Advanced Materials Research Vols. 550-553

Abstract: In this paper, we proposed the method to synthesize the modified polyamide polyamine enhancer, which takes PAE, styrene and acrylic as raw materials. Factors that would affect the preparation of the modified polyamide polyamine enhancer, such as monomer amount, reaction time, initiator amount and emulsion concentration, were discussed in detail. Experimental results showed that the modified polyamide polyamine enhancer achieved optimum effect the strength of tube roll base paper under the conditions: the amount of acrylic is 6%, the ratio of styrene and PAE is 2:1, holding time 4h, and the amount of initiator 0.7%. The modified polyamide polyamine enhancer applied to tube roll base paper. The optimum amount of modified polyamide enhancer was 1%. The ring crush strength of paper prepared in this condition can be increased by 44% and the stiffness can be increased by 46%.

Abstract: Some properties of paper sludge were analyzed, including water content, organic material content, pH value, fiber content, ash content,C,H,O,N,S and metal content in dried sludge. The results showed that water content was high, organic material content was high, pH value was in a neutral level, metal elements were varied. Besides, calorific value was detected in a thermal power plant.Disposal of residue wastes from pulp and paper mills is a paramount issue facing the world today. Paper sludge is the solid waste from papermaking industry. The sludge treatment and disposal process will bring about environmental pollution. Therefore,much attentions should be paid to disposal of paper sludge. It is expected that this paper can provide deep insights into the disposal of paper sludge.

Abstract: The effect of flotation parameters such as flotation consistency, temperature, flotation time, air to pulp ratio, and velocity of pulp flow (turbulence level) on OMG/MOW deinking efficiency was studied by using a high-consistency laboratory pulper and a laboratory deinking cell. The optimized flotation conditions were: flotation consistency 1.1%, 40°C, 8min, air to pulp ratio 40%, velocity of pulp flow 3.5m/s and pH 9.0. By using the optimized flotation conditions, the deinked pulp brightness could reach 70.56%ISO, 11.78%ISO higher than that of the control, the effective residual ink concentration was 108.46 mg/kg, which less than 378.14mg/kg of the control, theoretic deinking efficiency was up to 88.41%.

Abstract: Feather fibers dyed with the weak acid dyes in ultrasonic conditions. Influence of different dyeing time and dyeing temperature on dye uptake and the formaldehyde content was discussed through the multiple linear regression analysis method, respectively. This paper discussed the correlation between dye uptake, the formaldehyde content and dyeing time, dyeing temperature, and established linear regression equation of dye uptake, the formaldehyde content with different dyeing process conditions, respectively. The best dyeing time was 45min and the best dyeing temperature was 80°C, according to the linear regression equation. The experimental results showed that dye uptake could achieve 92.1% and the highest value of the formaldehyde content was 33.09 mg/kg. The linear regression of dye uptake and the formaldehyde content had a high fitting precision and a good predicting ability, which can be of guiding significance to the actual production.

Abstract: Softwood pulp was used to prepare dissolving pulp suitable for viscose fiber by three procedures (liquid hot water, sodium hypochlorite oxidation and alkali extraction). The impacts of main factors, such as temperature, reaction time, concentration and chlorine loading on the methylcellulose content and the polymerization degree were investigated. Firstly, the pulp was pretreated by liquid hot water, Under the optimized conditions (concentration 9.0%, temperature 180°C, treating time 40min), the methylcellulose content and the polymerization degree of pulp were 88.47% and 768, respectively. Secondly, the treated pulp was oxidized by sodium hypochlorite. Under the optimized conditions (chlorine loading 2.0%, treating temperature 50°C, treating time 1h), the methylcellulose content and the polymerization degree were 91.54% and 528, respectively. Finally, the oxidized pulp was treated by sodium hydroxide（ alkali loading 13%）under 20°C for 1h. After these procedures, the methylcellulose content and polymerization degree were 95.85% and 536, respectively. The quality of cellulose fiber can meet the utilization requirement for viscose fiber production.

Abstract: Paper printability directly affects the printing process and the final quality of printing matter. Therefore, it is significant to establish accurate, scientific, reasonable comprehensive evaluation model of the paper printability. Five art paper samples were researched in this paper. Different paper properties including whiteness, opacity, smoothness, ink absorption, tensile strength and burst strength were tested. The comprehensive evaluation model of art paper printability was obtained by using SPSS software. Then printing dot gain rate, printing density, printing glossiness and overprint rate were measured for verifying predicted results. Results show that the evaluation model can provide a practical and quantitative method for rapid evaluation of comprehensive printability of art paper.

Abstract: Different fiber materials were modified and the effects of modified fiber on paper performance were evaluated. It’s shown that the strength of paper can be promoted by modified fiber. When the mixing ratio of modified NBKP fiber was 5%, the tensile index was increased from 38.28 N•m/g to 47.21 N•m/g. When the addition ratio of modified HYP fiber was 1.5%, the internal bond strength of paper was increased from 49.41 J/ m2 to 55.30 J/ m2, and the tensile index was increased by 48.06%. When the addition ratio of modified fiber of sawdust was 1.5% and mixed with OCC, the tensile index of paper was increased from 18.89N•m/g to 27.55N•m/g, and the ring crush index was increased by 13.99%.

Abstract: The grafting copolymerization modification of OCC fibers with hexanelactam using potassium persulphate-sodium bisulfite as initiator under alkaline medium was discussed in this paper. The optimum process parameters of the grafting reaction were followed: the ratio of modifier dosage to fiber was 0.5, the ratio of initiator dosage to fiber was 0.08, the ratio of potassium persulphate to sodium bisulfite was 5:4, the reaction time was 2.5h, the reaction temperature was 60°C, The maximum graft ratio and the mechanical properties of handsheet could be obtained at the optimum process conditions. Finally, the structures of the grafted products were characterized by means of fourier transform infrared spectroscopy (FTIR).

Abstract: Offset paper properties have great influence on the quality of print matter. Eleven offset paper samples were printed by IGT printability tester, then the density and L*a*b values of printed samples were measured. The relationship between paper properties and optical density or color gamut of paper printed was studied. The results show that main density increases with the increased ink quantity before the main density reaches saturation, the saturation density becomes greater with increased ink absorbency. When the smoothness is larger, lower ink quantity is needed for reaching saturation density, and larger color gamut is obtained. This study will provide references for the paper making and printing enterprises.

Abstract: The Chinese poplar was used as the raw material in this study. Conversational Soda-AQ cooking was carried out. The acid-precipitating method was used to separate the dissolved lignin from the black liquor. The FT-IR spectra was quantitatively analyzed and compared in order to discover the change of lignin structures. The lignin 31P—NMR spectra of pH6 lignin samples was obtained and the functional groups of the lignin was quantitatively analyzed and compared in order to discover the change of lignin structures during Soda-AQ cooking. Syrinl-OH was 50~60 percent, Guaiacyl-OH was 40~50 percent. The pH6 lignin samples of 31P-NMR spectra aliphatic OH was 5.93 m mol/g, COOH was 0.99 m mol/g, total phenolic OH 7.07 m mol/g. The molecular weight distribution curves of lignin samples obtained from gel permeation chromatography analysis system was shown that Mw was 1506g/mol, Mn was 2888 g/mol and polydispersity was 5257 g/mol.