Evaluation of modified leather dyeing technique using black dyestuffs from the economical view

From the economical point of view, this work illustrates the effect of compact dyeing technique of chrome tanned leather on the final quality of wet-finished leather in which all wet-finishing steps are in one drum, using black dyestuffs (Acid Black 210 and Remazol black B), with low concentrations, this was done alternative to that used in leather industry. In case of soft leather dyed with Acid Black 210 and top dyed with Remazol Black B the colour strength of both grain and flesh sides increases when using a mixture of (chitosan/non-ionic surfactant, after storing for five days), while the dye penetration decreases compared with heavily retanned leather impregnated with a mixture of (sodium alginate/non-ionic surfactant, after storing for five days) under the same condition without affecting the exhaustion percentage of the dye bath. Using Remazol Black B, the colour strength and the dye bath exhaustion were not affected, while the total dye penetration through cross-section of the dyed leather was improved under the action of either sodium alginate mixture or the natural tanning materials. In addition, the effect of this new technology on the final properties of wet-finished chrome tanned leather such as light and rubbing fastness, mechanical properties and thermal stability were studied.