The Effect of Aluminum Mordant on the Colour Fastness of Fabrics Made of Cellulose Fibres When Dyeing with Onion Peels

Natural dyes have become an alternative option for textile dyeing. In the present study, the extract of on-ion (Allium cepa) peels, as food industry waste, was investigated as a natural textile dye. The aim of the study is to compare the colour fastness indicators of cellulosic fabrics dyed with the extract of onion peels, pre-treated with the alum mordant and without pre-treatment. Three different fabrics have been chosen for the study: 100% cotton, 100% linen, and cotton/linen blend. All researched fabrics are dyed in the same conditions. There are two different samples of each fabric. One sample of fabric is dyed, and another is pre-treated with alum mordant before dyeing. Different colour fastness tests were performed on all samples: the colour fastness to rubbing, perspiration, washing and daylight. All tests were performed and evaluated according to ISO standards.