Research On One-bath Pad Dyeing Of Cotton/polyester Blended Fabric

Printing and dyeing industry as the textile industry carbon peak,carbon neutral key field,the development of green and low-carbon printing and dyeing technology has become one of the important tasks of textile science and technology workers.Cotton/polyester fabrics have the advantages of both polyester and cotton,and take up an increasing proportion in textile fabrics.The traditional dyeing process has a long process,requires drying and washing for many times,consumes a lot of water and electricity,and has high emissions of carbon and wastewater.Therefore,it is urgent to develop the dyeing process of polyester/cotton interleaved material with low consumption,low emission and high efficiency.In this study,disperse dyes and reactive dyes were combined into a dyeing bath to reduce The Times of dip rolling,drying and washing,and effectively reduce the energy consumption in dyeing.Zeta potential distribution,particle size distribution and multiple light scattering spectrum were used to analyze the stability of disperse/reactive dye mixture.The distribution and movement of dyes and fixative solution on cotton/polyester interleaved fibers were studied by means of depth of field microscope,UV-vis spectrophotometer and ENERGY dispersive X-ray spectrometer,and the effect of structure of disperse dyes and reactive dyes on dyeing of cotton/polyester interleaved fibers was preliminaries explored.The effects of temperature,time,p H value of dyeing bath,type and concentration of solid base and steaming time on cotton/polyester interleaved dyeing in one-bath pad dyeing process were analyzed.The effects of alkali and steaming time on disperse dyes were observed by super depth of field microscope.At last,the dyeing effect and energy consumption of cotton/polyester interlace were compared between one bath pad dyeing process and traditional two bath and two step pad dyeing process.The results show that the mixture of disperse dye and reactive dye can maintain high stability under acidic conditions.The reactive dyes are almost completely adsorbed on the cotton fiber,and the disperse dyes are about 60%on the cotton fiber and 40%on the polyester.In the baking stage,disperse dyes transfer from cotton yarn to polyester,and the degree of transfer is closely related to the molecular weight of disperse dyes.The utilization rate of disperse dyes increases first and then decreases with the increase of molecular weight.The utilization rate of disperse dyes is greatly affected by baking temperature and baking time.With the increase of baking temperature,the utilization rate of disperse dyes increases rapidly,and the heat loss rate also increases correspondingly.Relatively high utilization rate and relatively low heat loss rate can be achieved at 190℃.With the extension of baking time,the utilization of disperse dyes first increases and then does not change,and 90 s is the best baking time.The dyeing effect of reactive dyes is greatly affected by the reactive group,fixing base and steaming time.The K/S value of dyed cotton/polyester interleaved fabric increased first and then decreased with the increase of the alkaline base or the prolongation of steaming time.The color fastness of dyed cotton/polyester interleaved fabric decreased obviously when the alkaline base was too strong or the steaming time was too long.Low concentration of Na₂CO₃ was used as solid base to dye reactive dyes with high activity,reducing the steaming time,reducing the influence of the steaming process on disperse dyes and polyester,and achieving better dyeing effect and higher color fastness.The optimized one-bath pad dyeing process can achieve similar color depth to that of two-bath dyeing process,and its rubbing color fastness can reach 4-5～5 grades.When dyeing 10,000 m cotton/polyester fabric with one-bath pad dyeing process,water consumption,electricity consumption and heat consumption can be saved by 45.5%,20.9%and 41.7%respectively.CO₂ emissions from power consumption and heat consumption can be reduced by 40.6%.