Study On The Method For Improving The Color Depth Of Dope Dyeing Viscose Fiber By Carbon Black

Compared with traditional method for coloring viscose fiber,spun-dyed viscose fiber has the advantages of energy-saving,excellent fiber fastness and uniform color.However,spun-dyed viscose fiber is difficult to dye darker color because the main colorant of spun-dyed viscose fiber is carbon black and it is easy to agglomerate in the fiber,so it is of great significance to improve the color depth of dope dyeing viscose fiber by carbon black.Base on the above analysis,the paper systematically studied the relationship between the process conditions of spun-dyed viscose fiber,the surface structure of carbon black,and the structure of fiber and the blackness of fiber.At the same time,the effect of carbon black and deepening finishing on the structure and properties of the dope colored viscose fiber was explored.The specific research content is as follows:Firstly,the paper studied the process of spun-dyed viscose fiber.The results showed that when the MA-100 carbon black as the colorant and the dosage as 3%,the modified styrene maleic anhydride as dispersing agent and the dosage as 20%,black/viscose cellulose membrane got excellent blackness.Diffusion study of ultrafine carbon black in viscose fiber showed that when the solidification bath temperature was 40°C,and sulfuric acid was 10%,the dispersant had a particularly low diffusion rate and the ultrafine carbon black was evenly distributed in spun-dyed viscose fiber and spun-dyed viscose fiber had a higher the blackness.When the dosage of ultrafine carbon black is the same,the thinner the viscose fiber is,the higher the blackness is.Secondly,the paper investigated the effect of ultrafine oxidized carbon black on structure and performance of spun-dyed viscose fiber.The results showed that the particle size of ultrafine oxidized carbon black was 154.8nm,and the Zeta potential was-44mv.The ultrafine oxidized carbon black was evenly dispersed in the water-based system,and the stability of heat resistance,centrifugal stability,acid-base resistance and electrolyte resistance were all greater than 85%.The ultrafine oxidized carbon black did not affect the rheological property of viscose spinning solution.When its content was 5%,it was still evenly distributed in viscose spinning fluid.Moreover,when the dosage of ultrafine oxidized carbon black was 3%,the surface of spun-dyed viscose fiber was smooth,and the cross-section morphology was dense.The ultrafine oxidized carbon black was evenly distributed in the fiber,and the fiber had higher breaking strength,elongation at break and blackness.In addition,spun-dyed viscose fiber by ultrafine oxidized carbon black has good thermal stability,solvent migration resistance and color fastness.In the end,the paper researched the effect of darkening finishing on structure and blackness of spun-dyed viscose fiber.The results showed that when spun-dyed viscose fiber was treated by low refractive index,the fabric deepening agent EC-CD-R had a better effect on the fiber deepening and the best process was:the resin dosage was 80 g/L,the rolling rate was 90%,the baking temperature was 150°C,and the baking time was 180s.The L value of spun-dyed viscose fiber decreased from 13.12 to 11.84 and the depenning ratio was 10.16%,and the fracture trength and elongation at break retention were 70.62%and 70.11%respectively.After fabric thickening agent EC-CD-R treatment,the surface of fiber became smooth,and the fiber structure was not seriously damaged,but the crystallinity decreased.The content of Si elements on the fiber surface increased.When spun-dyed viscose fiber was treated by acid,acetic acid treatment had a better effect on deepening viscose fiber.The best process was:concentration of acetic acid was 15%,treatment time was 40 min,and treatment temperature was 70°C.The L value of spun-dyed viscose fiber decreased from 13.18 to 12.08 and the depenning ratio was8.35%,and the fracture strength and elongation at break retention rate were 79.20%and 86.41%respectively.After the treatment with acetic acid,the macromolecular structure of colored viscose fiber remained unchanged and the crystallinity decreased,and the surface oxygen-containing functional groups increased.The R_a and R_q of viscose fiber increased from 96.3nm and 74.1nm to 170 nm and 137 nm respectively.When spun-dyed viscose fiber is modified by oxygen plasma,the best process is as follows:the processing time was 200 s,the discharge power was 200 W,and the vacuum degree was 80 Pa.After the oxygen plasma treatment,the L value of spun-dyed dye viscose fiber decreased from 13.12 to 10.99 and the depenning ratio was 16.23%,and the fracture strength and elongation at break retention were 91.73%and 78.53%respectively.After oxygen plasma treatment,the bulk structure of spun-dyed viscose fiber remained unchanged with crystallinity decreased,and the surface oxygen-containing functional groups increased.The Ra and Rq of viscose fiber increased from 96.3 nm and 74.1nm to 187 nm and 159 nm respectively.