Understanding the physical properties of foods is important as they are used in process design, product and process optimization, product development, food quality control and food process modeling. The chapter begins with a broad overview of woodwater relations, defining key concepts needed to understand the physical properties of wood. Top 6 properties of wood and timber used in construction. Physical properties of two tropical wood species from mozambique. Physical and mechanical properties of beech wood harvested in the greek public forests. Weight, volume, and physical properties of major hardwood ies. Kretschmann contents orthotropic nature of wood 41 elastic properties 42 modulus of elasticity 42 poissons ratio 42 modulus of rigidity 43 strength properties 43 common properties 43 less common properties 424 vibration properties 425. This lesson covers the physical and mechanical properties of wood. Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. Each of these components contributes to fiber properties, which ultimately impact product properties. This summary is a generalization and many manufacturers offer special formulations with special properties. Permeability is the rate at which water vapor will pass through the panel in the presence of a pressure gradient. Publications and articles on the mechanical properties of wood, and timber testing part iii.
Physical properties of wood wooden house, log house. Mechanical properties refer to the strength characteristics of wood. It provides an overview of woodbased products and exposes students to structural systems in wood. Wood moisture and properties associated with its change 3. Cutting tools during interaction with this anisotropic material are subjected to severe loads and transverse vibrations, thus, different wear characteristics and mechanisms are produced. Generally, specific gravity sg and the major strength properties of wood are directly related. The results obtained are in all cases reduced to 12 per cent moisture contents. Advantech, zip system, and huber blue panels are all consider ps2 compliant osb wood structural panels. The physical, mechanical, and chemical properties of wood are probably interdependent and affect the woods resistance to termites. Mechanical properties of wood forest products laboratory. Many of the mechanical properties of wood tabulated in this. In accordance with this standard, the follow properties apply. Pdf physical properties of wood in poplar clones i214. Physical properties, mechanical properties, pois son module, compression, oak.
This course introduces students to the physical and mechanical properties of wood. This study was conducted to determine the effect of wood species on some physical properties density, specific gravity, %. This method is useful with such species as the southern pines, douglasfir, and the ringporous hardwoods ash, hickory, and oak. Following properties of wood makes it good for use in construction specific gravity sg. Mechanical, physical and chemical properties of wood, heat. Basic techniques for physical measurement and mechanical testing are introduced by conducting and analyzing several laboratory experiments. Yildiz c the objective of this study was to evaluate the discoloration of european beech fagus sylvatica and scots pine pinus sylvestris specimens. Density lesson 1 showed that wood is a porous material made up of cells of various kinds. Because its physical and mechanical properties are so balanced, it rates highly for nearly all woodmachining processes. Pdf physical and chemical properties of wood ash from. Physical properties of wood in poplar clones i214 and s18 article pdf available in drvna industrija 672. Stressstrain diagrams of two longleaf pine beams 2. Students will investigate the density, stiffness, and elasticity of several species of wood. Wood handbookchapter 4mechanical properties of wood.
Wood beams strength of material bending and compression strength of wood species used in beams wood hardness soft and hardwood janka hardness wood, panel and structural timber products mechanical properties density, fibre stress, compressive strength and modulus of elasticity of clear wood, panel and structural timber products. A color change in the wood due to interaction of glue and wood. Physical and chemical properties of wood ash from burning and gasification processes. Publications of the united states government on the mechanical properties of wood, and timber testing illustrations frontispiece photomicrograph of a small block of western hemlock 1. Therefore, a fundamental understanding of wood machining properties. Summarizes information on wood as an engineering material. Pdf physical and mechanical properties of timber wood. Included are such properties as moisture content, density, dimensional stability, thermal and pyrolytic fire properties, natural durability, and chemical resistance. A chart of the physical properties of woods worlwide, excluding north america. Because of the greater density of latewood, the proportion of latewood is sometimes used to judge the strength of the wood. Wood properties forest products laboratory forest service. Weight, volume, and physical properties of major hardwood. It is well known that decaying wood can absorb many times its dry weight in water 10 because woody tissue is highly hygroscopic 11, and additionally, water is produced after fungal. Physical, chemical, and biological properties of soil under.
Physical properties and moisture relations of wood pdf 495 kb appearance moisture content shrinkage weight, density, and specific gravity working qualities decay resistance thermal properties electrical properties coefficient of friction nuclear radiation chapter 4. Characteristics the wood is hard, strong, and machines well. Wood is one of the most versatile and widely used materials in the world. This chapter discusses the physical properties of most. A chemical property is a characteristic that can only be seen when the material changes and a new material is formed. In many cases, more than one property of wood is important to the end product. These trees bear cones and most of them have needle. The hardwoods have a specific gravity ranging between 0.
Includes discussion of designing with wood and woodbased products along with some pertinent uses. Physical and chemical characterization of waste wood derived biochars erin n. Table 1 presents major chemical compositions of some wood species. Lesson two the physical and mechanical properties of wood. Physical properties of wood the properties of wood found in tests that do not lead to a change in chemical composition are called physical properties. Physical and mechanical properties of the wood used in. Properties of wood building and construction technology. Properties of wood there are fewer species of conifers. Wood main physical properties archiline wooden houses. The moisture content of wood is another property of timber which effects the quality of timber to. This was assumed to be the highest average moisture contents of seasoned wood.
This book provides a fundamental understanding of physical properties of foods. Definition the mechanical properties of wood are its fitness and ability to resist applied or external forces the mechanical properties of wood considered are 1 stiffness and elasticity, 2 tensile strength, 3 compressive or crushing strength, 4 shearing strength, 5 transverse or bending strength, 6 toughness, 7 hardness, 8 cleavability, 9. Part of the workshop companion, a collection of information on wood, woodwork, woodworking skills, woodworking materials, and woodworking plans that together form the core knowledge needed by woodworkers, furniture makers, cabinetmakers, turners, and other practioners of the wood arts to become competent. The narrow 1 to 2inch band of sapwood is gray to pale brown in dry lumber. Sometimes it grows over 90 metres high and four and one half metres in diameter. Presents properties of wood and woodbased products of particular concern to the architect and engineer.
To meet this need, a southwide study was initiated by the north carolina state hardwood research cooperative and the ljsda forest service. Softwoods comprise more than 80 percent of the total volume of standing timber in. Physical and mechanical properties of timber wooddestroying organism, termite. Physical properties of world woods workshop companion. Physical properties color and figure the heartwood of robusta eucalyptus is light red to reddish brown in color as it comes from the saw. Cork is the lightest wood having a specific gravity of 0. Includes discussion of designing with wood and wood based products along with some pertinent uses. Variations of the physical and mechanical wood properties of. The physical, mechanical, and chemical properties of wood are probably interdependent and affect the wood s resistance to termites. Any wood capable of yielding a minimum dimensional size can be termed as a timber or lumber.
The three moduli of rigidity denoted by glr, glt, and grt are the elastic constants in the lr, lt, and rt planes, respectively. The physical properties of wood, including color, weight, texture, grain, and pattern. Mechanical, physical and chemical properties of saw dust. This moisture relationship has an important influence on wood properties and performance. Few data, however, exist on the weight, volume, and physical properties of the total tree and its components for hardwood species of this region. Physical properties of wood this is a handson lesson in which students investigate the relationship between physical properties of wood and its suitability for construction purposes. The results of the physical and mechanical properties of swietenia macrophylla grown in mixed and monoculture plantation are presented in the table 1.
Sg for the major, usually used structural species ranges from roughly 0. This chapter discusses the structure of wood, its physical and mechanical properties, and the manufacturing and grading processes for sawn lumber and glulam. Basically, timber or lumber is a wood or firewood of growing trees. For example, to select a wood species for a product, the value of appearancetype properties, such as texture, grain pattern, or color, may be evaluated against the influence of. Physical and mechanical properties of selected wood species in. For easy comparison, these properties are examined in table 401.
Physical properties of wood designing buildings wiki. Physical properties are the quantitative characteristics of wood and its behavior to external. Part of the workshop companion, a collection of information on wood, woodwork, woodworking skills, woodworking materials, and woodworking plans that together form the core knowledge needed by woodworkers, furniture makers, cabinetmakers, turners, and other practioners of the wood arts to become competent craftsmen. Timber is a type of wood which has been processed into beams and planks. Presents properties of wood and wood based products of particular concern to the architect and engineer. Wood chemical composition hemicellulose a celluloselike material in the wood cell wall that is easily decomposed by dilute acid to yield simple sugars extractives organic material deposited during heartwood formation gums, resins, oils, alkaloids. It can be used in anything from wood carving and creating small wooden items, such as chairs and rocking horses, to building timber structures and sheds. Among the physical factors, wood density influences the termites ability to fragment the wood mechanically with its mandibles bultman et al. Pdf moisture relations and physical properties of wood. Physical properties refer to density and moisture relations that affect its use. Physical properties of wood designing buildings wiki share your construction industry knowledge. Physical and chemical characterization of waste wood derived. Hardness and strength of wood depend to a great extent on its density.
Earlywood is lighter in weight, softer, and weaker than latewood. Chapter 5 mechanical properties of wood modulus of rigidity the modulus of rigidity, also called shear modulus, indicates the resistance to deflection of a member caused by shear stresses. It provides an overview of wood based products and exposes students to structural systems in wood. The physical and mechanical properties of wood are important factors used in determining the. All physical properties change from panel to panel depending on the natural characteristics of the wood used to make the panel. Physical and mechanical properties of selected wood. Pdf physical and mechanical properties of beech wood. The present study deals with determination of physical, mechanical and combustion characteristics like mass, density, compressive strength, shearing strength, moisture content, total ash content, fixed carbon, volatile matter, gross calorific value of sawdust briquette. Physical and mechanical properties of selected wood species. It is an organic material a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood handbookchapter 3physical properties and moisture. To meet this need, a southwide study was initiated by the north carolina state. Moisture relations and physical properties of wood. Presentation pdf available october 2010 with 4,160.