The Reason Why Disperse Dyes Resistdye the Reactive Dyes has Poor Fastness to Dye the Dark Colour2012.05.31 09:28
Polyester/cotton yarn line with high temperature and high pressure dyeing method won’t produce poor fastness phenomenon generally as long as to select the reasonable dye, reasonable technique conditions.
From the view of dyeing prescription, to regard peregal O as the leveling agent when adopt disperse dyes to dye is not reasonable. For Peregal O’s cloud point is generally at 60-70 ℃, the high temperature and high pressure dyeing temperature is at 130℃. Although the dispersion dyes has been having a diffusion agent ( anion ) and can improve the cloud point if used it with peregal O in one bath, however dye aggregation is still unavoidable. Because dye dispersion was destroyed when the dyeing temperature exceed peregal O cloud point, and it would form colloidal material, deposited on the fibers in the dye bath, to produce melanin, color, while some disperse dyes did not dye on the polyster fibre successfully but attached on the cotton fiber.
On the other hand, Improper dosage of disperse dyes would reduce the fastness,especially the dark breed. Not the more dye use,the darker the color will be. When the dye dosage exceeded the maximum adsorption capacity of dyeing fibre, not only the color would not deepen, but also created a lot of color staining to influence the fastness. Since isperse black S-3BL dye is mixed dyes, if it is not producted by the authentic dye factory, it might has inferior quality. Whether going through reduction cleaning after dyeing or not, is the key effect of disperse dye fastness. As for reactive dyes resistdye, you must consider whether the dyeing technique is reasonable, has the hydrolysis of reactive dyes or not.Now that you adopted in two bath way, firstly you must test the fastness of yarn after dyeing the polyester, and use reactive dyes to resistdye cotton fiber to do the fastness again,then you can find out the problem in which link.
By Le Qi