Dyeing of microdenier polyester fabric in supercritical carbon dioxide

摘要

Supercritical fluid dyeing technology has been used to dye microdenier polyethylene terephthalate fibres at elevated pressure and temperature simultaneously. It is observed that the dye speck disappears when pressure increases beyond 200bar and dye uptake increases when pressure increases above 250bar. Temperatures above 120℃ are found to be suitable for the dyeing of polyester fabrics. As the pressure releases step by step, a deeper shade is obtained because of the incremental mixing of the fluid, dyestuff and substrate. Disperse Red 60, which own anthraquinonid structure, could be dissolved more easily in supercritical fluid system. Reduction cleaning is not required and the fastness properties of dyed samples still meet commercial requirements. The results also show that the dye uptake could be raised with solvents such as dimethyl formamide and dimethyl sulfoxide in combination with dyestuffs. DSC and X-ray analyses also indicate no obvious damage when polyester fabrics are dyed at 250bar pressure and 120℃ temperature for 10 min in supercritical fluid carbon dioxide.