Dyeing And Finishing Technology Of Polylactic Acid Fiber And Its Blended Fabrics

Polylactic acid?PLA?fiber is a new generation of ecological environmental protection synthetic polyester fiber,corn,cassava starch,such as raw material,through fermentation lactic acid,polylactic acid were obtained through the polymerization of the resin,finally made by spinning,it has excellent biocompatibility and biodegradable and belongs to the biomass synthetic fiber.Research on the performance of PLA fiber and dyeing and finishing technology have important significance.This topic mainly on the basic properties of PLA fiber,dyeing and finishing process of the influence of the fiber structure and properties of PLA/spun silk blended products,PLA fiber and dyeing properties were studied.By scanning electron microscopy?sem?,X-ray diffraction,thermal analysis methods of PLA fiber apparent morphology,structure and crystallization properties,thermal properties and mechanical properties were studied.The results showed that PLA fiber surface was smooth and shiny;the degree of crystallinity was about 51.50%;Breaking strength was 5.73 cN dtex^-1,elongation at break was 25.09%;Poor thermal stability of PLA fiber,melting temperature of only 169.55?.In order to provide the basis for the formulation of PLA fiber dyeing and finishing process,the heat stability and acid-base stability of PLA fiber were measured.The experimental results showed that the thermal stability of PLA fiber is poor,the dry heat treatment temperature should be controlled within 130?,the hot and humid temperature is controlled within 110?.The acid resistance of the fiber was strong,and the strength loss and crystallinity of the fiber were not obvious even at 95?for 30 min at 100 g/L sulfuric acid.However,the alkali resistance of PLA fiber was very poor,and the strength decreased significantly after treatment with 1 g/L sodium carbonate solution at 95?for30 min.By studying the influence factors from the different structure types of disperse dyes on the PLA fiber dyeing,The results showed that the optimum conditions were as follows:pH=5,temperature 110?,dyeing 40 min.Disperse dyes on PLA fiber lift is not very good,disperse dyes on PLA fiber dyeing percentage,the apparent color were not very high.In order to improve the apparent coloration of polylactic acid fiber,the effects of alkali concentration,temperature and time on the reduction rate and strong change of PLA fiber and the effect of alkali treatment on the dyeing properties of PLA fiber were discussed.The reduction rate of polylactic acid fiber increases with the increase of NaOH concentration,temperature and time.With the increase of decreasing rate,the breaking strength decreases.The percentage of dye uptake of PLA fiber after alkali treatment was improved,but the apparent color of the fiber did not increase.The effects of the amount of riser M-6119,the baking temperature and the baking time on the deepening effect of PLA fabric were discussed.The effect of deepening agent M-6119 on PLA fabric was increased obviously.The K/S value of polylactic acid fabric was increased by 29.38%under the condition of 60g/L and 120?baking for 1 min.The influence factors of dyeing of Lanasol series and Delosol series reactive dyes on silk were studied,and the optimum dyeing process was obtained:pH=5,100?for40min.Under these conditions,the two series of dye on the silk dyeing dyeing rate,fixing rate were very good,can reach more than 85%.The dyeing process of disperse dyes and reactive dyes on PLA/silk blended products was further studied.It was found that the dyeing color of the silk was more serious,and the dyeing degree increased with the increase of the dyeing temperature,and the degree of increase was different with the dye structure.While the reactive dyes on polylactic acid fiber stain less,basically not on the dye.There is no need to specifically consider the staining of polylactic acid fibers with reactive dyes during polylactic acid/silk bath dyeing.It was found that the K/S value obtained by the two-bath method was higher than that of the other dyeing process.At this time,the disperse dye had the least coloring to the silk;Polylactic acid/silk dyeing should be used two-bath dyeing process.