2001 Volume 9 Issue 5 Pages 42-48
The plastic bumpers used in automobiles are painted by the spraying process. The process is widely used because its simplicity. However, it is difficult to maintain the uniformity in sprayed layer thickness, since the process is affected by air flow and the shape of component parts to be painted. For good appearance, the uniformity of sprayed thickness is important. In this study, quality engineering was applied to find the conditions to obtain the uniformity of sprayed film thickness throughout the whole bumper. In the experiment, the number of spraying times as the input and the thickness of sprayed film as the output were considered to establish the generic function. Zero-point proportional equation was used in the calculation. The shape of bumpers was used as the noise factor. As a result, it was succeeded to obtain a better spraying condition where both the S/N ratio and sensitivity were improved.
