• 펄프종이기술
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• 제36권2호
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• pp.17-23
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• 2004

The effects of refining consistency and plate gap on the specific energy consumption and physical properties of liner were investigated. Higher refining consistency and narrower plate gap brought about the reduction of specific energy consumption to decrease the freeness. Refining consistency and plate gap did not affect the bulk, Taber stiffness and compression index. The reduction of freeness and/or the increase of specific energy consumption caused the decrease of bulk and Taber stiffness, but increased the compression index. The effect of grammage on bulk was not observed, but Taber stiffness and compression index were increased with grammage. The bulk was decreased with the reduction of freeness rapidly at the above 400 mL CSF, and then levelled off. It is expected that the reduction of energy consumption could be obtained from the application of higher refining consistency and narrower plate gap during refining.

• 펄프종이기술
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• 제35권2호
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• pp.6-11
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• 2003

Refining process is of critical importance unit process for papermaking that influences freeness as well as many mechanical and physical properties of paper. Refining is the process that requires extensive amount of electrical energy. Thus it is required to evaluate the refining process in terms of its influence on fiber and paper properties as well as its effect on energy consumption. In this study, to evaluate the efficiency of refining process the theory of inch contacts has been employed, and the influence of refining processes on fiber and paper properties has been determined and discussed.

• 펄프종이기술
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• 제36권3호
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• pp.44-51
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• 2004

The effect of refining conditions and grammage on the stiffness of linerboard was investigated. The correlations between Taber stiffness and resonance stiffness were very low due to the different measuring principle. The refining conditions did not affect sig nificantly on both Taber and resonance stiffness estimated here. This means that it is strongly recommended to find and apply the refining conditions which can reduce specific energy consumption. Taber stiffness showed very high correlation for the thickness and elastic modulus of linerboard, while the resonance stiffness showed much lower correlation. Effective thicknesses for Taber stiffness were very well fitted with measured thickness, while those for resonance stiffness depended on the grammage of linerboard.

• 펄프종이기술
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• 제47권2호
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• pp.61-69
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• 2015

A number of researches have been carried out regarding the utilization of nanocellulose(crystalline nanocellulose, microfibrillated cellulose, nanofibrillated cellulose) for the manufacture of various kinds of composites and functional products. However, only few research works on the manufacturing characteristics of nanocellulose could be found, although some companies started already the production of nanocellulose in commercial scale. However, the most important thing in commercializing of production and utilization of nanocellulose is to develop the economical and efficient process. Thus, this study was carried out in order to investigate the effects of refining, alkaline pre-treatment and grinder clearance on the characteristics of microfibrillated cellulose and energy consumption. There was no significant differences in crystalline index with the degree of microfibrillation. The initial fibrillation could be improved by refining pre-treatment, but its effect was not observed anymore since the fibrillation was done up to certain level by grinding. Refining pre-treatment did not improved the energy efficiency. Alkaline pre-treatment can be helpful because the swelling of pulp fiber will facilitate fibrillation. It was found that the decrease in grinder clearance was helpful to improve the energy efficiency.

• 펄프종이기술
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• 제31권1호
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• pp.39-45
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• 1999

Refining in papermaking plays an important role in changing fiber properties as well as paper properties. The major effects of refining on pulp fibers are internal and external fibrillation, fiber shortening, and fines formation. Many workers showed that internal fibrillation of the primary refining effects was most influential in improving paper properties. In particular, refining produces separation of fiber walls into several lamellae, thus causing fiber wall swelling with water penetration. This leads to the increase of fiber flexibility and of fiber-to-fiber contact during drying. If the fibers are very flexible, they will be drawn into close contact with each other by the force of surface tension as the water is removed during the drainage process and drying stages. In order to study the effect of fiber wall delamination on paper properties, cross-sectional image of fibers in a natural condition had to be generated without distortion. Finally, it was well recognized that confocal laser scanning microscope (CLSM) could be one of the most efficient tool for creating and quantifying fiber wall delamination in combination with image analysis technique. In this study, the CLSM could be used not only to observe morphological features of transverse views of swollen fibers refined under low and high intensity, but also to investigate the sequence of fiber wall delamination and fiber wall breakage. From the CLSM images, increasing the specific energy or refining decreased the degree of fiber collapse, fiber cross-sectional area, fiber wall thickness and lumen area. High intensity refining produced more external fibrillation.

• 한국기후변화학회지
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• 제3권2호
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• pp.101-116
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• 2012

녹색경영은 기후변화 대응이 전 세계적 이슈로 부각되면서 기존의 환경경영에 온실가스 저감, 대체에너지 개발 등 저탄소 녹색성장 요소가 추가된 확장된 개념으로 국내 외적으로 기업의 녹색경영 성과 측정에 대한 논의가 확산되고, 기업의 환경관리 수준 파악, 분석 및 평가의 중요성이 대두되면서 다양한 형태의 녹색경영 성과측정지표 체계가 개발되어 운영되고 있다. 하지만, 녹색경영에 관련한 구체적인 실행 방법론 제시는 미흡한 실정이다. 이에 본 연구에서는, 제시된 평가지표에 따라 기업간 녹색경영 수준 비교가 객관적으로 평가되게 하기 위해 가중치 산정을 위한 전문가 설문조사를 실시하였고, AHP(Analytic Hierarchy Process) 분석을 적용하였다. 국내외 10개 주요 정유/화학기업을 평가대상으로 선정하여 지속가능성 보고서 및 관련 문헌자료 등을 분석하였으며, 가중치가 부여된 세부 지표항목에 의거한 평가지표별 기업의 평가점수 도출 및 기업간 점수차이 분석을 실시 하였다.

• 한국분말재료학회지
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• 제31권2호
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• pp.132-136
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• 2024

This study investigated the effects of revolution speed and ball size in planetary milling on the microstructure and dehydrogenation behavior of TiH₂ powder. The particle size analysis showed that the large particles present in the raw powder were effectively refined as the revolution speed increased, and when milled at 500 rpm, the median particle size was 1.47 ㎛. Milling with a mixture of balls of two or three sizes was more effective in refining the raw powder than milling with balls of a single size. A mixture of 3 mm and 5 mm diameter balls was the optimal condition for particle refinement, and the measured median particle size was 0.71 ㎛. The dependence of particle size on revolution speed and ball size was explained by changes in input energy and the number of contact points of the balls. In the milled powder, the endothermic peak measured using differential thermal analysis was observed at a relatively low temperature. This finding was interpreted as the activation of a dehydrogenation reaction, mainly due to the increase in the specific surface area and the concentration of lattice defects.

• 한국해양환경ㆍ에너지학회지
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• 제7권3호
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• pp.122-130
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• 2004

원유는 유기물질들이 오랜기간에 걸쳐 서로 다른 지질학적 조건하에서 화학적으로 형성된 유기화합물질이다. 석유는 원유와 정제유를 포함하는 개념이며 정제유는 원유산지별, 정제, 처리, 취급 및 보관과정에 따라 구별되는 특징을 가지고 있다. 유지문기법은 이러한 특성을 이용하여 해상유출유의 오염원을 밝히기 위한 감식ㆍ분석기법을 말한다. 주로 사용되는 기기분석은 기체크로마토그래프법(GC), 형광분광광도법(FL), 적외선분광광도법(IR)이며 이중에서 가장 많이 사용되는 기법은 기체크로마토그래프법이다. 기체크로마토그래프를 이용한 유지문기법은 기기의 높은 신뢰성과 우수한 분리능 및 재현성으로 인하여 활용성이 높은 분석장비이나 해상유출유의 감식의 경우 비교적 시간이 많이 소요되는 경향이 있다. 본 연구에서는 이러한 단점을 보완하고자 최근 개발 보급된 패스트 기체크로마토그래프(fast GC)를 이용하여 기존의 분석시간을 1/2로 단축하고 분리능을 향상 시킬수 있는 분석방법에 대해 연구하였다.