• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.37 no.4 s.112
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• pp.38-43
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• 2005

Natural Com Starch(NCS) spray system has been widely used In multiply board mill for the better bonding strength between board layers. However the unsuitable NCS spray system could lead to a drop in plybond efficiency of multiply board. It could also result in the accumulation of unretained-starch in the white water system, which could not only rise in BOD and COD level but also reduce the effects of rosin-alum sizing system and other additives. In this study, the simple and rapid method by UV-spectroscopy for measuring the starch contents in the white water was proposed, and the quantitative analysis for dissolved starch content in white water was carried out in two kinds of board production process. It could be confirmed that about 150 ppm of oxidized starch was retained in white water dewatered from undertop ply of multiply board process, and about 470 ppm of natural starch was dissolved in white water originated from unsuitable spraying system in the multiply board production lines for cup base paper.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.2
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• pp.23-28
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• 2008

As well as crop cultivation, they could not avoid automatizing and using more environmental friendly process in cultivation of fruit. And also, the consumer ask more safe fruit which is produced with more clean method. This is why the usage of aid materials for fruit cultivation like as fruiting bags are increasing. Practical utilization of wax emulsion treated water repelling fruiting bags are developed continuously and it's properties is compared properties of nomal fruiting bags. The water repelling process was developed with wax emulsion coating. After the experiment of wax emulsion preparation from paraffin and DEA and/or OA in Lab. scale, the wax emulsion was manufactured on pilot scale. The wax emulsion coated paper was prepared in mill scale coater. The water repellency and properties of emulsion coated fruiting bags were evaluated and compared with that of current fruiting bags.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.6
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• pp.1-9
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• 2013

For the manufacture of linerboard with 100% KOCC, we tried to increase the solid content of wet web by employing GCC (grounded calcium carbonate) in the fiber furnish to save drying energy. Three different diameters of GCC, namely, 5, 10, and $35{\mu}m$, were used. To complement the strength loss by the addition of GCC, cationic starch and refining treatment were tried. It was found that the addition of $10-35{\mu}m$ dia. GCC to KOCC for $180g/m^2$ basis weight sheets increased the solid content of the furnish about 1-1.5% with better bulk and drainage properties. The loss of strength properties were compensated by the application of cationic starch and/or refining process to the KOCC furnish. The dia. of GCC of $35{\mu}m$ was, however, too large to make smooth surface of the sample sheet. So, the optimization process was required before implementing the results to the mill by selecting proper diameter and shape of the calcium carbonate.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.36 no.4 s.107
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• pp.16-24
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• 2004

The reduction of paper machine water usage is precursor to the water system closure of any mills. This reduction in water consumption reduces the loss of solids; especially fine particulates and their surface adsorbed chemical additives, from mills, which causes an inevitable increase of fine materials in papermaking systems. Also the reduction of paper machine water usage causes substantial increase of organic and inorganic substances in process water. The deterioration of the papermaking process water quality accompanying the reduction of papermaking system closure can be a prime source of the aggravation of paper quality and process efficiency. It is of great importance for paper mills to investigate the influence of the level of papermaking system closure on the paper properties and process runnabililty before implementing process closure. To predict the changes in paper properties at different levels of system closure, highly cotaminated white water was prepared using reverse osmosis technology and used to prepare handsheets from fine paper and newsprint stocks. Results showed that the quality of process water affects the strength. Preparation of highly contaminated process water and handsheet forming with headbox stocks provided important criteria to determine the relationship between the qualities of process water and paper products.

• Journal of Korea Foundry Society
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• v.17 no.6
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• pp.577-584
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• 1997

Evaluation of rolling contact fatigue damage as well as material development for roll of rolling mill is being studied until quite recently. In this paper, a focus has been imposed on evaluating the rolling contact fatigue damage. In order for this, the accumulating process of rolling contact damage using the ferritic, pearlitic and bainitic DCI has been analyzed by X-ray diffraction technique. The main finds are; 1) The graphite in DCI is considered to be a cause of interfering in the redistribution of stress. Eventually, it results in the branching of crack. 2) The evaluation of rolling contact fatigue damage can be estimated in terms of the change of residual stress and/or a half-value breadth on surface during rolling contact.

• Tribology and Lubricants
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• v.19 no.1
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• pp.1-8
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• 2003

Recently, PM-high speed steel(PM-HSS) has reportedly been a good alternative material for rolling mill because of its superior performance to conventional HSS. This paper has been aimed to investigate the possibility for application to rolling contact element for PM-HSS by X-ray diffraction technique. The X-ray elastic constant for PH-HSS has been found by X-ray diffraction during the four-point bending test. Residual stress and half-value breadth on the contact surface during rolling contact fatigue process by X-ray diffraction have also been measured. The result of this study shows that the application of X-ray diffraction technique to PM-HSS could be as possible alternative material as conventional HSS. Half-value breadth on rolling contact surface by X-ray diffraction is not changed during rolling contact fatigue process. On the other hand, the residual stress is changed. This suggests that dislocation reaction has been hardly occurred in rolling contact, depending on super-saturated carbon in PM-HSS.

• Journal of the Korean Ceramic Society
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• v.49 no.4
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• pp.352-362
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• 2012

This paper explores the use of a variety of carbon nanoparticles to impart electrical, thermal conductivity, good frictional properties to silicon nitride matrices. We used the highly promising types of carbon as carbon nanotubes, exfoliated graphene and carbon black nanograins. A high-efficiency attritor mill has also been used for proper dispersion of second phases in the matrix. The sintered silicon nitride composites retained the mechanical robustness of the original systems. Bending strength as high as 700 MPa was maintained and an electrical conductivity of 10 S/m was achieved in the case of 3 wt% multiwall carbon nanotube addition. Electrically conductive silicon nitride ceramics were realized by using carbon nanophases. Examples of these systems, methods of fabrication, electrical percolation, mechanical, thermal and tribological properties are discussed.

• Journal of the Korean Society of Industry Convergence
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• v.15 no.4
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• pp.103-109
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• 2012

To enhance the cutting performance of high speed steel(HSS) endmill, single and multilayer coating is applied on the substrated of the HSS endmill. Coating material reduces cutting force and enhances resistance against abrasive wear. This paper presents the physical vapour deposition(PVD) coating technology and evaluate the PVD coated HSS endmill. The performance of coated HSS endmills are fifteen times better than uncoated HSS endmill on proposed cutting conditions. The TiAlN monolayer coated endmills(futura nano coating) are better than those of multilayer coated endmills(futura coating) on machined surface and tool wear.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2230-2234
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• 2003

This paper proposes a distributed simulator for general control system in CEMTool. Systems can be described by SIMTool likes the simulink in Matlab. For distributed simulation, we can seperate any system into several parallel subsystems in SIMTool. The number of parallel subsystem can be determined by the system's property. After seperation, parallel simulator will do initialization, one-step-ahead simulation, block-distribution and ordering and so on. Finally, simulator will create independent C codes and executive files for each subsystem. The whole system is fulfilled by several PCs, and each PC executes one subsystem. There are communications among these subsystem using reflective memory or ethernet. We have made several experiments, and the 5-stand cold rolling mill control system is our main target. The result of parallel simulation has shown effective speedup in comparison with one pc simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.863-868
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• 2004

Reheating furnace is an essential facility of a rod mill plant where a billet is heated to the required rolling temperature so that it can be milled to produce wire. Sometimes, it is also necessary to control a transient billet temperature pattern according to the material characteristics to prevent a wire from breaking. Though it is very important objective to obtain a correct information of a billet temperature during furnace operation. Consequently, a billet temperature profile must be estimated. In this paper, a billet heat transfer model based on FEM (Finite Element Method) with spatially distributed emission factors is proposed and a measurement is also carried out for two different furnace operation conditions. Finally, the difference between the model outputs and the measurements is minimized by using the new optimization algorithm named uDEAS(Univariate Dynamic Encoding Algorithm for Searches) with multi-step tuning strategy. Hence, the information of billet temperatures can be obtained by using proposed model on various furnace operation conditions.