Fabric Finishing
Liquid ammonia or sodium hydroxide treatments are applied to cotton fabrics under tension to improve luster and dye uptake. The occurrence of mercerization film distortion happens when uneven chemical concentration or tension causes the thin film of moisture on the fabric surface to dry irregularly, leading to localized variations in fabric reflectivity. This results in patchy or streaky areas in the finished dyed fabric.
The chemistry relies on swelling the cotton cell wall from a bean shape to a round cross section. This change increases light reflection, making any uneven application highly visible as shiny or dull bands.
Tension Control
The mercerization range must maintain a uniform tension across the entire width of the fabric. Any variation in tension can trigger mercerization film distortion, which alters the fiber swell behavior and dye affinity. Proper calibration of the expander rolls helps prevent this physical defect.
Process Calibration
Operators must monitor the concentration of the caustic bath and the wash water temperatures continuously. If the alkali is not washed out evenly before the fabric leaves the stenter, the remaining chemical traces cause mercerization film distortion during the drying stage. Automated chemical dosing systems help maintain a stable process.
Inspection Sorting
Dyed fabrics are scanned under specialized lighting to locate these structural and visual variations. Correcting these surface defects is difficult because the physical changes in the cotton fibers are permanent. Rolls that display severe distortion are sorted and sold as lower-grade materials.
