• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.141-146
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• 2006

Mechanical fibres are commonly characterized by measuring their length distribution and freeness. These parameters, however, do not adequately characterize the influence of refining on their mechanical properties. In this work we conducted multiple compression on fibre mats prepared from different length fractions (Bauer McNet fractions) to generate stress-strain curves from which several quality parameters can be derived such as modulus, stress and toughness. We found that these characteristics of fibre are strongly influenced by the refining energy used to produce pulp; fibres of similar length exhibit different mechanical properties depending on the refining energy6 consumption.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.37-42
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• 2006

The paper discusses the combined use of softwood and eucalyptus kraft pulps in the production of printing and writing papers. Looking for process and paper quality optimization, refining pilot plant trails were carried to identify the effects of refining type (mixed or separate) and intensities (specific edge load), and also furnish composition (amount of each pulp in mixture) on final paper quality and process costs. The basic effects on pulp fibers were evaluated against paper quality properties, such as physical strengths, bulk, vessel picking, opacity and porosity, as well as the interactions with papermaking process, such as estimates of paper machine runnability, paper breaks and industrial refining control. The results show that the furnish composition and the type of refining has a significant effect on properties related with both final paper quality and total costs. The best alternative for printing and writing papers was identified for mixed refining, under the lowest refining intensity, and with the highest dosage of eucalyptus pulp.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06a
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• pp.105-110
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• 2006

In order to utilize coal fly ash (hereafter : coal ash ) discharged from coal boiler as a material for civil engineering usage such as snow melter or soil improver, we have to prevent leaching hazardous elements such as fluorine boron and heavy metals from the coal ash because the leaching concentrations of some elements in the ash exceed the Japanese standards for environmental soil quality. Through the laboratory experiments and mill trials we confirmed that the leaching concentrations of fluorine, boron and heavy metals were maintained below their environmental standards by mixing with fixation chemicals and curing for a short time.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.34 no.2
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• pp.61-66
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• 2002

This study was carried out to investigate sheet properties of Indian mallow hanji, made by different pulping methods such as alkali and sulfomethylated pulpings, and different stock compositions, various mixing ratios of bast fiber and woody core fibers. Effect of morphological properties of pulp stocks on the sheet formation and their optical properties were also evaluated using an image analyzer and confocal laser scanning microscope(CLSM). In addition, the effect of fiber distribution index(FDI), which was calculated based on the image in a z-direction of a sheet from CLSM, on the sheet properties of Indian mallow hanji was discussed. The proposed FDI had a good correlation with various properties of paper, such as apparent density, opacity, tear index, breaking length and zero-span tensile strength. Especially, sulfomethylated pulp sheets＇FDI was higher than alkali pulp sheets.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.2
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• pp.8-14
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• 1999

A screening has been performed to find hyper-ligninolytic fungi, which degtrade beech and pine lignin extensively in order to broaden the understanding of the ligninolytic enzymes elaborated by various white-rot fungi. One hundred and twenty two ligninolytic strains were selected from decayed woods with a selective medium for screening ligninolytic wood-rotting fungi. Two of them, Phanerochaete sordida YK-624 and YK-472, showed much higher ligninolytic activity and selectivity in beech-wood degradation than typical lignin-degrading fungi, phanerochaete chrysosporium and Coriolus versicolor. They also degraded birch dioxane lignin and residual lignin in unbleached kraft pulp(UKP) much more extensively than P. chrysosporium and C. versicolor. During fungal treatment of beech wood-powder, the fungus strain P. sordida YK-624 showed higher activity of extracellular manganese peroxidase (MnP) in the medium than P. chrysosporium. It also showed MnP activity, which would not be lignin peroxidast during treatment of oxygen-bleached kraft pulp(OKP) and under enzyme-inducing conditin.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.343-348
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• 1999

Presence of small amount of old newspapers printed with waterbased flexographic inks leads to a significant loss of brightness of the deinked pulp by flotation process. Recently there has been an increased interests in employing neutral deinking processes to solve the problems associated with waterbased flexo ink. A comparative experimental study was performed to evaluate the efficiency of neutral deinking and conventional alkaline deinking for ONP furnishes contaminated with flexo ink. Effects of the deinking processes on pulp quality and white water characteristics were examined. It was shown that neutral deinking would provide significant improvement in brightness, yield, and freeness as compared with conventional alkaline deinking. Three was no increase change in brightness when OMG was added in the furnish up to 20%, and it was attributed to the redeposition of flexo inks on chemical pulp fibers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.2
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• pp.16-22
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• 2008

The pilot scale ultrasonic deinking was carried out in order to confirm the commercialization possibility of ultrasonic deinking. White ledger was used as a raw material and the results were compared to the results obtained from the conventional deinking. The fraction of smaller ink particle was increased and the improved ink removal efficiency was also obtained by the ultrasonic treatment. The brightness and breaking length of ultrasonic deinked pulp were superior to those of the conventional deinked pulp. Most interesting findings in this study were that the significant improvement in effluent quality and the reduction of chemicals and energy cost were obtained by the ultrasonic deinking.

• Restorative Dentistry and Endodontics
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• v.37 no.4
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• pp.240-244
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• 2012

Crown reattachment is the most conservative treatment which can be used to restore fractured tooth, presumably with sufficient strength, while maintaining original contour, incisal translucency, and reducing chair time and cost. However, in case of crown fracture with pin-point pulp exposure, we should cautiously minimize the irritation to the pulp and consider pre-treatment pulpal status, choice of pulp capping materials, choice of bonding system and treatment sequence during crown reattachment procedures. This case reports the considerations while crown reattachment with direct pulp capping using calcium hydroxide (Dycal, Dentsply Caulk).

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.213-218
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• 1999

Friction and wear characteristics of novolac resin-based friction materials reinforced with aramid pulp and potassium titanate were investigated by using a pad-on-disk type friction tester. Friction properties such as friction stability, surface morphology, and wear rate varied according to the relative amount of aramid pulp and potassium titanate. The friction materials reinforced with both aramid pulp and potassium titanate showed superior friction stability and wear resistance due to the formation of durable transfer layer.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.401-411
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• 2006

The cationic chitosan is prepared in this paper. This kind of cationic chitosan is a good retention aid for bleached hardwood pulp, the filler retention increased by 33.0% when the cationic chitosan (DS=1.27) dosage was 0.05%. Because many of the materials used in papermaking process are excellent microbiological nutrients, these nutrients will result in the growth of bacteria; uncontrolled growth of bacteria and fungi in the papermaking process adversely affects machine runnability. According to the standard methods of microbe growth inhibition test, cell counting was conducted after proper cultivated time. This paper explored the factors that affecting the cationic chitosan's antibacterial effect.