Primary Wood Processing: Principles and Practice

ISBN-13: 9781402043925 / Angielski / Twarda / 2006 / 596 str.

John Walker

Opis

Samuel Johnson (of Boswell fame) said about writing, whatever is written without effort is in general read without pleasure and the unexamined word is not worth reading. However, even the most thoughtfully written text is unlikely to be described as a good read. This book is not an exhaustive review. Rather it is an uneven selection of examples whose interplay across disciplines hopefully illuminates what drives the practice of forest production, wood processing and consumer preferences. The choice of material is arbitrary reflecting personal biases. It is a summary of material presented to students at the NZ School of Forestry at the University of Canterbury. This book takes liberties with other peoples ideas, weaving them into fresh themes that are at best a work in progress. The philosopher Francis Bacon argued that science is a debate in progress not a body of knowledge and also truth emerges more readily from error than confusion . We have taken the position that it is preferable to venture a reasoned opinion and be proved wrong than to waffle; so don t swallow every sentence doubt everything . The reader s task is to unravel the conceits of generalizing and the risks of particularizing."

Recenzje

Aus den Rezensionen zur 2. Auflage:

"... Das Buch ... gibt einen sehr interessanten Überblick zu Struktur, Eigenschaften und Verwendung von Holz. Es ist dem Autor gelungen, in sehr kompakter Form ein gut lesbares Werk vorzulegen ... Es ist ... in sehr anschaulicher Form umfassend zusammengestellt. ... Insbesondere im Bereich der Grundlagen gelang es, das aktuelle Wissen ... sehr gut und dicht zusammenzustellen. ... zahlreiche neue Arbeiten ... ergänzen ... hervorragend die meist älteren Untersuchungen ... Die anwendungsorientierten Kapitel ... sind eher als erster Überblick für den Einsteiger oder den Studierenden der forstlichen Fachrichtungen ... sehr gut geeignet."

(Peter Niemz, in: Schweizerische Zeitschrift für Forstwesen, 2007, Vol. 158, Issue 3-4, S. 80)

Spis treści

Preface.- 1. The structure of wood: form and function. 1.1 Introduction. 1.2 The microscopic structure of softwoods. 1.3 The microscopic structure of hardwoods. 1.4 The microscopic structure of bark.- 2. Basic wood chemistry and cell wall ultrastructure. 2.1 Introduction. 2.2 The structure of cellulose. 2.3 The cellulose microfibril and cellulose biosynthesis. 2.4 The structure of hemicelluloses. 2.5 The structure of lignin. 2.6 The cell wall structure of a softwood tracheid. 2.7 Distribution of cell constituents. 2.8 Wood extractives.- 3. Water in wood. 3.1 Introduction. 3.2 Some definitions. 3.3 The density of wood tissue. 3.4 The amount of air in oven-dry wood. 3.5 The fibre saturation point. 3.6 Hysteresis and adsorbed water in the cell wall. 3.7 Measuring the fibre saturation point. 3.8 Theories of adsorption. 3.9 Distribution of water within the cell wall. 3.10 Where is the adsorbed water within the cell wall? 3.11 Characteristics of adsorbed water in the cell wall.- 4. Dimensional instability in timber. 4.1 Introduction. 4.2 Shrinkage and swelling of wood. 4.3 Extractive bulking. 4.4 Anisotropic shrinkage and swelling of wood. 4.5 Theories for anisotropic shrinkage. 4.6 Movement and responsiveness of lumber. 4.7 Coatings. 4.8 Dimensional stabilization. 4.9 Panel products.- 5. Wood quality: in context. 5.1 Introduction. 5.2 Market pull or product push. 5.3 Industry requirements. 5.4 Spatial distribution within trees. 5.5 Density. 5.6 Tree form: size, compression wood and knots. 5.7 Softwood plantation silviculture. 5.8 Eucalyptus for wood production.- 6. Wood quality: multifaceted opportunities.6.1 Introduction. 6.2 Moving closer to markets. 6.3 Stiffness. 6.4 Microfibril angle. 6.5 Breeding for increased stiffness. 6.6 Acoustics to select for stiffness. 6.7 Near infrared to predict wood quality. 6.8 Strength and adsorption of energy. 6.9 Fibre length. 6.10 Spiral grain. 6.11 Heartwood. 6.12 Growth stress and reaction wood. 6.13 Endgame.- 7. Sawmilling. 7.1 Introduction. 7.2 Basic saw types and blades. 7.3 Mill design. 7.4 Mill efficiency. 7.5 Aspects of optimising sawlog breakdown. 7.6 Flexibility.- 8. Drying of timber. 8.1 Introduction. 8.2 The drying elements. 8.3 Surface temperature. 8.4 The movement of fluids through wood. 8.5 The external drying environment. 8.6 Drying methods. 8.7 A conventional kiln schedule. 8.8 High-temperature drying above 100oC. 8.9 Drying degrade. 8.10 Practical implications of drying models.- 9. Wood preservation. 9.1 Introduction. 9.2 Organisms that degrade wood. 9.3 Natural durability. 9.4 Philosophy of protection. 9.5 Preservative formulations. 9.6 Treatment processes. 9.7 Health and environmental issues.- 10. Grading timber and glued structural members. 10.1 Introduction. 10.2 Theoretical strength of wood. 10.3 Timber grading for non-structural purposes. 10.4 Visual grading of structural lumber. 10.5 Machine-graded structural timber. 10.6 Adjusting structural timber properties for design use. 10.7 Glued structural members. 10.8 Fire. 10.9 Timber structures.- 11. Wood-based composites: plywood and veneer-based products. 11.1 Introduction. 11.2 Trends. 11.3 Plywood. 11.4 Raw material requirements. 11.5 Plywood manufacture. 11.6 Competition and technological change. 11.7 Sliced veneer. 11.8 Timber-like products.- 12. Wood-based panels: particleboard, fibreboards and oriented strand board. 12.1 Introduction. 12.2 Overview. 12.3 Markets. 12.4 Characterising wood-based panels.12.5 History of wood-based composites. 12.6 Raw materials. 12.7 Generalised panel production line. 12.8 Product standards and panel performance. 12.9 Conclusion.- 13

Blurb

This book is primarily a general text covering the whole sweep of the forest industries. The over-riding emphasis is on a clear, simple interpretation of the underlying science, demonstrating how such principles apply to processing operations. The book starts by considering the broad question "what is wood?" by looking at the biology, chemistry and physics of wood structure (first 4 chapters). This sets the scene. Next key chapters examine "wood quality" – explaining how and why wood quality can be so variable and implications for processing. Finally, in a series of chapters, various "industrial processes" are reviewed and interpreted. The 2^nd Edition is a total revision. A few chapters remain relatively unchanged (no change for the sake of change). Many have been totally rewritten. All chapters have been written by specialists, but the presentation targets a generalist audience.