A Study On Right-first-time Rate Of Cotton Knitted Fabrics Dyeing

Reactive dyes is currently the most widely used type of dyes for coloring cotton fabrics, but using reactive dyes to dye cotton fabrics couldn’t meet the requirements of customers for fabrics’ colors at one time, which may need to add or correct colors, even peel original colors and redye fabrics.This will not only increase the dyeing auxiliaries and energy consumption,and improve the production cost of printing and dyeing enterprises,but will also add the burden of dealing with sewage and reduce the intrinsic quality of textiles. Thus, it is very significant to improve the right-first-time rate of cotton knitted fabrics dyeing.The quality of the fabric pretreatment semi-product will directly affect the qua--lity subsequent processing. In order to obtain good quality texitle, we need to control the quality of the fabric pretreatment semi-product. Firstly, this experiment is to optimize cotton pretreatment process and adjust dosage and treatment condition of caustic soda, hydrogen peroxide and scouring agent MZ on the basis of guarant--ee the quality of the fabric pretreatment semi-product. Then get a set of optimum process conditions,caustic soda 2g/L, 30% hydrogen peroxide 5g/L,scouringagent MZ2g/L, chelating dispersant1g/L, degreaser DF 1g/L, processing temperature 90~95℃and 50 min.Secondly, checking and modifying the prescription of lab dyeing by doing sa--mples experiments to simulate devices operating conditions of mass production,and then put the revised dyeing prescription into mass production and statistical right-first-time rate of cotton knitted fabrics dyeing at this time.After several sample experiments, the right-first-time rate of cotton knitted fabrics dyeing of this factory can up to 70% from earlier 49.06%, which decrease the defective rate effectively.It comes out that samples experiments have strong application value.Finally, through productions practices, we could find that reactive turquoise blue HG-HC is the main factor which affects the right-first-time rate of turquoise blue and green of cotton fabrics dyeing, as the reactive turquoise blue has problems of poor dyeing reproducibility, many color stains and uneven dyeing, etc.This experiment researches the dyeing thermodynamics and kinetics of reactive turquoise blue HG-HC, and adjusts theexisting dyeing process.First, to resolve the above coloring problems,let the dyed fabrics at low temperature(60 ℃) heat preservation 20 min, properly to reduce the initial dyeing rate of the dye, then improves the temperature to 80℃ to solid color. Compared with the original technology, fabrics have good levelness.