往復式及び回転式シェーバーによる人工毛切断挙動観察

Abstract

The shaver is a popular electronic utility for male to cut their beard, hair and so on. It is roughly divided two shaving system as oscillating or rotating motion of an inner blade. The cutting hairs mechanism is also assumed that inner blade edge just cut hairs at the moment of contact between inner blade and hairs. However, the hairs were likely to pull into the shaver and a pulling force generated which we felt in use. The detail cutting motion and pulling force was observed and measured to clarify the differences between oscillation and rotation type by a high speed camera. Each shaving system showed same tendency that the inner blade penetrated to the hair at the first, then both the inner blade and hair moved together to the outer blade. Finally, the inner and outer blade cut the hair by scissor action with pulling force generation simultaneously. As regards oscillation shaver, it was indicated that the inner blade hit the hair several times before the hair was completely cut. The maximum pulling force was approximately 0.15 N and the average was 0.04 which was higher than rotation type of 0.13 N as maximum and 0.03 N as average. Finally, the relation between the inner blade speed and pulling force of rotating type shaver was investigated, and the rotating type showed lower pulling force generation nevertheless of its lower inner blade speed (1.18 m/s) than oscillation type (2.3 m/s).