• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.4
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• pp.28-34
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• 2001

Korea traditional handmade paper, Hanji, has been known for more than thousand years for its high strength, high whiteness, high gloss, good ink reception and long lasting quality. Main component fiber of the Hanji is called 'Dak', which is the bast fiber of the Korea paper mulberry ($\textit{Broussonetia kazinoki}$). Dak has long fiber length, and high cellulose DP, if processed properly. The quality of Hanji is partly from the superior quality of Dak over wood fiber, and partly from the traditional papermaking process. The traditional papermaking process includes pulping, bleaching, refining, use of natural polymer, and sheet making process. Every traditional process has its special role. Comparisons between the modern papermaking technology and the traditional process were made in this study. The traditional process effectively protected cellulose DP in pulping and bleaching process, protected fiber length in refining process, and developed the high strength in the sheet forming process over the modern papermaking process.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.2
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• pp.24-33
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• 2015

This study aims to suggest wastewater treatment options for diaper recycling by identifying characteristic analysis of wastewater from diaper recycling process and efficiency evaluation of wastewater treatment units. The wastewater characteristic analysis showed that the concentration of organic pollutants and ionic materials were very high comparing to seawater. Through the investigation of similar wastewater treatment, six treatment units were identified to reduce pollutants. It is found UF(ultra-filtration), DAF(dissolved air flotation), fenton oxidation, electro-coagulation and chemical-coagulation are effective in reducing organic pollutants while membrane system and ion exchanger are effective in reducing ionic materials. Even though the target of water quality should be secured in terms of managing organic pollutants level, the application of treatment unit for reducing ionic material needs lots of considerations. This result suggests that reuse of pulping wastewater after controlling organic pollutants is better than direct discharge of pulping wastewater. To select the appropriate wastewater treatment unit, an economic analysis about operation condition, wastewater flow, cost, efficiency should be considered.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.73-80
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• 2015

Corn stalk is the lignocellulosic biomass, which remain as leftover after harvesting. To use the corn stalk as raw material for paper industry, soda pulping was applied. In chemical compositional analysis, extractive contents of corn stalk (45.1%) was higher than hardwood. With corn stalk pith, soda pulp yield was 25.3% at 10.6 Kappa number, but 39.5% yield with 14.8 Kappa number for corn stalk rind. Higher extractives content in pith is one of the reason for lower pulp yield than rind. Pith pulp fibers had higher fines content than rind pulp. Pith parenchyma cell was removed as fines during pulping or washing process, which caused the lower yield. To use the corn stalks as a raw material for paper making, de-pith process is essential for higher pulp yield and longer pulp length.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.2
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• pp.1-8
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• 2011

The presence of high silica in bamboo hinders the use of this material for production of rayon grade pulp. Research has been carried out to overcome this deficiency and improve quality of rayon grade pulp with the modification in pulping and bleaching process. Effect of acid boosted water prehydrolysis, sulphuric acid pre-treatment of unbleached pulp, chlorination stage at lower pH and treatment of bleached pulp with $SO_2$ water were evaluated. Acid boosted water prehydrolysis of chips reduces prehydrolysis time by 50 minutes as compared to water prehydrolysis. Treatment of unbleached pulp with sulphuric acid reduces ash, acid insoluble, silica, calcium and iron contents of the pulp by 56, 31, 82, 84 and 60% respectively. The addition of acid, increase in kappa factor in $C_D$ stage and combination of both were effective in removing silica in the pulp. Treatment of final bleached pulp with $SO_2$ water removes silica to a great extent and improves optical properties of the pulp as compared to $H_2SO_4$ or PAA. Pretreatment of the pulp with acid and modification in the bleaching process can reduce silica substantially and improve the quality of rayon grade bamboo pulp.

• Journal of the Korean Chemical Society
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• v.55 no.1
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• pp.86-91
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• 2011

Modified lignins were prepared. Soda and peroxy lignins were precipitated from black liquor produced from bagasse pulping with soda and peroxyacid pulping process. The precipitated lignins were hydrolyzed using 10% HCl. Different functional groups were also incorporated into lignin by carboxylation and phosphorylation reactions. Moreover crosslinking of these lignins were carried out using epichlorohydrin. Characterization of the modified lignins and lignins derivative were carried out using Infrared spectroscopy. Thermal analysis of these compounds were also carried out using TGA and DTA techniques. Efficiency of sorption of metal ions by the modified lignin was also investigated. It was found that, the peroxylignin and its derivatives show higher efficiency toward metal ions uptake than the soda lignin.

• Journal of the Korean Wood Science and Technology
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• v.21 no.3
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• pp.67-73
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• 1993

This study was attempted to develop the Special Sheet Former for Hanji (Korean Traditional Paper), which could be easily used anyone who has no any special skill, and to evaluate its sheet forming characteristics. The sheet former for Hanji was designed, manufactured and tested its sheet forming features. This former was resulted in superior even basis weights and good formation of sheets without any special technological experiences, but poor consolidation according to the difficulty of web pressing during dewatering process. Sulfomethylated pulping resulted in the superior pulp with high yield and better quality compared to those of alkali and alkali-peroxide pulps. Since the pulp was so bright, there was almost no need additional bleaching.

• Journal of Forest and Environmental Science
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• v.9 no.1
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• pp.67-80
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• 1993

There are a lot of serious problums associated with conventional pulping processes, such as kraft and sulfite. In order to tackle these difficulties, organic acid pulping of Populus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. have been investigated as on alternative method. The acetic acid cooking of Populus tomentiglandulosa T. Lee achieved good delignification with pulp yields of 55-65% under almost all cooking conditions. In the acetic acid cooking of Pinus densiflora S. et Z., it was not cooked at a low temperature. The strength properties of the acetic acid pulps from Pinus tomentiglandulosa T. Lee showed the optimum with 95% acetic acid concentration at $185^{\circ}C$ maximum cooking temperature for 0.5hr cooking time. The strength properties of the acetic acid pulps from Pinus densiflora S. et Z. displayed excellent tear strength in comparison with those of the other softwoods. In the process of acetic acid cooking, glucose has been removed a little, but other sugars have been eliminated. The elemental compositions and $C_9$ formulas of acetosolv lignins from Populus tomentiglandulosa T. Lee were 63.88% carbon, 5.45% hydrogen and 30.67% oxygen and $C_9H_{9.15}O_{3.24}$ The elemental compositions and $C_9$ formulas of acetosolv lignins from Pinus densiflora S. et Z. were 61.85% carbon, 6.14% hydrogen and 32.01% oxygen and $C_9H_{9.15}O_{3.50}$ The Wt. av. MWT's of the acetosolv lignins from Pinus tomentiglandulosa T. Lee and Pinus densiflora S. et Z. were 731 and 725.

• Journal of the Korean Wood Science and Technology
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• v.44 no.1
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• pp.135-146
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• 2016

Three fiber sources including Russian spruce (Picea jezoensis) and larix (Larix leptolepis), and Myanmar bamboo (Phyllostachys bambusoides) for thermomechanical pulp were explored to replace domestic pine (Pinus densiflora) pulp that has some limitations in an aspect of supply and pitch trouble. Thermomechanical pulps were manufactured under the identical condition, and then compared with their representative pulp properties and pulping process. Both Russian larix and Myanmar bamboo contained large amounts of extractives that would negatively affect mechanical pulping processes. Russian spruce showed the least contents in shives and pitch. Russian spruce and domestic pine reached an optimum freeness level within a short pulp processing time, which consumed less amount of refining energy compared to larix and bamboo. In particular, the spruce wood showed the highest brightness level which might lead to a less consumption of bleaching chemicals. It was expected that Russian spruce could be replaced with the domestic pine wood in respect of both pulping process and pulp quality.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.5 s.108
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• pp.78-84
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• 2004

Lignin precipitated from black liquor of soda pulping of bagasse was used to prepare cation-exchange resin. The effect of sulfuric acid treatment, concentration of phenol and formaldehyde on the properties of the prepared cation-exchange resin was investigated. It was found that sulfonated resinified phenolated lignin gave a resin with an ion-exchange capacity higher than that of resin, which resulted from sulfonation of resinified lignin at zero phenol concentration. Infrared spectroscopy of the prepared ion-exchange resin shows anew bands at 1060, 1160, 1280 and $1330\;cm^{-1}$ which indicated to the presence of $SO_{3}$.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2010.04a
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• pp.303-308
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• 2010