Assessment of coffee-ring effect on wool and cotton fabrics inkjet printed with herbal inks

Abstract

In this study, the ecologically pre-treated wool and cotton fabrics were digitally printed with eco-friendly plant-based inks of blue, red, yellow, and black colours obtained from the plant extracts of bio indigo leaves, quebracho red bark and the flame of the forest flowers and evaluated for coffee-ring effect. The plant-based inks constituted from the Quebracho red bark and the flame of the forest flowers extract both demonstrated reduced dispersion diameter (i.e. diffused) for the Plasma Surface Treated (PST) wool and cotton fabric than the untreated. These findings could be applied for digital printing on photonics to combat the Coffee-ring effect. The possible explanation for the reduced coffee ring effect is the phenomenon known as Marangoni flow. The predominant phytochemicals functioning as chromophores namely indigotin, tannin and butein enclosed in inks constituted from the plant extracts of bio indigo leaves, quebracho red bark and the flame of the forest flowers respectively are highlighted. Additionally, the synthesis of plant-based ink, the colour scheme adapted for determining the inks colours, and the technique of print process as implemented in the study are explained. Likewise, the Colour patch, Percentage (%) Reflectance, and, Colour difference graphs as acquired from Datacolor tools are demonstrated. To end, the wash fastness, rub fastness, and light fastness test results obtained on wool and cotton fabrics digitally printed with innovative plant-based inks are detailed. The Life Cycle Analysis and assessment of functional phytochemicals on the resultant printed fabrics are suggested for future work.