Relationship between Slipperiness and Coefficient of friction on the Carpets.

The slipperiness of a floor covering is the important subject concerned with safety and walking comfort. We have examined walking proerties on carpets with a force plate and a lower limb muscles electro-myography. In this paper, the slipperiness of carpets has been examined by measuring a coefficient of friction.Results are obtained as follows :1. The slipperiness is greatly influenced by the outsole materials of shoes. The slipperiness is dependent on a contact area and hardness of the outsole of shoes. The harder an outsole material, the more slippery on carpets.2. Wetted carpets are more difficult to slip than dried carpets. This is because a coefficient of friction might become highly due to an increased contact area caused by falling of wetted soft pile fibers.3. The slipperines of carpets is More influenced by a pile form than by a pile material.This is because the coefficient of friction is related to a compressibity of carpets and a contact area when compressed by the outsole of shoes.4. There is a difference in slipperiness among directions of a carpet. The coefficient of friction become higher when shoes slip in the machine tufted direction than when shoes slip in the width direction.