As a craftsman in the dyeing workshop, the most fear is the hidden problems of pre-processing the cloth and the problems that may occur in pre-processing and pad dyeing. When such problems are discovered during dyeing polyester dope-dyed yarnand the machine stops to find the cause, it usually takes a lot of time to go. Deal with, and many questions are difficult to find answers. Based on many years of experience, when dyeing, take a cloth sample with a length equal to the width of the cloth from the pre-treatment process, use the warp direction as the weft direction, and the weft direction as the warp direction (that is, rotate 90°), together with the normal production cloth For dyeing, if you find a problem, compare the defect distribution and shape of the two cloths, and you can generally find the cause. For example, it can be distinguished whether the middle edge color is caused by pre-treatment or pad dyeing; it can be distinguished whether some continuous defects are caused by pad dyeing; some dark wrinkles in the pre-treatment that are not easy to find; the stop printing of the pre-treatment, etc.