Optimizing Vessel Volume in Continuous Knit Dyeing
Restricting vessel volume below fifteen litres ensures complete bath turnover within three minutes, stopping reactive dye hydrolysis and knit loop distortion.
Displacement Wedges
Physical Component
Dynamic fluid-control inserts placed inside dye pad troughs reduce the volume of liquid required to sustain a continuous processing run. By using displacement wedges, finishing mills can fill the trough with less dye liquor while maintaining the necessary immersion depth for the fabric web. This mechanical reduction of the bath volume ensures that fresh chemical mix replaces the consumed bath more rapidly.
Consequently, the average residence time of the dye in the trough is shortened, preventing early reactive dye hydrolysis in the padder.
Fluid Velocity
Narrowing the channel through which the dye flows increases the speed of the fluid movement around the fabric. This accelerated movement prevents the settling of suspended pigments and ensures a continuous supply of fresh, well-mixed liquor to the fabric surface. Under these conditions, the risk of chemical separation or tailing decreases significantly.
Dosing Control
Rapid bath turnover allows for more immediate control of the dye concentration during the production run. Because displacement wedges keep the active bath volume small, any adjustments made at the dosing pump are realized at the fabric within minutes. This rapid response is critical when correcting shading issues on long fabric runs.
Maintenance Requirement
Frequent cleaning is required to prevent chemical build-up on the surface of these inserts. If dye residue is allowed to accumulate, it can flake off and cause spot defects on the fabric. Therefore, displacement wedges must be designed for easy removal and thorough washing during recipe changes.