• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.4
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• pp.53-60
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• 2007

LbL multilayering technology introduced by Decher is a nano technique that a substrate surface is layered by the successive deposition of polyelectrolytes with positive and negative charge. We investigated the electrochemical properties of LbL multilayered pulp fibers with poly-DADMAC and PSS. Three types of pulp-Hw-BKP, BCTMP and KOCC- were treated with polyelectrolytes. Zeta potentials of multilayered fibers ranged from +30 mV to +40 mV, depending on the intial zeta potential of pulp fibers and fines content. All kinds of pulp which were examined in this study, however, showed a similar zeta potential of -35 mV after layering with PSS. To obtain pulp fiber with a uniform and stable zeta potential, BCTMP and KOCC pulp fibers should be multilayered above 5 times. The addition level of polyelectrolytes had little influence on the zeta potential of pulp fibers.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.4
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• pp.38-44
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• 2007

In order to utilize unsorted ONP, which contains leaflets (printed coated papers), to produce pulp mold, optimum conditions for a repulping process were investigated with a laboratory high consistency pulper. It was concluded that medium or high consistency pulping is necessary to accelerate the rate of deflaking of unsorted ONP. Considering flake content, fines content and pulping energy, the optimum conditions for the laboratory Helico pulper were 11% of repulping concentration and 3 min of repulping time. The repulping temperature shall be at least $30^{\circ}C$. Aging of paper slows down the rate of de flaking but in an actual pulp molding process its effect could be negligible.

• International Commerce and Information Review
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• v.10 no.4
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• pp.395-416
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• 2008

The advance information for oceangoing cargoes destined to th United States enable CBP to evaluate the potential risk of smuggling WMD and to facilitate the prompt release of legitimate cargo following its arrival in the Unites States. On January 1, 2008, CBP promulgate regulations, also known as 10+2 rule, to require the electronic transmission of additional data elements for improved high-risk targeting, including appropriate security elements of entry data for cargo destined to the United States by vessel prior to loading of such cargo on vessels at foreign seaports. The potential impact to an importer's international supply chain will be as follows ; Firstly, importers will take incremental supply chain costs and filing costs. Secondly, anticipate delay in shipment of containerized cargo. Thirdly, importers could be charged fines if they fail to file and file inaccurate or missing data. Companies exporting to the United States should be interested in 10+2 rule, analyze their current processes and procedures to ensure that they are prepared to handle the additional filing requirements of 10+2 rule. And they should focus on how 10+2 impacts their supply chain in terms of costs and sourcing. They will be necessary to revise service legal agreements with their forwarders, customs brokers or carriers in order to meet filing requirements of 10+2 rule.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.1
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• pp.59-66
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• 2006

We studied on the effects of the enzyme treatment of pulp fiber on physical properties of coated paper were elucidated using four types of enzymes. The results of this study showed that the blank in which enzyme was not treated showed the highest $St{\ddot{o}}ckigt$ and Hurcules sizing degrees. And when the enzyme treated base paper was used for coating, the coated paper has average 5.7 % higher gloss and whiteness than when untreated base paper was used. Brightness showed 0.12 % higher results with the enzyme treated base papers than the blank while it is considered to show similar trends. Whiteness of coated paper was not influenced by the enzyme treatments but by the properties of coating color. Coated paper whose base paper was enzyme treated showed improved roughness while smoothness of those samples except the ${\beta}$-Glucosidase treated one was relatively low due to the high fines content. Also the coated paper whose base paper was not enzyme treated showed high porosity.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.395-400
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• 2006

Polylactic acids polymer (PLA) was applied as an additive to improve the strength properties of handsheets prepared from three unbleached southern pine kraft pulps with different kappa number and an aspen bleached chemithermomechanical pulp (BCTMP). The results showed that PLA could greatly improve the tensile and burst strength of the pulp handsheets. Heat pressing effect was also important to enhance the strength properties. For unbleached kraft pulps, it was found that an appropriate amount of residual lignin in pulps had a positive effect on the handsheets strength improvement when adding PLA. The thickness of the handsheet did not change the PLA strengthening effect. In general, PLA effect on tear strength improvement could be neglected. However, it had a significant effect on the improvement of tear strength for the aspen BCTMP handsheets not containing sufficient amount of fines.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.23-32
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• 2015

In this study, chemical and physical changes of dissolving pulps which have similar viscosity by dry milling and fractionation were investigated. We used two types of dissolving pulp made from wood and cotton linter fiber, respectively. Dry milling was executed by knife cutter and pulp powders were fractionated by sieve shaker into 4 grades. We analyzed fiber properties, crystallinity index, viscosity, molecular weight of pulp sheet and powders. It was found that poly-dispersity index of cotton linter pulp was smaller than that of wood pulp, meaning that cotton pulp has more narrow molecular weight distribution. It was assumed that these were related to exposure times to chemical treatment which cut cellulose chains not evenly. At least 4 times of chemical treatments for wood pulp were executed and only two times of chemical treatments for cotton linter pulp were done. After dry milling average molecular weight and crystallinity index of cotton linter pulp powders were reduced and these were related to fines content and shape of pulp powders.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.2
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• pp.58-64
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• 2003

Because of its tendency of making strong Hoc on the fiber surface with fines, Meogujaengi has not been valued as a material of Hanji. As an attempt to manufacture high value-added products using the material made from Jumchihanji, this study performed morphological classification and chemical component analysis and selection of pulping of Meogujaengi method. As a result, it can be concluded as follows, 1. Meogujaengi is assumed to be a local variety of Broussonetia karinoki and its outward appearance is distinguished from Broussonetia kazinoki. 2. The bast fiber of Meogujaengi is longer and thinner than that of Broussonetia papyrifera or Broussonetia kazinoki. However, because of the coarse linear of fiber tissue, there are many clusters. 3. The cluster phenomenon of Meogujaengi is nothing to do with its chemical components. Although the contents of its chemical components are different from those of Broussonetia kazinoki, no component was found that obstructs pulping. 4. The pretreatment for suppressing the occurrence of clusters of Meogujaengi was effective, and it was necessary to do secondary beating using hollander beater after beating mixed with PAM using knife beater.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.18-24
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• 2000

To evaluate the efficiency of various cationic starches in improving retention drainage and strength properties of newsprints which are being made using extensive amount of domestic recycled wastepapers in a highly closed papermaking system diverse cationic starches have been prepared and tested. In the case of cationic starches with low charge density as the degree of substitution increas-es fines retention increased. Results also showed that the retention efficiency decreased sub-stantially for cationic starches with low DS when the conductivity of white water inceased. Tensile strength increased with the addition of cationic starches and then decreased. On the other hand internal bonding strength increased linearly with the addition of cationic starch. Oxidizing treatment of cationic starch was detrimental for retention and freeness improve-ment. Also crosslinking treatment of wet processed cationic starches made cationic starches less effective in retention and drainage.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.6
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• pp.57-65
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• 2015

Microfibrillated cellulose (MFC) or Nanofibrillated cellulose (NFC) has been used to reduce the use of raw pulp and to improve paper strength. The problem of MFC preparation is high manufacturing cost. In this study, it was carried out to prepare MFC after enzyme beating and estimated properties of MFC. Endo-D was the best beating efficiency among three type of endo-glucanase. As the grinder pass number increased, the viscosity and the fines of MFC suspension increased while the crystallinity and the porosity of MFC sheet decreased. Also enzyme beating MFC was higher value in the crystallinity and lower value in the viscosity than non-enzyme MFC. In addition, the aspect ratio of MFC was the highest at 5 pass. MFC addition improved the handsheet strength and the air permeability but worsened the drainage.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.4
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• pp.41-49
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• 2006

Since particle size distribution curves are useful to estimate permeability of soil, many formulae for permeability coefficient (k) have been published using the parameter from the curves and factors, such as grain size, particle shape and void ratio of soils. However, the parameters such as $C_c,\;C_u$ and $D_n$ derived from only some discrete points on the curve are insufficient to represent the whole gradation. In this paper fractal dimension which is quite new concept and known to be able to represent the entire curve of particle size distribution is employed for the parameters. An empirical formula of permeability coefficient has been developed with fractal dimension and percent of finer than 0.075 mm. The formula developed from this study has confirmed its effectiveness by a series of laboratory tests and comparison to other published formulae. It is found that permeability coefficient is proportional to fractal dimension and inversely proportional to percent of fines.