Asian Journal of Current Research

This study evaluated the effect of dyeing temperature on the dyeing performance of silk fabric using a fungal pigment obtained from Talaromyces purpurogenus. The silk fabric was pre-treated to remove impurities before dyeing. In the present study, the coloured liquor extract from the fungal source Talaromyces purpurogenus F. was used for dyeing. It was obtained from the Department of Biological Sciences, College of Basic Sciences and Humanities, G.B.P.U.A. & T., Pantnagar. T. purpurogenus F. was subcultured on Czapek yeast extract agar plates. After 7 days of cultivation at 30 ºC, agar discs were cut from the plate. One disc was added to a flask containing 50 ml of sterile medium at pH 5, with 0.3% nitrogen and 3% sucrose. After inoculation, the flask was placed on a rotary shaker at 150 rpm and 30 ºC for 3 days. Shake-flask production was performed in a 500 ml Erlenmeyer flask containing 150 ml of cultivation medium. The cultivation parameters were a temperature of 30 ºC, pH 5, and 200 rpm for 7 days. Dyeing was carried out at pH 5, with a material-to-liquor ratio of 1:30, for 60 minutes at five temperatures: 50 °C, 60 °C, 70 °C, 80 °C, and 90 °C. The dyed samples were rinsed, shade-dried, and assessed for percentage absorption, washing fastness, and rubbing fastness. Percentage absorption was determined by measuring the optical density of the dye liquor before and after dyeing.

The results showed that dye absorption increased as the dyeing temperature rose from 50 °C to 80 °C. The percentage absorption values were 41 ± 0.5% at 50 °C, 51 ± 0.5% at 60 °C, 52 ± 0.5% at 70 °C, and 67 ± 0.5% at 80 °C. At 90 °C, absorption declined to 53 ± 0.5%. Silk dyed at 80 °C showed the highest percentage absorption and exhibited very good to excellent washing and rubbing fastness. The findings indicated that dyeing temperature influenced the interaction between the silk fabric and Talaromyces purpurogenus fungal pigment under the tested conditions. Based on absorption and fastness performance, 80 °C was identified as the most suitable dyeing temperature among the levels tested.