Showing papers in "China Wood Industry in 2004"

Study on a Foamed Material from Plant Fibers

Abstract: Theoretical and experimental research on a foamed material from plant fibers was conducted. Results showed that all the chemical and physical properties of the foamed material were affected by the distribution and size of the bubbles. Plant fibers freely joined each other forming a three dimensional structure as a result of the tension and force of the bubbles. At the same time, the tri dimensional structure was further strengthened by the action of an adhesive and a surface activating agent.

Mechanical Behavior of Bamboo with Large DeformationII. The Characteristics of Microcosmic Deformation

Abstract: The relationship between the changes of microstructure and mechanical behavior of Moso Bamboo (Phyllostachys pubescens) with large compressive deformation were determined with a microscope-loading device. Bamboo samples were compressed in three directions: radial, tangential and longitudinal. The results indicated that: 1) under radial and tangential compression, parenchymatous ground tissue was the basic component for transferring loads. It exhibited the same yield performance and, therefore, bore the same yield limit. In the same way, the bamboo wall revealed the same macro mechanical behavior, which showed bamboo could be regarded as a two-dimensional composite material. 2) Under longitudinal compression, the loads were borne by bamboo fibers and, therefore, the yield limit of bamboo with longitudinal compressive deformation is three times higher than that with transverse compressive deformation.

Drying Characteristics and Drying Schedule for Plantation Grown Poplar and Chinese Fir Lumber

Abstract: This paper describes the drying characteristics of lumber from plantation grown Poplar [Populus×euamericana (Dode) Guineir cv'I-214'] and Chinese Fir (Cunninghamia lanceolata). Two drying processes were used for this study: a continuous schedule and conventional step drying schedule. The results were analyzed and showed that plantation grown wood from Poplar and (Chinese) Fir were easy to dry. After being dried at 100℃, no internal checks occurred but there was some severe cross deformation in the lumber. The lumber dried by the continuous schedule had (better) drying quality with less drying stress and deformation than that dried by the conventional step schedule, on the whole.

Radio Frequency/Vacuum Drying Technology for Plantation Grown Poplar

Abstract: Drying experiments for plantation grown Poplar (Populus×euamericana cv.Ⅰ-214)lumber were conducted by radio frequency/vacuum (RF/V) drying method under various RF/V conditions. The drying speed and drying quality of the lumber were determined. A reasonable RF/V drying schedule was established and test results showed that under this RF/V drying condition, Poplar lumber could be dried efficiently and rapidly resulting in good quality lumber compared with the common steam drying method or the high-temperature vapor drying method.

ACQ Preservative and Preservative-treated Wood

Abstract: Ammoniacal copper quaternary (ACQ) is a wood preservative being used as a (replacement) for the preservative chromated copper arsenate (CCA) that is being phased out. This article presents the basic physical and chemical properties, performance statistics, safety to (humans,) animals and the environment from ACQ. It also covers treating methods, handling (procedures), the effect ACQ has on wood properties, and recommendations on how and where it should be used. The purpose of this article is to present information showing that ACQ is a very good preservative for treated wood products and works very well when used in them.

The Furniture Industry in Europe

Abstract: In the EU, furniture represents 2%~4% of the production value of the manufacturing sector, around 2% of the GDP and 22% of the total workforce There are about 250 000 persons who work in the supply network and 600 000 persons who work in retail industries In the year 2001, the furniture industry's turnover reached 822 billion EUR The European furniture industry, as a whole, accounts for about half of the world furniture production This paper reviewed the production and marketing situation in the European furniture industry, and suggested that China's furniture manufacturers should focus on the EU market instead of only on the US market

Liquefaction of Wood and its Utilizations

Abstract: Liquefaction of wood means a thermal chemical process in which wood powder is turned into a sticky liquid with some organic solvent. The advances in wood liquefaction in the past twenty years, involving the methods, mechanism and applications of the products, were reviewed in the (paper. )

Design and Implementation of Digital Control Lumber Processing Systems

Abstract: This paper discussed transformation and upgrading of digital control processing systems. Based on an analysis of current digital control lumber processing systems in China, both the problems and solutions were reviewed. Specific points that were covered included the design structure of the system, overall function, programming, network, and process operation. After upgrading and transformation, the digital control systems did not only maintain the original precision and function, but also had gained modern capabilities such as network communication, data transmission, CAD, CAM, and simulation, that made its function and performance meet the standards of modern science and technology.

A New Test Method for Shear Strength Parallel to Wood Grain

Abstract: In order to determine the shear strength parallel to grain for small-diameter logs or thin lumber, this paper describes a new test method in which the width of the specimen was cut to half its standard size. The feasibility of using the modified shear specimen, as a substitute for a standard specimen, was determined by comparing the shear strength between modified and standard (specimens) from both Chinese Fir (Cunninghamia lanceolata) and Poplar I-214 [Populus × euramericana (Dode) Guineir cv.'I-214'] lumber. Results showed that the absolute values of the relative differences of the shear strength between the standard and modified specimens for matched (condition) were under 3%, and there was no significant difference at the 0.05 probability level. This provided a useful method for measuring the shear strength parallel to the wood grain for small or undersize timber.

Computerized Simulation of Veneer Slicing Based on CT Scanning

Abstract: This paper introduces a new processing method for hardwood log veneer based on a computed tomography (CT) image. The process mainly involves log CT scanning, CT image (processing,) 3-D reconstruction of the log on a computer, simulated flitch slicing, and a virtual (display) of veneer. The application of the process and the benefits of the method are described. It (also) (analyzes) the possibility of applying a CT machine to the wood processing industry. Results showed that the method could be an efficient way to help operators with decisions on log sawing and flitch (slicing.)

A Study on Processing Edge Jointed Veneer

Abstract: Three wood species, Manchurian Ash(Fraxinus mandshurica), Manchurian Walnut(Juglans mandshurica) and Spruce (Picea jezoensis var. komarovii),and two kinds of adhesives, (water)based polymer-isocyanate and water-solidified polyurethane, were selected to make laminated flitches. The water resistance of the flitches, along with the thickness warp and surface roughness of the sliced laminated veneer cut from the fliches, were tested. After hydrothermal treatment, (only)part of the Ash Laminated flitches made with water based polymer-isocyanate were found to have peeled, whereas the other two species of laminates made either with water-solidified polyurethane or water based polymer-isocyanate, showed good bond property and water resistance. The surface roughness of the three species of laminated veneer at 0.60 mm thick could meet the (corresponding)requirements in National Standard GB/T 13010-1991.

A Design for a Temperature-controller Based on Fuzzy Algorithm for an Adhesive Preparation Process

Abstract: The preparation of an adhesive is a lengthy, nonlinear and time-varying process with big inertia and pure delay. The author designed an intelligent control system by combining Smith pre-estimate control with fuzzy logic to help understand and develop better control of the process. The theory of Smith pre-estimate control, its structure and application, are presented in this paper. The simulation results indicate this control system is efficient and can be adopted in an adhesive preparation process.

An Experiment on Selecting Antifungal and Anti-insect Agents for Indoor Wood-based Flooring and Other Wood Products

Abstract: This paper investigates six kinds of selected preservatives as antifungal and anti-insect (agents) for wood flooring and other wood products and their application, such as the compound of boride and sodium pentachlorophenol, organophosphorus agent, quaternary ammonium salts and pyrethroids. To evaluate their resistance against Coriolus versicolor and termites, a series of experiments for Korean Pine (Pinus koraiensis) wood sample were carried out. By comparison between treated samples and controls, the results showed the mixture of quaternary ammonium salts and pyrethroids was the most effective but least harmful preservative, and was suitable for wood flooring and other indoor wood products. The results also established a base for developing a standard for this preservative treatment.

The Wood Chemical Composition and Its Flame Retardancy

Abstract: The flame retardancy of wood is based on its chemical composition and structure The objective of this study was to explore the (relationship) between the primary chemical properties of wood composition and its pyrolysis and combustion and to analyze the reaction path between the (reacting) flame retardants and wood composition The conclusion showed that the key point was (temperature) at 200～300 ℃ where the flame retardant was able to promote dewatering and (charring) of wood It also showed that a reacting type flame retardant was an efficient way to prevent the preservative from leaching Finally, some suggestions for flame retardancy were made, such as (applying) Nanometer technology for wood flame retardant development and for exploring a versatile, efficient frothing type flame retardant