• Journal of the Korean Wood Science and Technology
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• 제12권2호
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• pp.35-43
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• 1984

This study was carried out to investigate the block shear strength of the 2ply laminated wood composed of Pinus thunbergii with ureaformaldehyde resin as adhesives according to pressure (6, 9, 12, 15kg/$cm^2$), pressing time(5, 10, 20, 30 hrs.), amount of spread(54, 108, 217, 324g/$cm^2$), hardener(10, 20, 30, 40% of 10% $NH_4CL$ on resin) and extender(0, 5, 10, 15% wheat flour on resin), and the bending strength and bending young's modulus of laminated beam according to the number of ply. The results were summarized as follows; 1. According to pressing pressure with amount of spread 217g/$cm^2$ both dry and wet shear strength of laminated wood showed the highest in 15kg/$cm^2$, and hot-cold soaking treatment showed the highest in 9kg/$cm^2$, while all shear strength of dry, wet and hot-cold soaked laminated wood have been reduced with the increasing of pressing time. 2. According to amount of spread, adhesion strength with the dry, wet and hot-cold soaking treatments revealed the highest in 217g/$cm^2$ and have been reduced under or over 217g/$cm^2$ of spread. 3. According to addition of hardener and extender, all shear strength of laminated block with the dry, wet and hot-cold soaking treatments have been reduced in increasing of addition amount of hardener and extender. The bending strength of beam according to the number of ply showed the highest in 2ply laminated wood and horizontal loading beam to glue line had the higher in strength than the vertical loading.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.317-320
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• 2008

The Hot Stamping process, which is the hot pressing of steel parts using cold dies. can utilize both case of shaping and high strength due to the hardening effect of rapid quenching during the pressing. We carried out experiments of quenching rate and tempering treatments at temperatures of $200^{\circ}C$ and $300^{\circ}C$ and different soaking times. Tn this study, the mechanical properties and microstructure of micro boron alloyed steels after heat treatments are compared.

• Journal of the Korean Wood Science and Technology
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• 제14권4호
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• pp.21-28
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• 1986

Plywood used for construction as a decorative inner material is inflammable and can fire accident, causing destruction of human life and property. In this study, 3.5mm Kapur plywoods were soaked in the 23% monoammonium phosphate solutions by cold soaking method 3, 6, 9hrs and hot-cold bath method for 3/3hrs, and redrying was carried out by press-drying at the platen temperature of 110, 130, 160, 180$^{\circ}C$, and then fire test was carried out to investigate burning point, flame exhausted length, frame spread length, back side carbonized area and weight loss. The results are as follows; 1. In cold soaking method for 3, 6, 9hrs. retentions of monoammonium phosphate were 0.377, 0.448, 0.498kg/(30cm)$^3$ respectively, and in hot-cold bath method for 3/3hrs, the retention was 1.331kg(30cm)$^3$ that exceeded the minimum retention 1.124kg/(30cm)$^3$. 2. Correlation coefficients among the variable were shown in table 2. From the table, it could be recognized that there were close negative correlations between the treatment and burning point, flame spread length, back side carbonized area, flame exhausted time and weight loss, and there was negative correlation between treating time and back side carbonized area, but there was positive correlation between platen temperature and burning point. 3. From table 3, it can be observed that there were highly significant differences for burning point, flame spread length, flame exhausted time, back side carhonized area, weight loss between treatments. And in 2-way interactions, there were also highly significant for burning point, flame spread length, flame exhausted time, weight loss between time x treatment. 4. It was observed that burning point, flame exhausted time, flame spread length, back side carbonized area, and weight loss in fire-retardant treated plywood were the best effects in fire-retardant treated plywood, water treated plywood and nontreated plywood. In conclusion, I can estimate that absorbed chemical contents by hot-cold bath method for 3/3hrs, have a lot of effects on fire-retardant factors such as burning point, flame spread length, flame exhausted time, backside carbonized area and weight loss, but platen temperatures have a little effects on the fire factors.

• 한국산림과학회지
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• 제56권1호
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• pp.1-25
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• 1982

건책물(建策物)의 내장(內裝)에 많이 사용(使用)하고 있는 합판(合板)은 가연성(可燃性) 물질(物質)로서 각종(各種) 대형(大型) 화재(火災)를 유발(誘發)하여 많은 인명(人命)과 재산(財産)의 손실(損失)을 초래(招來)하고 있다. 따라서 이로 인(因)한 피해(被害)를 최대한(最大限)으로 줄이기 위하여 내화합판(耐火合板) 제조(製造)의 필요성(必要性)이 절실(絶實)히 요구(要求)되며 또한 내화합판(耐火合板) 제조(製造)에서 우선적(優先的)으로 해결(解決)해야 될 합판(合板)의 건조(乾燥)에 관(關)해서 연구(硏究)할 필요가 있다고 생각한다. 본(本) 연구(硏究)에서는 3.5mm으로 합판(合板)과 5.0mm 합판(合板)에 황산(黃酸)암모늄, 제(第) 1 인산(燐酸) 암모늄, 제(第) 2 인산(燐酸) 암모늄 및 수분처리(水分處理)는 6 및 9시간(時間)으로 처리(處理)하고 붕사(硼砂)-붕산(硼酸) 및 미나리스는 1, 3, 6 및 9시간(時間)으로 처리(處理)하였으며 90, 120 및 $150^{\circ}C$ 등(等)으로 열판건조(熱板乾燥) 실시(實施)한 후(後), 건조곡선(乾燥曲線), 건조속도(乾燥速度), 내화제(耐火劑)의 흡수량(吸收量) 및 내화도(耐火度) 등(等)을 연구검토(硏究檢討)한 결과(結果)를 요약(要約)하면 다음과 같다. 1) 온냉욕법(溫冷浴法)으로 9후간(後間)의 내화처리(耐火處理) 실시(實施)하므로써 얻은 두께 3.5mm합판(合板)의 약제(藥劑) 보유량(保留量)은 제(第) 1 인산(燐酸) 암모늄 $1.353kg/(30cm)^3$, 제(第) 2 인산(燐酸) 암모늄 $1.331kg/(30cm)^3$, 황산(黃酸)암모늄 $1.263kg/(30cm)^3$ 붕사(硼砂)-붕산(硼酸) $1.226kg/(30cm)^3$으로 최저(最低) 보유량(保留量)에 도달(到達)하였으나 미나리스는 $0.906kg/(30cm)^3$로 미달(未達)되었다. 두께 5.0mm 합판(合板)의 약제(藥劑) 보유량(保留量)은 황산(黃酸)암모늄 $1.356kg/(30cm)^3$, 제(第) 2 인산(燐酸) 암모늄 $1.166kg/(30cm)^3$로서 최저(最低) 보유량(保留量)에 도달(到達)하였으나 제(第) 1 인산(燐酸) 암모늄, 붕사(硼砂)-붕산(硼酸)과 미나리스는 미달(未達)이었다. 2) 3.5mm와 5.0mm 합판(合板)의 건조곡선(乾燥曲線)은 6시간(時間)과 9시간(時間)의 내화처리(耐火處理)에서 약제처리(藥劑處理) 합판(合板)이 수분처리(水分處理) 합판(合板)보다 건조곡선(乾燥曲線)의 경사(傾斜)가 더 적었다. 그리고 두께에 따른 건조속도(乾燥速度)는 3.5mm 합판(合板)의 경우(境遇) 5.0mm 합판(合板) 건조속도(乾燥速度)보다 약(約) 3배(倍) 이상(以上) 더 빨랐다. 3) 약제별(藥劑別) 건조속도(乾燥速度)는 열판온도(熱板溫度) $120^{\circ}C$로 건조(乾燥)하였을 때 두께 3.5mm의 합판(合板)에서 제(第) 2 인산(燐酸) 암모늄이 가장 높은 경향(傾向)을 나타내었고 두께 5.0mm의 합판(合板)에서도 제(第) 2 인산(燐酸) 암모늄이 가장 높은 경향(傾向)을 나타내었다. 그러나 처리시간(處理時間) 6시간(時間) 이상(以上)에서 수분처리(水分處理) 합판(合板)의 건조속도(乾燥速度)가 더욱 높았다. 4) 열판온도(熱板溫度)에 따른 건조속도(乾燥速度)는 열판온도(熱板溫度)가 상승(上昇)함에 따라 뚜렷하게 상승(上昇)하였으며 두께 3.5mm 합판(合板)의 경우(境遇) 열판온도(熱板溫度) 90, 120 및 $150^{\circ}C$에서 각각(各各) 1.23%/min., 6.54%/min., 25.75%/min. 였고 두께 5.0mm의 합판(合板)에서는 각각(各各) 0.55%/min., 2.49%/min., 8.19%/min.를 나타내었다. 5) 내화처리(耐火處理) 합판(合板)의 내화도(耐火度)에 있어서 약제(藥劑)사이의 중량(重量) 감소율(減少率)은 두께 3.5mm와 5.0mm 합판(合板)에서 제(第) 2 인산(燐酸) 암모늄이 가장 적었고 다음은 제(第) 1 인산(燐酸) 암모늄이었으며 그 다음은 황산(黃酸)암모늄, 미나리스 및 붕사(硼砂)-붕산(硼酸)의 순서(順序)로 증가(增加)하였다. 착화시간(着火時間), 잔화시간(殘火時間), 이면(裏面)의 탄화면적(炭火面積)에 있어서는 제(第) 2 인산(燐酸) 암모늄이 가장 우수(優秀)하였고, 다음은 제(第) 1 인산(燐酸) 암모늄, 황산(黃酸) 암모늄, 붕사(硼砂)-붕산(硼酸), 미나리스순(順)으로 효과(効果)를 나타냈다.