• Title/Summary/Keyword: fiberboard

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Formaldehyde Emissions and Moisture Content Change of Wood Composites during Bake-out

  • Lee, Young-Kyu;Kim, Hyun-Joong
    • Journal of the Korean Wood Science and Technology
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    • v.40 no.2
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    • pp.101-109
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    • 2012
  • Wood composites are a hygroscopic material and have ability to exchange its moisture content with air. This study investigated the formaldehyde emission and moisture content change of four wood composites (particleboard (PB), medium density fiberboard (MDF), high density fiberboard (HDF), laminated HDF (L-HDF)) as a function of bake-out temperature and time. The composites were baked out for 1, 3, 5, 7, 10, 14, 21, and 28 days at temperatures of $20{\pm}2$, $35{\pm}2$, and $50{\pm}2^{\circ}C$ in a dry oven. The moisture content change was used to determine the emission bake-out of the composites. Best bake-out time results were obtained with after 7 days all composites. Formaldehyde emission values of composites decreased with decreasing moisture content for both temperatures. The formaldehyde emission results of bake-out temperature 35 and $50^{\circ}C$ showed a similar tendency.

Manufacture of Medium Density Fiberboard from Exploded MDF Waste (폐 MDF 폭쇄 섬유로부터의 MDF제조)

  • Lee Hwa-Hyoung;Seo In-Su;Cho Youn-Min;Park Han-Sang
    • Journal of the Korea Furniture Society
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    • v.16 no.1
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    • pp.9-16
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    • 2005
  • This study was carried out to displace traditional virgin wood fiber by exploded MDF-waste fiber for the manufacture of medium density fiberboard. MDF waste was exploded in condition of $215^{\circ}C,20$ minutes. The higher the mixing ratio of exploded MDF-waste fiber, the lower the MOR and IB of MDF. There was no difference of formaldehyde emission by desiccator method between virgin wood fiber and exploded MDF-waste fiber. Adding $25^{\circ}C$ of exploded MDF-waste fiber met the KS of MDF 15 type.

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Shape Optimal Design to Minimize Stress Concentration in the Journal of the Heating Drum for a Hot-Rolling Press (열간압연 프레스용 가열드럼 저어널부의 응력집중 최소화를 위한 형상 최적설계)

  • Kim Won-Jin;Lee Boo-Youn
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.3 s.168
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    • pp.137-145
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    • 2005
  • The present research deals with structural analysis and optimal design of the heating drum of a hot-rolling press for medium density fiberboard. Stress concentration in the journal of the heating drum is analyzed by the submodel technique of the finite element method. The fatigue life under operating conditions is analyzed and evaluated by the stress-life theory. Shape optimal design problems, to minimize the maximum stress occurring in the journal, are formulated and shape parameters of the corner fillets of the journal are defined as the design variables. The problems are solved by the numerical optimization method and optimal shapes are found. The optimal designs are shown to be reliable in terms of the maximum stress and the fatigue life.

Strength Optimization of Ventilating Container(II)-Finite Element Analysis (통기성 상자 구조물의 강도적 최적화 연구(II)-유한요소해석)

  • Park, Jong-Min
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.7 no.2
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    • pp.25-30
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    • 2001
  • Corrugated board is composed of cellulose fibers which are arranged with the same direction as the board manufactured. The direction is classified with machine direction (MD) and cross-machine direction (CD). Therefore, corrugated board is orthotropic material that has totally different strength properties at each direction and especially, at machine direction, the mechanical properties of fiberboard is superior. The compression strength of the corrugated fiberboard boxes is very important information to the manufacturers and the end users. This study was carried out to design the optimum pattern, size, and location of ventilating hole for ventilating container through the finite element analysis. The optimum pattern and location of ventilating and hand hole were vertical oblong, a short distance to the right and left from the center of panel, and center or a short distance to the top of both sides, respectively. We identified the effect on both stress dispersion and stress level from the analysis of redisigned hand hole.

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