• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.4
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• pp.69-75
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• 2014

Effects of alkali swelling of HwBKP (hardwood bleached kraft pulp) at a low concentration below 2 percent (based on the oven-dried weight of pulp) on handsheet properties were investigated. Swelling treatment of HwBKP was performed at various low NaOH concentrations with/without beating. Then, the changes in handsheet properties were evaluated in terms of bulk, optical and strength properties. It was found that bulk was slightly increased when the alkali concentration was increased. When the pulp was only swollen without beating, paper optical and strength properties was slightly decreased or not changed with alkali concentration. When the pulp was alkali-swollen after beating, paper strength and opacity showed almost no changes while brightness was increased. When the pulp was beaten after NaOH swelling, alkali concentration showed almost no effect on brightness and opacity of paper. Paper strength was slightly decreased with alkali concentration, suggesting that alkali pretreatment before refining could adversely affect refining efficiency.

• 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.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.2
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• pp.42-49
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• 1999

Although many researches have been made on the adsorption of cationic starches onto chemical pulp fibers, only limited studies have been reported for deinked pulp(DIP) and thermomechanical pulpI(TMP). In this experiment, the adsorption behavior of the cationic starches onto DIP and TMP fibers investigated. Almost complete adsorption of cationic starches onto the pulp fibers were observed when the addition rate of starch was low. Adsorption ratio decreased abruptly when 3.5% and 4.0% of cationic starches were adsorbed onto deinked pulp and thermomechanical pulp, respectively. Adsorption of cationic starches increased as the degree of substitution decreased and as the pH of the pulp slurry increased. TMP fibers adsorbed more cationic starches than DIP because of its greater charge density, and this led to greater improvement in strength properties for the TMP sheets.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11c
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• pp.757-763
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• 2000

It is fundamental to control individual condition of every seedling. Automatic individual control is used by data control and analysis at on-line. As a result the best condition system was build without all waste. This system uses one of new technology irrigation system. This irrigation system supply accurate quantity of nutrient solution in the shortest time. The system named the upward injection irrigation system. First of all it is necessary to be considered whether the soil is proper or improper for upward injection irrigation system. It is important that root absorb nutrient solution as fast as possible. The ability of spreading, storing water, contamination of environment and cost were considered when choose the medium. The soil of organic culture is developed recently. The soil consists of paper pulp and vermiculite. The new soil is more suitable than ordinary medium for growing plant because this medium is made of paper pulp. The ability of store and spread of water is it's feature. We can make paper tray of this paper pulp's raw material. It is possible that pulp tray replaced plastic tray. The original plug tray of growing seedling system can make which consist of pulp medium and pulp tray. In this study, it was examined whether the plug seedling of paper pulp medium grow with upward injection irrigation system in this seedling plant system. At the same time, examine ability of store and spread of water and how to grow plant on the paper pulp medium.

• 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.43 no.3
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• pp.11-20
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• 2011

The conditions to which pulp fibers are exposed during paper production, converting, storage, use, and recycling can induce various changes in fiber morphology, surface characteristics, and suitability for paper production by recycled fibers. Most of those changes can be described by hornification. Paper has highly hygroscopic properties which affect dimensional change by relative humidity variation of surrounding condition. The purpose of this study was to investigate the dimensional stability, moisture contents and dip elongation of handsheets at different relative humidity conditions of recycled kraft pulp and BCTMP. By using recycled fibers, dimensional stability was increased because hygroscopic properties of fibers decreased with repeated recycling treatment. Dip elongation of recycled pulp was higher than that of virgin pulp because of its weak fiber-to-fiber bonding. By recycling pulp, the relative bonded area was decreased because fiber could not swell more than virgin pulp. Dimensional stability largely depended on the equilibrium moisture contents of paper, the fiber-to-fiber bonding strength, and the relative bonded area.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.1 s.119
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• pp.1-7
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• 2007

Internal fibrillation of pulp fiber is an important factor affecting paper properties. Internal fibrillation of pulp fiber is usually introduced with several kinds of modifications of fiber by the mechanical treatment such as refining, high shear and/or high consistency mixing, etc. Unfortunately there are no standardized methods that can characterize the extent of internal fibrillation and its contribution on the paper properties. The purpose of this study is to try and find the potential methods that can characterize the internal fibrillation of pulp fiber quantitatively. Softwood bleached kraft pulp was treated with Hobart mixer to introduce the internal fibrillation without the significant fiber damage and external fibrillation. The extent of internal fibrillation was increased with the increase of mechanical treatment consistency. Several fiber properties were measured to find the potential means that could characterize and quantity the internal fibrillation. Laminated area could not be used as a means for quantifying the internal fibrillation because of the effect of swelling and the different internal fibrillation behavior at different mechanical treatment consistency. Micro and macro internal fibrillation models were proposed for describing the different behavior for the mechanical treatment at low and high consistencies of pulp. The Internal fibrillation showed good correlation with swelling of fiber wall. This trend was confirmed through the measurement of wall thickness and/or cross section area of fiber. Therefore the internal fibrillation possibly can be described as the indices indicating the change of wall thickness and/or cross section area.

• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.383-391
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• 2011

Traditional international trade theory assumes that import goods and domestically produced goods of the same industry are equal in quality. However the substitutability of the two goods is imperfect. This article estimated the import functions of pulp and paper using econometric and vector autoregressive models, and calculated the elasticities of substitution between imported and domestically produced pulp and paper. The import of pulp is inelastic to import price and domestic price, and elastic to national income in econometric model. And it is inelastic to import price, domestic price and national income in vector autoregressive model. On the other hand, the import of paper is inelastic to domestic price, and elastic to import price and national income in econometric model. And it is inelastic to import price and domestic price, and elastic to national income in vector autoregressive model. The elasticity of substitution between imported and domestically produced pulp was positive, and the elasticity was respectively 0.42 and 0.20 in econometric and vector autoregressive models. This may be because of the high proportion of imports. On the other hand, the elasticity of substitution between imported and domestically produced paper was positive, and the elasticity was respectively 0.75 and 0.81 in econometric and vector autoregressive models. This may be because the quality of imported paper is different from that of domestically produced paper.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.2
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• pp.35-39
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• 2000

Refining is very important process of fibers treatment for proper paper properties. An extent of refining is usually measured by freeness, although freeness gives complicated meanings. One of a direct way of studying the refining effects on pulp fibers is making photomicrographs of beaten fibers. The conventional microscopy like light microscopy(LM) and scanning electron microscopy(SEM) require to preserve the wet structure of pulp fibers morphologically since most of papermaking process is carried out almost entirely in water. Recently developed microscopy, especially confocal laser scanning microscopy(CLSM), offers the possibility of examining fully hydrated pulp fibers. Cross-sectional images of wet pulp fibers are also generated using optical sectioning by CLSM and image analysis in order to verify and quantify the extent of fiber wall swelling indicating the internal fibrillation. At low beating load such as 2.5 kgf, in the same freeness, breaking length is higher than that of high beating load such as 5.6 kgf. fiber wall thickness at low beating load is greater than that at high beating load. This result is accounted for the fact that internal fibrillation in the low beating load was high.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.88-94
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• 2010

Cattail (Typha L.) was used as a raw material for producing both bio-ethanol and pulp for papermaking at the same time. Pretreatments of cattail stems and leaves with acid ($H_2SO_4$) and alkali (NaOH) in three different addition levels were studied before soda pulping. The acid pretreatment gave reducing sugar of 15.2% of initial weight, but alkali pretreatment close to 1%. Soda pulping of the pretreated cattail gave 3% reduction in pulp yield and less bonding properties in paper; however, refining of the pulp from the pretreated cattail with alkali restored their fiber bondings up to that of the pulp from no-pretreated cattail at equivalent freeness.