Progressive Electrolyte Metering Schedules for Low Liquor Jet Dyeing Heavy Duck
Progressive electrolyte metering controls reactive dye strike rates on heavy duck canvas in low liquor jets, preventing unlevelness and core shading defects.
CIEDE2000 Levelness
Metric Definition
Color uniformity across dyed fabric surfaces is evaluated by calculating small color differences between multiple sample points using a specialized mathematical model. CIEDE2000 levelness measures spatial shade consistency by quantifying chroma and lightness deviations across a single fabric roll or lot. Spectrophotometers record spectral reflectance across defined coordinates to detect unlevel dyeing that human inspection misses under variable lighting.
Standard quality control protocols require systematic spatial sampling across fabric width and length to verify batch consistency.
Formula Calculation
Modern shade assessment relies on the CIEDE2000 color difference formula, which incorporates specific weighting functions for lightness and chroma. The equation corrects non-uniformities in human visual perception, particularly within neutral gray and highly saturated color spaces. Interactive compensation terms adjust for rotation in the blue region and micro-variations along chroma axes.
Spectrophotometric data converted through these equations produce a single numerical value representing total color variation across fabric zones.
Dyebath Variance
Irregular dye uptake during industrial exhaustion processes leads to high local variance values. Inconsistent temperature distribution, localized pH shifts or improper fabric circulation speed produce spatial shade gradients. High numerical values indicate noticeable visual banding or streakiness across dyed rolls.
Laboratory technicians isolate dyebath parameters when spectrophotometric readings exceed customer tolerance limits.
Pass Criterion
Commercial acceptance thresholds depend on end-use requirements and buyer tolerance specifications. Automotive and technical textile applications mandate strict limits, often requiring color difference values below half a unit. Exceeding designated limits leads to batch rejection or expensive re-dyeing operations.