K. N. Ninge Gowda

Dyeing and Color Fastness of Natural Dye from Psidium guajuva on Silk

Dyeing behavior of natural dye extracted from the leaves of Psidium guajuva L on silk fabric has been studied. Color values and color coordinates in terms of L*, a*, b*, C, and h were examined. A range of shades were obtained when dyed with different mordants and mordanting techniques. The extracted dye was tested for some of the ecoparameters using atomic absorption spectrophotometry and GC/MS. The test results were compared with the set standards to determine the ecofriendliness of natural dye. Their concentrations were found to be lower than the stipulated limits. Dyed samples were tested for antimicrobial activity against Gram-positive and Gram-negative bacteria. The dyed silk fabrics showed acceptable fastness properties and also were found to possess antibacterial activity.

Antioxidant Property of Cotton Fabric Dyed with Natural Dye Extracted from Bark Peel of Araucaria columnaris

This research was concerned with dye extraction from bark peel of Araucaria columnaris and with the application of this dye for cotton fabric. Dyeing without any mordant was compared with those obtained with pre-mordanting, simultaneous-mordanting and post-mordanting with alum and myrobalan. The cotton fabrics dyed with and without mordant were evaluated for their color strength (K/S) values. Furthermore, the colorfastness to washing, light, rubbing and perspiration was investigated, the results of which showed fair to good fastness. The antioxidant property of the dyed samples was determined by DPPH method. The results of DPPH assay were positive for all the samples, confirming that natural dyes extracted from Araucaria columnaris bark peel have potential applications for fabric dyeing and producing cotton fabric with efficient antioxidant property.