Cotton Ply Twist Multipliers in Continuous Reactive Dyeing
Yarn ply twist multiplier controls intra-bundle pore radius; multipliers above 4.0 cause surface ring-dyeing frosting while values under 3.2 provoke migration.
Surface Color Yield
Dye Efficiency
The perceived intensity of color on the exterior of a fabric relative to the amount of dyestuff applied determines the economic value of a dyeing process. High surface color yield means that the majority of the pigment remains near the fiber surface where it is visible, while minimizing loss in the effluent. This metric is particularly important in printing and continuous dyeing where dye penetration can vary.
Measurement Method
Spectrophotometers measure the K/S value, which is a mathematical ratio of light absorption to scattering. A higher K/S value indicates a greater surface color yield for a given concentration of dye. Factors like fiber cross-section, fabric texture and the presence of finishing chemicals all influence this reading.
Processing Impact
Mercerization of cotton increases the fiber’s crystallinity and surface area, leading to a measurable boost in the resulting shade depth. Conversely, poor surface color yield can be caused by excessive dye migration during the drying stage. Controlling the moisture levels and heat profiles in the drying range prevents the color from moving away from the face of the fabric.
Economic Value
Improving this yield allows a mill to achieve the same visual result using less chemical input. The reduction in raw material usage directly lowers the cost per meter of the finished goods.