Appropriate surface treatment methods should be selected according to different plastics and process requirements: such as polyolefin (PE, PP) non-polar plastic, flame or corona treatment; polyester plastic containing benzene ring, its optical activity can be UV light treatment; nylon can be treated with phosphoric acid to improve the printability of plastic products.
The flame treatment is suitable for the surface treatment of small plastic containers. Its purpose is to decontaminate the surface with high temperature and melt the surface of the film layer, thereby improving the performance of the surface-adhering ink.
The container to be treated is put into the gas flame, the flame core length is controlled to be 6-19mm, the flame core tip is 6-25mm from the surface, the contact time is 0.1-1s, and the rotation speed is 100-150rpm. Strict operation requirements, if not careful will lead to product deformation, scrapped. This method has the advantages of good treatment effect, no pollution and low cost, and is currently mainly applied to the surface treatment of relatively thick plastic products.
Source: China Washing & Dyeing Industry Information Center