Papers by Author: Yu Xin Liu

Abstract: The shoe board emphasizes the strength and the bear to fold especially, so it chooses the long fiber raw material. The experiment confirms optimal beating condition and formula through the analysis of beating of the jute pulp and the softwood (Larch) pulp and a series of condition experiment. The board raw material category is: jute: softwood = 7:3; Jute: 40 oSR, softwood: 30 oSR. The properties of original board are: breaking length: 6115 meters, index: 15.79mN·m²/g, fold endurance: 2125 times.

Abstract: In this paper, the hemicelluloses extraction of bagasse with NaOH/borax was studied, and some parameters which may affect the hemicelluloses yield and properties were discussed, such as alkali charge, borax charge, liquid-to-solid ratio, temperature and time of extraction. The compositions and characteristics of hemicelluloses were analyzed by FT-IR, GC, GPC. The results showed that compared with the conventional alkali extraction, the hemicelluloses dissolution rate was increased and degradation degree of the hemicelluloses was decreased with NaOH/borax. When the alkali charge was 65%(based on NaOH)and borax charge was 7% at a liquid-to-solid ratio of 15:1 at 90 °C for 180 min, the dissolution rate of hemicelluloses up to 84.5% (to the hemicelluloses content in material).

Abstract: In this paper, the process of cellulase pretreatment before alkali-oxygen pulping of bagasse was studied. The effect of cellulase pretreatment on subsequent pulping was also researched. The results showed that some small-sized components and sugars dissolved into the effluent in the process of cellulase pretreatment. UV spectroscopy showed that there was no significant lignin content in the pretreatment effluent.It was also found that pulping properties were promoted when the cellulase dosage was 2 ECU/g pulp, in that under the same cooking conditions, pulp kappa number was decreased by 1.3 and pulp brightness was increased by 2.5 %ISO, while the viscosity of pulp also increased slightly. Moreover, the tensile index, tear index and folding endurance were increased by 8%, 7% and 30%, respectively, but burst index showed no significant change. The above results illustrated that cellulase pretreatment was only beneficial to the dissolution of sugars and fine components from bagasse and it was an effective method of promoting alkali-oxygen pulping of bagasse.

Abstract: The black liquor from NaOH-AQ pulping of bagasse was treated by conventional alcohol precipitation method to separate hemicelluloses. In the system of alcohol/methanol, some parameters which may affect the hemicelluloses precipitation were discussed, such as mixed alcohols charge, temperature, pH and time. The obtained hemicelluloses were analyzed by FT-IR. The results showed that compared with conventional separation system of hemicelluloses by alcohol, when the V_alcohol : V_methanol was 5:5 and pH was 4.5 at 45°C, the consumption of alcohols was decreased by 17% to 30%. Moreover, the addition of flocculants of PAC/A PAM in the process of hemicelluloses separation, the consumption of organic solvents would be further decreased.

Abstract: The Americal Old Corrugated Containers (AOCC) was treated with laccase. Fiber morphology, molecular weight and distribution of lignin were analyzed by scanning electron microscope (SEM) and gel permeation chromatography (GPC). Through the model compound of lignin (ferulic acid) was treated by laccase, the correlative mechanism for improvement of the wet-strength of pulp by laccase was discussed. The results showed that the molecular weight of lignin decreased and the lignin adhered on the fiber surface after the pulp was treated by laccase. While the laccase treated pulp with heating treatment, the condensation degree of lignin and adhesion area on fiber increased. In addition, when the ferulic acid was treated by laccase, the results were similar to AOCC pulp.