Study On New Pretreatment Process Of The Flax Short Fiber

As senior spinning raw materials,which has natural spindle-shaped structure and unique bias hole of pectin, flax stable has given its good air permeability, good moisture absorption of sweat and salubrious. Flax stable comes from cast tow and carding machines, which has thick hard property and impurity high quantity. The discrete of fiber between each index of performance is very large and gives its poor spinnability. And it has quite high crystallinity and orientation, together with more impurities such as lignin and hemicellulose than long hemp, conventional process of scouring and bleaching with energy intensive or highly polluting cannot achieve good effect.In this paper, on the base of the scouring in atmospheric pressure, we mainly studied the technique of Doubled-boiled by recycling alkali waste-water (DRAW) and Urea Peroxide bleaching in atmospheric pressure situation for flax stable in order to meet the spinning requirements of cotton spinning equipment. The main content included that:Flax stable was treated by the scouring in normal pressure. In scouring process, we discussed the influence facts of alkali,sodium silicate, time. And approximate range of each parameter was confirmed by means of unifactor experiment, then the best parameters were found by orthogonal experiment and verfied the reliability by experiment. Then the flax stable was treated by the scouring of DRAW and verified the urea role when it goes. The feasibility of the DRAW process is discussed through contrast research of the scouring in single and cycle reboiling Meanwhile,meanwhile the reliability of the best project was verified.In order to remove pigment and lignin and increase whiteness, the synthesis conditions of new bleaching agent urea peroxide were analyzed, the mechanism of bleaching liquor of UP were studied. With building up a new bleaching system, the bleaching process was used in the flax short fiber. The parameters of urea peroxide, pH, temperature and time were selected. Under this conditions, we complexed JFC, sodium pyrophosphate and EDTA and analyzed the effect of these new aids on the flax stable bleaching and selected the most appropriate amounts of aids. Then, the parameters of urea peroxide, pH, temperature and time were determined. Finally, optimal match between the level of factors was confirmed by orthogonal experiment and verfied the reliability of the best bleaching process parameters by experiment.The flax stable was treated by DRAW scouring and UP bleaching in atmospheric pressure situation which effectively removed the pectin, lignin pigments and other impurities and improved split degree and spinnability.The spinning ability of flax stable by the optimal process is:whiteness71.55%,strength1.45/cN·tex-1,reduction rate1.32%and tensile stretch3.16%,which fulfill the spinning requirements of cotton spinning equipment.