Research On The Principle And Application Of Alginate Fiber Dyeing

In the international environment of advocating green and environmental protection,the textile printing and dyeing industry is also developing towards an environmentally friendly direction,and the development and research of new green fibers has become a major trend.Alginate fiber is a kind of biomass fiber produced by wet spinning using sodium alginate as the spinning stock and calcium chloride as the coagulation bath.In addition to good biodegradability,it also has advantages such as flame retardancy and antibacterial properties,and has been concerned in the fields of textiles and medicine.The dyeing of alginate fibers has always been a difficult problem that cannot be overcome in the textile field,limiting the further expansion of the application field of alginate fibers.Especially the new generation of washable alginate fibers,due to their special production process,their adsorption capacity for dyes has further decreased.In order to explore dyes and dyeing processes suitable for alginate fibers,researchers have adopted traditional dye dyeing,fiber modification,stock solution dyeing,and specialized dyes,respectively.These methods always have certain shortcomings,such as insufficient dye uptake,some additives that have a significant impact on the performance of the alginate fiber itself,and also high costs and complex processes.Therefore,considering the current cost and process,the dyeing technology of alginate fibers currently only stays in the laboratory stage of small batch production.There is still a need to explore a large batch of alginate fiber dyeing methods that can be applied to factories.Through preliminary experiments,it was found that after modification with a laboratory made cationic modifier,washable alginate fibers can be dyed without the need for salt or alkali in the entire process.This article uses three direct dyes,Direct Red 4BS,Direct Yellow RS,and Direct Lake blue 5B,to dye modified alginate fibers.The optimal modification process is obtained by examining the uniformity,K/S value,adsorption capacity of the fiber to the modifier,and Zeta potential before and after modification under different conditions.The modified alginate fibers were dyed at different temperatures,and the dyeing kinetics and thermodynamics were investigated to obtain the optimal dyeing process.In order to investigate whether modification and dyeing have an impact on the excellent properties of alginate fibers themselves,XRD,apparent morphology,strength changes,color fastness to soap washing,color fastness to friction,flame retardancy,and antibacterial properties of the modified and dyed alginate fibers were tested.In addition,in order to explore the applicability of dyeing methods,modified alginate fibers were blended with Tencel to prepare blended yarn,which was then woven into knitted fabric on a hosiery machine,and the resulting fabric was dyed.Test the dyeing uniformity,strength change,and color fastness of dyed knitted fabrics.The experimental results showed that:(1)The optimal modification condition is for a5%(owf)concentration modifier to be modified at 25 ℃ for 10 minutes.During the process of dyeing modified alginate fibers with three dyes,the dyeing kinetics followed the Elovich model at lower temperatures,the dyeing thermodynamics followed the Freundlich model,and after reaching a certain temperature,the dyeing kinetics followed the quasi second order kinetics model,while the dyeing thermodynamics followed the Langmuir model.Based on the comprehensive results,it is determined that the optimal dyeing temperature for Direct Red 4BS is 80 ℃.The dyeing effects of Direct Yellow RS and Direct Lake Blue 5B can both meet the requirements at 25 ℃ and 60 ℃.(2)The modification and dyeing did not damage the apparent morphology of the alginate fibers,and the strength remained between 2-2.4 c N,without a significant decrease in strength;Color fastness to soaping: Color fastness to discoloration: 3-4 levels,with acetate fiber and wool staining reaching over 4 levels.Overall,the color fastness to soaping is good,but due to the special nature of direct dyes,the color fastness to rubbing is slightly poor;The modification and dyeing did not affect the flame retardancy and antibacterial properties of alginate fibers,the ultimate oxygen index remained above 36.6.(3)The dyeing uniformity of alginate fiber/Tencel blended fabric is good,and the DE value is within the range of 0-0.5;After dyeing,the longitudinal strength of the fabric has increased by about 10%-30%,and the transverse strength has increased by about 25%-40%;The color fastness to soaping exceeds level 4,with acetate fiber and wool staining reaching level 4-5,and polyester and acrylic staining exceeding level 3.This article explores the dyeing kinetics and thermodynamics of seaweed fibers after controlling variables to obtain the optimal modification process,and determines the optimal dyeing process for three different direct dyes suitable for seaweed fibers.The dye uptake of alginate fibers has significantly improved,with good color fastness and no impact on the properties of the alginate fibers themselves.The blended knitted fabric made of modified alginate fibers and Tencel can also be dyed normally,with uniform dyeing,good color fastness,and excellent performance.A salt free dyeing method suitable for alginate fibers and their blended fabrics is provided.