That's because the shrinkage rate of flame retardant fabric is not well done when it is post-treated; Judging from the production and processing technology of flame retardant fabrics, the main problems are mercerizing and tentering. Here, it is explained that mercerizing stabilizes the fabric structure, so generally there will be a width after mercerizing, and the width will increase after tentering. However, when tentering does not meet water, it will return to the width of mercerizing stage, so many small workshops and informal manufacturers measure it according to the width after tentering, without considering what is washed, so no matter what kind of products they make, they will come again.