The Study On Scouring And Bleaching Process Of Flaxand Forecasting Methods

As for the raw materials with multi-species and small batch in the flax factories, the scouringand bleaching process is the spotlight. It is the key to make the correct scouring and bleachingprocess in the present situation which determine whether the high quality thread (spinning the highquality’s yarn) can be made. The chemical components of flax roving influences fiber movementin the process of spinning draft directly which will affect yarn evenness and strength. In this paper,we made a long-term observation of the flax roving after scouring and bleaching by the flaxfactory, measuring the roving’s chemical composition of the sample and the quality of thespinning. Selected the optimal yarn with the best quality and measured the chemical compositionof the optimal yarn, formulating the standard for roving’s ingredient content which contained lipidclasses, water-solubles, pectin, hemicellulose and lignin with the contents of0.6%,1.7%,0.85%,12%and0.9%respectively.Then we analyzed the variation among the chemical concentration of the roving includingsodium chlorite concentration, sodium carbonate concentration, hydrogen peroxide concentrationand the chemical component of the roving. We concluded that the sodium chlorite played a mainrole in removing the lignin of roving. The content of lignin decreased from2.7094%to0.9534%and the removal rate of lignin reached64.8%which reached the ideal level comparing with thestandard0.9%of lignin content. The sodium carbonate also played a main role in removing thepectin of roving. The content of pectin decreased from hemp’s2.8034%to0.8250%, and it isabove the content of the standard. Hydrogen peroxide has a certain effect on lignin and pectin, butthe effect is not obvious. According to the relationship between chemical concentration and chemical composition ofroving, we used the taxonomy and analogy methods to determine the chemical concentration withother hemp during the scouring and bleaching process. This paper chosen three different hemp’schemical composition to determine the main chemical concentration during the scouring andbleaching process and spin different counters’ yarns to make the chemical composition of rovingreach standard’s content. It showed that quality of all the different counts’ yarn reachedthe excellent level according to the results of quality index. It verifies the method that be used inthe paper to determine the main chemical concentration during the scouring and bleaching processis reliable.In order to make scouring and bleaching process plan of Flax rapidly and accurately, thepaper adopts the BP artificial neural network to predict the concentration of main chemicalsduring the scouring and bleaching process. Input the difference value of chemical composition ofscutched flax and flax roving after scouring and bleaching process, theoretical whiteness of flaxroving into the BP artificial neural network, then write out the concentration of main chemicals inthe scouring and bleaching process. Apply the predicted concentration of chemicals into thescouring and bleaching experiments, and the result of whiteness test and flax composition testshowed that it is reasonable to predict the scouring and bleaching process under BP artificialneural network. The experimental result is close to theoretical whiteness and chemicalcomposition of benchmarking. The above research provided certain theoretical basis for factory todetermine the scouring and bleaching process of flax roving.