Mass Transfer Rate Drift in Heated Dye Pad Troughs under Variable Relative Humidity
Relative humidity drops accelerate solvent evaporation in heated pad troughs, concentrating liquor and causing head-to-tail shade drift in continuous dyeing.
CMC 2 to 1
Evaluation Metric
Mathematical weighting of lightness, chroma, hue, and saturation differences provides a single numerical value for assessing the commercial acceptability of textile shades. The cmc 2 to 1 equation modifies the CIELAB color space to better align with human visual perception of small color shifts. By applying a lightness weighting of two and a chroma weighting of one, the formula becomes less sensitive to lightness variations than to hue or saturation changes.
Tolerance Ellipsoid
Ellipsoidal volumes define the match criteria around a standard color within a three-dimensional space. These shapes vary in size depending on the position of the target color in the color space. Darker or more saturated colors typically allow for larger numerical deviations than pale or neutral tones.
Commercial Standard
Procurement contracts often specify a pass/fail limit based on the cmc 2 to 1 result. A common threshold of 1.0 ensures that different batches of fabric appear identical when sewn into the same garment. Digital color measurement replaces subjective visual inspection with this repeatable metric.
Calculation Variable
Adjusting the l to c ratio changes how the software interprets the distance between coordinates. A 2 to 1 ratio is the industry default for apparel because the human eye is more forgiving of lightness differences. Using other ratios would yield a narrower tolerance that might lead to unnecessary rejections.