Influence of Warp Cover Factor on Dye Circulation in Jet Processing
High warp cover factors reduce fabric liquid permeability, requiring wider rectangular nozzles and slower heating ramps to prevent surface shade unlevelness.
Rectangular Slit Nozzle
Flow Geometry
Wet processing machinery for rope-form textiles utilizing high-velocity liquid or gas streams to drive the fabric rope often employs specialized acceleration chambers. A rectangular slit nozzle shapes the fluid flow into a wide, flat stream that contacts the fabric rope over a larger surface area than circular nozzles. This flat flow profile is designed to spread the fabric rope as it passes through, which helps prevent the yarn assembly from twisting and reduces the risk of rope marks.
Transport Force
Energy transfer from the moving fluid to the fabric rope depends on the velocity and contact area of the jet stream. In machines equipped with a rectangular slit nozzle, the wide stream distributes the driving force more evenly across the fabric width, which minimizes the mechanical tension applied to the yarns. This even distribution helps prevent the fabric from stretching, which is essential for maintaining the dimensional stability and elasticity of knitted garments, as it ensures that the physical dimensions of the garment pieces remain stable during subsequent laundry cycles and retail wear.
Fabric Type
Heavyweight cotton knits and synthetic blends are the primary materials processed using this nozzle configuration. Because the rectangular slit nozzle helps keep the fabric rope flat, it is particularly effective for fabrics that are highly susceptible to running creases or surface pile damage. This protective action is less critical for lightweight woven fabrics, which can be processed using standard circular nozzles without the same risk of physical distortion.
Nozzle Adjustment
Operational efficiency depends on matching the nozzle dimensions to the weight and thickness of the fabric rope. Technicians can adjust the opening of the rectangular slit nozzle to optimize the fluid velocity for different fabric styles. This adjustment ensures that the machine generates enough driving force to move the fabric rope without using excessive amounts of liquid or gas, which helps reduce the utility consumption of the dyehouse.