• Title/Summary/Keyword: structural plywood

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Nail Withdrawal Resistance and Embedding Strength of Structural Wood Panels with Water Absorption (수분의 흡수에 따른 구조용 목질판넬의 인발 및 함입성능)

  • 오세창
    • Journal of the Korea Furniture Society
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    • v.10 no.2
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    • pp.1-8
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    • 1999
  • The use of structural wood based panels like plywood, OSB in many applications involves the use of nails, and data on the performance of panel-nail connection are needed for design and comparative purpose. This study was carried out to develop basic information on nail performance(withdrawal, embedding, nailhead push through) with water absorption in plywood and OSB. In withdrawal resistance test, initial stiffness of plywood performed better than OSB in 24hr soaked condition. The soaked condition reduced average nail withdrawal resistance value about 46% (12d mail), 53%(8d nail) in OSB, 17%(12d mail), 24%(8d mail) in plywood. The nail embedding strength of plywood also performed better than that of OSB and retention value(wet strength/dry strength) yielded similar in each nail types. The nail head push through capacity of OSB was higher than that of plywood in dry condition, but equal or lower in soaked condition. Therefore, critical consideration about structural panels is required in moist applications. The average values of nail withdrawal, nail embedding strength and nail head push through resistance of tested materials meet the minimum requirement of various specification and standards.

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Determination of slip modulus of cold-formed steel composite members sheathed with plywood structural panels

  • Karki, Dheeraj;Far, Harry;Al-hunity, Suleiman
    • Steel and Composite Structures
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    • v.43 no.4
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    • pp.511-522
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    • 2022
  • An experimental investigation to study the behaviour of connections between cold-formed steel (CFS) joist and plywood structural panel is presented in this paper. Material testing on CFS and plywood was carried out to assess their mechanical properties and behaviour. Push-out tests were conducted to determine the slip modulus and failure modes of three different shear connection types. The employed shear connectors in the study were; size 14 (6mm diameter) self-drilling screw, M12 coach screw, and M12 nut and bolt. The effective bending stiffness of composite cold-formed steel and plywood T-beam assembly is calculated based on the slip modulus values computed from push-out tests. The effective bending stiffness was increased by 25.5%, 18% and 30.2% for self-drilling screw, coach screw, nut and bolt, respectively, over the stiffness of cold-formed steel joist alone. This finding suggests the potential to enhance the structural performance of composite cold-formed steel and timber flooring system by mobilisation of composite action present between timber sheathing and CFS joist.

Examination of Newsprint Residue as a Plywood Adhesive Filler (합판의 충전제로서 신문용지 잔사의 조사)

  • Oh, Yong-Sung
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.2
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    • pp.42-45
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    • 1996
  • A residue from the newsprint waste was investigated as a filler in adhesive for bonding southern pine plywood. The residue was prepared by drying the wet residue to 8% moisture content and grinding the dry material using a laboratory Wiley mitt with a 75-${\mu}m$(200-mesh) screen. The residue was compared to a commercial filler commonly used in structural plywood adhesives. A total of 48 three-ply panels. 12.7mm nominal thickness and 0.3 by 0.3 m in size, were fabricated at two press times(4 and 5 min) and three assembly times(20, 40 and 60 min). Evaluations of the residue were carried out by performance tension shear tests after two 4-hour boil accelerated aging tests on plywood. The test results included tension shear strength and estimated wood failure values. All plywood made with the residue filler were comparable to the control-bonded plywood. These results indicate that residue from the newsprint waste streams would be suitable as filler for plywood adhesives.

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Cryogenic Mechanical Characteristics of Laminated Plywood for LNG Carrier Insulation System (LNG운반선 방열시스템에 적용되는 적층형 플라이우드의 극저온 기계적 특성 분석)

  • Kim, Jeong-Hyeon;Park, Doo-Hwan;Choi, Sung-Woong;Lee, Jae-Myung
    • Journal of Ocean Engineering and Technology
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    • v.31 no.3
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    • pp.241-247
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    • 2017
  • Plywood, which is created by bonding an odd number of thin veneers perpendicular to the grain orientation of an adjacent layer, was developed to supplement the weak points such as contraction and expansion of conventional wood materials. With structural merits such as strength, durability, and good absorption against impact loads, plywood has been adopted as a structural material in the insulation system of a membrane type liquefied natural gas (LNG) carrier. In the present study, as an attempt to resolve recent failure problems with plywood in an LNG insulation system, conventional PF (phenolic-formaldehyde) resin plywood and its alternative MUF (melamine-urea-formaldehyde) resin bonded plywood were investigated by performing material bending tests at ambient ($20^{\circ}C$) and cryogenic ($-163^{\circ}C$) temperatures to understand the resin and grain effects on the mechanical behavior of the plywood. In addition, the failure characteristics of the plywood were investigated with regard to the grain orientation and testing temperature.

Use of Polyethylene as an Additive in Plywood Adhesive (합판 접착제의 첨가제로서 폴리에틸렌의 이용)

  • Oh, Yong-Sung
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.1
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    • pp.14-18
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    • 1998
  • A low density polyethylene(LDPE) was examined as an additive in phenol-formaldehyde(PF) resin adhesive for bonding radiata pine plywood. The LDPE was supplied by the commercial manufacturer. The LDPE was compared to a commercial filler commonly used in structural plywood adhesives in the United States. The adhesive mixes were made by following the recommended procedure of Georgia-Pacific Resins Inc.. using plywood-type PF resin. A total of 48 three-ply plywoods. 6.3 mm nominal thickness and 30 by 30 em in size, were made at two press times (4 and 5 min). two press temperatures (150 and $160^{\circ}C$) and 30 minute assembly times for four adhesive mixing types. Evaluations of the LDPE addition were carried out by performance tension shear tests after two cycle boil aging tests on plywood per the U.S. Product Standard PS I-83. After accelerated-aging tests. plywoods were exhibited no delamination. The test results included tension shear strength and estimated wood failure values. The plywood test results support the use of polyethylene as an additive in plywood adhesives.

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Effect of Filler Types on Phenol-Formaldehyde Resin Adhesive for Plywood (충전제의 종류가 합판용 페놀수지 접착제에 미치는 효과)

  • Oh, Yong-Sung
    • Journal of the Korean Wood Science and Technology
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    • v.26 no.3
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    • pp.48-52
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    • 1998
  • Residues such as walnut, pinenut and peanut shells were used as a filler in adhesive for bonding radiata pine plywood. The nutshell residues were prepared by simply drying to 8% moisture content and grinding the dry material using a laboratory Wiley mill with a $75{\mu}m$ (200 mesh) screen. The nutshells residues were compared to a commercial filler commonly used in adhesives by the structural plywood and laminated veneer lumber industry in the United States. The adhesive mixes were made by following the recommended procedure of Georgia-Pacific Resins, Inc., using phenol-formaldehyde resin. For each filler type, three-ply plywoods, 6 mm nominal thickness and 30 by 30 cm in size, were fabricated at two press times (4 and 5 min) and around 30 minute assembly time. Evaluations of the nutshell residues were carried out by tension shear tests after cyclic boil tests on plywood. The results of the performance test included tension shear strength and wood failure. All plywoods made with the nutshell fillers were comparable to those made with the control filler. These results indicate that nutshell residues would be suitable as filler for plywood adhesives.

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Performance Evaluation of Softwood Plywood as Structural and Concrete-Form Panels (침엽수 합판의 구조용 및 콘크리트 거푸집용으로서의 성능 평가)

  • Lee, Jun-Jae;Kim, Gwang-Chul;Lee, Guk-Sik
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.3
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    • pp.14-24
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    • 2000
  • In present research, the plywoods made of radiata pine or Japanese larch, the potential softwood species in mass supply, were discussed to examine their feasibility as the structural and concrete form panels through the basic properties test. First, plywood qualities and its nail performance were tested. The performance test for concrete form or structural panel by concentrated and uniformly distributed load were conducted to investigate the possibility as structural material for light frame and concrete constructions. Test results of basic quality such as specific gravity, cupping, bowing, and twisting appeared to satisfy the criteria for structural use. Also, nail performance test results, for roof and wall sheathing panels, nail lateral resistance, nail withdrawal resistance, and nail push head resistance proved to meet the required standard for structural use. The test results on performance as structural panel by concentrated and uniformly distributed load and as concrete form panel showed that these two species could be used for structural sheathing, subfloor, and concrete form panels.

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Shear Strength of Nailed Connection of Domestic Plywood as a Substitute for OSB (OSB 대체용 국내산 합판의 못 접합부 전단내력 성능)

  • Suh, Jin-Suk;Hwang, Sung-Wook;Hwang, Kweon-Hwan;Jeong, Gi-Young;Joung, Ha-Hyun
    • Journal of the Korean Wood Science and Technology
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    • v.40 no.4
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    • pp.287-293
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    • 2012
  • This study was carried out in order to compare nail shear strength between domestic plywood and imported OSB for structural sheathing members as infill wall of wooden construction. The differences of nail shear strength between parallel-to-grain direction and perpendicular-to-grain direction of sheathing material to frame material were distinct at the plywood composition. The shear strengths of plywood and OSB with nail met current design values. The plywood of P-4 type, which uses MLH at surface layer and constructs 7 ply, showed greater than OSB regardless of grain direction of sheathing material to frame material. When the plywood as sheathing material to frame material was used, it was found out that the overall construction of perpendicular-to-grain direction of plywood had greater nail shear strengths than the construction of parallel-to-grain.

Study on the Possibility of Recycling for Shipbuilding Plywood Waste to Use as the Structural Members (조선산업 합판 폐기물의 구조용재로의 재활용 가능성에 대한 연구)

  • Kim, Gwang-Chul
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.1
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    • pp.29-36
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    • 2009
  • Recycling of wood wastes or residues is a good solution for a shortage of wood resources and a rise in the price. Shipbuilding wood wastes were almost used to produce the boards by milling. However, considering the economic value and insufficient resource, recycling with milling is dissatisfied method. This study has been carried out to investigate the recycling possibility of shipbuilding wood waste. There are two kinds of shipbuilding wastes: plywood waste and solid waste. From the results of this study, the following conclusions have been made: 1. Bending properties of plywood and laminated plywood lumber were tested by Korean Standard. 2. The main fracture mode of plywood waste and laminated plywood lumber is that of simple tension. 3. The recommended application for the recycling of shipbuilding wood waste are outdoor wood furnishings, indoor wood furnishings and some wooden building construction materials: interior raw material, wooden pallet, siding, paneling, flooring. picnic table, deck components, porch swing, landscaping timbers, residential fencing, patios, and boardwalks etc.

Credibility Evaluation of Versatile Weight Lightening Plywood Using Piercing (천공공법을 이용한 다목적 경량 합판의 신뢰성 평가)

  • Kim, Jin-Woo;Kim, Hye-Soo;Kim, Chang-Uk;Song, Jung-Il
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.4
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    • pp.55-60
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    • 2013
  • In this study, mechanical properties of versatile light weight plywood(manufacturing using piercing) are studied. A credibility evaluation was carried out for different perforation patterns including octagonal shape, rectangular shape and circular shape. A static structural analysis is conducted to find the stresses produced. Circular perforations are found to have better strength to weight ratio. Results of each type of perforation are discusses and compared.