Journal of Textile Science & Engineering

Pistachio Hulls, A New Source of Fruit Waste for Wool Dyeing

Abstract

Amir Kiumarsi and Mazeyar Parvinzadeh Gashti

Natural dyes have been employed in dyeing Persian carpet piles for many years. In this study, the dried pistachio hulls were powdered and used for dyeing wool yarns. The Iranian wool yarn was first scoured with nonionic detergent and mordanted using some metal salts including Cu, Cr and Al. It was then dyed with different amounts of dried pistachio hull powder. Taguchi statistical method was employed to find the effective factors and results of the planned experiments, in order to optimize the dyeing factors. A L18 orthogonal array (seven factors in three levels) was employed to evaluate the effects of different parameters in dyeing process. The colorimetric properties of the dyed yarns were evaluated in CIELAB system. Pistachio hulls found to have good agronomic potential as a natural dye in Iran. Metal mordants when used in conjunction with pistachio hulls were found to enhance the dyeability and its fastness properties. The stepwise process of dyeing with pre-mordanting showed to be energy and time saving and found to achieve high dye retention. Therefore this natural dye has good scope in the commercial dyeing of wool yarns used as Persian carpet piles.