Optimization of Mordant Dyeing Process of the Natural Dyestuff Extracted from <i>Camellia oleifera</i> Seed for Silk Fabric and Its Property

The natural dyestuff extracted from <i>Camellia oleifera</i> seed was applied to dyeing silk fabric in this paper. In order to achieve both good dyeing effect and color fastness of silk fabric, five mordants were chosen to apply in its mordant dyeing process for silk fabric. The effects of mordant kinds and mordant dyeing methods on silk fabrics were studied by K/S value, colorimetric parameter, and color fastness, and further the optimized mordant dyeing process was obtained. The experimental results indicated that the silk fabric obtained by pre-mordant dyeing process using FeSO₄ as mordant had the highest K/S value and the best color fastness. The optimized pre-mordant dyeing process was determined by the orthogonal experiment as follows: mordant dosage 4% (omf), pre-mordanting temperature 60°C, pre-mordanting time 30 min, dyestuff dosage 20% (omf), dyeing temperature 95°C, dyeing time 50 min, and pH value 4.0. Compared with the direct dyeing process, its optimized pre-mordant dyeing process could effectively improve color fastness and K/S value of silk fabrics due to the formation of strong silk-mordant-dyestuff chelates. Meanwhile, their strength retention rates also had an acceptable range of 95.2% and 96.4%. Finally, a good dyeing method of the dyestuff extracted from <i>Camellia oleifera</i> seed for silk fabrics was established and enhanced its commercial application in dyeing industry.