Indigo Dyeing of Cyperus rotundus Fibers: A Sustainable Approach to Developing Environmentally Friendly Materials

Natural indigo dyeing has re-emerged as a sustainable alternative to synthetic dyes, driven by increasing global demand for eco-friendly materials and the need to reduce chemical dependence in textile and craft production. In response to these sustainability challenges, this study aimed to apply natural indigo dyeing techniques to Cyperus rotundus fibers as an innovative material process and to design community-based products derived from C. rotundus within the framework of the green economy. The results showed that the color shades of C. rotundus and C. mitis fibers varied depending on the mordanting conditions. Dyeing experiments were conducted using three formulations, and color characteristics were evaluated using the CIELAB system to assess hue variation and color depth. Mechanical properties were further examined through tensile testing to determine material performance. Fibers pre-soaked in clay solution produced dark blue to indigo-green hues with good color fastness, though with some uneven color distribution (a* = –9.63; b* = 3.21). Fibers dyed with indigo mixed with vinegar exhibited dark green to yellowish hues, also displaying uneven coloration (a* = –6.88; b* = 1.28). The moisture content of dyed C. rotundus fibers averaged 11.55%, while tensile strength measurements recorded maximum forces of 112.15 N, 44.54 N, and 62.78 N (average 73.16 N). These findings confirm the feasibility of converting dyed C. rotundus fibers into sustainable, environmentally friendly materials suitable for community-level product innovation. Overall, the study highlights the potential of utilizing C. rotundus, an invasive weed, as an alternative natural fiber source for eco-friendly and culturally rooted community products that support sustainable livelihoods and contribute to the creative economy.