Natural Dyes and Mordants for the Textile Industry: A Study on Waste from Pomegranate Peel and Coffee Husks and Aloe Vera
摘要
Sustainable materials that integrate technologies, environment, communities, and culture that emerge as products are still seen as a challenge. The textile industry is complex, with a wide variety of raw materials and techniques that are used. However, it is one of the most polluting sectors, contributing greatly to environmental impact, poor working conditions, energy and water waste, and contamination mainly due to the dyeing processes. This study aimed to investigate husk coffee (Coffea arabica) and peel pomegranate (Punica granatum) residues as natural dyes. Pomegranate peel extracts were also tested as bio-mordants, in addition to Aloe vera (L.) Burm. f. The meta mordants potassium aluminum sulfate (KAl(SO4)2.12H2O) and ferrous (II) sulfate (FeSO4.7H2O) were also studied. The dyeing’s processes were carried out under different methods and conditions pre-mordanting, simultaneous mordanting, post-mordanting and meta-mordanting. After dyeing, the color palette could be visually evaluated, and the color coordinates and K/S color intensity, and fastness to washing and perspiration could be analyzed. The results indicate that under the conditions tested, pre-mordanting and post-mordanting dyeing presented better results for fastness to washing. In the case of fastness to alkaline sweat, post-mordanting dyeing presented lower scores and for fastness to acid sweat, the best results were for meta-mordanting dyeing.