• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.3
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• pp.77-82
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• 1999

The delignification, and optical and strength properties were determined to compare the ozone treatment effect in hardwood and softwood CTMPs. During ozone treatment, the delignificantion was much higher in hardwood pulp than in softwood pulp . The optical and strength properties which were very dependent upon the lignin content in pulp were significantly improved in the case of hardwood pulp . The ozone treatment of high yield pulp was more effective in hardwood pulp than that of softwood pulp.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.3
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• pp.18-23
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• 2001

The effect of pulp consistency on the deinking properties in the ozone deinking of ONP was investigated in order to develop the environmentally friendly deinking method. The pulp consistency and ozone treatment time were varied for this purpose. Higher pulp consistency during ozone treatment gave better ink removal efficiency than the conventional deinking method. In was also found that the increase of pulp consistency can decrease the ozone treatment time which can meet the deinking quality. WRV of ozone deinked pulp obtained at 10% and 30% of pulp consistencies was lower than those of the conventional deinking method. However, the higher pulp consistency during ozone treatment improved WRV. Highest brightness was obtained at the ozone treatment condition of 30% pulp consistency and 10 minutes. The lower brightness at the other ozone treatment condition should be originated from the excessive decrease of ink particle size and then decrease of true ink removal efficiency. Scott bond was increased with the increase of pulp consistency and treatment time. However, the improvement of breaking length with ozone treatment was no significant.

• The Journal of the Korean dental association
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• v.57 no.8
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• pp.464-473
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• 2019

For dental pulp treatment of immature permanent teeth, direct pulp capping or partial/cervical pulpotomy (apexogenesis) procedures can be used if the dental pulp is vital. MTA (Mineral Trioxide Aggregate) is regarded as the first choice dressing material for these procedures because its higher success rate. It can be also used successfully for devitalized dental pulp which has been treated by calcium hydroxide. This apexification procedure with MTA has a few advantage such as short treatment period and increase of resistance against root fracture. Recently, regenerative endodontic treatment was introduced for devitalized immature pulp. It can maintain pulp vitality and lead to continuing root development although the dental pulp was devitalized.

• Journal of the Korean Wood Science and Technology
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• v.27 no.4
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• pp.65-71
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• 1999

This study was carried out to investigate the effect of xylanase pretreatment of the unbleached hardwood kraft pulp during the conventional Chlorine-Extraction- Hypochlorite (CEH) bleaching on pulp property. Optimum bleaching condition was evaluated by using Novozym produced from the fungus Humicola insolens. Also the effect of chelating agent prior to enzyme treatment was analyzed. The kappa number of enzymatic bleached pulp at the enzyme charge 10 IU/ml was slightly similar to that of bleached pulp without enzyme. By enzyme treatment, the chlorine charge in conventional CEH bleaching process of hardwood KP could be reduced by 17%, while no adverse effect on pulp yield and strength was. The optimum condition for enzyme pretreatment was 10 IU/ml xylanase charge, 3 to 4 hrs treatment, and 2% pulp consistency. In sugar composition in the enzyme pretreated pulp, arabinose and mannose were not much different, but more xylose was retained. This high content of hemicellulose in pulp seems to play an important role in pulp properties. The pulp pretreatment by chelating agent prior to enzyme treatment could improve the enzyme activity and enhance the bleaching effect at 0.2% diethylenetriamine pentaacetic acid (DTPA) charges.

• Journal of the Korean Graphic Arts Communication Society
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• v.30 no.3
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• pp.35-43
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• 2012

Internal bonding strength of printing paper was increased with sea-algae pulp treatment. Spacially, 9% contents sea-algae pulp treatment in the hardwood pulp are more effective than in the softwood pulp. Most effective mixture ratio of the raw matrials for improvement of the internal bonding strength are softwood pulp 30%, hardwood pulp 70%, sea-algae pulp 9%. Internal bonding strength is effective in more sea-algae pulp contents and softwood pulp contents and wetness.

• 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 Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.2
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• pp.40-44
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• 2000

A microscopic study was carried out to get the fundamental informations for the ozone deinking technology. The differential interference microscopic observation showed that ozone treatment was helpful to detach the toner ink from the surface of pulp fiber. The modifications of fiber surfaces by ozone treatment were observed with scanning electron microscope. Modification of fiber surfaces was not severe at the early stage of ozone treatment, but it increased with ozone treatment time and pulp consistency, Therefore, it would be possible to improve the properties of deinked pulp by controlling the condtion of ozone treatment.

• The Journal of the Korean dental association
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• v.54 no.8
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• pp.658-665
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• 2016

Treatment of immature permanent teeth with irreversibly damaged pulp has been challenging in dental practice because of the lack of apical constriction, thin dentinal walls, and short roots. This may lead to the extrusion of filling materials, and fracture of the root due to its more fragile feature during shaping of the root canal. Apexification with calcium hydroxide or MTA is one of the treatment options for these cases. Although favorable results of apexification have been reported, these treatment procedures do not guarantee the increase of root length and/or width even after a long term period. Thus, treated teeth are still prone to fractures. Recently, pulp revascularization has been proposed as an alternative treatment for immature teeth with necrotic pulp and periapical pathosis. Pulp revascularization allows the stimulation of the apical development and the root maturation. There have been many treatment protocols using various materials such as antibiotics and calcium hydroxide medicament. In this case report, literature review about pulp revascularization and two related cases are presented.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.3
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• pp.47-54
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• 2015

In this study, effects of kneading treatment on the properties of hardwood bleached kraft pulp (HwBKP), softwood bleached kraft pulp (SwBKP) and hardwood bleached chemi-thermo-mechanical pulp (HwBCTMP) were elucidated with a laboratory two-shaft kneader. Kneading treatment was performed at 30% (w/w) of pulp concentration and the number of passes through the kneader was adjusted from 0 to 10 passes. Then, changes in properties of pulp fibers were evaluated. It was found that fiber characteristics were influenced by kneading treatment. Fiber length was decreased with kneading while other morphological properties such as fiber width, curl and kink became increased as the number of passes through the kneader increased from 0 to 5 passes. The magnitude of changes in the morphological properties of softwood chemical pulp was the largest, followed by hardwood chemical pulp. The morphological properties of HwBCTMP were little influenced by kneading treatment. Swelling of fiber measured by WRV was increased with kneading except of HwBCTMP.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2000.04a
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• pp.39-46
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• 2000

In pulp and papermaking process, enzymatic treatment of pulp fibres has been a topic of increasing interest in last decade. Lots of patents, papers and research reports were published on the application of enzymes in the fields of enzymatic bleaching, deinking, slime control, pitch control, waste water treatment and fibre modification. Cellulase and hemicellulase are the principal enzymes used for the modification of fibre property. This study was carried out for determinating the behaviors of enzyme to pulp fibres. A commercial enzyme, Denimax BT which is consisted with cellulase and hemicellulase, was treated to the kraft pulp produced from domestic hardwood mixtures. Results were mainly concentrated on the behaviors of freeness, drainability and fines content of fibres, and physical properties of paper with enzyme treatment. The freeness levels and dewatering ability were developed, and the fines contents were decreased. The creation of fines were controlled by the method of pre-enzyme treatment prior to fibre beating. The mechanical strength of paper, like tensile, burst, tear strength and folding endurance, were remarkably improved by the pre-enzyme treatment.