Where adequate test data are available, therefore, the design properties. Plywood properties have traditionally been separately tabulated as section properties and design stresses. The properties of plywood include increased stability, surface dimensional stability, highimpact resistance, chemical resistance and a high strengthtoweight ratio. These are multiplied together to obtain a capacity. Moisturerelated properties of wood and the effects of. As a result, wood possesses material properties that may be significantly different from other materials normally encountered in. Each of these materials has its own unique properties and qualities, and so each is used in specific applications.
These trees bear cones and most of them have needle. The aim of this study was to determine the effects of three variable parameters. At all stages of manufacture the plywood is controlled for veneer thickness, glue spread, dimensional accuracy, overall thickness, bonding strength and other requirements. Any wood defects have been repaired with synthetic filler, so the veneer can be painted, making it ideal for furniture or cabinet doors. This report presents data from tests of plywood of various ply thicknesses and numbers. Plywood is an engineered wood sheet material made up of fine layers or flimsy strands of wood veneers attached together placing wood grains 90 degrees to one another. However, very little information is provided to common people, this can be the area where most customers get deceived. Kretschmann, research general engineer 51 the mechanical properties presented in this chapter were obtained from tests of pieces of wood termed clear and straight grained because they did not contain characteristics such as knots, cross grain, checks, and splits. Wood veneers are unique with production and so with the beauty they are adding to the furnitures. Physical and mechanical properties of plywood produced with 1. The applicable section properties table c can be divided into load capacity to determine design strength and stiffness. Some properties, such as tension parallel to the grain, and all properties for some imported species are based on a more limited. Included in this standard are test methods to determine compliance and a glossary of trade terms and definitions.
Enhanced impact absorption properties of plywood sanita zike, kaspars kalnins riga technical university, institute of materials and structures sanita. Aug 19, 2015 flexo plywood it is flexible and is used for making curved parts. Plywood manufactured by apa member mills is available in a wide variety of appearance grades, ranging from smooth, natural surfaces suitable for finish work to more economical grades used for sheathing. Therefore, the growth of the plywood market is increasing day by day across the world. All physical properties change from panel to panel depending on the natural characteristics of the wood used to make the panel. These species also split easier shrink more, are average in workability, and perform somewhat less favorable than white ash when exposed to extreme cycles of moisture content. Because of the greater density of latewood, the proportion of latewood is sometimes used to judge the strength of the wood. It is an engineered wood from the family of manufactured boards which includes mediumdensity fibreboard mdf and particle board chipboard. Plywood thickness commonly ranges from 3 mm to 50 mm depending on its construction and purpose. When plywood is exposed to a constant relative humidity rh it will eventually reach an equilibrium moisture content emc.
Because these values are plywood specific, the appropriate panel grade and construction adjustment factors, c. For complete concrete form design and treatment information, refer to apas designconstruction guide. This lesson covers the physical and mechanical properties of wood. Plywood is made from layers of wood pressed together and bonded with an adhesive. Presentation of this design information is not intended to preclude further development. Osd plywood osd and cdx plywood are both commonly found on construction sites, because builders and contractors rely on both types of plywood to get the job done. Section properties are presented below both for plywood having all plies of group 1 species, and for plywood made. Methods are given for computing the strength and elastic properties. Fauhan rosli, a,b, che mohd ruzaidi ghazali, b mohd mustafa al bakri abdullah, a,b, and kamarudin hussin b,c due to the shortage of solid wood as a raw material of plywood and the abundance of oil palm trunk opt waste in malaysia, opt has become one of the. Moisture performance properties of exterior sheathing.
These stress gradings are strictly only applied to plywood manufactured to that standard, such as hoop pine f14 plywood. Plywood is a wonderful combination of lightness, strength and flexibility. Standard test methods for evaluating properties of wood. These standards have evolved over time from earlier documents ohalloran 1979, 1980. Earlywood is lighter in weight, softer, and weaker than latewood. Finnish birch betula pendula, hardwood and spruce picea abies, softwood are the most important raw materials in the plywood process. For plywood, the bending e is 10% higher than the effective e values. With more than a dozen common thicknesses and over twenty different grades, plywood is wellsuited to a multitude of demanding applications. Changes in temperature can have a profound effect on building materials, and although plywood doesnt react as dramatically to extreme temperatures as some other materials do, its thermal properties can help determine what construction roles its best suited to play. Many of the mechanical properties of wood tabulated in this chapter were derived from extensive sampling and analysis procedures.
The most commonly used softwoods for manufacturing plywood are firs and. Softwoods generally correspond to coniferous species. The sheets are composed so that the directions of the grain of the superimposed sheets are usually perpendicular to each other. Experimental test results of physical and certain important mechanical properties of commercial. When plywood is exposed to a constant relative humidity rh it will eventually reach an. Osb is a relatively new product that is produced from various. Plywood has a crosslaminated structure and is durable through drastic temperature and moisture. While it can be tailored to suit an extensive range of applications, the normal product consists of at least 3 plies, with the grain in the alternate plies running at right angles.
Pdf preparation and characterization of cork layered. Plywood is an assemblage of wood veneers bonded together to produce a flat sheet. Pdf properties of plywood manufactured from compressed. Apa 1981 and represent a consensus opinion of the makers, sellers, and users of plywood. Standard test methods for evaluating properties of woodbase. Pdf the objective of this study is to evaluate some of the physical and mechanical properties of plywood manufactured from compressed veneer of birch. Properties of wood there are fewer species of conifers. A quality certification program is provided whereby qualified testing agencies inspect, sample, and test products identified as complying with this standard. Department of forestry and wood technology, federal university of technology akure, ondo state, nigeria. It is one type of manufactured board which can be described as a mixture of medium density fibreboard mdf and chip board particle board. In this study, we determined the flexural properties and tensile shear strength of fiveply plywood panels produced with eucalyptus eucalyptus grandis, beech. Transportation plywood s excellent strengthtoweight ratio and the armorlike durability of an overlaid surface make both hdo and mdo ideal for truck and trailer linings. A is the best and most expensive, and d the least expensive.
Mechanical properties refer to the strength characteristics of wood. In addition to strength, modulus of elasticity and shear modulus the density and. Some mechanical properties of plywood produced from eucalyptus, beech, and poplar veneer bekir cihad bal 1, ibrahim bektas1 abstract in this study, we determined the flexural properties and tensile shear strength of fiveply plywood panels produced with eucalyptus eucalyptus grandis, beech fagus orientalis, and hybrid poplar. This article reports on the use of carbon fiber cf and waste rubber wr as reinforcing agents for plywood. Engineering properties of plywoods the following engineering data are those specified in australian standards, particularly as 1684, 1720 and 2269 for structural plywood having stress gradings of f8, f11and f14. Bs 1088 plywood must use a glue, which has been tested and shown to be highly resistant to weather, microorganisms, cold and boiling water, steam and dry heat. Plywood plywood is the original wood structural panel.
Development and material properties of reinforced plywood. Moisture performance properties of exterior sheathing products made of spruce plywood or osb abstract plywood and osb oriented strand board are building boards that are made of timber and glue and that have good structural strength. Preparation and characterization of cork layered composite plywood boards. Plywood design specification supplement 5 november 2008. The experiment was laid out in complete block design cbd. Pdf properties of plywood manufactured from compressed veneer. Nowadays, due to the beneficial properties of plywood, it has become the most demanding building materials over traditional materials like natural wood, bricks, plastic, etc. Apa 1981 and represent a consensus opinion of the makers, sellers, and users of plywood products as well as other concerned parties. As a result, wood possesses material properties that may be significantly different from other materials normally encountered in structural design. This method is useful with such species as the southern pines, douglasfir, and the ringporous hardwoods ash, hickory, and oak. These features place hdo and mdo among the most durable construction materials on the market today. Birch plywood is characterized by excellent strength and stiffness properties, and therefore it performs very well in applications demanding high strength and rigidity. Plywood is a necessity for many projects, from building cabinetry in the laundry room to building your dream gazebo in the backyard. These properties are represented as the average mechanical properties of the species.
Properties of plywood boards composed of thermally modified and nonmodified poplar veneer. The objective of this study is to evaluate some of the physical and mechanical properties of plywood manufactured from compressed veneer of birch betula pubescens and alder alnus glutinosa. Wood is a hygroscopic material, which nearly always contains a certain amount of water. Physical properties and mechanical characteristics. Properties of plywood boards composed of thermally modified. Below learn about the unique properties of wood veneers veneer is genuine wood veneer is economical veneer enable durability veneer is unique. Plywood always has an odd number of layers, each one consisting of one or more plies, or veneers. Typical size is 4 ft x 8 ft, but other sizes may also be produced. In some cases, the number of plies is indicated, because two plywood panels of the same thickness can display different characteristics depending on. Physical and mechanical properties of selected wood. Because of its uniform texture, red alder is excellent for turning and polishing and takes glue, paint, and stain lumber.
Resin impregnation is used to improve the quality of plywood manufactured from opt fig. Possibilities for use of thermally modified poplar veneer were evaluated for the production of plywood boards in industrial conditions. Cdx southern pine plywood, of allsweetgum plywood, and of. Standard test methods for evaluating properties of woodbase fiber and particle panel materials1 this standard is issued under the. In birch plywood board, there is usually an odd number of sheers at least three, so the direction of grain of the surface sheets is always the. Department of forestry and wood technology, federal university of technology akure, ondo state, nigeria, between may 2012 and september 2012. It is composed of thin sheets of veneer, or plies, arranged in layers to form a panel. Apatrademarked plywood is suitable for a variety of end uses including subflooring, singlelayer flooring, wall and roof sheathing, sheathing ceilingdeck, structural insulated panels, marine applications, siding, webs of wood ijoists, concrete forming, pallets, industrial containers, mezzanine decks, and furniture. Cf content, wr content, and cf length, on the mechanical and physical properties of the plywood. It is one type of manufactured board which can be described as a mixture of medium density. Advantages and disadvantages of plywood civil engineering. Astm d 291503 standard practice for evaluating allowable properties for. Aleksandar lovric, vladislav zdravkovic, ranko popadic, and goran milic. For plywood structural design this publication presents section properties, allowable stresses, and practices to be followed in designing buildings and related structures with plywood.
Plywood is a material manufactured from thin layers or plies of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. Firpine douglas fir, hemlock, pine, white fir, wood species balsam, larch, etc. High and medium density overlay plywood hdo and mdo combine the toughness of exteriortype plywood with the superior wear of an overlaid surface. The bs 1088 standard is a marine plywood specification that applies to plywood made from untreated tropical hardwood veneers that have a stated level of resistance to fungus growth. Characteristics of oil palm trunk opt and quality improvement of palm trunk plywood by resin impregnation. Plywood is made by glueing together thin sheets of wood veneer. Engineered wood products are a good choice for the environment. This publication from apa the engineered wood association describes the properties of hdo and. Density lesson 1 showed that wood is a porous material made up of cells of various kinds. Load capacities in table a are based on normal duration of load for untreated panels under dry conditions. Sometimes it grows over 90 metres high and four and one half metres in diameter. We set out the 18 different types of plywood here by ply, wood type as well as other wood sheets made from other materials.
Therefore, you need to carefully consider its advantages and disadvantages of plywood before you use. In the manufacturing of plywood, a log is turned on a lathe and a long knife blade peels the veneer. Physical and mechanical properties of selected wood species. Physical properties refer to density and moisture relations that affect its use. Many of the physical properties of plywood are affected by the amount of moisture present in the wood. Plywood has high tensile strength due to the cross lamination of panels which distributes the force over a large area and reduces tensile stress. Impregnation can be defined as any technique using pressure or nonpressure to fill a wood substance with an inert material, resulting in a desired performance change hill 2006. However, if youre not an experienced plywood shopper, the numerous options at the hardware store can seem overwhelming youll find various prices matched with multiple materials, ply, sizes, veneers, grades, and more. Some properties, such as tension parallel to the grain, and all properties for. Wood handbookchapter 4mechanical properties of wood. Transportation plywoods excellent strengthtoweight ratio and the armorlike durability of an overlaid surface make both hdo and mdo ideal for truck and trailer linings. Agrade plywood features a smooth, sanded surface without knots. An updated version of this publication, released in 2010, is available at wood handbook, 2010 pdf, 15 mb.
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