• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2001.11a
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• pp.100-103
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• 2001

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.3
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• pp.25-31
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• 2000

It is required to use substantial amount of wet strength resin for producing multi-functional mulch papers since these paper products shold maintain its strength properties when they exposed to outdoor weather for several months. While producing mulch papers it is usual to observe significant amount of foam at white water silo. Thus it is imperative to use defoaming or antifoaming agents. In this study diverse defoaming and antifoaming agents have been tested for their effective-ness in eliminating foams that produced. It was shown that combined use of a silicone type defoamer and a fatty acid type anti-foaming agent was msot effective in eliminating foams. These chemicals were used in trial production of mulch papers and their influence on paper-making wet end system was examined including one pass retention cationic demand con-ductivity pH etc. It was found that the defoaming agents were very effective for removing foams in trial production. Tensile strengths of the mulch papers produced were significantly greater than commericial mulch papers produced in Japan.

• ETRI Journal
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• v.27 no.5
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• pp.484-490
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• 2005

We fabricated 40 Gb/s front-end optical receivers using spot-size converter integrated waveguide photodiodes (SSC-WGPDs). The fabricated SSC-WGPD chips showed a high responsivity of approximately 0.8 A/W and a 3 dB bandwidth of approximately 40 GHz. A selective wet-etching method was first adopted to realize the required width and depth of a tapered waveguide. Two types of electrical pre-amplifier chips were used in our study. One has higher gain and the other has a broader bandwidth. The 3 dB bandwidths of the higher gain and broader bandwidth modules were about 32 and 42 GHz, respectively. Clear 40 Gb/s non-return-to-zero (NRZ) eye diagrams showed good system applicability of these modules.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2002.11a
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• pp.4-10
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• 2002

색지와 무늬지를 주로 생산하는 팬시지 공장의 경우 고객의 다양한 기호와 수요에 대응하기 위해서는 잦은 색상 및 지종교체가 필요하다. 기존 wet-end 시스템과 color control 시스템으로는 높아진 고객의 품질 욕구를 충족하기 어려울 뿐만 아니라 잦은 지종교체로 인한 생산성, 원가, 조업안정성 등의 손실을 수반한다. 이에 당사는 wet-end volume을 획기적으로 줄여 빠른 응답시간의 장점이 있는 POM 시스템(compact papermaking system) 과 on-line color control이 가능한 CLCC (closed loop color control) 시스템을 동시에 적용하여 각각의 장점을 활용한 지종 교체시간 단축과 색상의 균일성을 확보한 사례이다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.34-38
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• 2000

The trend of cutting process today goes toward higher precision and higher efficiency. Many thermal/frictional troubles occur in high-speed machining of die and mold steels.In this paper, the thermal characteristics are evaluated in high sped ball end-milling of hardened steel(HRc42). Experimental work is performed on the effect of cutting environments on tool life and cutting temperature. Cutting environments involve dry, wet(20bar), compressed chilly air at -9$^{\circ}C$, compressed chilly air at -35$^{\circ}C$. The measuring technique of cutting temperature using implanted thermocouple is used. The cutting temperature is about 79$0^{\circ}C$, 35$0^{\circ}C$ and 54$0^{\circ}C$ in dry, wet and compressed chilly air at +9$^{\circ}C$, respectively. The tool life for compressed chilly air at -9$^{\circ}C$ is longer than all other cutting environments in experiment.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2005.11a
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• pp.259-263
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• 2005

This study was performed to introduce recently developed Polyvinylamine as a wet-end process improving aids and paper properties improving aids. As a retention and drainage aids, cationicity of Polyvinylamine was a very important factor of BCTMP and ONP stock condition. As a dry tensile strength aids, The hydrogen bond of acrylamide functionality and hydroxyl functionality of the pulp was a very important factor of LBKP stock condition and cationicity of Polyvinylamine was a very important factor of BCTMP and ONP stock condition.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.5
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• pp.12-20
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• 2001

The consequence of water system closure and reduced water consumption in Paper Mills is increased white-water conductivity associated with increased total dissolved solids. This leads to difficulties man-aging the wet end chemistry of paper machines, mainly due to stearic hindrance effects on wet end chemical additives. This in turn causes poor productivity and Inefficient chemicals usage. The success of a number of projects is reported. The application and development of new multi-component micro-particle systems which can further assist in achieving a significant degree of system closure or Zero Effluent is described.

• 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.8-15
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• 2007

In an effort to develop control strategies for the wet-end of paper machines, dynamic models for retention and formation processes have been developed. The retention process, including headbox total and filler consistencies, white water total and filler consistencies, the basis weight and the ash content of paper, can be modeled from first-principles (mass balances). To include the effect of wet-end chemistry variables, first-pass retention was included as a parameter dependent on operating conditions. In addition, dynamics of formation was simulated by developing an empirical model of formation and coupling with the dynamic models for the retention process. A series of experiments were performed using a pilot paper machine. The experimental results and the model predictions showed relatively good agreement.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.29 no.4
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• pp.86-94
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• 1997

• Industrial Engineering and Management Systems
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• v.9 no.3
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• pp.242-250
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• 2010

For economical and environmental reasons, the aim of this research is hence to monitor the cutting conditions with the dry cutting, the wet cutting, and the mist cutting to obtain the proper cutting condition for the plain carbon steel with the ball end milling based on the consideration of the surface roughness of the machined parts, the life of the cutting tools, the use of the cutting fluids, the density of the particles of cutting fluids dispersed in the working area, and the cost of cutting. The experimentally obtained results of the relation between tool wear and surface roughness, the relation between tool wear and cutting force, and the relation between cutting force and surface roughness are correspondent with the same trend. The phenomena of surface roughness and tool wear can be explained by the in-process cutting forces. The models of the tool wear with the cutting conditions and the cutting times are proposed to estimate the tool cost for the different cooling strategies based on the experimental data using the multiple regression technique. The cutting cost is calculated from the costs of cutting tool and cutting fluid. The mist cutting gives the lowest cutting cost as compared to others. The experimentally obtained proper cutting condition is determined based on the experimental results referring to the criteria.