Fluid Force
Textile wet processing in jet machines relies on the momentum transfer from a moving liquid stream to transport fabric through the internal circulation tubes. The hydrodynamic drag represents the force exerted by the dye liquor on the fabric rope, which must overcome the mechanical friction of the machine and the weight of the wet material. This mechanical interaction dictates the speed of fabric movement, which is critical for ensuring that the fabric rope passes through the nozzle regularly to avoid uneven exposure to the dye, thereby guaranteeing a consistent shade across the entire length of the production run.
Rope Speed
Efficient dyeing requires the fabric to complete a full circulation through the machine within a specific time window. Adjusting the hydrodynamic drag by changing the nozzle pressure or diameter directly alters the rope velocity, preventing the fabric from stalling in the storage chamber. This control is necessary because if the fabric moves too slowly, the prolonged exposure to the dye stream at the nozzle can create streaks or uneven color lines across the fabric width.
Liquor Ratio
Low liquor ratio machines must generate sufficient driving force with a smaller volume of liquid. In these modern systems, optimizing the hydrodynamic drag involves using specialized nozzle configurations that maximize the contact area between the liquid jet and the fabric rope. This design allows the machine to run with less water, which reduces the consumption of chemicals and the energy needed for heating.
Machine Design
Hardware engineers design the internal flow paths of jet dyeing machines to minimize excessive turbulence that can damage delicate fibers. If the hydrodynamic drag is too high, it can stretch or distort knitted fabrics, which leads to dimensional instability and distortion of the finished garments. This drag must be balanced to ensure stable fabric transport while protecting the physical structure of the yarns.
