• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 1999년도 Proceedings of Pre-symposium of the 10th ISWPC
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• pp.149-152
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• 1999

A new process for deinking of colored offset newsprint, i.e. enzyme treatment in cooperation with ultrasonic wave was developed in the present study. The physical characteristics such as fiber length, coarseness, crystallinity index of the deinked pulps were investigated and the sugar residues released from the treatment were analyzed. It was found that colored offset newsprint could be deinked effectively by cellulase treatment when ultrasonic wave was applied. The brightness increased by 5% ISO over that of control experiment and the pigment content was reduced markedly. Though the ultrasonic wave had little effect on the strength and crystallinity of the pulp, the treatment of enzyme combined with ultrasonic wave reduced the coarseness and fiber length to some extent. It was also found that ultrasonic wave could accelerate the hydrolysis of cellulose and hemicellulose during the cellulase treatment.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 추계학술발표회 논문집
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• pp.143-149
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• 2011

In recent, many forest residues have been generated by the National Forest Management Operation. Unfortunately, most of the forest residues are supposed to be used as raw materials for burning fuels like wood pellets. In this study, we investigated whether or not this forest biomass mixed in various ages and species could be used as raw materials for making kraft pulps in a view of optical properties.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1370-1372
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• 1994

Power transformer has been expected to work with safety and reliability during the long period over 30 years. Pressboard has been effectively used as the insulating materials of transformer and they seem to be used as in insulating materials of transformer. This paper describes the results of a basic study on the electric strength, resistivity, permittivity and dielectric loss properties of pressboard to be made with some kinds of pulp and different waters.

• Restorative Dentistry and Endodontics
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• 제6권1호
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• pp.27-35
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• 1980

This study was to evaluate the effectiveness of a few disinfectant on amputated pulps of domestic dogs. The materials employed for the purpose were zinc oxide eugenol paste, calcium hydroxide as control groups and guaiacol (1%, 5%, 10% by weight) added zinc oxide eugenol paste and formaldehyde (1%, 5%, 10% by weight) added calcium hydroxide as experimental groups. Following were the results obtained throngh histo-pathological examination. 1) In calcium hydroxide-formaldehyde groups, secondary dentin formation was observed in the 2 weeks, but the remaining pulp tissue was severely atrophied according to the concentration of formaldehyde and the time increased. 2) In zinc oxide eugenol-guaiacol groups, the first evidence of secondary dentin formation was observed in the 3 weeks. It seems that the concentration variety of guaiacol influenced very little to the potential ability of dentin formation. 3) Except 1% formaldehyde containing calcium hydroxide group, every group showed severe pulp degeneration. In all groups of zinc oxide eugenol-guaiacol cases revealed the tendency of recovery.

• Journal of the Korean Wood Science and Technology
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• 제21권2호
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• pp.49-56
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• 1993

This study was performed to investigate the pollution-free Korean traditional papermaking characteristics from paper mulberry by sulfomethylation pulping. Bast fibers were pulped by sulfomethylated cooking liquor, and by alkali and alkali-peroxide processes for the comparison. 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. Pollutant loads of sulfomethylated pulping effluent were very low in terms of pH, turbidity and color compared to those of alkali. Pollution-free effluents was accomplished by simple filtering treatment with pine bark, charred rice hull and sawdust compost. Pine bark was the most effective in reduction rate of pollutants.

• 펄프종이기술
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• 제29권3호
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• pp.51-59
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• 1997

Dissolving pulp is a low yield(30∼35%) bleached chemical pulp that has a high cellulose content (95% or higher) suitable for use in cellulose derivatives such as rayon, cellulose acetate. This research was studied for dissolving pulp preparation as the raw material of viscose rayon from commertial pulps. (TMP, CP, DIP) In the change of pulp(cellulose) characteristics after sodium hypochlorite and solvolysis treatment. the following results were obtained In the case of sodium hypochlorite pretreatment, we have obtained pulp that high purity cellulose, but degree of polymerization was inclined to decrease less than 170∼240. Comparing sodium hypochlorite pretreatment and solvolysis pretreatment, solvolysis pretreatment is superior to sodium hypochlorite process for making dissolving pulp. We think that the low degree of polymerization of cellulose because of increasing degradation of cellulose during delignification treatment.

• 펄프종이기술
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• 제33권5호
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• pp.30-36
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• 2001

Caro's acid (persulphuric acid) has been proposed as a promising reagent used in pulping of lignocellu-losic materials. Bagass was subjected to caro's acid pulping under different pulping conditions of per acid concentration (2~8 percent), pulping temperatures (40~$60^{\circ}C$) and pulping time (120~240 min). The influence of different parameters of caro's acid pulping process on the chemical and strength properties of the produced pulps had been studied. Peracid concentration and pulping temperature are the most important variables of the pulping process. High degree of delignification and good deliberation were achieved at moderate pulping conditions in the studied range. Pulping experiments of bagasse by using caro's acid had been carried out for determination of the optimum comditions of the process. In inch case to effectively tackle the problem, a specific design of an experiment is selected depending on the goals to be achieved in the experimentation. The study could enable us to excepect the bagasse pulp properties (yield, Kappa number, DP) that be stated as function of the independent variables of caro's acid pulping process (per acid concentration, pulping temperature and pulping time).

• 펄프종이기술
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• 제45권6호
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• pp.88-95
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• 2013

Effects of beating and water immersion time on fiber swelling and paper properties were elucidated for the fundamental study of producing high bulk paper. Chemical pulps were beaten for various freeness and the beaten pulp was immersed in water up to 24 hours. Fiber swelling was evaluated by measuring water retention value (WRV). It was found that fiber swelling, bulk and paper strength were quickly changed at the initial stage of beating. Immersion in water did not significantly increase WRV, paper density and strength, implying that soaking in water alone could not effectively swell fiber wall. In order to swell further, hydrogen bonds between fibrils in fiber wall and hence fiber wall structure shall be broken by mechanical force during beating.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.285-290
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• 2006

As an alternative method to solve air pollution problem and difficulty of pulp bleaching of kraft pulping process, NaOH-Urea pulping was applied. The properties of NaOH-Urea pulp were compared to those of NaOH and kraft pulps. Addition of urea in low alkali charges retarded delignification rate compared to NaOH pulping. But, in high alkali application, delignification was significantly enhanced not from the addition of urea but from the high alkalinity. It was disclosed that urea did not participate on delignification reaction by the experiment using lignin model compound. Compared to paper strengths at the same level of sheet density, NaOH-Urea pulp gave as almost same breaking length and tensile index as those of kraft pulp. Especially tensile energy absorption and burst index were higher than those of kraft pulp.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.361-364
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• 2006

Generally, aging of paper is evaluated by folding endurance and degree of yellowing. It was known as that lignin, hemicellulose and metallic ion affect yellowing of mechanical or chemical pulps. Among these elements, especially, the study of hemicellulose that affect at yellowing of pulp is insufficient. In this study, we examined into the influence that glucuronoxylan or glucomannan and metallic ion($Cu^{2+},\;Fe^{2+},\;Fe^{3+},Mn^{2+}$) residued in pulp get each or when mixed at yellowing. Filter paper was treated with each metallic ion, glucuronoxylan and the mixture of glucuronoxylan and metal ions, and brightness and CIE $L^*a^*b^*$ was measured after accelerated aging. As the results of measurements, the filter paper processed by 10% glucuronoxylan was dropped 2-3% on the brightness after accelerated aging for 24 hours. Also, the filter paper treated with glucuronoxylan and $Fe^{2+}$ was dropped 7% on the brightness.