요소수지와 토난접착제 혼용이 합판의 접착력에 미치는 영향

이필우,박헌 한국목재공학회 1984 목재공학 Vol.12 No.1

Taro-UF mixed type resin system was developed for gluing plywoods. The taro adhesive that was activated with sodium hydroxide was mixed with the definite ratios of UF resin adhesive. At the sametime, wheat-UF mixed type resin was also applied with the same method as Taro-UF mixed type resin. The mixing ratios of taro or wheat adhesive: UF resin were 0:100, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 80:20, and 100:0 by weight. In addition, the UF resins extended with wheat powder at the extending ratios of wheat powder UF resin, 10:90, 20:80, 30:70, 40:60, and 50:50 by weight, were also used. The dry and wet shear strengths of the plywoods of 30:70 (taro adhesive : UF resin) mixing ratio were highest.. The dry shear strengths of the plywoods manufactured with the UF resin-mixing taro adhesive were higher than those of the plywoods with the UF resin-mixing wheat adhesive at 10:90, 20:80, 30:70, 40:60, 50:50, and 60:40 (taro or wheat adhesive : UF resin) mixing ratios. At all mixing ratios, the wet shear strengths of the plywoods manufactured with the UF resin-mixing taro adhesive were higher than those of the plywoods with the UF resin-mixing wheat adhesive. The dry and wet shear strengths of the plywoods manufactured with the UF resin-mixing wheat adhesive were higher than those of the plywoods with the wheat powder-extending UF resin at the mixing ratios, 10:90, 20:80, 30:70, and 40:60 (wheat adhesive or wheat powder : UF resin). So. it was found that the plywoods manufactured with the UF resin-mixing taro adhesive and the UF resin-mixing wheat adhesive had better shear strength than the plywoods with the wheat powder-extending UF resin. It was because the taro adhesive and wheat adhesive themselves took the bonding properties after being activated with alkali.

양버즘나무 ( Platanus occidentalis L . ) 팽장조직의 해부학적 특성

이필우(Phil Woo Lee),정연집(Youn Jib Chung) 한국산림과학회 1993 한국산림과학회지 Vol.82 No.1

The swollen tissue of wound origin formed after nailing c-shaped fastener to a stem of Platanus occidentalis L. was compared with normal tissue in the qualitative and quantitative anatomical aspects. The swollen tissue appeared to differ from normal tissue in irregular cell orientation, occurrence of tyloses in vessel element, less common appearance of pore multiples, narrower and shorter vessel element, lower vessel frequency, shorter and highly thick-walled wood fiber, greater number of bars per scalariform perforation plate in vessel element, larger ray frequency, larger ray width and lower ray height.

학교 현장의 인권교육 실천 사례: 학생자치활동을 통한 갈등해결과 소통문화 만들기

이필우 한국법과인권교육학회 2010 한국법과인권교육학회 학술대회 Vol.2010 No.1

요소 및 석탄산수지 (石炭酸樹脂) 합판의 토란증량에 (土卵增量) 관한 연구

이필우,배영수 ( Phil Woo Lee,Young Soo Bae ) 한국산림과학회 1982 한국산림과학회지 Vol.57 No.1

This study was carried out to examine the possibility to replace imported wheat flour with taro. Taro and wheat flour were used for the extenders after oven drying(100±3℃)and pulverized into 80-100mesh minute powder by laboratory willey mill. Urea- and phenol-fromaldehyde resin adhesives were used for plywood manufacture, and the extending materials mixed with the extension at the ratio of 10, 20, 30, and 50% to each resin solution. The results obtained at this study were summarized as follows; 1) In dry and wet shear strength of urea-formaldehyde resin adhesive, taro showed very excellent bonding strength compared with wheat flour in all extending ration. Therefore taro showed the possibility that be usable to taro in place of wheat flour 2) In dry and wet shear strength of phenol-formaldehyde resin adhesive, in general, wheat flour showed higher bonding strength than taro. But in dry shear strength, taro showed higher shear strength than wheat flour in 30 and 50% extension.

제이인산 암모늄에 의한 합판의 내화처리 (Ⅰ) - 온냉침지처리와 (溫冷浸漬處理) 열판에 의한 처리합판의 재건조 -

이필우,정우양 ( Phil Woo Lee,Woo Yang Chung ) 한국산림과학회 1983 한국산림과학회지 Vol.60 No.1

Plywood, the representative interior decorative or structural material, is so inflammable that it may cause big fires. Therefore, it is required inevitably to manufacture the $quot;Fire retardant treated plywood$quot;, and it will be a study on the redrying of treated plywood that we ought to solve. This study was carried out to investigate the absorption of 20% (NH₄)₂HPO₄ solution into the soaked plywoods by hot/cold soaking for 3/3, 6/3, 9/3 and 12/3 hours and to study drying process with drying curves and drying rates by press-drying at the platen temperature of 130, 145, 160 and 175℃. Solution absorption of plywoods in hot/cold soaking method increased steadily with the prolonged soaking time, and water absorption is higher than DAP absorption, and then chemical retention (DAP) exceeded the minimum retention [ 1.125 Kg/(30㎝)³] even in the shortest soaking treatment. Drying curves of water-soaked plywoods inclined more steeply than those of DAP soaked plywoods. And the drying proceeded rapidly with the increase in platen temperature and terminated in 2.51 minutes at the temperature of 160 and 170℃. Drying rate also increased generally with the increase of platen temperature. So it was at 175℃ in DAP-soaking and at 160℃ in water-soaking when the drying rate became above 10%/min.

졸참나무 지재 (枝材) 섬유에 관한 연구

이필우,엄영근 ( Phil Woo Lee,Young Guen Eom ) 한국산림과학회 1983 한국산림과학회지 Vol.60 No.1

According to the worldwide decreasing tendency in raw materials and increase in wood demands since 1970, the efficient utilization of raw materials was required internationally. Therefore this study dealt with the dimensional characteristics of branchwood fiber of Ouercus serrata Thunb for the complete utilization of whole tree. According to the branch individuals, parts and positions within a tree, fiber length, width and wall-thickness were measured. The results obtained are as follows: 1) As the height of individual branchwood increases from ground toward, fiber length and width, and wall-thickness decreased linearly and their regression equations obtained, were Y=770.03-22.643X, Y=27.444-0.71385X and Y=12.308-0.57320X respectively 2) From the main stem to branch in distal direction, fiber length, width and wall-thickness linearly decreased and their regression equations obtained were Y=752.70-0.6724X, Y=26.152-0.0084867X and Y=11.258-0.006205X, respectively. 3) As the radial direction from pith to hark increases, fiber length, width and wall-thickness increased linearly and their regression equations obtained were Y=679.73+11.231X Y=25.382+0.0925X and Y=10.521+0.11787X, respectively. 4) Mean value of fiber length, width and wall-thickness were 625-765, 26 and 11㎛, respectively.

내화처리 (耐火處理) 파티클보오드의 COMPLY 접착이 휨강도와 전단강도에 미치는 영향

이필우,권진헌 ( Phil Woo Lee,Jin Heon Kwon ) 한국산림과학회 1984 한국산림과학회지 Vol.64 No.1

This research was conducted to examine the effect of bonding on the bending and shear strength of COMPLY-board when used with meranti face veneer and fire retardant treated particle-board core. For ammonium sulfate, modulus of rupture (MOR) of COMPLY-board increased with increasing chemical concentration up to 10 percent and then decreased after that concentration. However, Minalith showed reverse effect to the result for ammonium sulfate. Modulus of elasticity (MOE) of COMPLY-hoard decreased with increasing chemical concentration and its differences were not significant between concentration. Shear strength was shown better when treated with ammonium sulfate than with Minalith. Wood failure of COMPLY increased with increasing chemical concentration up to 15 percent and then decreased after that concentration, The products of parallel and cross veneer laminated were better than those of COMPLY composed of fire retardant treated particleboard core. Nontreated particle-board was the least in strength. MOE of fire retardant treated COMPLY increased by 136 percent and its MOE by 170 percent as compared with non treated particle-board.

리기다소나무 ( Pinus rigida Miller ) 의 목재해부학적 및 물리학적성질에 관한 연구 - 간 (幹) , 지 (枝) , 근 (根) , 소두목의 (소頭木) 특성을 중심으로 -

이필우 ( Phil Woo Lee ) 한국산림과학회 1972 한국산림과학회지 Vol.16 No.1

Pitch pine (Pinus rigida Miller) in Korea has become one of the major silvicultural species for many years since it was introduced from the United States of America in 1907. To attain the more rational wood utilization basical researches on wood properties are primarily needed, since large scale of timber production from Pitch Pine trees has now been accomplishing in the forested areast hroughout the country. Under the circumustances, this experiment was carried out to study the wood anatomical, physical and mechanical properties of Pitch Pine grown in the country. Materials used in this study had been prepared by cutting the selected pitch pine trees from the Seoul National University Forests located in Suwon. To obtain and compare the anatomical and physical properties of the different parts of tree such as stem, branch, top and rootwood, this study had been divided into two categories (anatomical and physical) . For the anatomical study macroscopical and microscopical features such as annual ring, intercellular cannal, ray, tracheid, ray trachid, ray parenchyma cell and pit etc. were observed and measured by the different parts (stem, branch, root and topwood) of tree. For the physical and mechanical properties the moisture content of geen wood, wood specific gravity, shrinkage, compression parallel to the grain, tension parallel and perpendicular to the grain, radial and tangential shear, bending, cleavage and hardness wree tested. According to the results this study may be concluded as follows: 1. The most important comparable features in general properties of wood among the different parts of tree were distinctness and width of annual ring, transition from spring to summerwood, wood color, odor and grain etc. In microscopical features the sizes of structural elements of wood were comparable features among the parts of tree. Among their features, length, width and thickness of tracheids, resin ducts and ray structures were most important. 2. In microscopical features among the different parts of tree stem and topwood were shown simillar reults in tissues. However in rootwood compared with other parts on the tangential surface distinctly larger ray structures were observed and measured. The rnaximum size of unseriate ray was attained to 27 cell (550μ) height in length and 35 microns in width. Fusiform rays were formed occasionally the connected ray which contain one or several horizontal cannals. Branchwood was shown the same features like stemwood but the measured values were very low in comparing with other parts of tree. 3. Trachid length measured among the different parts of tree were shown largest in stem and shortest in branchwood. In comparing the tracheid length among the parts the differences were not shown only between stem and rootwood, but shown between all other parts of tree. Trachid diameters were shown widest in rootwood and narrowest in branchwood, and the differences among the different parts were not realized. Wall thickness were shown largest value in rootwood and smallest in branchwood, and the differences were shown between root and top or branchwood, and between stem and branch or top wood, but not shown between other parts of tree. 4. Moisture contents of green wood were shown highest in topwood and lowest in heartwood of stem. The differences among the different parts were recognized between top or heartwood and other parts of tree, but not between root and branchwood or root and sapwood. 5. Wood specific gravities were shown highest in stem and next order root and branchwood, but lowest in topwood. The differences were shown clearly between stemwood and other parts of tree, but not root and branchwood. However the significant difference is realized as most lowest value in topwood. 6. In compression strength parallel to the grain compared among the different parts of tree at the 14 percent of moisture content, highest strength was appeared in stem, next order branch and rootwood, but lowes

낙우송 (落羽松) ( Taxodium distichum Rich . ) 지재의 (枝材) 압축이상재 및 대응재에 관한 해부학적 특성

이필우(Phil Woo Lee),정연집(Youn Jib Chung),권미(Mi Kwon) 한국산림과학회 1991 한국산림과학회지 Vol.80 No.3

Compression wood and opposite wood formed in a branch of Taxodium distichum Rich. is described and compared in qualitative and quantitative anatomical aspects. The qualitative features of compression wood appeared to differ from those of opposite wood in very gradual tracheid transition from earlywood to latewood, roundish tracheid shape on cross surface, tracheid tip distortion on radial surface, and existence of intercellular spaces and helical cavities. In quantitative features, compression wood tracheids showed shorter lengths than opposite wood. The ray density and the number of uniseriate rays were greater in compression wood than in opposite wood but the height of uniseriate rays in compression wood was smaller than in opposite wood.

아미노수지를 (樹脂) 보강제로 (補强劑) 이용한 경질섬유판 (硬質纖維板) 제조에 관한 연구

이필우(Phil Woo Lee),이화형(Hwa Hyung Lee) 한국산림과학회 1974 한국산림과학회지 Vol.24 No.1

This study was carried out to examine the subsitution possibility into water soluble amino resins instead of phenolic resin as a sizing material for the strength increase on the wet forming hardboard. The properties of hardboard, manufactured with amino-resins based urea, melamine, formaline, and methanol which were low priced domestic products, were examined in comparison with those of hardboard treated with phenolic resin. In this study by the results and discussions, it may be summarized as follows: 1. Amino-resins are ble to be substituted for the phenolic resin as a good sizing material for strength increase in the manufacture of wet forming hardboard. Under the considerations of economic advantages and properties of hardboard, modified urea-melamine resin was given a best results. 2. The specific gravities of hardboard that were treated with phenolic resin was equal to that treated with modified amino type resin, and in case of urea-melamine resin, the specific gravity value were lowest among them. 3. The results of moisture contents were satisfied the standard which calls for 13 percent or below. There were no differences in moisture contents between hardboards, treated with melamine resin and modified urea-melamine resin but hhenolic resin. The moisture contents of hardboard treated with phenolic resin was shown the lowest. 4. The water absorption of hardboard treated with phenolic resin was greater than those treated with amino resins, and to satisfy the standard of water resistance, the treatment of 2 percent paraffin wax emulsion was needed in this case. There were no differences in water absorptions between hardboards, treated with melamine resin and modified urea-melamine resin. To satisfy the standard of water resistance in this case the treatment of 1 percent paraffin wax emulsion was shown good results. 5. The differences among the flexural strength in using tested three adhesives were significant. The flexural strength were shown the signification by order of melamine resin, modified urea-melamine resin, and phenolic resin. In all cases to satisfy the standard of flexural strength, the treatment of 3 percent sizing materials for strength increase was needed.