| 摘要 |
PURPOSE:To make difficult at the appearance of a ground mark on the surface of a metal plated layer and to improve outer appearance quality of the metal plated layer by buffering in the lengthy direction by way of stopping polishing in the circumferential direction at the time when proportion of surface roughness against thickness of the metal plated layer becomes enough. CONSTITUTION:By polishing a tubular body 1 in the circumferential direction by way of pressing a polishing tape 3 delivered from a polishing device on its surface while rotating it around its shaft center and by simultaneously gradually moving the polishing tape 3 in the lengthy direction of the tubular body 1, the overall periphery of the tubular body 1 is polished. When proportion of surface roughness against thickness of a metal plated layer becomes roughly less than 10%, polishing in the circumferential direction is stopped and buffering in the lengthy direction is carried out with a buff 10. At the time, by omitting the buffering range from the inside and a part directing downward which become a non-outer appearance surface at the time of mounting the tubular body as a muffler on a car body, a range of about half of the surface area of the tubular body 1 is made an object. Consequently, a ground mark 6 is polished roughly in the orthogonal direction. |
