Principles of Wood Science and Technology: I Solid Wood

ISBN-13: 9783642879302 / Angielski / Miękka / 2012 / 592 str.

Franz F. P. Kollmann; Wilfred A. Jr. Cote; Franz Kollmann

Opis

Modern forest products research had its start hardly fifty years ago. Today we are in a position to apply the title "wood science" to the field of wood technology that is based on scientific investigation, theoretical as well as experimental. It is this research that fosters new uses for wood as a raw material and that creates the foundation for new industries for the manufacture of wood-base materials such as plywood, laminated products, particle and fiber board and sand- wich construction. Wood technology in its broadest sense combines the disciplines of wood anatomy, biology, chemistry, physics and mechanical technology. It is through this interdisciplinary approach that progress has been made in wood seasoning, wood preservation methods, wood machining, surfacing and gluing, and in the many other processes applied in its utilization. In 1936 the senior author published a book entitled, "Technologie des Holzes," which was a first approach to a universal reference book on wood technology. The first edition of Volume I of the Textbook of Wood Technology, co-authored by H. P. BROWN, A. J. P AN SHIN, and C. C. FORSAITH, was published in 1948. An indication of the rapid development of this field can be gained from the fact that the second edition of "Technologie des Holzes und der Holzwerkstoffe," completely revised, was needed by 1951. It contains 2233 pages compared with the 764 pages of the 1936 edition.

Spis treści

1. The Structure of Wood and the Wood Cell Wall.- 1.0 Introduction.- 1.1 Gross Structure of Wood.- 1.1.1 Cellular Composition.- 1.1.2 Wood Rays.- 1.1.3 Planes of Wood.- 1.1.4 Sapwood and Heartwood.- 1.1.5 Growth Increments.- 1.1.6 Axial Parenchyma.- 1.1.7 Intercellular Canals.- 1.1.8 Other Gross Features.- 1.2 Microscopic Structure of Wood.- 1.2.1 Major Cell Types.- 1.2.2 Cell Sorting and Arrangement.- 1.2.3 Cell Inclusions.- 1.2.3.1 Tyloses.- 1.2.3.2 Crystals.- 1.2.3.3 Oil cells.- 1.2.3.4 Gums and Resins.- 1.3 Organization of the Cell Wall.- 1.3.1 The Microfibril.- 1.3.2 Generalized Structure and Terminology.- 1.3.3 Microfibrillar Orientation.- 1.3.4 Cell Wall Sculpturing.- 1.3.4.1 Pit Structure.- 1.3.4.2 Helical Thickenings.- 1.3.4.3 Wart Structure.- 1.3.4.4 Dentate Ray Tracheid Thickenings.- 1.4 Reaction Wood Anatomy and Ultrastructure.- 1.4.1 Compression Wood.- 1.4.2 Tension Wood.- Literature Cited.- 2. Chemical Composition of Wood.- 2.0 Introduction.- 2.1 Chemical Constituents of Wood and their Determination.- 2.2 Characteristics of the Principal Wood Constituents.- 2.2.1 Cellulose.- 2.2.1.1 Isolation from Wood.- 2.2.1.2 Structure.- 2.2.1.3 Properties.- 2.2.2 Hemicellulose.- 2.2.2.1 Hemicelluloses of Hardwoods.- 2.2.2.2 Hemicelluloses of Softwoods.- 2.2.3 Other Wood Polysaccharides.- 2.2.4 Lignin.- 2.2.4.1 Isolation from Wood.- 2.2.4.2 Structure.- 2.2.4.3 Properties.- 2.3 Wood Extractives.- 2.4 Distribution of Chemical Constituents in Wood.- Literature Cited.- 3. Defects and Abnormalities of Wood.- 3.0 Introduction.- 3.1 Natural Defects.- 3.1.1 Knots.- 3.1.2 Eeaction Wood.- 3.1.2.1 Compression Wood.- 3.1.2.2 Tension Wood.- 3.1.3 Cross Grain.- 3.1.4 Variations in Log Form.- 3.1.5 Shake.- 3.1.6 Miscellaneous Natural Defects.- 3.2 Defects due to Processing.- 3.2.1 Manufacturing Defects.- 3.2.2 Seasoning Defects.- 3.2.2.1 Checks.- 3.2.2.2 Warp.- 3.2.2.3 Casehardening.- 3.2.2.4 Collapse.- 3.2.2.5 Honeycomb.- 3.2.2.6 Washboarding.- 3.2.2.7 Miscellaneous Seasoning Defects.- 3.2.3 Raised Grain.- 3.2.4 Loosened Grain.- Literature Cited.- 4. Biological Deterioration of Wood.- 4.0 Introduction.- 4.1 Fungi causing Wood Deterioration.- 4.1.1 Characteristics of Wood-destroying Fungi.- 4.1.1.1 Comparison of Brown Rot and White Rot.- 4.1.1.2 Soft Rot.- 4.1.2 Characteristics of Wood-staining Fungi.- 4.1.3 Physiological Requirements of Wood-destroying and Wood-inhabiting Fungi.- 4.1.3.1 Temperature.- 4.1.3.2 Oxygen.- 4.1.3.3 Moisture.- 4.1.3.4 Nutrients.- 4.1.3.5 Hydrogen Ion Concentration.- 4.1.3.6 Natural Durability.- 4.1.3.7 Relationship of Wood Preservation to Physiological Requirements.- 4.1.4 Mechanism of Wood Decay.- 4.1.5 Influence of Decay on Mechanical Properties.- 4.2 Wood-boring Insects.- 4.2.1 Termites.- 4.2.1.1 Characteristics.- 4.2.1.2 Control.- 4.2.2 Powder-post Beetles.- 4.2.2.1 Lyctidae.- 4.2.2.2 Wood-feeding Anobiidae.- 4.2.2.3 Cerambycidae. Long-horned Beetles or Round-headed Borers.- 4.2.2.4 Bostriehidae. Auger or Shot-hole Borers.- 4.2.2.5 Control Measures.- 4.2.3 Carpenter Ants.- 4.2.4 Carpenter Bees. Order Hymenoptera.- 4.2.5 Horntails. (Siricidae).- 4.3 Marine Borers.- 4.3.1 Molluscan Borers.- 4.3.2 Crustacean Borers.- 4.3.3 Protection against Marine Wood Borers.- Literature Cited.- 5. Wood Preservation.- 5.0 Introduction.- 5.1 General Considerations.- 5.1.1 Effect of Structure on Treatment.- 5.1.2 Timber Preparation.- 5.2 Wood Preservation Processes.- 5.2.1 Non-pressure Processes.- 5.2.1.1 Brushing or Spraying.- 5.2.1.2 Dipping.- 5.2.1.3 Steeping and Cold Soaking.- 5.2.1.4 Hot-and-Cold Bath.- 5.2.1.5 Diffusion Method.- 5.2.2 Pressure Processes.- 5.2.2.1 Pull-cell Processes.- 5.2.2.2 Empty-cell Processes.- 5.2.3 Miscellaneous Processes.- 5.3 Wood Preservatives.- 5.3.1 Characteristics of Preservatives.- 5.3.2 Preservative Materials Toxic to Insects, Fungi and Marine Borers.- 5.4 Fire Retardant Treatment.- 5.4.1 General Remarks about the Combustibility of Wood.- 5.4.2 Developed Heat and Strength.- 5.4.3 Course of Temperature and Chemical Phenomena in Combustion of Wood.- 5.4.4 Effects and Properties of Fire Retardants.- 5.4.4.1 Water Soluble Salts.- 5.4.4.2 Alkali Silicates.- 5.4.4.3 Foam Forming Organic Compounds.- 5.4.4.4 Other Fire Retardants.- 5.4.5 Testing of Fire Retardants.- 5.5 Dimensional Stabilization.- 5.5.1 Theory.- 5.5.2 Methods.- Literature Cited.- 6. Physics of Wood.- 6.1 Density and Specific Gravity.- 6.1.1 Density, Porosity, Specific Gravity of Wood Substance and of Wood Constituents.- 6.1.2 Effect of Moisture Content in Wood on its Density.- 6.1.3 Density of Green Wood.- 6.1.4 Variations in Density.- 6.1.5 Density of Springwood and Summerwood, Correlation with Width of Annual Rings.- 6.1.6 Content of Solid Matter in Piles of Wood and Wood Residues.- 6.2 Wood-Liquid Relations.- 6.2.1 Moisture Content, Definition.- 6.2.2 Determination of Moisture Content.- 6.2.2.1 Oven-drying Method.- 6.2.2.2 Distillation Method.- 6.2.2.3 Titration According to K. Fischer (1935); Eberius (1952, 1958).- 6.2.2.4 Hygrometric Methods.- 6.2.2.5 Electrical Moisture Meters.- 6.2.3 Sorption and Equilibrium Moisture Content.- 6.2.4 Recommended Moisture Content for Wood in Service.- 6.2.5 Fiber Saturation Point, Maximum Moisture Content of Wood.- 6.2.6 Thermodynamics of Sorption.- 6.2.7 Shrinkage and Swelling.- 6.2.7.1 Maximum Volumetric Shrinkage and Swelling, Influence of Drying Temperature.- 6.2.7.2 Anisotropy of Shrinkage and Swelling.- 6.2.7.3 Super-position of the Components of Swelling, Restrained Swelling.- 6.2.7.4 Swelling in Aqueous Solutions and Organic Liquids.- 6.2.7.5 Dimensional Stabilization of Wood.- 6.3 Capillary Movement and Diffusion in Wood.- 6.3.0 General Considerations on the Movement of Water in Wood Above and Below Fiber Saturation Point.- 6.3.1 Capillary Movement of Water in Wood.- 6.3.2 Diffusion of Water in Wood.- 6.3.3 Drying of Wood as a Diffusion Problem.- 6.3.3.1 Analogy to Fourier’s Analysis for Heat Conduction.- 6.3.3.2 Approximated Calculation of the Drying Time.- 6.3.3.3 Stamm’s Theoretical Drying Diffusion Coefficients.- 6.4 Physical Aspects of Wood Impregnation.- 6.4.1 Nonpressure Processes.- 6.4.2 Pressure Processes.- 6.4.2.0 General Considerations.- 6.4.2.1 Theory of Pressure Treatment of Wood.- 6.5 Thermal Properties of Wood.- 6.5.1 Thermal Expansion.- 6.5.2 Specific Heat of Wood.- 6.5.3 Thermal Conductivity of Wood.- 6.5.3.0 General Considerations.- 6.5.3.1 Influences of Structure and Density, Moisture Content and Temperature on the Thermal Conductivity of Wood.- 6.5.4 Diffusivity of Wood, Change of Temperature in Heated Wood.- 6.5.5 Radiation of Heat with Respect to Wood.- 6.6 Electrical Properties of Wood.- 6.6.1 Direct-current Properties: Electrical Resistance and Electrical Conductivity.- 6.6.2 Alternating-Current Properties of Wood.- 6.6.2.1 Resistivity.- 6.6.2.2 Dielectric Constant.- 6.6.2.3 Power Factor.- 6.6.3 Magnetic Properties of Wood and Wood Constituents.- 6.6.4 Piezoelectric Properties of Wood.- 6.7 Acoustical Properties of Wood.- 6.7.0 General Considerations.- 6.7.1 Sound Transmission in Wood.- 6.7.1.1 Sound Velocity.- 6.7.1.2 Sound Wave Resistance, Damping of Sound Radiation and Internal Friction.- 6.7.2 Acoustics of Buildings.- 6.7.2.1 Sound Energy.- 6.7.2.2 Sound Transmission Loss for Various Types of Construction.- 6.7.2.3 Sound Absorption.- Literature Cited.- 7. Mechanics and Rheology of Wood.- 7.1 Elasticity, Plasticity, and Creep.- 7.1.1 Hooke’s Law, Modulus of Elasticity.- 7.1.2 Rhombic Symmetry of Wood, Systems of Elastic Constants.- 7.1.3 Poisson’s Ratios.- 7.1.4 Compressibility (Bulk Modulus).- 7.1.5 Determination of Elastic Constants.- 7.1.5.1 Determination by Static Tests.- 7.1.5.2 Determination by Dynamic Tests.- 7.1.6 Influences Affecting the Elastic Properties of Wood.- 7.1.6.1 Grain Angle.- 7.1.6.2 Density.- 7.1.6.3 Moisture Content.- 7.1.6.4 Temperature.- 7.1.6.5 Knots and Notches.- 7.1.7 Plasticity and Creep.- 7.1.7.1 Stress-strain Behavior.- 7.1.7.2 Creep and Creep Recovery.- 7.1.7.3 Rheological Models and Mathematical Considerations.- 7.2 Tensile Strength.- 7.2.1 Tensile Strength of Cellulose Molecules, of Single Wood Fibers, and Breaking Length.- 7.2.2 Determination of Tensile Strength Along the Grain.- 7.2.3 Factors Affecting the Tensile Strength Along the Grain.- 7.2.3.1 Grain Angle.- 7.2.3.2 Density.- 7.2.3.3 Moisture Content.- 7.2.3.4 Temperature.- 7.2.3.5 Knots and Notches.- 7.2.4 Determination of Tensile Strength Perpendicular to the Grain, Cleavage.- 7.2.5 Fatigue in Tension Parallel to the Grain.- 7.3 Maximum Crushing Strength and Stresses in Wood Columns.- 7.3.0 General Considerations.- 7.3.1 Testing in Compression Parallel to Grain.- 7.3.2 Testing in Compression Perpendicular to Grain.- 7.3.3 Influences Affecting the Crushing Strength.- 7.3.3.1 Grain Angle.- 7.3.3.2 Density.- 7.3.3.3 Moisture Content.- 7.3.3.4 Temperature.- 7.3.3.5 Knots and Notches.- 7.3.3.6 Chemical Constituents.- 7.3.4 Fatigue in Compression Parallel to the Grain.- 7.3.5 Stresses in Solid Wood Columns.- 7.4 Bending Strength (Modulus of Rupture).- 7.4.0 General Considerations.- 7.4.1 Testing of Small Wooden Beams under Static Center Loading.- 7.4.2 Influences Affecting the Bending Strength (Modulus of Rupture).- 7.4.2.1 Grain Angle.- 7.4.2.2 Density.- 7.4.2.3 Moisture content.- 7.4.2.4 Temperature.- 7.4.2.5 Shape and Size of Beams, Knots and Notches.- 7.4.2.6 Fatigue in Bending.- 7.5 Shock Resistance or Toughness.- 7.5.0 General Considerations.- 7.5.1 Determination of Shock Resistance.- 7.5.1.1 Single Blow Impact Test.- 7.5.1.2 The Hatt-Turner Test (Successive Blows Impact Test).- 7.5.2. Comparison of Impact Test Results.- 7.5.3 Influences Affecting the Shock Resistance.- 7.5.3.1 Shape and Size of Beams, Notches (Izod-test).- 7.5.3.2 Grain Angle.- 7.5.3.3 Density.- 7.5.3.4 Moisture Content.- 7.5.3.5 Temperature.- 7.5.3.6 Anatomical Properties, Chemical Constituents, Decay.- 7.5.3.7 Types and Phenomena of Failures in Impact Bending.- 7.6 Torsional Properties and Shear Strength.- 7.6.0 General Considerations.- 7.6.1 Determination of Torsional Strength.- 7.6.2 Determination of Shearing Strength Parallel to Grain.- 7.7 Hardness and Abrasion Resistance.- 7.7.0 General Considerations.- 7.7.1 Hardness Tests.- 7.7.2 Factors Influencing the Hardness of Wood.- 7.7.3 Abrasion Resistance.- 7.7.4 Some Aspects of Nondestructive Testing of Wood and Timber Grading.- Literature Cited.- 8. Steaming and Seasoning of Wood.- 8.0 General Considerations.- 8.1 Air-drying.- 8.1.1 Moisture Content of Green Wood.- 8.1.2 Course of Air-drying.- 8.1.3 Yard Seasoning.- 8.1.3.1 Lumberyard Layout.- 8.1.3.2 Seasoning Periods.- 8.1.4 Accelerated Air-drying, Predrying.- 8.1.4.1 Fan Air-drying.- 8.1.4.2 Air-drying by Means of Swings or Centrifuges.- 8.1.4.3 Air-drying by Solar Heat.- 8.1.4.4 Predriers.- 8.2 Steaming.- 8.2.1 Reasons for Steaming.- 8.2.2 Methods of Steaming and Heat Consumption.- 8.2.3 Effects of Steaming on Wood.- 8.3 Kiln Drying.- 8.3.0 General Considerations.- 8.3.1 Fundamental Drying Factors.- 8.3.2 Defects in Wood due to Kiln Drying.- 8.3.2.0 General Considerations.- 8.3.2.1 Staining.- 8.3.2.2 Deformations (Warping, Twisting, Cupping).- 8.3.2.3 Casehardening.- 8.3.2.4 Collapse.- 8.3.3 Types of Kilns and Instruments.- 8.4 Special Seasoning Methods..- 8.4.1 High Temperature Drying.- 8.4.2 Drying by Boiling in Oily Liquids.- 8.4.3 Solvent Seasoning.- 8.4.4 Vapor Drying.- 8.4.5 Vacuum Drying.- 8.4.6 Chemical Seasoning.- 8.4.7 Drying by Direct Application of Electricity.- 8.4.7.1 Drying by Joule’s Heat.- 8.4.7.2 High-frequency Dielectric Drying.- 8.4.8 Drying by Infrared Radiation.- Literature Cited.- 9. Wood Machining.- 9.1 Introduction.- 9.2 Technology of Sawing.- 9.2.1 Sash Gang Sawing.- 9.2.1.1 Cutting Velocity..- 9.2.1.2 Chip Thickness and Average Cutting Resistance.- 9.2.1.3 Consumption of Energy.- 9.2.1.4 Effects of Tooth Geometry, Tooth Height and Pitch.- 9.2.1.5 Influence of Setting.- 9.2.1.6 Strain and Stresses in Gang Saw Blades; Thermal Effects.- 9.2.1.7 Surface Quality.- 9.2.1.8 Yield.- 9.2.2 Band Sawing.- 9.2.2.1 General Considerations, Saw Blade Dimensions.- 9.2.2.2 Cutting Velocity and Cutting Resistance.- 9.2.2.3 Influence of Feed Speed.- 9.2.2.4 Effect of Depth of Timber Cut and of Grain Orientation.- 9.2.2.5 Effect of Tooth Geometry and Pitch.- 9.2.2.6 Band Tension and Stability.- 9.2.3 Circular Sawing.- 9.2.3.1 Introduction, Saw Blade Geometry, Kinematics.- 9.2.3.2 Effect of Cutting Velocity on the Cutting Resistance.- 9.2.3.3 Cutting Force and Cutting Power, Effect of Feed Rate or Feed per Tooth.- 9.2.3.4 Specific Cutting Energy.- 9.2.3.5 Effect of Depth of Timber Cut and of Grain Orientation.- 9.2.3.6 Effect of Blade Diameter and Blade Thickness.- 9.2.3.7 Effect of Tooth Geometry and Pitch.- 9.2.3.8 Chip Formation.- 9.2.3.9 Thermal Effects, Stresses, and Stability of Circular Saw Blades.- 9.2.3.10 Special Types of Circular Saw Blades.- 9.2.4 Chain sawing.- 9.2.4.1 Introduction.- 9.2.4.2 Machine Types.- 9.2.4.3 Chip Formation, Power Requirements.- 9.3 Proposed Methods of Chipless Wood-Cutting.- 9.3.1 Peeling and Slicing.- 9.3.2 Cutting with Vibration Cutters.- 9.3.3 Cutting with High-energy Jets.- 9.3.4 Cutting with the Laser.- 9.4 Technology of Jointing, Planing, Moulding and Shaping.- 9.4.1 General Considerations.- 9.4.2 Geometry of Cutterhead-knives.- 9.4.3 Cutting Velocity and Cutting Force.- 9.4.3.1 Effect of Cutting Velocity on the Cutting Force.- 9.4.3.2 Effect of Cutting-Circle Diameter, Feed Speed, and Number of Knives.- 9.4.3.3 Effect of Grain Orientation, Inclination of the Cutting Edge, and Chip Thicknes.- 9.4.3.4 Effect of Wood Species, Moisture Content and Temperature.- 9.4.3.5 Effect of Cutter Materials.- 9.4.3.6 Effect of Cutting Depth.- 9.4.3.7 The Blunting of Cutter Head Knives.- 9.4.4. Formation of Chips through Knife-cutting.- 9.4.4.1 Influence of Wood Moisture Content on Chip Formation.- 9.4.4.2 Influence of Knife Geometry on Chip Formation.- 9.4.4.3 Other Cutting Factors and their Effect on Chip Formation and Quality.- 9.5 Sanding.- 9.5.1 General Considerations.- 9.5.2 Abrasives.- 9.5.3 Technology of Sanding Process.- 9.6 Turning.- 9.6.1 General Considerations.- 9.6.2 Effects on the Turning of Wood.- 9.6.3 Quality of Turned Surfaces.- 9.7 Tenoning, Mortising and Boring.- 9.8 Bending of Solid Wood.- 9.8.1 General Considerations.- 9.8.2 Strains and Stresses in Wood Bending.- 9.8.3 Pretreatment of the Wood Prior to Bending.- 9.8.4 Methods and Machines for Wood Bending.- 9.8.5 Properties of Bent Wood.- 9.8.5.1 Sorption Properties.- 9.8.5.2 Mechanical Properties.- 9.9 Laminated Bending.- Literature Cited.- Author Index.