A STUDY OF SUSTAINABLE COLORATION OF LYOCELL FABRICS USING EXTRACTS OF TROPICAL ONION SKINS

Abstract

Lyocell is considered as a new fiber that represents a milestone in the development of environmentally sustainable textiles.  Lyocell is spun from wood pulp cellulose via a green chemical process with NMMO (N-methylmorpholine-N-oxide) solvent. Following the concept of lower the environmental impact of fashion clothing, this study aims to determine the suitable natural dyes recipes with the color extracting from tropical onion skins. Colorants were extracted by dissolving crushed dried onion skins with boiled in water at 100ºC for 20-25 minutes. The ratio of extracting and dyeing are 1:25 and 1:30 respectively. The optimal dyeing condition was found out at 80ºC, 45 minutes with 75% v/v. In addition, a variety of the most commonly used mordants including Potassium aluminum sulfate, Copper (II) sulphate and Iron (II) sulphate were used for mordanting in order to compare the differently mordanted and unmordanted dyed fabrics via color strength (K/S) and CIE L*a*b* color values. It was found that mordant type had an effect on color strength and the color coordinates of fabric dyed with onion skin, which can supply variety of color choices for the same colorants.