• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.445-450
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• 2006

The stress and strain properties of KOCC were modified to improve the performance of KOCC as a packaging raw material. The refining consistency, refining degree and the grammage of handsheet were varied. The stress strain properties, tensile energy absorption were measured for prepared handsheets. The refining improved significantly the stress and strain properties of paper, especially at lower refining consistency. The increase of grammage also had contributed to improve the stress and strain of paper. It was also found that both refining and grammage contributed to the improvement of tensile energy absorption. However, it is strongly recommended to introduce the combination of refining consistency, refining degree and mechanical treatment.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.1-9
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• 2000

The MDDA (Modified Dynamic Drainage Analyzer) was developed to evaluate the drainage characteristics on paper machine. The initial forming vacuum velocity was decreased with the increase of stock consistency and there were no significant effects of the applied vac-uum. On the other hand the initial forming drainage velocity was rapidly decreased with the increase of stock consistency above the 0.35 bar of applied vacuum. The final drainage time and wet web permeability showed similar trends under 0.075% consistency but increased rapidly at the higher consistencies. SFR(Specific Filtration Resistance) and drainage obtained for different vacuum level applied and deposited weights measured by using MDDA showed the linear relationship.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.5
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• pp.25-29
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• 2001

Dimethyldioxirane (DMD), which is a source of active oxygen, is effective agent that can be used in chemical pulp bleaching. In this study, delignification of kraft bagasse pulp has been carried out by using DMD. The effect of the applied charge of DMD (as active oxygen) and pH of the delignification medium were studied. The optimum conditions of the applied DMD charge and pH of the delignification reaction were achieved at pH range from 8~9, 2% of DMD (as active oxygen) and the rest of delignification reaction conditions were $25^{\circ}C$, 60 min, and 12% pulp consistency. The development of brightness per unit kappa number removal (ΔBrightness/ Δ Kappa number) has highest value at the optimum condition. The study showed that the reactivity of kraft bagasse pulp be enhanced to wards alkaline hydrogen peroxide bleaching by pulp treatment with DMD.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2003.04a
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• pp.202-206
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• 2003

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.5 s.113
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• pp.56-62
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• 2005

The catalytic effect of molybdovandophosphate heteropolyanion (HPAs) on the delignification of kraft bagasse pulp by hydrogen peroxide has been investigated. Very small amounts of the catalyst (0.05 0.3 mM/l) gave convenient results. Partial reduction of the catalyst was also studied. The effect of reaction medium (water, ethyl alcohol and acetone) on the bleaching was also studied. The results obtained show that the optimum condition for bleaching in presence of polyoxometalate were 0.05 mM/l catalyst concentration at $70^{\circ}C$ reaction temperature and $7\%$ consistency at pH 2 in aqueous medium. The ratio of water to solvent of 60:40 from acetone gives higher brightness than ethyl alcohol. The catalyst solution can be reused for 5 times without any reduction in brightness. ESR for the blank and exhausted solutions under different conditions was also carried out to find the relation between reduced metals and pulp brightness.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.2
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• pp.68-73
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• 2001

This experiment was executed to clarify the optimum condition of reductive bleaching for 100% color papers. The reductive bleaching of the color paper was desirable to be done under such conditions as high temperature over $60^{\circ}C$ and high consistency within possibly short time. The FAS bleaching like the sodium hydrosulfite required oxygen-free condition. Especially, as the mixture between pulps and chemicals was favored in case of the high consistency, it was actively recommended. Therefore, it is desirable to control the dosage with the type of the dyes, the nature, the dye content, the paper compositions, and the targeting initial and final brightness.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.130-139
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• 1999

In order to manage the wet end chemistry on paper machines, our goal is to control sub-processes through which we can influence the entire wet end operations with maximum effect. The most important sub-processes are: consistency, ash, and chemistry. The management of these three main groups is based on on-line maesurements and automatic control. This paper presents a new wet end management platform, a new analyzer. This new analyzer utilizes a modular structure and modem software. It is part of a new paper machine concept. The controls of this concept are feedback and feedforward solutions that control retention, consistencies, ash, and charge, resulting in a more stable wet end (30...80%), more uniform paper, and better rnnability.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.3
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• pp.52-59
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• 2004

The greater Increase of the demand for environmental friendly materials especially for packaging industry leads to the larger interest in the reusable and recycable materials such as pulp mold. Although the pulp mold has great characteristics for packaging, some deficiency compared with other packaging material like EPS(Expandable Polystyrene) need to be overcome, for example, the relative higher cost. In this report, since the water drainage rate at the forming zone of a wet pulp mold process could have a great influence on the economical efficiency not only by increasing machine speed but also reducing the drying energy, the optimum ways for increasing drainage were investigated The mechanism of vacuum drainage In pulp mold forming was successfully evaluated by using RDA(Retention and Darinage Analyzer). Since the conditions of stock were greatly affected by the pulping time of low consistency pulper, the optimum pupling time was investigated with considerations of all stock preparation processes. The change of stock temperature and the addition of polyelectrolyte could improve the vacuum drainage rate. It was founded that the wire mesh types of mold former had a little influence on the retention because of the relatively mild vacuum drainage. However, the bigger size of dewatering hole showed better drainage rate and could reduce the plugging and con lamination of mold.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.16-23
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• 2001

Hydraulic transport of fines up to the surface of flotation cell was supposed to be a mechanism of fines fractionation through the froth-flotation. Efficient fractionation of fines means efficient skimming out of flotation rejects as much as possible with least long fiber loss. The selectivity of fines fractionation was found to be mainly affected by long fibers flocculation degree in this study. Lack of sufficient flocculation of long fibers could lead to extensive loss of long fibers. It was also found that higher flotation flux caused higher flotation reject as well as the increase of long fiber loss, but did not affect the fine content ratio in the flotation reject. We controlled the flotation flux and the stock consistency, and chose a cationic polymer to maximize the flocculation of long fibers and to increase the amount of flotation reject. The highest efficiency of fines fractionation was obtained at 1.3% of stock consistency and at 100L/min of flotation flux in our experimental set up. The cationaic polymer we chose was found to be very effective in fiber flocculation and flotation froth stabilization. New definitions of fractionation efficiency were introduced in this study to compare the results more clearly.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.43 no.5
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• pp.43-48
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• 2011

Filler loading at thick stock was carried out in order to verify if the dual addition of filler can be used as a means to reduce the detrimental effects of filler on the strength properties of paper. PCC was added to 3.5% pulp slurry blended with HwBKP, BCTMP and SwBKP. Cationic starch was used as a fixing agent. The mixture of PCC and pulp was stirred for 5, 10 and 20min. at 1,000 rpm. The remaining PCC was washed out before handsheet making. PCC particles were flocculated and fixed on the pulp fiber and/or space between fibers. It is expected that the flocculation and inclusion of PCC can be helpful to improve the strength properties of paper due to the reduction of detrimental effect in fiber bonding. The distinct tendency in PCC flocculation and fixing on pulp fiber was not observed by the change of cationic starch dosage and treatment time.