Continuous Dyeing Tension Dynamics in Jammed Greige Fabric Architecture
Continuous dyeing of jammed greige fabrics requires web draft below 0.5 percent to prevent capillary collapse and preserve liquor penetration across yarn cores.
Hydrodynamic Boundary Layer Pressure
Fluid Force
Dynamic resistance generated by a moving liquid layer against a solid surface governs the rate of chemical transport in continuous open-width washing ranges. This hydrodynamic boundary layer pressure resists the diffusion of wash water into the internal pore structure of the running fabric. Overcoming this fluid barrier is the primary objective of modern high-efficiency spray nozzles and vacuum extraction systems.
Shear Effect
High-speed fabric movement pulls a thin film of water along with the material, creating a barrier to chemical exchange. Increasing the turbulence of the wash bath disrupts this stagnant layer, allowing fresh water to contact the fiber surface directly. This action accelerates the removal of unfixed dye molecules and chemical residues from the fabric during the final washing stages.
Processing Impact
Inadequate removal of residual alkali leads to yellowing during subsequent drying and storage. By managing hydrodynamic boundary layer pressure through high-pressure spray bars, finishing mills reduce the water volume required to achieve clean fabric. It improves the efficiency of washing after reactive printing, preventing staining of unprinted areas.
Design Control
Adjusting the nozzle angle optimizes the impact force. Placing spray bars closer to the fabric surface maximizes the disruption of the boundary layer.