Wood Science and Technology

http://link.springer.com/journal/226

List of Papers (Total 92)

Sliding mode controller design for wood drying process

This paper deals with the design of sliding mode controllers for the wood drying process. Prediction models based on a nonlinear autoregressive model with exogenous inputs of dry-bulb temperature and equilibrium moisture content during drying were built to design the controllers. A comparative study was performed in order to determine the controller presenting the better...

Analysis on the influence of grain size and grain layer thickness on the sorption kinetics of grained wood at low relative humidity with the use of water vapour sorption experiments

Water vapour sorption (WVS) experiments on grained Norway spruce wood (Picea abies) at low relative humidities were carried out to test the influence of grain size and grain layer thickness on the sorption kinetics. Samples were compared under identical climatic conditions (i.e. humidity and temperature), and the kinetic behaviour was analysed with selected modelling approaches...

Rheological behavior of wood in stress relaxation under compression

Rheological behavior of wood under uniaxial compression along and perpendicular to the grain in constant environment was examined. Tests with constant deformation rate until failure and stress relaxation tests with constant deformation applied stepwise were carried out. The experimental results of stress relaxation showed nonlinear material behavior over time that got more...

Enzymatic biocatalysis of bamboo chemical constituents to impart antimold properties

Current antimold agents that capitalize on broad spectrum biocidal toxicity for their efficacy can create potential hazards in the environment, as in many cases these biocides are not chemically bonded to the wood. They can therefore leach into the ecosystem to jeopardize off-target organisms. In this study, “bio-catalysis” of potassium iodide (KI) was used to impart non...

Experimental techniques for characterising water in wood covering the range from dry to fully water-saturated

Water plays a central role in wood research, since it affects all material properties relevant to the performance of wood materials. Therefore, experimental techniques for characterising water within wood are an essential part of nearly all scientific investigations of wood materials. This review focuses on selected experimental techniques that can give deeper insights into...

Differentiation between pine woods according to species and growing location using FTIR-ATR

Attenuated total reflectance-Fourier transform infrared (FTIR-ATR) spectroscopy was applied to 120 samples of heartwood rings from eight individual pine trees from different locations in Spain. Pinus sylvestris cores were collected at the Artikutza natural park (Ps-ART). Pinus nigra cores were collected in Sierra de Cazorla (Pn-LIN) and in La Sagra Mountain (Pn-LSA). Three...

Evaluation of wood material models for the numerical assessment of cutting forces in chipping processes

Generally, wood chipping represents an important procedure in the wood processing and forestry industry. To improve structural components like chipping tools, knowledge of the properties of local timber including resistance against chipping as well as the dynamically acting process forces is of utmost significance. The aim of this work is to experimentally evaluate service...

Influence of hot water extraction on cell wall and OSB strand mechanics

The exposure of wood to elevated temperatures during hot water extraction (HWE) has been shown to significantly influence a variety of physical and chemical properties of the wood. Aspen (Populus tremuloides) and hemlock (Tsuga canadensis) strands underwent HWE at 160 °C for four different periods of time. The weight loss (WL) associated with the processes ranged from 2.9 to 17.3...

Growth layer and fibre orientation around knots in Norway spruce: a laboratory investigation

The strength of structural timber largely depends on the occurrence of knots and on the local material directions in the surroundings of such knots. There is, however, a lack of methods for establishing a full dataset of the local material directions. The present research aims at the development and application of a laboratory method to assess the geometry of growth layers and...

Coupled two-dimensional modeling of viscoelastic creep of wood

Three coupled two-dimensional viscoelastic creep models for orthotropic material are analyzed. The models of different complexity are mathematically formulated and implemented in a finite element software. Required viscoelastic material parameters are determined by calibration procedure, where numerical results are compared against experimentally obtained viscoelastic strains...

Lattice Boltzmann simulations of diffusion through native and steam-exploded softwood bordered pits

Bordered pits connect adjacent tracheid cells in softwoods and enable water transport between them. Knowledge of how large molecules, such as polysaccharides and enzymes, are transported through pits is important to understand the extraction process of valuable biopolymers from wood. The main mass transport mechanism for large dissolved molecules in wood is diffusion, and this is...

Analysis of DNA profiles of ash (Fraxinus excelsior L.) to provide evidence of illegal logging

Illegal logging is a major problem in many European countries. Recent progress in molecular biology, however, has significantly improved the ability to accurately identify wood material. In this paper, the first application of microsatellite DNA markers is described in a case of illegal logging of European ash wood in Polish State Forests. The genetic fingerprints of seized ash...

A possible explanation for the structural inhomogeneity of lignin in LCC networks

Lignin has a very complex structure, and this is partly due to the monomers being connected by many different types of covalent bonds. Furthermore, there are multiple covalent bonds between lignin and polysaccharides in wood, and it is known that the structure of lignin covalently bound to the hemicellulose xylan is different to lignin bound to the hemicellulose glucomannan. Here...

Predicting the pore-filling ratio in lumen-impregnated wood

Lumen impregnation, unlike most other wood modification methods, is typically assessed by the pore-filling ratio (PFR) (i.e. the fraction of luminal porosity filled) rather than by weight percentage gain (WPG). During lumen impregnation, the impregnants act on the voids in the wood rather than on the solid mass (e.g. cell walls), but the PFR cannot be measured as conveniently as...

Micromechanics of the internal bond in wood plastic composites: integrating measurement and modeling

In this study, an integrated approach combining experimental measurements and numerical modeling was used for characterization of load transfer in the wood/matrix interface in wood plastic composites (WPCs). The experimental methodology was based on optical measurement of surface displacements and strains in model WPC specimens subjected to tensile loads. The model specimens...

Conversion of various types of lignocellulosic biomass to fermentable sugars using kraft pulping and enzymatic hydrolysis

The aim of this work was to assess the utility of seven different kraft pulps produced from softwood (pine), hardwood (poplar, birch and beech), wheat straw and hemp (bast and harl) as potential sources of sugar feedstocks for fermentation processes. The pulps contained low amounts of hemicelluloses (1.9–8.2% d.w.) and lignin (1.7–15% d.w.). The crystallinity index values ranged...

Modelling and simulation of deformation behaviour during drying using a concept of linear difference method

This study deals with the development of a two-dimensional model to simulate the deformations in wood samples during the wood drying process for the evaluation of the drying quality. The samples cut from sapwood of beech were used to analyse the moisture content distribution of the samples at two different drying conditions. A new concept based on a linear difference method was...

Mechanistic study of microstructural deformation and stress in steam-exploded softwood

Steam explosion pretreatment results in the formation of microcracks in the cell walls of wood. In the present study, steam explosion experiments were performed and structural changes in Norway spruce were identified using scanning electron microscopy. The cellular structure of the softwood spruce was simulated using the finite element method, and the effects of pressure...

Nanocellulosic fillers for waterborne wood coatings: reinforcement effect on free-standing coating films

Coatings fulfill an important function in providing functionality and service life to wood surfaces. In the present study, the potential of nanocellulosic fillers toward improving waterborne wood coating mechanics is evaluated using free-standing coating films. At 2% filler content, significant improvements in static and dynamic mechanical properties were observed. The extent of...

Time-resolved laser spectroscopy for the in situ characterization of methacrylate monomer flow within spruce

Time-resolved diffuse optical spectroscopy (TRS) was investigated as a nondestructive method to characterize the post-impregnation distribution of methacrylate monomers within spruce (Picea abies). TRS was also used to monitor the flow of methacrylate monomers in situ, within spruce, during impregnation with both spatial and temporal resolution. The data were compared to fluid...

Porosity estimation of Phyllostachys edulis (Moso bamboo) by computed tomography and backscattered electron imaging

This study aims to investigate and quantify the porosity in the cross section of Phyllostachys edulis (Moso bamboo) culm wall. The porosity results are expected to be utilised in numerical study of heat and moisture transfer. Computed tomography (CT) and backscattered electron (BSE) imaging methods are utilised in this study because these two methods allow measurements of the...

The influence of chemical degradation and polyethylene glycol on moisture-dependent cell wall properties of archeological wooden objects: a case study of the Vasa shipwreck

Cell wall measures allow for direct assessment of wood modification without the adverse effect of varying density and microstructure. In this study, cell wall properties of recent and archeological oak wood from the Vasa shipwreck were investigated for cell wall stiffness, hardness and creep with respect to effects of chemical degradation, impregnation with a preservation agent...