Advanced Materials Research Vols. 236-238

Abstract: This paper studied the plasma’s impacts on spruce CTMP. Spruce CTMP was treated with air, nitrogen and oxygen plasma respectively. Morphology of the CTMP fiber was captured with SEM, and carbon, oxygen and nitrogen content on the CTMP fiber surface were determined with XPS. The results showed that no matter what types of plasma were used, the roughness of the CTMP fiber would increase in the initial stage and recovered to its original roughness level following further treatment. Tensile index of the CTMP increased by 79%, 32% and 54% and the wet strength index increased by 64%, 65% and 22% with air, nitrogen and oxygen plasma treatments respectively. The increase in the tensile index and the wet strength index of the CTMP sheet was originated from the increase in C₂, C₃ and oxygen. C₁ and nitrogen present on fiber surface wasn’t favorable to CTMP sheet strength.

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: The properties of art paper and offset paper were measured, including whiteness, smoothness, gloss and absorbability. And these paper samples were printed using machine proofing with the uniform printing processes. Dot percentage and the tri-stimulus values (X, Y and Z) of dot areas and solid areas were tested with the spectrophotometer X-Rite 530 on the print paper samples. At last, dot gain curve and chromatic diagram were drawn after data analyzing and processing, and then the influences of paper properties on printing dot gain and gamut of color were analyzed. The results showed less dot gain value and greater gamut of color occurred because of higher smoothness, gloss, whiteness and lower absorbability to art paper when the printing conditions were definite, so the dot reproduction quality on the surface of art papers was better. But which of the above-mentioned were opposite to offset papers.

Abstract: The research reported here gives some new insights into the influence of lignin content on paper strength properties. The relative amount of total lignin in CTMP was varied by using multistage ClO₂ bleaching method. Few differences were observed in fiber morphology charcteristics of CTMP during ClO₂ treatments. Linear correlations greater than 99% were found between total lignin content and paper strength properties. The influences of lignin content on Scott bond and tensile strength were greater than that of tear and burst strength.

Abstract: Paper is the main print material, whose performance is a factor that effects the printing’s dot gain which is bad to image clarity and color reproduction. In the paper, Yule-Nielsen neugebauer spectral modal is analyzed , and the relation between paper’s spectral reflectance and the printing’s dot gain is discussed. By experiments, the paper’s spectral reflectance is adopted as correction index, which can reduce the dot gain value of the light color patch , and in the same printing conditions the dot gain is effected by the paper’s spectral reflectance, ink’s type, dot area percentage and wavelengths. The research has a certain significance for controlling printing quality and reducing the producing cost.

Abstract: The precipitated calcium carbonate (PCC) flocculation kinetics and floc structures induced by cationic tapioca starch were recorded by the Malvern Mastersizer 2000 (Malvern Instruments Inc, Malvern, UK). Of particular interest, a population balance model for PCC flocculation was employed to extract the flocculation constants, namely collision efficiency, magnitude of energy dissipation rate and restructuring rate. The model made an attempt to take aggregation, breakage and flocs restructuring into account simultaneously to describe the PCC flocculation by aggregation and breakage mechanism. Through a response surface methodology (RSM) involving a central composite design, the effects of temperature, polymer dosage, ionic strength, and shear rate on flocculation parameters were investigated in this paper.

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: Carbon fiber paper was coated with multiple layers coating composed by conductive and magnetic fillers. The electromagnetic shielding and conductive properties of the coating were investigated. The effluencing factors such as the ratio of conductive and magnetic fillers, the composition of magnetic fillers, the contrast of coating method, the structure of shielding layer were assessed according with effectiveness. The results showed the best component for the coating layer was: conductive substrate, conductive coating layer and magnetic coating layer sequently. The compound of magnetic fillers with differenet electromagnetic interaction mechanism would produce a complementary magnetic loss, and display a high absorption in broader frequency band. The shielding effectiveness of multi-layer coated carbon fiber paper at 1.5 GHz was shown up to 45 dB.

Abstract: Aramid paper was manufactured using poly (m-phenyleneisophthalamide) (PMIA) fibers and fibrids, and poly(ethylene oxide) (PEO) was used as dispersant to improve the uniformity of fiber distribution. The Paper Perfect Formation Analyzer (PPF) and the BFT-1 type β Formation tester were used to determine the formation of the aramid paper, and the relationship between the formation and the mechanical strength of aramid paper was discussed. Results showed that the tensile strength and tear strength of aramid paper before hot calendering is affected strongly by its grammage standard deviation, but is less affected by its formation nonuniformity as a function of the scale of foramtion, the R² correlation between tensile strength and grammage standard deviation was 0.63, and the R² correlation between tear strength and grammage standard deviation was 0.73. However, the nonuniformity of formation in the range of scale of formation 0.8-22.7mm has great influence on the tensile strength of aramid paper after hot calendering, and the R² correlation between tensile strength and formation nonuniformity in this range of scale of formation was greater than 0.58.

Abstract: Calcium sulphate is rich in natural resources and by-product of many industrial processes. However, most calcium sulphate product was only used with low added value or treated as waste, harmful to environment. If the calcium sulphate can be used as papermaking filler, very high added value can be gained and also the environment problem can be solved. In this paper calcium sulphate from by product of industry was characterized by X-ray diffractometer (XRD) and scanning electron micrograph (SEM), and then used as papermaking filler. The influence of calcium sulphate filler on pulp suspension and paper properties was studies. The results showed that the calcium sulphate fillers were composed of three crystal forms, dihydrate, hemihydrate, anhydrite, and it was needle or fiber shape, hollow in the middle; calcium sulphate showed high brightness and high conductivity in water, compared with talc or ground calcium carbonate(GCC) filler. When calcium sulphate filler was used in papermaking process the filler retention was very small because of its high solubility in water. Calcination at high temperature can lower the solubility of calcium sulphate and slightly increase the retention, but the retention was still quite small. The future work should focus on controlling the solubility of calcium sulphate.