Study On The Properties Of Glycerol Solvent Pulping For Pulping Fibers And Bamboo Fibers

The main purpose of this paper was to explore the feasibility of glycerol solvent pulping,providing basic data and reference for the development of a new organic solvent pulpingprocess. At the same time, combining the pulping and paper principles applied in thepreparation of bamboo fibers, use the glycerol cooking method, bamboo fiber was separated bymechanical forces which was a supporting role. The main results are as follows:Using single factor cooking experiments, combined with two evaluations, unscreened yieldand screened yield, the optimum conditions of glycerin pulping of aspen can be derived:cooking temperature of210℃, cooking time60min and liquid ratio of1:8. Under thiscondition, the unscreened yield was75.9%, screened yield was71.4%.The lignin dissolution rate of glycerol solvent pulping was about58.3%, lower dissolutionrate of lignin made a higher pulping yield. Secondary adsorption phenomena caused the yieldincreased at the same time.Within the same time, the increase of freeness for glycerol solventpulping was greater than the RMP.The glycerol pulping met the requirements of papermaking, the fiber aspect ratio and kink,curl degree were higher than RMP, the glycerol pulping gave good flexibility and plasticity offibers. Under the considerable freeness, the tensile index of glycerol pulping was309.2~397.7%higher than RMP, burst index was20.8~61.3%higher than RMP, while the bulk density was13.8~28.7%lower than RMP.The crystallinity of glycerol solvent pulping increased slightly, the process of glycerolpulping mainly acted on the non-crystalline regions of cellulose, with small damage and bigstrength.The electron micrograph showed that the fibers of different degrees were in the action ofextrusion, kneading and so on, increasing the surface area of fibers, improving the flexibility offibers, with a favor of binding to improve the strength of paper.The main process of glycerol cooking for bamboo fiber was: Bamboo materials wereheated at high temperature in glycerol solvent, lignin dissolved into glycerol, with an auxiliaryforce, fibers dissociated into single fiber. First cooking, obtained crude fibers; secondarycooking, obtained bamboo fibers with a yield of11.2~17.1%.From glycerol cooking, the length of bamboo fiber was2.2~7.0cm, with an average of4.8cm, diameter in the range of16~82μm, with an average of43μm. Fineness in the range of8.7~20.3tex, the average fineness was13.8tex.The breaking strength of bamboo fiber from glycerin cooking was1.9~3.6cN·(dtex)-1,elongation at break of3.9~5.8%, so that, bamboo fiber was a high-strength low-elongationtype of brittle fiber. Bamboo fiber was a typical cellulose Ι, the crystallinity of65.3%. At standard conditions, moisture regain rat of bamboo fiber was about5.4%. After cooking, itsantibacterial properties were declined.