Abstract: The elastic damage of elastic denim will happen during the ozone washing process, which will seriously affect its wearing property. In this paper, polyether polyurethane fiber was treated by ozone washing, and the effect of washing parameters, including ozone concentration, treatment time, pH value and moisture content, on the elastic recovery rate, breaking strength and fiber morphology was discussed, and the elasticity loss mechanism of polyether polyurethane fiber under ozone washing was investigated.

The result indicates that the ozone mainly acts on the soft chain section of polyurethane, which oxidizes and breaks the chain segment, causing the elasticity loss of polyether polyurethane fiber. In addition, the hydroxyl radical is produced when the ozone is dissolved in water, which is another reason caused the elasticity loss of fibers. Thus, for elastic denim fabrics that contain polyether polyurethane fibers, the excellent process conditions are ozone treatment time less than 30 min, moisture content at 60% and pH value at 5 ～ 7.

Key words: ozone washing; elastic denim; polyether polyurethane fiber; elastic recovery rate; breaking strength