Introduction of Water Molecules into Water Repellent Fabrics by Rubbing.

Abstract

Cotton cloth coated with a fluorocarbon polymer lost its water repellency with rubbing but the repellency was recovered by a heat treatment. Rubbing of the cloth reduced its water repellency due to detachment of the water repellent film covering the textile fibers. The repellency also decreased by the introduction of water molecules into the water repellent film by rubbing with other cloths. These observations were verified from changes in the contact angle of water and electric surface resistance caused by the heat treatment of the rubbed cloths. Water molecules could also be introduced by dipping the finished cloth into hot water. The introduced water molecules could not be removed completely by vacuum drying at room temperature.