Study On Low Temperature Dyeing Of Polyester Fiber

Aiming at environmental protection, low toxicity and energy-saving, the thesis chooses a variety of eco-friendly aromatic esters for applying them to low temperature dyeing of polyester fibers. The paper focused on the dyeing properties of diethyl terephthalate in dipping dyeing and pad dyeing of polyester fabric, and obtained the optimized dyeing process parameters. In addition, the application of a set of esters individually or combined with each other as a carrier to low temperature dyeing of polyester fiber is also studied.Diethyl terephthalate is used for low temperature dipping process of polyester with concentration of the ester 0.3g/L, dyeing temperature 105℃(25℃ less than 130℃ in conventional HTP dyeing), holding time 40 min, bath ratio of 1:10. Under this condition the dyed fabric can get the similar color depth to that with high temperature pressure conditions. And the low temperature process has no negative impact on the fabric strength, color fastness and shade.Thermosol dyeing properties for polyester fabric using diethyl terephthalate was studied mainly on the relationship between dyeing depth with the baking temperature, baking time, anti-migration agent concentration, and the ester concentration. Using high-temperature disperse dyes by orthogonal experiment the optimized process conditions were determined: the ester concentration 0.5g/L, baking time 3min, baking temperature 180℃(30℃ less than 210℃ in conventional thmosol dyeing), anti-migration agent 8g/L, padding liquid temperature 60℃. Under theses conditions, the depth of the dyed fabric can be achieved to the degree in the conventional 210℃ conditions, and both the shade and the color fastness dyed with the two methods were substantially similar.Followed by studing dimethyl terephthalate, diethyl terephthalate, diethylene glycol dibenzoate, dioctyl terephthalate and methyl p-hydroxybenzoate were used individually or compounded with each other in the low temperature dyeing for polyester fabric. It is shown that the effect of low-temperature dyeing of these esters were not satisfactory when used individually, but combination of those esters can obviously improve the dyeing yield. Among them, the mixture of methylparaben and dimethyl terephthalate can even get higher dyeing depth than the forein like product.