Mobile phone cover, shell, box: plasma cleaning machine can not only clean the shell in the injection process of the oil, but also to a large extent on the activation of the surface of the plastic shell, enhance its printing, coating adhesion. The connection between the coating and the substrate of the shell is very firm, the coating effect is very uniform, the appearance is more beautiful, the wear resistance is greatly improved, and the paint will not be rubbed off after long-term use.