Title
Optimization of hemp fabric natural dyeing in supercritical carbon dioxide medium by response surface methodology
Authors
SEMIHA EREN, MERVE ÖZTÜRK, ALIYE AKARSU ÖZENÇ and HÜSEYIN AKSEL EREN

Received October 14, 2024
Published Volume 59 Issue 7-8 July-August
Keywords scCO2 dyeing, cellulose, hemp fabric, natural dye, henna, response surface methodology

Abstract
This study explores the dyeing of hemp fabric, a natural cellulosic material, using henna as a natural dye in a supercritical carbon dioxide (scCO2) medium. Given the significant environmental impact of conventional textile finishing, the research aims to provide an eco-friendly alternative to synthetic dyes. Response surface methodology (RSM) was applied to optimize dyeing conditions, focusing on temperature, pressure, and time. The dyed samples were evaluated in terms of color fastness properties to assess the dye uptake and performance. The results showed that efficient dyeing was achieved without water, with maximum color strength (K/S value) at 120 °C, 21 MPa, and 90 minutes. The experimental K/S value closely matched the predicted value, validating the model's accuracy. Overall, the study demonstrated that natural dyeing of hemp in scCO₂ is feasible and sustainable, offering a waterless and environmentally friendly alternative for textile coloration.