Why Does Polyester Tablecloth Become Softer With Washing?

The main reason is that industrial washing uses a large amount of strong alkali, which leads to alkali reduction under high temperature. Alkali reduction refers to the process of treating materials (especially polyester fabrics) with NaOH solution at room temperature or a certain temperature. The treated polyester fabric has a soft hand feel and a soft luster. Due to the sensitivity of ester bonds to alkali, during the alkali treatment process, the ester bonds on the surfaces of amorphous and crystalline regions are first hydrolyzed, and then the large molecular aggregates in the fibers are completely detached, causing fiber weight loss and leaving grooves on the surface. These grooves reduce surface reflection and soften the fabric gloss. When the concentration of alkaline solution is high and the treatment temperature is high, the phenomenon of thinning of the cross-section of polyester fiber monofilament may even occur. Due to the thinning of fibers, the fibers feel soft to the touch. After alkali treatment, the fibers form grooves or even become thinner, and the quality of the fibers decreases, which is called alkali reduction.