| 摘要 |
PROBLEM TO BE SOLVED: To provide a marking method onto a polyvinyl chloride product easily applicable even to extrusion, capable of clearly marking even the dark color product. SOLUTION: In this marking method, a laser beam is irradiated on a surface of the polyvinyl chloride product such as a joint, a pipe or the like to mark a bar code, a character, a symbol or the like on the surface of the product by the laser beam. |
