Abstract:

Tieguanyin tea extract was used as natural dye to dye wool fabrics directly at pH vallues of 3.5, 5.5 (pH of original tea extract), 7.5 and 9.5. The antibacterial properties of dyed wool fabrics were studied. The results indicated that dye solution pH value has great influence on K/S value and color of wool fabrics. When the pH value of dye solution was 5.5, the dyed wool fabric exhibited the maximum K/S value. The dyed wool fabrics have good rubbing and washing fastness, but poor sunlight fastness. The fabrics became darker under light, and the effect of light decreased as dye solution pH value rose. When dye solution pH value was 5.5, the antibacterial rate of dyed wool fabrics to Escherichia coli and Staphylococcus aureus was highest, at 98.9% and 93.2%, respectively. The antibacterial rate decreased when dye solution was more acidic or alkaline, especially the dye solution was alkaline.

Key words: tea natural dye, wool fabric, pH value, antibacterial property