Shortwave Infrared Band Selection for Cotton Contaminant Removal
Targeting 1450 nm and 2200 nm shortwave infrared bands differentiates polypropylene and organic contaminants from cotton lint with high optical contrast.
Cellulosic Reflectance
Light Scattering
Spectrophotometric assessment of cotton and linen textiles measures the ratio of reflected light to incident light across specific wavelengths. Measuring cellulosic reflectance helps determine the purity of raw materials before chemical processing begins.
Bleaching Evaluation
Chemical scouring and bleaching stages are monitored by tracking changes in the light reflection of the textile. High cellulosic reflectance values indicate that the bleaching process has successfully oxidized the natural yellow pigments in the cotton fibres. Insufficient reflectance suggests that the dwell time or chemical concentration in the bleaching bath was inadequate to achieve the required base white.
Mercerization Effect
Caustic soda treatment alters the shape of cotton fibres and changes how they interact with light. While raw cellulosic reflectance relies on highly convoluted, ribbon-like fibres that scatter light in many directions, mercerized cotton fibres swell into round cylinders. This structural change reduces diffuse scattering and increases specular reflectance, which gives the yarn a lustrous appearance.
Spectrophotometric Measurement
Quality control laboratories use specialized instruments to measure the reflectance of the textile under standard illuminants. Spectrophotometers calculate the cellulosic reflectance across the visible spectrum to ensure color consistency in subsequent dyeing stages. This measurement ensures that different production batches can be dyed to the same shade with minimal metamerism.