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.

제지 슬러지 - 폴리프로필렌수지 복합재의 기계적 성질

이필우,손정일 한국목재공학회 1999 목재공학 Vol.27 No.3

The objective of this research is to develop paper sludge reinforced thermoplastic composites which incorporate the advantages of each component materials. The effects of paper sludge content(0, 10, 20, 30, 40%), mesh size(20∼40, 60∼80, less than 100mesh), and coupling agent(Epolene E-43 and Epolene G-3003) on the mechanical properties of paper sludge-polypropylene composites were investigated. Composite density increased with an increase in the paper sludge content. When paper sludge is incorporated into a polypropylene matrix, the flexural properties of the composite increase significantly with an increase in the paper sludge mixing ratio. Especially, flexural modulus was improved with increasing paper sludge content. The flexural strength of composites was improved, but flexural modulus reduced somewhat with decreasing paper sludge particle size. The flexural properties of paper sludge-polypropylene composites were improved by using coupling agents to enhance the bonding between reinforcing filler and matrix. Use of the epolene E-43 and G-3003 resulted in considerable improvement in the flexural strength over control specimens. The flexural strength of the G-3003 composite system is higher than that of the E-43 system. Generally, izod notched impact strength of paper sludge-polypropylene composite decreased slightly, whereas izod unnotched impact strength decreased significantly with increasing paper sludge contents. There was no effects of paper sludge particle size on impact strength of paper sludge-polypropylene composites. And izod unnotched impact strength of epolene E-43 composite system sharply decreased but that of G-3003 composite system was no tendency with increasing additive content.

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.

산소지수법에 (酸素指數法) 의한 내화처리합판의 (耐火處理合板) 연소시험

이필우(Phil Woo Lee),엄영근(Young Geun Eom),김현중(Hyun Joong Kim) 한국산림과학회 1989 한국산림과학회지 Vol.78 No.4

To obtain relative effectiveness in fire: resistance among fire retardant chemicals, oxygen indices were determined for 3.5 mm thick, three-ply, meranti plywoods, treated with 5 commercial chemicals and water and then press-dried, through Up and Down method following oxygen index test of ASTM D 2863-77. The oxygen indices obtained were 28.4 for ammonium sulfate, 26.9 for monoammonium phosphate, 43.4 for diammonium phosphate, 30.1 for borax-boric acid, 32.4 for minalith, and 25.5 for water. Therefore, diammonium phosphate was found to rank first in fire-retardant effectiveness, followed by minalith, borax-boric acid, ammonium sulfate, and monoammonium phosphate in turn, judging from the fact that highly flammable materials are likely to have a low oxygen index.

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.

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.

학교 현장의 인권교육 실천 사례: 학생자치활동을 통한 갈등해결과 소통문화 만들기

이필우 한국법과인권교육학회 2010 한국법과인권교육학회 학술대회 Vol.2010 No.1

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.

효소지수법에 (酵素指數法) 의한 목질판상재료의 연소시험

이필우(Phil Woo Lee),정인주(In Ju Chung) 한국산림과학회 1989 한국산림과학회지 Vol.78 No.4

The oxygen index test was carried out to obtain the relative flammability of wood-based materials (plywood, MDF, particleboard) and their oxygen indices. The oxygen index is the minimum concentration of oxygen, expressed as volume percent, in a mixture of oxygen and nitrogen that will just support flaming combustion of a material under the specified laboratory conditions. In this study the oxygen indices were calculated by using the Dixon and Massey`s Up and Down method($quot;N$quot; Large method). The obtained results were as follows : 1. The oxygen indices calculated with Up and Down method were 27.9% for plywood, 26.9% for MDF, and 26.2% for particleboard, indicative of plywood being more difficult to burn than MDF and particleboard Lender the same surrounding conditions. 2. The oxygen indices were not affected by the total gas flow rate.