Abstract:

The velocities of the chip flow could be as high as 60 m·s^－1 during MDF milling process, which made chip flow boundary and diffusion angle very difficult to be estimated. Meanwhile, the efficiency of dust absorbing could also be directly affected by characteristics of chip flow. In this research, clear images of chip flow were taken by CCD cameras from MDF milling process. The thresholds of these images were computed by applying Otsu's method. Based on those calculated thresholds, the images obtained from CCD cameras were converted to the binary images. Principle of eightconnectivity was adopted to collect the coordinates of chip flow boundary pixels. The boundary lines of the chip flow in the images could be detected and further traced by linking suitable boundary pixels based on their coordinates. Furthermore, diffusion angles of chip flow were determined when the least square method was applied. The experimental results showed that the diffusion angle of the chip flow dramatically increased when milling velocity was higher than 60 m·s^-1. Therefore, image processing method presented in this paper could provide the insightful understandings of characteristics of chip flow. Also this study could help further researches on both of highefficiency dust removal systems and dust collection hood design.

Key words: MDF, milling speed, digital image processing, chip flow, diffusion angle