Migratory Index
Ion migration quantification calculates dye loss during wet processing of cellulosic yarn. Dyestuff mobility away from the primary fibre site determines shade uniformity across packaged wound packages. Production facilities verify this transfer number during high temperature exhaust dyeing cycles to prevent uneven staining on adjacent white polyester carrier yarns.
Chemical Boundary
Electrolyte concentration gradients inside dye liquor baths restrict active ionic transport. High salt additions depress molecular movement by increasing viscosity near the boundary layer of the substrate. Temperature rises accelerate thermal agitation which overcomes electrostatic repulsion between direct dyes and hydroxyl groups on cellulose surfaces.
Laboratory Verification
Spectrophotometric extraction measures residual dye concentration inside exhausted dyebath liquors after standard holding periods. Technicians compute migration ratios by comparing optical densities of auxiliary solutions against control samples drawn from identical dye lots. Certified testing protocols mandate exact liquor ratios alongside specified pH buffers to eliminate variability during commercial dispute resolution between mills and converters.
Performance Limit
Equilibrium migration ceases once thermal energy balances diffusion forces across the yarn interface. Uneven reactive dye fixation occurs when processing parameters exceed maximum molecular speed thresholds. Strict dyehouse scheduling controls heating rates to maintain stable transfer kinetics throughout industrial production runs.
