• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.441-444
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• 2006

A lot of water is using in the paper mill for dilution, washing, sealing, and other process operation. As the regulation of water environment has been more tightened than ever before, water management in the paper mill becomes the most important task. Topics on reducing fresh water and increasing recycling water have been studied. Further, an interest in zero-effluent system has been increased. The pH of waste water in paper mill is usually weak acidic or neutral. The waste water in the paper mill includes water insoluble organic materials that are not easy to be dissolved in the water, inorganic materials that never react with water and chemical additives that are used to recycled fiber. This study investigated on the effect of various materials used in paper mill on COD. This data could be used to control the environmental load in paper mill. COD caused by raw materials and NBDCOD (Non Bio Degradable COD) after the activated sludge process are investigated in this study. Results obtained in this study can be used in a simulation program designed to control environmental load in the paper mill.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.2
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• pp.55-63
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• 2009

This study was performed to evaluate the heavy metal contents in various packaging board. Domestic and foreign OCC (old corrugated containers) and old duplex boards were used as raw materials. Tests were made for the printed and unprinted parts of the sample. Heavy metal contents of old food packaging boards made from virgin pulp fibers were also evaluated. The contents of heavy metals including lead (Pb), cadmium (Cd), barium (Ba), arsenic (As), antimony (Sb), selenium (Se), and mercury (Hg) were determined using ICP-AES (Inductively Coupled Plasma - Atomic Emission Spectrometer), and CV-AAS (Cold vapor-atomic absorption spectrometer) after digesting the samples in a microwave oven. The contents of heavy metals contained in domestic packaging board were higher than those in overseas samples, and OCC showed higher contents of heavy metals than old duplex boards. Printed parts gave greater heavy metal contents than unprinted parts. Results indicate that recycling of paper and paperboard products increases the heavy metal contamination of the paper packaging products and this derives mostly from the heavy metals contained in printing inks. Recycling processes that decrease heavy metals in recycled fibers and new printing inks that contains less heavy metals should be developed to solve the problem associated with the heavy metals in packaging paper products.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.2
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• pp.41-45
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• 2010

This study was performed to evaluate the effect of paper property changes by internal addition of surface strength agent on printability. Advances in printing technique has required the development of paper qualities in many aspects. Basically paper structure is composed of hydrogen bonds which induce many problems in high speed printing machine because of weak bonding strength. One of the important printing problems is surface picking when mechanical pulp or recycled pulp are used. It was caused by the ink-stained blanket in printing process because accumulations of pollutant in white water and other elements which are bonded weakly or do not have hydrogen bonds. Debris at paper surface adheres to blanket which deteriorates printing efficiency and causes various problems. To complement these problems, Pennocel 5137 of polysaccharide structure was used as an agent to improve paper's surface property, strength and printability. Paper surface picking was analyzed by RI-1 test. As the dosage amount increased tensile strength, fiber bonding strength and ZDT strength were improved. Further more formation, smoothness and surface picking resistance were improved. It was confirmed that when adding polysaccharide structure polymers to improve surface strength such as surface picking resistance, it was also possible to improve tensile strength, fiber bonding strength, formation and smoothness.

• Journal of the Korean Wood Science and Technology
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• v.23 no.2
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• pp.37-46
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• 1995

The substitution of carboxymethylated hydroxyl group in pulp revealed more hydrophilic than hydroxyl group. And then fibers were more flexible, swell more which leads to better conformation between fibers in turn this raise paper strength. In this paper, we tried to chemical modifyings of recycled fiber, OCCs(old corrugated containers). Many researchers have examined chemical modification of papermaking fiber by partial carboxymethylation(PCM) using a organic solvent processes. We made modified PCM processes adapted waters m replace of the organic solvent. Our testings for the optimum conditions on the new method, conditions as reaction time, temperature, liquor ratios were designed likely plant system. Freenesses(SR$^{\circ}$) were increased following on carboxyl content of the samples. Handsheets of untreated samples and partial carboxymethylated OCCs were made by optimum conditions on different concentrations of the reagent. As results, maximum 25% strength increasing effects were obtained by the new method.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.4
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• pp.160-167
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• 2015

The reduction of energy consumption in papermaking process has been considered as one of the major issue in the paper technology. The energy efficiency of paper mill becomes more significant for the mill which manufacture the board grade products such as linerboard with recycled paper such as OCC. The application of lignocellulose spacer to the board grade paper stock would be the feasible solution by increasing the paper bulk and the drying efficiency. The major defects originated from the application of the lignocellulose spacer could be the loss of strength properties. In this study, the ways for improving the strength properties of the spacer-added linerboard were suggested and evaluated. The effects of the addition of various types polyelectrolytes were tested and the different methods of polyelectrolytes were applied for finding the efficient way. The pretreatments of lignocellulose spacer with the polyelectrolytes during wood spacer hydration resulted in the higher strength properties than the typical application method such as the addition to the mixed stock. Multilayer treatments of the spacer with polyelectrolytes were also evaluated and leaded to the higher strength properties with the similar bulk improvement.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.6
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• pp.43-49
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• 2012

In this work, the non-ionic polyethylene oxide(PEO)/phenolic formaldehyde resin(PFR) retention system, which was less affected by furnish charge, was analyzed for possibility and effectiveness when using recycled stock. When the micropolymer was added at the PEO/PFR retention system and the PAM/bentonite retention system, performance of retention and drainage was improved. When the cationic micropolymer was added on the PEO/PFR retention system, the highest retention was achieved. The Polyacrylamide(PAM)/bentonite system induced flocculation of white pitch by electrostatic flocculation. On the other hand, the non-ionic PEO/PFR retention system induced less flocculation of white pitch than the PAM/bentonite retention system.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.6
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• pp.58-69
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• 2012

As the meaning of dictionary terminology, scum refers to a layer of impurities that accumulates at the surface of a liquid. In papermaking process, scum indicates the floated solid waste generated by a flotation process during the primary wastewater treatment. In this study, different kinds of stocks and scums collected from newspaper, liner, tissue and fine paper were analysed in details. The purpose of this study was firstly to demonstrate the composition characteristics of different sources of scum, secondly the analysis of environmental hazardous materials, and thirdly the evaluation of reutilization ability of fibrous materials from collected scum. As mentioned the meaning of solid waste, scum was actually differ from the waste sludge in sources, compositions and recycling abilities. In the same manner of waste paper, the sludge which is generated within onsite of papermaking processes would be reused as a raw material. The general compositions of scum from waste water were mainly inorganic ash materials, fine fibre fractions, recycled fibre debries, and ink particles. If the scum is able to reuse as fibrous additives in papermaking process, it could contribute to the savings of running costs in both the subsidiaries of fibrous material and the solid waste treatment with even small quantity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.2
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• pp.58-67
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• 2001

MOW (Mixed Office Waste) mainly consisted of photocopied paper is being recycled to produce tissue or fine paper products. Toner particles that are fused and set on paper surface in photocopying process turns into large and plate-shaped particles after repulping which prevents them to be removed effectively in flotation deinking. The immediate purpose of this study is to find the effective deinking technology that increases the recycling potential of photocopied papers for manufacturing tissue and fine paper products. In this study the effects of pulping temperature and the type of hydrophobic groups of nonionic surfactants on the deinking efficiency of photocopied paper has been investigated. Particle size distribution of the toner particles after pulping and flotation, brightness, yield and ash removal were investigated. The size of toner particles after pulping increased as the pulping temperature was increased. When pulping at the low temperature finer toner particles were generated, however, greater amount of toner particles was found to attach to the fiber. When the pulping temperature was greater than Tg of the toner, the amount of coarse hairy particles increased. When nonionic surfactants with a double bond in hydrophobic groups were used, toner removal efficiency, brightness and ash removal were increased. As the addition level of surfactant was increased, yield decreased rather sharply without improving brightness.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.3
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• pp.1-8
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• 2005

Increase in the utilization rate of recycled paper and closing level of papermaking system increased the problem associated with stickies that include decrease in process runnability and product quality. It is required to establish a process for removing the micro stickies to solve the problems associated with stickies. In this study, the application of flotation process as a method to remove micro stickies was examined. Model micro stickies (MMS) were prepared using microcrystalline cellulose (MCC) and pressure sensitive adhesives (PSA), and the influence of three nonionic surfactants on the removal efficiency of MMS from flotation process was examined. Also the effect of surfactants on the deposition of micro stickies that remaining in the papermaking wet end onto wire was examined. Removal efficiency of MMS by flotation was increased when the proportion of nonionic surfactant with propylene oxide (PO) type hydrophilic tail was increased and stock pH was 7. It was suggested that this nonionic surfactant minimized the increase of surface energy of hydrophobic MMS. The MMS with high hydrophobicity remaining in the papermaking system, however, would cause more serious deposition problems on papermaking wet end. Therefore, it is of great importance to increase the removal efficiency of MMS in flotation process for the prevention of papermaking system contamination caused by stickies deposition.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.1
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• pp.13-18
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• 2003

This study was done in an effort to evaluate the possibility of recyclability of moisture-proof paper. Because it is difficult to recycle laminated moisture-proof paper, a mixture of styrene-butadiene latex(SB latex) and wax emulsion was used as moisture-proof paper chemicals. A bar coater was applied to make moisture-proof paper and the coated weight was 17 g/$m^2$. The mixing ratios of SB latex to wax emulsion were 85 : 15, 87 : 13, and 90 : 10, respectively. It was observed that the moisture-proof paper treated with SB latex and wax emulsion at the appropriate ratio could be recycled effectively. The moisture-proof paper was similar to base paper in degree of pulping, and there was no significant difference in dispersion between moisture-proof paper and base paper. Most of wax particle which caused the spots during drying process could be removed by flotation process. Tensile strength and tear strength of handsheets made of both moisture-proof paper and base paper after pulping was measured to examine the fiber bonding and no significant difference in mechanical properties was observed.