PROPER SELECTION OF FOOT INSOLE FOR SLIPPERS

In the present work, the friction coefficient (µ) between bare foot and foot wearing socks sliding on insoles to facilitate the proper selection of the insole materials. In order to avoid car accidents, it is necessary that the value of friction coefficient between the surfaces of foot skin and insoles should be enough high to prevent foot slip on the braking pedal pad. When the foot slides on the insole to a certain distance for people wearing slipper, the risk of car accident is arising. Two types of natural leather and four types of polymeric insoles, used in manufacturing of shoes and slippers, were tested to determine friction coefficient between bare foot and the tested insoles The experiments revealed that µ decreased with increasing the normal load displayed. The sliding of bare foot against natural leather (I, II) insole showed relatively higher values than foot wearing sock. In addition, polymeric insole (III) experienced relatively higher µ compared to that observed for the natural leather. While insole (IV), bare foot displayed higher µ than foot wearing sock. As for insoles (V and VI) of rougher surfaces, significant increase in µ was observed compared to the insoles of smooth surfaces, where the values of µ can be considered quite good to guarantee to limit slip. Finally, it is proposed to roughen the insole surface to increase µ values.