• 펄프종이기술
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• 제37권3호
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• pp.33-40
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• 2005

In this study, a nano-colloidal silica sol was applied to control the anti-slip property by spraying on kraft paper. Two kinds of nano-colloidal silica sol which have cationic and anionic charge were applied in kraft paper, and the friction and physical strength properties of kraft paper were investigated. The application of colloidal silica sol on wet web in wet-end process by spraying method was tried to improve the friction property and to avoid the general problems of machine contaminations caused by the scattering of sprayed silica particles in dryer part. The physical properties of sheet were also improved by the application of wet web spraying method, and the optimum conditions of wet web spraying operation were closely related with the conditions of pH and electrical charge of wet web and silica sol.

• 펄프종이기술
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• 제35권1호
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• pp.48-53
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• 2003

The objective of this study was to find in what color Korean handmade paper(Hanji) is dyed when it is dyed with a pigment extracted from waste onion peelings using different kinds of mordant, and how the paper is discolored and variety of strength under the condition of accelerated aging test. The results of this experiment are as follows. 1. Korean handmade paper was dyed in different colors according to the kinds of mordant. Mainly it was dyed in orange-brown, and sometimes in gold or khaki. 2. Korean handmade paper dyed was not discolored much, which suggests that the pigment is strong under the condition of aging. 3. As for durability, Korean handmade paper dyed in gold was strongest. Korean handmade paper, to which aluminum sulfate, iron sulfate or sodium dichromate was applied as mordant, had poor durability. Thus, these were not suitable as mordant.

• 펄프종이기술
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• 제35권5호
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• pp.1-9
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• 2003

Effectiveness of the microparticle retention systems in improving drainage, retention, formation has been recognized for many years. In this study the effectiveness of crosslinked cationic corn starches and silica-based microgels as components of Compozil system has been evaluated. It was shown that improvements in retention and strength could be achieved by employing crosslinked cationic corn starches especially at high conductivity. Silica-based microgels with better performance in retention and drainage than a commercial colloidal silica sol have been made through a reaction of sulfuric acid and sodium silicate solutions.

• 펄프종이기술
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• 제42권3호
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• pp.37-42
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• 2010

The properties of paper are very susceptible to moisture content originated from relative humidity. This propensity of PVA impregnated paper was investigated in this study. Especially the hardening effect of borax treatment after PVA impregnation on the response of paper sample to the relative humidity was evaluated. When the moisture content was increased with the relative humidity, tensile stretch and tear resistance were increased while tensile strength and stiffness were decreased. A great increase in folding endurance of PVA impregnated paper sample was found at the higher relative humidity. The borax treatment could reduce the response of PVA impregated paper to the relative humidity.

• 펄프종이기술
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• 제41권4호
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• pp.8-14
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• 2009

Characteristics of biodegradable polymers for mulching mat for seedling were investigated. The solvent solubility of polymers is highest in methylene chloride and chloroform. Tensile strength and breaking elongation of polymer dipped paper were increased to the 0.43-1.46 kN/m and the 0.03-0.26%, respectively. PLAs had showed lower glass transition temperature and melting point than those of polyester. As a result, PLA should be most suitable polymer for mulching mat manufacturing. After biodegradation of polymers by lipase, surface of polymers was change to more flat due to enzymatic degradation.

• 펄프종이기술
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• 제41권4호
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• pp.1-7
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• 2009

One commercial Xuanji and five traditional paper which were made in south china were collected and its chemical, physical, optical properties were investigated and compared to those of Hanji. Extractives(cold, hot, 1% NaOH and Alcohol-benzene) of bamboo paper had higher contents compared with other papers. Strength properties had been highest Hanji, but had been lowest Xuanji 1 and 2. Brightness of all paper were decreased as following order; Xuanji, Hanji, Thai paper, bast paper 1, bast paper 2, Dongpa paper, bamboo paper.

• 펄프종이기술
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• 제35권3호
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• pp.59-65
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• 2003

This research was conducted to investigate the physical properties of Hanji made using maize, konyaku, and wheat powders at various concentrations. Regardless of the starch types, the most effective concentration to increase the physical properties of Hanji was 2 percent. They were significantly improved even at the treatment conditions of 0.1 percent. All the Hanji treated showed the increase of the breaking length, bust index, and tear index and the decrease of the folding number. The strength properties of the Hanji treated were markedly improved at 8 to 10 percent weight increase. The highest mechanical properties were found in the Hanji treated with konyaku powder.

• 펄프종이기술
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• 제36권3호
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• pp.44-51
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• 2004

The effect of refining conditions and grammage on the stiffness of linerboard was investigated. The correlations between Taber stiffness and resonance stiffness were very low due to the different measuring principle. The refining conditions did not affect sig nificantly on both Taber and resonance stiffness estimated here. This means that it is strongly recommended to find and apply the refining conditions which can reduce specific energy consumption. Taber stiffness showed very high correlation for the thickness and elastic modulus of linerboard, while the resonance stiffness showed much lower correlation. Effective thicknesses for Taber stiffness were very well fitted with measured thickness, while those for resonance stiffness depended on the grammage of linerboard.

• 펄프종이기술
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• 제35권3호
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• pp.37-42
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• 2003

Physical properties of paper can be explained in terms of the changes in fiber's morphological properties. As the paper machine speed increases, the basis weight decreases and the mixing ratio of inferior recycled fibers increases, paper break becomes important than ever before. One of the objectives of this study is to analyze paper's physical, mechanical and fracture mechanical properties depending on softwood(SW) and hardwood(HW) mixing ratios and recycling. Fibers were refined by Valley beater to 450 mL CSF. Handsheets of 30 g/$\textrm{m}^2$ were prepared at different mixing ratios. Fracture toughness was measured as the amount of energy applied to cracked sample before total failure. Fracture toughness showed different trend to other strength properties. At the mixing ratio of SW 80: HW 20, papers showed the maximum fracture toughness. At this mixing ratio, flexible softwood fibers were mostly broken and stiff hardwood fibers were mostly pulled out.

• 펄프종이기술
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• 제42권2호
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• pp.75-81
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• 2010

Characteristics of mixing biodegradable polymers and polymer impregnated paper for mulching mat for seedling were investigated. The mixed film of 70% PLA was most easily biodegradable. The surface of polymer films were changed to more rough due to enzymatic degradation of lipase. Tensile strength and breaking elongation of PLA mixed films were increased to the 0.04-0.31 kN/m and the 0.17-0.96%, respectively. With higher PLA contents, intensities of ester originated carboxyl group(about $1,748cm^{-1}$) were increased. Physical properties of prepared mulching mats were increased with PLA contents and stiffness of mulching mat was not so much changed.