang Tiantai Duobang Packaging Materials Co., Ltd

Corona treatment of film surface can produce oxidation and polarity on the film surface, and micro roughness on the film surface is conducive to the drying and fastness of film printing. In order to do a good job in corona treatment of film, the process is required as follows.

1. The corona processor must operate normally with accurate corona force and sufficient standby corona processors.

2. For the film used for printing, the dispatcher of the production planning department should make a weekly plan, and in principle, the time from blow molding to printing should be shortened as much as possible. No more than 15 days are allowed. During the operation of film blowing, cutting and printing, the corona effect of the film shall be continuously tested. If the printed text pattern reaches 36 dyne and the printed large color block reaches more than 38 dyne, it shall be actively remedied.

3. If one-sided printing only needs corona treatment on the front, the corona surface should be used as the working surface for rewinding and printing. Full plate gravure printing adopts quartz glass tube or silicone tube with lower electrode sleeve, and the upper knife exceeds the film diameter by 25px for corona treatment. According to the intensity of corona treatment, more than two corona machines can also be used for combined corona treatment.

4. The distance between two electrodes is required to be within 3mm, and it is not allowed to exceed. The knife edge should be straight and smooth. After using it for a period of time, it needs to be sanded and trimmed in time to prevent the oxidation of the blade and reduce the efficiency. It should be kept clean at ordinary times to ensure the corona effect.

5. The corona treatment shall not be stopped, skipped or leaked in the middle. The film blowing quality inspector shall constantly detect the corona treatment effect as the film blowing quality assessment index.

6. After corona, the film will generate electrostatic adsorption, and each process and transportation must ensure that the film is clean.

In a word, BOPP on the surface of plastic film should not be lower than 38 dynes, and the corona value of PET film should be higher than 42 dynes.