내부천공이 중밀도 섬유판(MDF)의 종압축강도에 미치는 영향

蘇元澤 전남대학교 농업과학기술연구소 2000 農業科學技術硏究 Vol.35 No.-

This experiment was carried out to investigate the effect of internal holes on the compressive strength parallel to the grain of MDF. The diameters of holes are 5mm to 21mm, the locations of holes are 1/2 to 1/5 point from sample ends, and the numbers of holes are 1 to 4 pcs. In the size of internal holes, the compressive strengths of MDF were decreased significantly with the increase of diameter of holes, and the relationship between diameters(D) of holes and compressive strength(σc) of MDF is σc=-5.26D+144.39, (r=-0.99**). The effects of hole-locations on the compressive strengths of MDF were very small. The compressive strengths of MDF were decreased with the increase of number of holes, but the decreasing rate were very small.

양버즘나무의 素材 및 集成曲木製造에 關한 硏究(Ⅱ) : -蒸煮에 의한 集成휨加工性-

蘇元澤 全南大學校 農漁村開發硏究所 1992 農業科學技術硏究 Vol.27 No.-

This study was carried out to investigate laminated-wood bending properties of plane trees(Platanus occidentalis Linn)grown in Korea and then to develop their end -uses for the replacement of imported wood by domestic wood as industrial timber. The size of bent-wood specimens tested was 15X15X350mm, and the depth of laminar was respectively 2.0mm, 3.0mm, 5.0mm and 7.5mm for steaming treatment. The specimens were dried to 15±1% before bending. The results obtained were as follows : 1. By steaming treatment, the minimum laminated bending radius of 2mm, 3mm, 5mm, and 7.5mm thick laminar was 5mm,10mm, 40mm, and 90mm respectively. 2. The spring back of bent-wood was very slight. The bending stress was setted successfully both through room temperature and 80℃ C-15hrs drying after bending, but the bent-wood by 80℃-setting showed slightly negative spring back. 3. The M.O.R. and M.O.E. of bent-woods were both Improved as the thickness of their laminars decreased and their loss of bending strength was higher in the concave side than in convex side of loading direction.

Effects of Boiling , Steaming , and Chemical Treatment on Solid Wood Bending of Quercus acutissima Carr . and Pinus densiflora S . et Z .

Won Tek So 한국산림과학회 1986 한국산림과학회지 Vol.72 No.1

This study was performed to investigate: (i) the bending processing properties of silk worm oak (Quercus acutissima Carr.) and Korean red pine (Pinus densiflora S. et Z.) by boiling and steaming treatments; (ii) the effects of interrelated factors sapwood and heartwood, annual ring placement, softening temperature and time, moisture content, and wood defects - on bending processing properties; (iii) the changing rates of bending radii after release from a tension strap, and (iv) the improving methods of bending process by treatment with chemicals. The size of specimens tested was 15 × 15 × 350㎜ for boiling and steaming treatment and 5 × 10 × 200㎜ for treatments with chemicals. The specimens were green for boiling treatments and dried to 15 percent for steaming treatments. The specimens for treatments with chemicals were soaked in saturated urea solution, 35 percent formaldehyde solution, 25 percent polyethylene giycol -400 solution, and 25 percent ammonium hydroxide solution for 5 days and immediately followed the bending process, respectively. The results obtained were as follows; 1. The internal temperature of silk worm oak and Korean red pine by boiling and steaming time was raised slowly to 30℃ but rapidly from 30℃ to 80-90℃ and then slowly from 80-90℃ to 100℃. 2. The softening time required to the final temperature was directly proportional to the thickness of specimen. The time required from 25℃ to 100℃ for 15㎜-squared specimen was 9.6-11.2 minutes in silk worm oak and 7.6-8.1 minutes in Korean red pine. 3. The moisture content (M.C.) of specimen by steaming time was increased rapidly first 4 minutes in the both species, and moderately from 4 to 20 minutes and then slowly and constantly in silk worm oak, and moderately from 4 to 15 minutes and then slowly and constantly in Korean red pine. The M.C, of 15mm-squared specimen in 50 minutes of steaming was increased to 18.6 percent in the oak and 22.4 percent in the pine from the initial conditioned M.C. of 15 percent. The rate of moisture absorption measured was therefore faster in the pine than in the oak. 4. The mechanical properties of the both species were decreased significantly with the increase of boiling time. The decrement by the boiling treatment for 60 minutes was measured to 36.65.0 percent in compressive strength, 12.5-17.5 percent in tensile strength, 31.640.9 percent in modulus of rupture, and 23.3-34.6 percent in modulus of elasticity. 5. The minimum bending radius (M.B.R.) of sapwood and heartwood was 60-80 ㎜ and 90 ㎜ in silk worm oak, and 260 - 300 ㎜ and 280 - 300 ㎜ in Korean red pine, respectively. Therefore, the both species showed better bending processing properties in sapwood than in heartwood. 6. The M.B.R. of edge-grained and flat-grained specimen in silk worm oak was 60-80 ㎜, but the M.B.R. in Korean red pine was 240-280 ㎜ and 260-360 ㎜, respectively. Comparing the M.B.R. of edge-grained with flat-grained specimen, in the pine the edge-grained showed better bending processing property than the flat-grained. 7. The bending processing properties of the both species were improved by the rising of softening temperature from 40℃ to 100℃. The minimum softening temperature for bending was 90℃ in silk worm oak and 80℃ in Korean red pine, and the dependency of softening temperature for bending was therefore higher in the oak than in the pine. 8. The bending processing properties of the both species were improved by the increase of softening time as well as temperature, but even after the internal temperature of specimen reaching to the final temperature, somewhat prolonged softening was required to obtain the best plastic conditions. The minimum softening time for bending of 15 ㎜-squared silk worm oak and Korean red pine specimen was 15 and 10 minutes in the boiling treatment, and 30 and 20 minutes in the steaming treatment, respectively. 9. The optimum M.C. for bending of silk worm oak 20 percent, and the M.C. above fib

국산재 묘목가구 제조를 위한 Microwave - heating system 활용에 관한 연구 (3) - 목재 함수율이 microwave 휨가공성에 미치는 영향

소원택 ( Won Tek So ) 한국산림과학회 1997 한국산림과학회지 Vol.86 No.4

Black locust(Robina pseudo-acacia L.) and hornbeam trees(Carpinus laxiflora BL.) are widely growing in Korea and have relatively good wood qualities. However, they have seldom been used as industrial materials. This study was carried out to investigate the effect of wood moisture content on microwave-bending processing. The bending processing of the both species are improved as the increase of wood moisture from 30% to green, and the maximum limit of wood moiture content is 50%. The minimum solid-bending radii of black locust and hornbeam green wood were 60㎜ and 40㎜ for micro-wave bending, respectively. In conclusion, the microwave-heated green wood showed very good bending processing properties for bent-wood furniture.

소나무 집성판의 표면화장 재료별 외관품질 및 접착성 평가

소원택 ( Won Tek So ) 한국목재공학회 2007 목재공학 Vol.35 No.1

표면마감처리에 따른 목질보드의 포름알데히드 방산특성에 관한 연구

소원택 ( Won Tek So ),임진아 ( Jin Ah Lim ) 한국목재공학회 2006 목재공학 Vol.34 No.3

전건법에 의한 목재의 함수율추정

소원택 ( Won Tek So ) 한국목재공학회 1981 목재공학 Vol.9 No.3

家具用 部材의 曲加工 特性 : Ⅱ. 煮沸處理에 의한 리기다소나무 曲木製造 Ⅱ. Solid Wood- Bending of Pitch Pine by Boiling Treatment

蘇元澤,蔡正基 全南大學校 農業科學技術硏究所 1996 農業科學技術硏究 Vol.31 No.-

This study was performed to investigate the solid wood bending properties of pitch pine (Pinus rigida Mill.) grown in Korea by boiling treatment. The specimens were green and their dimension was 15×15 ×350mm. The optimum conditions for solid wood bending process of pitch pine are showed in Table 5 and the minimum solid-bending radius was 220mm in boiling treatment. The effects of pin knots, diagonal grains, and tom grains on the concave side of bent wood on the degradation of bending processing properties were very severe and their bending failures were 75%, 25%, and 35%, respectively, when bent to a 300mm radius.

건조전 선별에 의한 Southern pine 재의 고온건조

소원택,Taylor, Fred W 한국목재공학회 1992 목재공학 Vol.20 No.2

This study was performed to investigate the effect of green sorting before drying on the high-temperature drying characteristics of southern yellow pine dimension lumber(2$quot;×6$quot;×12'). To test the advantages of weight sorting, green lumber was seperated into heavy(above 55 1b), medium(50-55 1b), and light(below 50 1b)weight classes. Pieces in each weight class were subgrouped into high(above 35%) and low(below 30%) latewood groups. Groups were dried and seperated by a standard commercial high-temperature schedule ; dry bulb temperature 245°F, wet bulb temperature 180°F, and all velocity 1200fpm. The results obtained were as follows : 1. There was a highly significant correlation between annual rings per inch(X) and percent-latewood(Y). The regression equation was Y-=24. 5047+1.3272X. 2. There were highly significant correlations between either annual rings per inch(X₁) or percent-latewood(X₂) a.d specific gravity in green wood(Y). Their regression equations were Y=0.4260-1-0.0081X₁ and Y=0.3749+0.0029X₂, respectively. 3. Heavier weight charges dried more slowly than lighter weight charges. 4. Board-to-hoard variation in green or dry moisture content was less for all seperate weight classes than for unseperated control charges. 5. Lower latewood pieces had higher initial moisture content than higher latewood pieces, and then drying time for lower latewood pieces was longer than higher latewood pieces.

초산비닐 수지 에멀젼접착제를 사용한 푸라타나스의 판재접착성

소원택 한국목재공학회 1983 목재공학 Vol.11 No.5

This research was performed to investigate the gluing characteristics of platanus (Platanus occidentalis L.) lumber glued with polyvinyl acetate resin emulsion adhesives. According to the results, the optimum gluing conditions for platanus lumber were as follows: the amount of spreading glue, assembly time, pressure, and pressing time were respectively 200 g/㎡, 20min, 10 ㎏/㎠, and 10 hrs. There was highly significant correlation between the addition ratio(x) of urea resin to PVAc emulsion and the block shear strength(Y), and the regression equations were respectively as follows: in dry test Y=56.898+0.531x and in wet test Y=17.293+0.432x. The maximum bending strength and Young's modulus of two-ply parallel grained panels were respectively 782.5 ㎏/㎠ at the addition ratio of urea resin 40% and 89.4 x 103 ㎏/㎠ at 50%, which were higher than those of solid lumber.