• 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.47 no.1
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• pp.93-101
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• 2015

The purpose of this study is to examine the reusability of the fluff pulp recycled from paper diaper. To do this, the physical and optical properties of each handsheet made from these fluff pulp sample as well as the properties of the fiber recycled from paper diaper were analyzed and compared with those of non-recycled diaper fluff pulp samples and conventional pulp samples. These comparisons show that the characteristics of fiber such as length, width, curl, kink of the pulp recycled from paper diaper were similar to those of non-recycled diaper fluff pulp as well as to those of commercial pulp. The fine content of recycled diaper fluff pulp was lower than that of other pulp samples, while the ash content of the former was higher than that of the latter. Furthermore, it was also found that the bulk of handsheets made from the recycled fluff pulp was higher than that of other pulp samples, while the formation of the former was worse than that of the latter. The mechanical properties of the handsheet sample made from the recycled diaper fluff pulp was higher than those of the unused diaper fluff pulp and was lower that those of commercial fluff pulp and softwood tissue pulp handsheet. But, it was higher than that of hardwood tissue pulp handsheet. The optical properties of recycled diaper fluff pulp handsheet was lower than those of each handsheet samples made from other pulps due to its low fine content.

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.153-164
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• 1990

Human dental pulps obtained from normal teeth, hypersensitive teeth and teeth with inflamed pulp were studied to measure and to compare the endogenous levels of arachidonic acid metabolites in order to see the relative activities of the different pathways involved in arachidonic acid metabolism. Pulp homogenates were incubated with $^{14}C$-arachidonic acid and lipid solvent extracts were separated by thin layer chromatography (TLC) to be analyzed by autoradiography and TLC analyzer. 1. The most significant metabolite was HETEs showing $96.9{\pm}37.8$pmol/mg tissue protein/hr in normal pulp, $169.2{\pm}76.7$ in hypersensitive pulp and $385.4{\pm}113.2$ in inflamed pulp. In normal pulp $LTB_4$, 6-keto-$PGF_{1\alpha}+PGE_2$, $TXB_2$ and unidentified metabolite were formed in decreasing order. While in hypersensitive and inflamed pulp 6-keto-$PGF_{1\alpha}+PGE_2$, $LTB_4$, $TXB_2$ and unidentified metabolite were formed in decreasing order. 2. In hypersensitive pulp only HETEs were significantly increased when compared with that in normal pulp. The levels of all the converted metabolites in inflamed pulp were significantly increased compared with those in normal pulp. In inflamed pulp, the levels of $TXB_2$ and HETEs were significantly increased compared with those in hypersensitive pulp. 3. The ratio of each metabolites to the total converted metabolites showed an increased value of $TXB_2$ and 6-keto-$PGF_{1\alpha}+PGE_2$, as the degree of inflammation was increased, while that of HETEs decreased both in hypersensitive pulp and inflamed pulp more than in normal pulp. 4. The relative amounts of the total metabolites formed in lipoxygenase pathway to cyclo-oxygenase pathway were 6.8 fold in normal pulp, 4.4 fold in hypersensitive pulp and 3.8 fold in inflamed pulp.

• 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.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 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 Biosystems Engineering
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• v.43 no.4
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• pp.362-368
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• 2018

Purpose: Self-sufficiency in paper production is desired in Nigeria. This study was aimed at evaluating the performance of a locally fabricated batch pulp digester. Methods: The pulp yields of sheaths generated as waste in the production of bamboo (Bambusa vulgaris) laminates were determined at different liquor concentrations and treatment time after preliminary experiments to ascertain the conditions under which the sheath started to pulp. Moreover, the optimum pulping conditions and fiber characteristics were determined and estimated, respectively, to ascertain the pulp fiber suitability for paper production. Results: An optimum pulp yield of 65.1% was obtained at 50% NaOH and 25% $Na_2S$ liquor concentration (w/w) when the cooking time was 4 h. The results of fiber characterization of the pulp indicated an average fiber length of 2.19 mm with a low Runkel ratio of 1.63, both of which signify the suitability of the pulp for medium quality paper production. Conclusions: Softwood pulp can be blended with the fibers to improve the strength of the produced paper; further investigation should be carried out to use other non-woody plants for pulp and papermaking.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.48 no.3
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• pp.66-72
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• 2016

The applicability of rice husk fiber as a raw material for eco-friendly pulp mold was evaluated in this study. The higher demand of environmental friendly packaging material resulted in the more interest for the natural fiber based pulp mold. The rice husk which is an abundant agricultural byproduct in Asia could be defiberized by an alkaline digestion process. The changes in the pulp mold making process and the properties of pulp mold by the addition of the rice husk were investigated. The addition of rice husk fiber to the pulp mold made with OCC or UBKP resulted in the increase in drainage at the pulp mold forming process. In case of UBKP pulp mold, the addition of rice husk fiber increased the drying efficiency after pulp mold forming since the structure of pulp mold became more bulkier by the addition of the rice husk fiber. Those results showed the rice husk fiber could be applied to the pulp mold manufacturing as one of the eco-friendly natural fiber resources.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.6
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• pp.72-77
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• 2013

Tissue and paper manufacturing companies have common problems with increasing cost of imported virgin pulp and the restriction of using woods in the forest. Possibility of using bagasse pulp for solving those problems was studied. In order to reduce the production cost and study the dependency on pulps, bagasse pulp has been studied for mixing with Sw-BKP and Hw-BKP. Optimum blending ratio of wood pulps and bagasse pulp to enhance tissue properties were analyzed. Various properties of the hand sheet after blending of wood pulp and bagasse pulp were measured. As results, the bagasse pulp could substitute the hard wood pulp with similar properties of tissue. Therefore, we judged that the bagasse pulp was suitable for replacement of the hardwood pulp.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.183-199
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• 2001

Alternative way of shaping fibers suitable for papermaking was introduced. Impact refining, which was done simply by hitting wet fibers with a metal weight vertically, was intended to keep the fibers from shortening and to cause mostly internal fibrillation. Virgin chemical pulp, its recycled one and OCC were used in the experiment. It was noticed from the experiment that impact refining on virgin chemical pulp kept the fiber length and Increased bonding properties greatly, However, in the recycled fibers from the chemical pulp, fiber length and bonding properties were decreased. In OCC, which seems to contain fractions of semi-chemical pulp and mechanical pulp (GP), and which is recycled pulp from corrugated boxes, fiber length and bonding properties were decreased disastrously. We believe recycled cellulosic fibers (recycled chemical pulp and OCC in this case), which went through hornification, were less resistant to the mechanical impact than virgin chemical pulp. For virgin chemical pulp, impact refining allowed no significant fiber length shortening, high WRV, and high mechanical strength.