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.
Frosting Fastness
Surface Abrasion
Resistance to color change caused by the localized wear of fiber tips determines the durability of dyed fabrics. In frosting fastness, the mechanical action of rubbing removes the surface layer of dyed fibers, exposing the lighter colored core or undyed interior. This phenomenon is common in fabrics containing fibers with poor dye penetration and the stiff construction of heavy twills.
Rating System
Laboratory technicians evaluate the color difference between the abraded area and the original fabric using a standard grey scale. Low frosting fastness ratings indicate that the textile will quickly show white or faded patches at high-wear areas like cuffs or knees. The test typically uses a wire screen or a standard abrasive cloth to simulate harsh wear.
Evaluation of the sample occurs under standardized lighting to ensure objective scoring.
Fiber Influence
Blends of cotton and synthetic fibers show this defect if the dyeing process only colors one component. Poor frosting fastness results when the dyed fiber is more easily abraded than the undyed one. Resin treatments used for crease resistance can increase fiber brittleness and exacerbate the problem.
Market Relevance
Durability standards for workwear and uniforms prioritize this metric to ensure the garment maintains a professional appearance. Fabrics that fail this test are unsuitable for heavy-duty applications.