家具構造用 콤플라이의 휨강도와 半剛接合 特性

이필우(Phill Woo Lee),박희준(Hee Jun Park),한유수(Yu Soo Han) 한국가구학회 1991 한국가구학회지 Vol.2 No.2

This study was carried out for investigating the bending properties, characteristics of semi-rigid joint and screw holding strength on L-type specimmens of one com-ply(bonded with particleboard and plywood) and 15mm particle- board and 18mm particleboard.<br/> The obtained results were as follows;<br/> 1. M.O.R. and S.P.L. on bending of com-ply were higher than those of particle-board. Also M.O.E. of com-ply showed much higher than that of particleboard.<br/> 2. The results showed that the difference in bending properties between flatwise bending and edgewise bending were present. The average M.O.E.. M.O.R. and S.P.L. of flatwise loading were higher than those of edgewise loading.<br/> 3. The stiffness coefficients of the specimens constructed with two dowels were in the 10-3 level. indicative of flexible joint. And stiffness coefficients of joint type A and C were lower than that of type B.<br/> 4. The moment of joint type A and C constructed with two dowels were higher than that of joint type B. And the joint moment of comply was higher than that of particleboard.<br/> 5. Maximum screw holding strength on the face of comply was about 200% higher than that on the face of particle board.

週期的 調濕處理가 表面材料와 芯板比重을 달리한 콤플라이의 치수 安定性에 미치는 影響

이필우(Phill Woo Lee),김대준(Dae Jun Kim),박희준(Hee Jun Park) 한국가구학회 1992 한국가구학회지 Vol.3 No.1

The research was carried out investigate the effect of four repeated 50-90-50% humidification on the dimensional stability of Com-ply. manufactured according to the three specific gravity levels of particleboard core and veneer or plywood as the face back materials.<br/> The obstained results were summarized as foliows:<br/> Com-ply followed a pattern of increasing dimensions and weight on adsorption cycle and decreasing on the desorption cycle. After the fourth cycle, the dimensions and weight of Com-ply were greater than those of originally measured. Most part of increase in thickness, volume and weight of Com-ply occured during the first humidification cycle.<br/> The length, thickness and volume change of Com-ply increased the specific gravity of core board. The dimensional stability of Com-ply bonded with pltwood was better than that of the Com-ply bonded with vender. Genenally, the dimension stability of Com-ply bonded with 3mm thick veneer less than those of the other types of Com-ply. <br/>

가구 구조용 목질 복합재 개발에 관한 예비연구

이필우(Phil Woo Lee),박희준(Hee Jun Park) 한국가구학회 1991 한국가구학회지 Vol.2 No.1

This research was carried out to investigate the static bending properties(MOR, MOE and SPL) of wood composite which was fabricated particleboard core and veneer or plywood as the face and the side materials.<br/> The obtained results were summarized as follows;<br/> 1. Specific gravity of wood composite was decreased by adhesion of veneer or plywood on the faces and the sides of composite. but bending properties of composite were remarkably improved.<br/> 2. Modulus of rupture. modulus of elasticity and stress at proportional limit of composite were much higher than that of particle - board but were lower than that of lauan.<br/> 3. The effects of veneer or plywood thickness or area ratio on bending properties(MOR, MOE, SPL) showed that the values of MOR. MOE and SPL of the composite were increased by application of 1mm, 2mm and 3mm thick veneer or plywood on the particleboard surfaces.<br/>

國産 파티클보드와 導入 美松 및 라왕材로 製作한 移動式 선반의 Creep 擧動

박희준(Hee Jun Park),이필우(Phil Woo Lee) 한국가구학회 1993 한국가구학회지 Vol.4 No.1

This study was carried out to investigate the creep behavior of domestic particleboard and imported Douglas-fir and lauan solid boards to evaluate the suitability of domestic particleboard as shelves for furni ture<br/> All shelves were cut into 20.0 by 94.0 em size and were subjected to a creep test under a uniformly distributed load of 0.022 kgf/cm2 for 96 hours.<br/> Total deflections of 15mm and 18mm thickness particleboard were very higher than those of Douglas-fir and White lauan solid during the testing periods.<br/> For all shelves, the values of relative creep increased linearly with time but creep modulus decreased during 96 hours.<br/> The predicted length over deflection ratios were 26.55 and 46.73 for 15mm and 18mm thickness particleboard. respectively, But the values for Douglas-fir and white lauan were 164.84 and 103.09, respectively. which were very higher than those of

목재와 목질판상의 Dowel-Joint 판강접합 특성에 관한 비교분석

박희준,이필우(Hee Jun Park),Phil Woo Lee 한국가구학회 1990 한국가구학회지 Vol.1 No.1

The dewel joint is one of the most widely used joint types in modern woodworking, especially in wooden furniture manufacturing.<br/> L-type specimens of two solid woods(Antiaris, Sepetir) and three wood based materials (Plywood, Particleboard, and Medium Density Fiberboard), 15mm thick, 100mm wide, and 150mm long in size, were constructed with 1, 2, 3 and 4 dowels of 6, 8, and 10mm diameter by polyvinyl acetate resin adhesive in this study. Stiffness coefficient and strength of the L-type specimens were determined by the aid of universal testing machine.<br/> The stiffness coefficients of the specimens constructed with one dowel was in the 10^-3 level, indicative of flexible joints but those with 2, 3, 4 dowels were in the 10^-4 level, indicative of relatively stable joint. The 8mm dowel was superior to 6 and 10mm dowels in bending strength, and the bending strength increased with the increase of dowel number from 1 to 4, however, the increasing rate of bending strength from 1 to 2 dowels was higher than from 3 to 4 dowels.<br/> The most superior joints strength was obtained in constructions with 4 dowels of 8mm diameter for wood based materials (Plywood, particleboard and Medium Density Fiberboard) and with 4 dowels of 10mm diameter for solid wood(Antiaris and Sepetir), respectively.

이태리 포플라와 낙엽송 세이빙으로 제조한 보드의 휨강도와 박리강도

박희준(Hee Jun Park),윤형운(Hyoung Un Yoon),이필우(Phil Woo Lee) 한국가구학회 1996 한국가구학회지 Vol.7 No.1

Non-oriented shaving boards were made with Italian popular(Populus canadensis Moench), Japanese larch(Larix letolepis Gorden) planer shavings and commercal coarse chips and UF resin, PF resin and MDI adhesives.<br/> Physical properties and manufacturing cost were ε valuated. Physical properties evaluated were static bending and internal bond strength.<br/> Boards made of lower density species were superior static bending properties to particleboard made of coarse chips and commercial particleboard. Especially, boards of shavings from low density species shower superior mechanical properties according to increasing the compression ratio.<br/> As a result, the shaving board, though its specific gravity is lowered by 0.05 to 0.1, is expected<br/> not to be less than commercial particleboard in physical properties.<br/>

파티클보드 제조공정의 (製造工程) 최적화 모델개발에 관한 연구

정주상(Joo Sang Chung),박희준(Hee Jun Park),이필우(Phil Woo Lee) 한국산림과학회 1993 한국산림과학회지 Vol.82 No.4

In this paper, a nonlinear programming model to determine the optimal operating policy to minimize production costs for particleboard plants is presented. The model provides optimal values for three decision variables : specific gravity of particleboard, mat moisture content and mat resin content. These decision variables are key factors influencing the cost and quality of particleboard manufacturing processes. In formulating the nonlinear programming model, the minimum quality standards for internal bond strength and modulus of rupture of particleboard are used as industry-wide quality constraints. These quality standards are expressed as nonlinear functions of the decision variables. In order to demonstrate the applicability of the proposed model, the model is applied to solve for optimal solutions of four theoretical problems. The problem scenarios are built to investigate effects of changes in hot-pressing speed and purchase price of chip and resin.

주기적 조습처리(調濕處理)가 파티클보드와 콤플라이의 치수 안정성에 미치는 영향

이필우,박희준,김대준 한국목재공학회 1992 목재공학 Vol.20 No.3

This research was carried out to investigate the effects of cyclic humidification on the dimensional stability of particleboard manufactured according the three specific gravity levels and com-ply fabricated with a core of particleboard and veneer or plywood as the face and back materials. Both the particleboard and com-ply were subjected to four cycles of 50-90-50% relative humidity. The results are summarized as follows : Particleboard and com-ply followed a clear pattern of increasing dimensions and weight on the adsorption cycle and decreasing dimensions and weight on the humidification cycle. After the fourth cycle, the dimensions and weight of both particleboard and com-ply were greater than r-hose originally measured. The greater part of increase in occurred during the first humidification cycle. The specific gravity of particleboard has a significant effect thickness and volume change. The dimensional stability of com-ply was better than that of particleboard, In addition, the dimensional stability of com-ply bonded with plywood was better than that of comply bonded with veneer.

국산 파티클보드와 중밀도섬유판의 나사못유지력 예측식

이필우,박희준,한유수 한국목재공학회 1991 목재공학 Vol.19 No.4

This study was carried out to determine the withdrawal strength of various screws according to root diameter of screw and embeded length on the face and edge of domestic particleboard and medium density fiberboard. The obtained results were as follows 1. The withdrawal strength of screw in domestic particleboard and medium density fiberboard was closely related to embeded length c~F the screw but less dependent on root diameter of the screw. 2. The withdrawal strength on the face and edge of domestic particleboard could be predicted by means of the following expression F_(Pf)=4.60×D^(0.24)×L^(1.14)(R²=0.87) F_(Pe)=0.54×D^(0.43)×L^(1.73)(R²=0.84) Where : F_(Pf) : withdrawal strength an the face of particleboard(kgf) F_(pE)=withdrawal strength on the edge of particleboard(kgf) D=diameter of the screw(㎜) L=embeded length(㎜) 3. The withdrawal strength on the face and edge of domestic, medium density fiberboard could be predicted by means of the following expression : F_(Mf)=1.53×D^(0.53)×L^(1.39)(R²=0.93) F_(Me)=1.14×D^(0.66)×L^(1.36)(R²=0.87) where : F_(Mf)=withdrawal strength on the face of medium density fiberboard(kgf) F_(Mf)=withdrawal strength on the edge of medium density fiberboard(kgf)

Dowel 직경이 목재와 목질재료 접합부의 인발강도에 미치는 영향

이필우,오세창,박희준 한국목재공학회 1990 목재공학 Vol.18 No.2

Traditional complex joints have used to a wide variety of wooden furniture construction. Dowel joint is the most popular joints. however design of this joint to meet specified service condition has been hampered by a lack of proven design formulas which can be use to predict their strength. The object of this study is to investigate the withdrawal strength and effect of dowel diameters in wood and wood based materials. The obtained results were as follows ; 1. The relationship between withdrawal strength and dowel diameter is found to be linear. 2. Withdrawal strength of medium density fiberboard and Sepetir in end-to-side joints is superior to Antiaris, particleboard and plywood. 3. In end-to-end joints, withdrawal strength of medium density fiberboard is the most superior joint, but Sepetir, Antiaris and plywood have similarly strength and particleboard is inferiority. 4. Withdrawal strength in end-to-end joints of Antiaris and plywood is higher than in end-to-side joints. But in end-to-end joints of Sepetir, medium density fiberboard and particleboard is similarity in end-to-side joints.