In the washing and dyeing process of denim products, once the spandex is degraded and the loss of elasticity occurs, it is basically impossible to repair, so it is necessary to prepare samples before production to ensure that there will be no quality problems during mass production. According to the physical and chemical properties of polyurethane fibers. , Elastic denim products containing spandex cause loss of elasticity during the washing process. The main reason is that the spandex breaks and dissolves due to improper processing formula or operation during the washing process, and finally causes loss of elasticity.

During the rinsing process, because spandex is not resistant to chlorine bleach, it will form a nitrogen-chlorine bond in the hypochlorite solution to damage the fiber, and the damage of polyether spandex is more serious. When the water temperature in the tank is too high or the time is too long during rinsing, the spandex will degrade, causing the fabric to lose elasticity. So how to avoid missing bullets during rinsing?

(1) Do a good job of pre-production testing;

(2) Floating water in production must be adjusted before it can be injected into the tank, and direct feeding is prohibited;

(3) Floating water must be added when the equipment is rotating to prevent the local concentration from being too high and causing loss of bombs;

(4) When the bleaching water remains on the clothes after high temperature drying, the release of chlorine will cause the spandex to degrade. Pay attention to the cleaning after bleaching;

(5) Strengthen personnel management of online work, monitor production conditions, and prevent quality problems caused by processing temperature or time exceeding process requirements.