Improvement of Chipping Phenomena for Crustaceous Materials Rounding by Centrifugal Barrel Finishing

摘要

Barrel finishing is a surface finishing treatment method used for various parts. In particular, the centrifugal barrel finishing is used for rounding electronic components made of crustaceous materials such as MLCC, because it is high productivity and small-volume production in great varieties. However, because the finishing method has the highest finishing power among barrel finishing, a chipping occurs at the ridges of MLCC made of crustaceous materials. The chipping causes product defects. In this study, in order to reduce the chipping, we investigated the causes of the chipping by observing the contents's (Mass) behavior in the finishing tank by using a high-speed camera. From the observation result, we found that the phenomena which the Mass was thrown out and collided against finishing walls in the processing. For this reason, the chipping occurred. In order to prevent from the phenomena, we considered flowing the Mass is always touching some wall surfaces of the tank by changing the angle of the tank rotation axis. Commonly, the angle of the tank rotation axis is θ = 0°. However, the Mass did not be thrown out by changing the angle of θ = 45°. This reason is the Mass always touching some wall surfaces of the tank. As a result of this test, it is possible to reduce chipping's volume by 80% in comparison with the conventional method.