Presumption of Fiber Cutting Load by Hair-Cutting Scissors

Abstract

An essential function of scissors is cutting a material efficiently. Sometimes it is said that the easiness of using and longevity of scissors are also important, in addition to their cutting efficiency, because they are hand tools. However, the importance of these characteristics are secondary and should come after the cutting efficiency. In this study, in evaluating hair-cutting scissors, the efficiency of cutting a string was investigated. It was carried out by changing various parameters of scissors. A nylon string was chosen to be the material to be cut. As a result, three parameters affecting the cutting load were found. They were the state of tightness of the screw, the edge angle and the sharpness of the edge tip. Next, their effects on the cutting load were investigated. The state of tightness of the screw affected the clearance at cutting. When the screw was loosened, the clearance and cutting load increased. On the other hand, when angle was changed, the direction of the power transmitted to the string changed. As for the sharpness of the edge tip, when the tip became dull, compression transformation was observed on the string. For this reason, extra power for the transformation was required.