Study On Mechanism Of Micro-suspension Dyeing Technique

Micro-suspending dyeing (MSD) is a new environment-protecting dying processwhich can receive a good dyeing property. Now the application properties of MSDhave been matured. In this article, three different micro-suspending dyeing systems(Lanasol CE series dyestuff for cashmere and their corresponding micro-suspendingauxiliary WPN, Lanasol series dyestuff for cashmere and their correspondingmicro-suspending auxiliary WAO, reactive dyestuff for cotton and their correspondingauxiliary XY-1) were chosen to investigate the status of dyestuff in dyeing liquor, thethermodynamics and the dynamics during dyeing process.The status of dyestuff in dyeing liquor was studied by testing the absorptionspectrum of dyeing bath, diameter of micro-suspending particle and the surfacetension. It showed that the micro-suspending auxiliary and the dyestuff formed intoaggregation under low temperature (40℃). The dyeing liquor possessed a minimumabsorbance at the maximum absorption wavelength under the optimized auxiliarydosage. The analysis of the micro-suspending dyestuff particle diameter indicted thatthe particle diameter got increased with the increase of auxiliary content. Comparedwith traditional dyeing process, the micro-suspending dye liquor had a lower surfaceintension, which leaded to the diffusion of dyestuff into fiber.The investigation on thethermodynamic analysis of MSD process, it was found that the new dying processdidn’t change the style of absorption isotherm tough the allocation rate of dyestuffwas promoted by the new dyeing stuff. The absorption isotherm fit the character ofLangmuir and it belonged to chemical allocation absorption.The wool fiber and cashmere fiber were dyed with Lanasol CE series dyestuffand Lanosol series dyestuff separately through MSD process. It was found that thedyeing rate of MSD process was faster than that of the traditional dyeing process.Especially for Lanasol CE series dying wool, the dyestuff could be absorbed on fiberunder low temperature and the dye uptake of the micro-suspending dyeing processwould be the same to the dye uptake of traditional dyeing process. Compared withtraditional dyeing process, the dyestuff equilibrium absorption capacity, the dyeingrate constant and the diffusion coefficient of micro-suspending dyeing process werebigger and its half dyeing time was less. The K/S values of cotton fabric samples dyed though different padding processesare tested. The results show that micro-suspension dyeing technology can effectivelyalleviate the phenomenon of “tail head deep and tail shallow” in the padding processof cotton fabric. The breaking force, the elongation at break, the friction coefficientand the SEM of the fibers dyed through different dyeing process separately werecompared, it was found that the breaking force loss ratio and the damage to squamasof the fibers dyed through MSD process were lower. The verse and reverse frictioncoefficient of squamas declined. The fibers dyed through MSD process had moresmooth and fluffier feeling which is easier for the subsequent process.