Dyeing quality of walnut shells on polyester and polyester/viscose blended fabrics

Abstract

This paper reports an investigation on the dyeing efficiency of walnut (Juglans regia) shells for dyeing of polyester and polyester/viscose blended fabrics. Various extraction conditions, such as material - liquor (M : L) ratio, extraction temperature, extraction time and pH have been studied in order to obtain highest color depth. Optimal production of natural dyes from walnut shells with extraction is achieved at 80°C for 75 min keeping the M : L ratio as 1:30 at pH 2. The effects of dyeing time, mordant and dyeing method are investigated in terms of color strength (K/S). Optimum dyeing with Juglans regia shells is achieved with meta-mordanting method for 90 min treatment using AlK (SO₄)₂·12H₂O (alum) mordant for polyester fabric. For polyester/viscose blended fabric, best dyeing conditions are achieved in the presence of FeSO₄·7H₂O mordant, using meta-mordanting method for 90 min treatment. The fastness properties are evaluated with respect to light, washing and rubbing. The results show that walnut shell extract with metal mordants has potential applications on polyester and polyester/viscose blended fabrics.