UV protection properties of silk fabric dyed with eucalyptus leaf extract

A natural dye extracted from eucalyptus leaves was applied to a silk fabric using two padding techniques, namely the pad-batch and pad-dry techniques, under different conditions. It was observed that with an increase in the dye concentration, the ultraviolet (UV) protection factor (UPF) values ranged between good and excellent for the silk fabric. In addition, a darker colour, such as that provided by a FeSO4 mordant, gave better protection because of higher UV absorption. A silk fabric dyed in a solution containing the eucalyptus leaf extract showed a shade of pale yellowish-brown. The exception was when the fabric was dyed with the FeSO4 mordant, resulting in a shade of dark greyish-brown. The colour fastness to washing and rubbing of the silk fabrics treated with the mordant after dyeing was investigated and the results showed good fastness, whereas colour fastness to light was at a fair level. The results confirmed that natural dyes from eucalyptus leaf extract with metal mordants have potential applications in fabric dyeing and in producing UV-protective silk fabrics.