Optimizing Dyeing Vessel Liquor Ratios for Fabric Quality
Optimizing liquor ratios requires balancing steam and salt savings against pump turnover rates to prevent severe shade unlevelness and mechanical creasing.
Crack Marks
Surface Discontinuity
Irregular linear creases appear as pale or dark streaks across the surface of processed knitted or woven fabrics. These defects, commonly referred to as crack marks, are caused by the sharp folding of the textile rope during wet processing in rope-form machines. They arise when the fabric remains folded in the same position under pressure for too long.
Stress Generation
Heavy woven cellulosic fabrics and high-twist synthetic fabrics are highly susceptible to these creases because they have low wet resilience. When the fabric rope passes through the nozzle, the mechanical compression forces a hard fold into the damp structure. This line then acts as a barrier to dye liquor penetration, or it creates localized friction that damages the surface fibres.
Prevention Practice
Lubricants are added to the dye bath to increase the pliability of the fabric and facilitate smoother movement within the machine. These auxiliary agents reduce the friction between different folds of the rope, allowing the textile to open and shift position constantly. This shifting action ensures that no fold remains stationary long enough to become set into the fibres.
Evaluation Method
Visual inspection under standardized lighting represents the primary means of identifying these defects on the finished roll. Light is directed at an angle to highlight any dimensional distortion or shade variation along the crease lines.