Natural Dyeing of Protein-Based Textiles with Prunus spinosa L. Fruit Extract: An Integrated Assessment of Dyeing Performance, Mordant Effects, and Dye-Bath Reuse

Abstract

Prunus spinosa fruit extract was investigated as a plant-derived coloring system for protein-based textiles by evaluating the effects of substrate, mordanting, dyeing conditions, and dye-bath pH. Knitted wool, woven wool, and silk were dyed without mordant or with alum or black tea biomordant and evaluated by K/S, CIELAB parameters, apparent dye-bath exhaustion, residual-bath reuse, and color fastness. Dyeing performance varied with substrate and processing conditions, with knitted wool consistently exhibiting the highest color strength. At 100 °C, extending dyeing from 1 to 3 h increased K/S from 4.52 to 8.55 without mordant, 4.67 to 7.24 with alum, and 5.59 to 11.13 with black tea. Black tea produced marked color differences for knitted wool (ΔE* = 5.121) and silk (ΔE* = 4.707), but only a minor change for woven wool (ΔE* = 0.306). Adjustment of the dye baths from their initial pH to pH 3.5 did not consistently improve color strength. Apparent exhaustion did not consistently parallel color strength, while cumulative exhaustion indicated progressive dye-bath depletion and measurable coloration persisted through the initial dyeing and four successive residual-bath reuse cycles. Black tea showed potential as a biomordant, yielding higher overall color strength and high fastness in knitted wool.