• 펄프종이기술
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• 제46권6호
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• pp.94-102
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• 2014

The physical and chemical properties of recycled fibers from mixed waste paper are more and more deteriorated because of unknown history of recycling times. In order to improve the mechanical properties of liner paper, the recycled fibers from wasted cotton clothes were used in papermaking process, and their applicabilities were evaluated in several points of fiber modification. Thus, two kinds of fiberizing methods from waste cotton clothes were considered by using rotary sandpaper and grinder mill. Finally, the rotary sandpaper method was relatively desirable in preserving longer fiber length and fibrillated fiber surface. The recycled cotton fibers by swelling treatment with NaOH and bleaching with reductive chemicals were mixed with OCC fibers, and the handsheets were prepared to basis weight of $80g/m^2$ and evaluated the mechanical properties of paper. The fibrous properties showed outstanding results in freeness and WRV improvements by alkali treatment and high brightness by reductive bleaching treatment. The physical and mechanical properties of sheet by mixing OCC fibers and recycled cotton fibers were also highly improved in tensile, burst strength and specially folding resistance.

• 한국환경복원기술학회지
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• 제5권6호
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• pp.37-42
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• 2002

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with polypropylene fiber, and to confirm the reinforcing effects with admixture such as polypropylene fiber. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and polypropylene fiber reinforced soil. In order to determine proper moisture contents and mixing ratio, pilot test was carried out for natural soil and PFRS(polypropylene fiber reinforced soil). And the mixing ratio of mono-filament fiber and fibrillated polypropylene fiber admixture was 0.1%, 0.3%, 0.5% and 1.0% by the weight of dry soil. From the experimental results, it was found that the optimum moisture contents(OMC) increased with the mixing ratio of fiber, but the maximum dry unit weight and the volume change was decreased with the mixing ratio. It means that the improvement of the workability and the reduction of the weight of embankment was done by the addition of the polypropylene fiber. And, from the compression test results, it was found that the addition of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil was more effective than the mono-filament polypropylene fiber reinforced soil.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.82-83
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• 2015

Recently, the research on steel fiber reinforced concrete has been actively conducted to compensate the defect of brittle fracture of concrete and to enhance toughness. Therefore, the effect of the mixture rate of straight steel fiber on flexural behavior of high strength steel fiber reinforced concrete was evaluated in this research. As a result, when 2% of steel fiber was mixed with concrete volume ratio, it showed the best flexural capacity.

• Journal of the Korean Wood Science and Technology
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• 제20권2호
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• pp.9-22
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• 1992

The aim of this research was to investigate physical and mechanical properties of various composition panels, each fabricated with a ratio of fiber to particle of 2 to 10. Type A consisted of fiber-faces and particle-core in layered-mat system. Type B consisted of fiberboard-faces on particleboard-core. Type C consisted of fibers and particles in mixed-mat system. The results obtained from tests of bending strength, internal bond, screw holding strength and stability were as follows: 1. The bending strength and internal bonding of both the Type A panel and the Type B panel were higher than those of the Type C panel and three-layered particle board. 2. The mechanical properties of the Type C panel showed the lowest values of all composition methods. It seems that the different compression ratios of the particle and fiber interrupted the densification of the fibers when hot pressed. 3. The dimensional stability of layered-mat system panels consising of fiber-faces and particle-core was better the than control particleboard. 4. In composition methods of particle and fiber, layered-composition method was more resonable than mixed-composition. The Type B panel had the highest mechanical properties of all the composition types. 5. The Type A panel was considered the ideal composition method because of its resistance to delamination between the particle-layer and the fiber-layer and because of its lower adhesive content and more effective manufa cturing process.

• 한국세라믹학회지
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• 제29권11호
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• pp.893-899
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• 1992

Composite specimens, which are composed MDF cement of HAC-PVA system were prepared by adding carbon fiber, hydrated silica and SiC powder, and we studied effect of additives on the flexural strength of the composites. All of additives is effective in the improvement of flexural strength of the composite specimens. The size of average pore diameter in the specimens which have high flexural strength property was small. Specimen mixed with hydrated silica was effective in the particle compact property. Flexural strength of carbon fiber reinforced MDF cement composites were improved because of crack deflection of carbon fiber in cementitious matrix.

• 한국염색가공학회지
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• 제5권2호
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• pp.139-143
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• 1993

The effects of air-gap distance on properties of cellulose fiber spun from the 6 wt% solution of cellulose in monohydrate N-methylmorpholine N-oxide (NMMO) were investigated. The diameter of fiber spun was drastically reduced in 10 cm of air-gap distance at fixed drawing speed, however, no great change was observed beyond 40 cm. As the distance lengthened, the Cellulose II structure was first appeared and followed by Cellulose II and IV mixed morphology. Also the degree of crystallinity and the size of crystals were tending to decrease.

• 한국염색가공학회지
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• 제6권1호
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• pp.44-48
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• 1994

Cellulose triacetate(CTA) liquid crystal solutions obtained via dissolution of CTA in solvent mixture of triflucroacetic acid and methylene chloride were spun and saponified in various chemicals. Among chemicals, methanol/sodium hydroxide mixture endowed highest tenacity as well as modulus to regenerated cellulosic fiber and the fiber thereof showed Cell I or Cell IV morphology, or mixed morphology of Cell I and IV.

• 한국염색가공학회지
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• 제2권1호
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• pp.21-30
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• 1990

In order to obtain high dye uptake initially, polyethylene terephthalate (PET) filaments were dyed with C.I.Disperse Orange 3 and Red 1 in mixed solvents of tetrachloroethylene acidic solvent, ethyl alcohol and tetrachloroethylene basic solvent, DMF. The dyeing behavior in the mixed solvent of tetrachloroethylene and basic solvent, DMF, the initial uptake of disperse dyes increased rapidly. The shrinkage of PET increased when the solubility parameter values of PET fiber and mixed solvent approached graduately.

• 펄프종이기술
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• 제45권4호
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• pp.65-74
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• 2013

In the manufacture of corrugated box, the fibrous raw materials are mainly consisted of recycled papers, such as KOCC(Korean Old Corrugated Container), kraft sack, and AOCC(American Old Corrugated Container). Among these recycled waste paper, the proportion of KOCC is relatively higher than others in fibrous raw materials. Generally, KOCC shows some poor fiber properties and contains hazardous heavy metal sources. Therefore, it is to evaluate the property of recycled paper sources for eco-friendly corrugated box manufacture. In this study, the physical and mechanical properties of 3 kinds of recycled fibers and their mixed stocks were analyzed. The environmental assessment was also evaluated by analyzing the 4 representative heavy metal contents and evaporation residues in waste papers. As the results, KOCC showed the poorest fiber qualities and had the highest heavy metal contents and evaporation residues among the recycled fibers. Finally, the mechanical strength properties were increased by decreasing KOCC proportion of mixed stock conditions. In addition, the heavy metal contents and evaporation residues were also decreased by increasing recycled AOCC and kraft sack proportion.

• 한국지반신소재학회논문집
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• 제3권1호
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• pp.43-52
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• 2004

단섬유를 혼합한 토사를 뒤채움재료로 사용한 보강토옹벽의 재하하중 단계 및 보강재 포설단수 별 거동특성을 평가하기 위하여 일련의 축소모형실험을 수행하였다. 높이 $100cm{\times}$길이 $140cm{\times}$폭 100cm 인 모형토조를 사용하여 1m 높이의 모형 보강토옹벽을 축조하였다. 본 모형실험에서 보강재로는 최대인장강도 0.79t/m인 지오네트와 최대인장강도 2.26t/m인 지오그리드를 사용하였으며, 화강풍화토에 폴리프로필렌 단섬유를 혼합한 토사를 뒤채움재로 사용하였다. 모형 보강토옹벽 축조후 5단계의 등분포하중($0.5kg/cm^2$, $1.0kg/cm^2$, $1.5kg/cm^2$, $2.0kg/cm^2$, $2.5kg/cm^2$)을 재하하면서 보강재의 인장변형 보강토옹벽 수평변위를 측정하여 하중재하시 모형 보강토옹벽의 거동특성을 평가하였다.