Abstract:
Silk being one of the organic natural fibers, is susceptible to microorganisms attack thus leading to
loss of physical aesthetic and mechanical properties. The present study was focused on optimizing the dyeing
process parameters (Extract concentration and dyeing temperature) of dyestuff extracts from the Galinsoga
Parviflora plant and analyzing the antibacterial activity of the dyed silk fabric. The Pad-dry method was used
for the application of herbal dye extract onto selected silk fabric and the AATCC 100:2019 test method was used
in assessing the treated fabric quantitatively against Staphylococcus Aureus and Pseudomonas Aeruginosa
bacterial strains. Dyeing conditions obtained using Central Composite Design (CCD) indicated that dye
concentration and temperature of 39.14 percent and 70 0 C respectively could be deemed as optimum. Also, the
Analysis of Variance (ANOVA) results showed that extract concentration has a statistically significant effect on
bacterial count whereas the effect of temperature was not so much influential. Silk fabric dyed with optimized
values demonstrated a 99.33% and 99.15% reduction in the bacterial count against Staphylococcus Aureus and
Pseudomonas Aeruginosa bacterial strains respectively. Also, its fastness properties to light, washing, and
Rubbing ranged from very good to excellent (4-5 to 5). Thus, in general, this research confirmed that Galinsoga
Parviflora plant leaves, abundantly available in most parts of Uganda can be used as an antibacterial finish on
silk fabric for improved bacterial resistance.
