The moisture content of the pre-shrunk process fabric is an important process condition. The moisture in the fabric is like a lubricant, causing slippage between the fiber yarns; making each yarn wet, so it can shrink at any time.
Before pre-shrinking, the moisture content of general fabrics is controlled at 10%~15%, and for heavy fabrics, it is controlled at 15%~20%. Low moisture content will affect the pre-shrinking process effect, and high moisture content is not good. Aurora and wrinkles will occur during processing, which will affect the process speed. The on-line humidity measurement and control of the wet card is adopted to ensure that the moisture content of the fabric is appropriate and stable, so that the wetness and uniformity, relatively high pre-shrinkage rate, and good process reproducibility.
The pre-shrinked fabric controls the moisture content of the fabric to 4%, which is beneficial to the stability of the fabric size after the fabric is dropped.