Study On Efficient Pretreatment Of Cellulose Knitted Fabric

Cellulose fiber knitted fabric has the advantages of soft hand,good moisture absorption and permeability,and comfortable wearing,and is widely used in the fabric of the close fitting fabric.However,the traditional pretreatment process of cellulose fiber knitted fabric is long and complicated,with low production efficiency,large consumption of water,electricity and steam,and a large amount of waste water,which does not meet the requirements of sustainable development and green environmental protection.In order to solve these problems,this topic of paper is based on the processing flow of Italia MCS D&F MACHINERY continuous production equipment,the washing efficiency after alkali treatment and the high-efficiency hot alkali boiling process of cellulose fiber fabrics（cotton knits,modal knits and viscose/cotton blended knits）were studied to provide the process parameters of form a complete set for equipment modification.Realize efficient short process pretreatment.Fabric pretreatment is usually followed by multiple washes,which consumes a lot of water and produces a lot of waste water.Based on the three washing processes of Italia MCS D&F MACHINERY continuous production equipment,the paper studies the washing efficiency after alkali treatment,and explores the influence of the number of washing channels,washing time,washing bath ratio and washing temperature on the washing effect,The effect of washing after alkali treatment was evaluated by measuring NaOH concentration or content of the residual solution.The optimal treatment process conditions is as follows:the water bath ratio is 1:20,the temperature of washing is 70℃,the washing time is 20 s,the washing effect is good enough.Therefore,the number of washing tanks for continuous production equipment is determined to be3.In the third chapter,the high efficiency pretreatment technology of cotton knitted fabric is studied.The influence of the concentration of sodium hydroxide,the concentration of hydrogen peroxide,the amount of auxiliary agent and time on the pretreatment process of hot alkali boiling is studied.By testing the capillary effect,whiteness,shrinkage rate,bursting strength,weight loss rate,stiffness,and combining with the K/S value and evenness of the dyed fabric,the pretreatment effect was evaluated.Through orthogonal optimization,the optimized process conditions are as follows:the concentration of NaOH is 10 g/L,the concentration of H₂O₂ is 12 g/L,the time is 5min,the high efficiency refining agent CA is 1.0 g/L,the high efficiency chelating dispersant MD is 1.0 g/L,the high efficiency hydrogen peroxide treatment agent PSH is 0.1 g/L,the temperature is 100℃,and the bath ratio is 1:20.After treatment,the whiteness of cotton knitted fabric is 80.4,the capillary effect is 12.0cm/30min,the bursting strength is 255.43 N,the strength decline rate is18.5%,the transverse shrinkage rate is 19.3%,the weight loss rate is 3.8%,and the fabric stiffness is 1.80 cm.In chapter four,the high efficiency pretreatment technology of modale knitted fabric is studied.The influence of the amount of hydrogen peroxide,the concentration of sodium hydroxide,the amount of auxiliary agent and the time on the pretreatment process of hot alkali boiling is studied.The optimized process conditions are as follows:the concentration of NaOH is7.0 g/L,the concentration of H₂O₂ is 30.0 g/L,the time is 6 min,the high efficiency refining agent CA is 0.5 g/L,the high efficiency chelating dispersant MD is 0.5 g/L,the high efficiency hydrogen peroxide treatment agent PSH is 0.05 g/L,the temperature is 100℃,and the bath ratio is 1:20.After treatment,the whiteness of modale knitted fabric is 81.9,the capillary effect is14.7cm/30min,the bursting strength is 156.57 N,the strength decline rate is 25.7%,the weight loss rate is 3.0%,the fabric stiffness is 1.88 cm.After blending viscose fiber with other fibers,it can enhance the size stability and improve the quality of viscose fiber.In chapter five,the high efficiency pretreatment technology of viscose/cotton blended knitted fabric is studied.The influence of the amount of hydrogen peroxide,time,the concentration of sodium hydroxide and the amount of auxiliary agent on the pretreatment process of hot alkali boiling is studied.The optimized process conditions are as follows:the concentration of NaOH is 5.0 g/L,the concentration of H₂O₂ is 35.0 g/L,the time is 8 min,the high efficiency refining agent CA is 0.5 g/L,the high efficiency chelating dispersant MD is 0.5g/L,the high efficiency hydrogen peroxide treatment agent PSH is 0.05 g/L,the temperature is100℃,and the bath ratio is 1:20.After treatment,the whiteness of viscose/cotton blended knitted fabric is 81.2,the capillary effect is 14.2cm/30min,the bursting strength is 257.38 N,the strength reduction rate is 5.1%,the weight loss rate is 1.7%,the fabric stiffness is 1.80 cm.