Papers by Author: Chuan Shan Zhao

Abstract: In this paper, we studied the possibility of wood powder in place of mechanical pulp in paper making to get high bulkness, also the dry-bleaching method of wood powder, the strength enhancement and retention effect for wood powder during paper making were all introduced and analyzed in detail.

Abstract: The aims of prehydrolysis are mainly removing pentose and decreasing viscosity in the preparation process of dissolving pulp. In this paper, the effect of prehydrolysis in the preparation process of poplar and bamboo dissolving pulp were investigated under different prehydrolysis conditions. The optimum prehydrolysis process conditions of poplar were obtained as followings: the liquid ratio of 1:6, the highest temperature of 160±2°C, heating time of 90min, holding time of 120min, H₂SO₄ of 1.0%, the P-factor was 1537. Under this condition, the results showed that the content of pentosan decreased from 24.10% to 7.85%. The optimum prehydrolysis process conditions of bamboo were obtained as followings: the liquid ratio of 1:8, the highest temperature of 160±2°C, heating time of 90min, holding time of 120min, H₂SO₄ of 1.0%, the P-factor was 1549.And the content of pentosan was also decreased from 19.64% to 6.76% by the prehydrolysis process.

Abstract: In this paper, Water glass and sulfuric acid were used as raw materials to do the synthesis of hydrated silica by the method of precipitation, and then hydrated silica is applied in paper coating. By examining the changes of the coated paper’s various properties to study the effects of different reaction conditions to the final products. And then we obtained a optimal synthesis conditions: sulfuric acid concentration 25%, reaction time 50min, reaction temperature 80°C, sodium silicate modulus 2.8, stirring speed 150r/min, the relative amount of sodium sulfate content compared to SiO2 is 25% .And at last the outward appearance of the hydrated silica and the structural changes in paper coating were observed by scanning electron microscopy.

Abstract: More and more case boards were used in our society. Shade adjusting plays an important part in case board manufacturing. Tinting pigment can replace dyes used in color adjusting of paper making. Tinting pigment has the advantages of less dosage, better coverage, better stability and also lower cost. In this article, the shortages of dye used in adjusting color and the present situation of tinting pigment used in adjusting color were introduced. The factors of beating degree of soft wood, the additives of AKD, contact time and PH to the tinting pigment adjusting color were investigated also. The results showed that the effect of color adjusting was best when the beating degree of wood soft was 44°SR. AKD was good to color adjusting of pigment in papermaking. The best contact time of red pigment and yellow pigment choose 6 minutes. The best contact time of orange pigment choose 4 minutes. With the increasing of PH, the value of a* and b* improved first and then declined. The red pigment reached the maximum value when the PH was 5.5, while the yellow pigment and orange pigment reached the maximum value when the PH was 6. So the best PH of red pigment was 5.5. The best PH of yellow pigment and orange pigment were 6.

Abstract: In this paper, the effect of microwave treatment on the hydrogen peroxide bleaching of Soda-AQ wheat-straw pulp was investigated. The results showed that microwave treatment could increase the brightness of the hydrogen peroxide bleached pulp. The fiber coarseness of microwave enhancing peroxide bleached pulp was higher than that of the peroxide bleached pulp. However, the arithmetic average fiber length, the length weighted average fiber length and weight weighted average fiber length of the former was lower than that of the latter. Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD) spectra showed that CrI(%) crystallinity of microwave enhancing peroxide bleached pulp was similar as that of the peroxide bleached pulp but all higher than that of the Soda-AQ wheat-straw pulp. N·O′KI infra-red crystalline index of microwave enhancing peroxide bleached pulp were lower than that of the peroxide bleached pulp. The FTIR spectra of lignin showed that the microwave treatment had some influences on the methoxyl and phenolic group in lignin.

Abstract: The residues from wheat straw pulping mainly include uncooked chips and fiber bundles. In order to achieve high quality pulp, the residues require removal from the system. It was not necessary that the residues were re-cooked because of its high contents of non-cellulosic constituent. The achievement of low density foamed buffer material with the residues of wheat straw pulping would make the second pollution problem of the residues be solved, and achieve a replacer of foamed plastic material. The paper discussed the producing techniques of foamed buffer material with the residues of wheat straw pulping. The result showed that the best foamed properties of the residues were achieved with proper dosage of natural bonding agent like wheat flour, inorganic foamed agent, crosslink agent, and proper foamed temperature. The density and compression of foamed buffer material with the residues of wheat straw pulping were achieved with 60 kg /m³ and 60 kPa respectively at the optimum foaming condition.