Research Of Alkali-urea Modification Of Flax Fiber And Its Dyeing Characterization

Flax fiber is excellent environmental natural textile raw material but it is also bast fiber. In addition to containing cellulose, flax fiber also contains the orientation of the impurity component pectin, lignin and hemicellulose, which causes problems like poor dyeing property. To solve these problems, it is necessary to make the fibers have good water absorption, and solution can be uniformly penetrated into the interior of the fiber in subsequent processing and remove impurities. In view of those problems, researches to alkali- urea modified flax fiber and the modified dyeing properties were made through referring to the literature.Based on the physical and chemical properties of the characteristics of flax fiber, researches to alkali- urea modified flax fiber and the modified dyeing properties were made. Changes of flax fiber at different physical and mechanical properties of reagent were studied by single factor experiments and selected the best solution of modification technology. To change conditions in the dyeing process for passing the researchers modified flax orthogonal experiment at different dye treatment. Conditions were sodium sulfate concentration, solid color temperature, alkali concentration, impacts of fixing time for the dyeing properties of flax fibers. To determine the dyeing process, dye uptake, powerful changes after dyeing fixation rate and fiber dyeing process for selecting optimal process.By analyzing the test results, the alkali- urea modification can improve the flax fiber spinnability. By scanning electron microscopy and X-ray diffraction pattern image, respectively proving changes of the microstructure of urea-modified flax fiber and reducing the crystallinity of flax fibers. By univariate analysis experiments, considering all the factors, electing the optimal solution of urea modified flax fiber: Na OH concentration of 15%, urea concentration of 2%, the processing time 15 min. To dye the modified flax fiber, dyeing rate increases, dyeing depth becomes deeper while little change in strength after testing, which improved the dyeing performance of flax fiber. By orthogonal design flax fiber dyeing orthogonal analysis, when sodium sulfate concentration was 40 g / L, fixing temperature was 60 ℃, sodium carbonate concentration was 20 g / L, fixing time was 40 min, it was the optimal solution to dye the modified flax fibers.