European Union Timber Regulation Impact on International Timber Markets

1

57th SWST International

Convention

7th Wood Structure and Properties

Conference

6th European Hardwood

Conference

June 23–27, 2014

Technical University in Zvolen

Zvolen, Slovakia

Edited by: H. Michael Barnes and Victoria L. Herian

Overall General Co-Chairs: Michael Wolcott, Washington

State University, USA and Marian Babiak,

2

Table of Contents

Hardwood Research & Utilization

Session Co-Chairs: Rado Gazo, Purdue University, USA and Róbert Németh, University of West Hungary, Hungary

Rado Gazo, Juraj Vanek, Michel Abdul-Massih, and Bedrich Benes, Purdue University, USA CT Scanning of Logs – Analysis and Optimization for Better Utilization of Hardwoods…... 15 Roman Réh, Technical University in Zvolen, Slovakia

Decorative Veneer Properties of Black Walnut (Juglans nigra L.)……… 16 Leandro Passarini, Université Laval; Cédric Malveau, Université de Montréal ; Roger Hernández, Université Laval, Canada

Distribution of the Equilibrium Moisture Content in Four Hardwoods Below Fiber Saturation Point by Magnetic Resonance Microimaging……… 22 Bryan Dick, Perry Peralta, and Ilona Peszlen, North Carolina State University, USA

Changes in the Anatomy of Exposed Roots of Some Hardwood Species………... 24 Szabolcs Komán, University of West Hungary, Hungary; Wilfried Beikircher and Christian Lux, University of Innsbruck, Austria

Mechanical Properties of Common Beech (Fagus sylvatica L.) after Microwave Drying in

Comparison to Naturally and Laboratory Oven-dried Material……….. 25 Róbert Németh, Dimitrios Tsalagkasand Miklós Bak University of West Hungary, Hungary Protecting Effect of Beeswax Impregnation on the Modulus of Elasticity During Soil Contact…… 35

Solid Wood Manufacturing

Session Co-Chairs: Bob Rice, University of Maine, USA and Levente Dénes, University of West Hungary, Hungary

Douglas J. Gardner, Ashley A. Hellebrand, Barbara J.W. Cole, Raymond C. Fort Jr., University of Maine, USA

Processing Conditions Contributing to Formaldehyde Emissions from “Native” Wood……… 45 Thomas Krenke, Stephan Frybort, Oliver Vay, Kompetenzzentrum Holz GmbH, Austria ; and Ulrich Müller, BOKU – University of Natural Ressources and Life Sciences, Austria

A New Method of Dynamic 3D-cutting Force Analysis of Wood……….. 47 Yaroslav Sokolovskyy, Yu. Prusak and I. Kroshnyy, National Forestry University of Ukraine, Ukraine

Mathematical Modeling of Rheological Behaviour of Capillary- Porous Materials with Fractal Structure During Drying……….. 53 Levente Dénes, Balázs Bencsik, Zsolt Kovács, János Kalmár, Viktória Csanádi,

University of West Hungary, Hungary

Monte Carlo Simulation of Window’s Air Tightness Performance………. 61 Nikolay Skuratov and Anatoliy Vojakin, Moscow State Forest University, Russia

3

Forest Products Policy, Global Trade, and Value Chain Management

Session Co-Chairs: Eric Hansen, Oregon State University, USA and Mikulas Supin, Technical University in Zvolen, Slovakia

Henry Quesada-Pineda, Edgar Arias, and Robert Smith, Virginia Tech, USA

Factors Impacting the Export of US Hardwoods in Germany, China and Vietnam……… 70 Manja Kuzman, Mirko Kariž, and Martina Zbašnik-Senegačnik, University of Ljubljana, Slovenia Timber Passive House Technologies of Slovenian Contemporary Architecture……… 78 Yvonne Brodrechtova, Marek Trenčiansky, Daniel Halaj, Technical University in Zvolen, Slovakia Dynamics of Slovakian Timber Market in Retrospect………. 89 Michael Burnard and Andreja Kutnar, University of Primorska, Slovenia

Restorative Environmental Design: Wood as a Material for Sustainable, Healthy Environments….. 97 Alexandru Giurca, European Forest Institute, Sweden; Ragnar Jonsson, European Commission Joint Research Centre, Italy; Marko Lovrić, European Forest Institute, Finland; and Ed Pepke, European Forest Institute, France

European Union Timber Regulation Impact on International Timber Markets……….105 Erlend Nybakk, Norwegian Forest and Landscape Institute, Norway; Eric Hansen, Oregon State University, USA; Andreas Treu,Norwegian Forest and Landscape Institute, Norway;

and Tore Aase, UMB School of Economics and Business, Norway

Chemical Suppliers’ Views and Impact on Innovation in the Wood Treating Industry……….120

Sustainable Forest Management

Session Co-Chairs: Ilona Peszlen, North Carolina State University, USA and Jaroslav Kmeť, Technical University in Zvolen, Slovakia

Julie Bossu, CNRS, UMR Ecofog, French Guiana; Jacques Beauchêne, CIRAD, French Guiana, Bruno Clair , CNRS, French Guiana

Looking for “Paradoxical” Species for a Sustainable Forest Management in French Guiana……...127 Ubong Ime Udoakpan, University of Uyo, Nigeria

A Comparative Study of Wood Properties of Pinus caribaea (Morelet) in Two Plantation Ages in Oluwa Forest Reserve, Ondo State, Nigeria………...136 Anton Zbonak, Department of Agriculture, Fisheries and Forestry, Australia; Henri Bailleres and Rob McGavin, Forest Products Innovation, QDAFF, Australia

Veneering of Plantation Grown Sub-tropical Species from Thinning Experiments………..137 Tahiana Ramananantoandro, Université d’Antananarivo, Madagascar; Miora F. Ramanakoto, Institut Universitaire de Technologie de Tarbes, France; Patrick H. Rafidimanantsoa, Université d’Antananarivo, Madagascar

Influence of the Tree Diameter and Shade-tolerance on Wood Density and its Radial Variation in Madagascar Rainforest……….. 145 Perry Peralta, Ilona Peszlen, and Vincent Chiang North Carolina State University, USA Bridging Forest Biotechnology and Biomaterials Engineering………..147

Lignocellulosic Material Science and Wood Quality

Session Co-Chairs: Barry Goodell, Virginia Tech, USA and Alfred Teischinger, Universität für Bodenkultur, Austria

4 Roger Rowell, University of Wisconsin, USA

Accessibility and Reactivity of Hydroxyl Groups in Wood………...149 Barry Goodell, Virginia Tech, USA; Valdeir Arantes, University of British Columbia, Canada; Jody Jellison, Virginia Tech, USA

Non-enzymatic Deconstruction Systems in the Brown Rot Fungi……….155 Jerrold Winandy, University of Minnesota, USA; H.Michael Barnes and P.David Jones, Mississippi State University, USA

Modeling Severity of Exposure Relationships Between Laboratory and Field Exposures

for FRT Plywood………156 Chloé Maury, Khalil Jradi, and Claude Daneault, Université du Québec à Trois-Rivières, Canada Study of Mechanical Properties of Composites Based on TEMPO-oxidized Cellulose Gel

and Silica Nanoparticles……….160 Dimitrios Tsalagkas, University of West Hungary, Hungary; Rastislav Lagańa, Technical University in Zvolen, Slovakia; Levente Csóka, University of West Hungary, Hungary

Morphological and Structural Changes of Ultrasound-treated Bacterial Cellulose………161 Stefan Pinkl, Kompetenzzentrum Holz GmbH, Austria; Stefan Veigel, BOKU, University of Natural Resources and Life Sciences, Austria; Erik van Herwijnen, Kompetenzzentrum Holz GmbH, Austria; Wolfgang Gindl-Altmutter, BOKU, University of Natural Resources and Life Sciences, Austria Fibrillation of Different Lignocellulose Suspensions and their Bonding Strength to

Wood Compared with Nanocellulose……….170 Yaroslav Sokolovskyy and O. Storozhuk, Ukrainian National Forestry University, Ukraine Determination of the Non-isotropic Elastic Features for Wood by an Ultrasonic Method…………178 Galina Gorbacheva, Moscow State Forest University, Russia; Yuri A. Olkhov, Russian Academy of Sciences, Russia; Boris N. Ugolev and Serafim Yu. Belkovskiy, Moscow State Forest University, Russia

Research of Molecular-Topological Structure at Shape-Memory Effect of Wood………187 Peder Gjerdrum, Norwegian Forest and Landscape Institute, Norway

Grain Angle Variation in Norway Spruce: Overall Pattern and Stochastic Dissimilarities Within and Between Stems……….196 Ilona Peszlen, Perry Peralta, Zachary Miller, Charles Edmunds, and Zhouyang Xiang; North Carolina State University, USA

Variation in Cell Morphology of Genetically Engineered Aspen and Cottonwood………...202 Hyeun-Jong Bae, Chonnam National University, Korea

Rapid Hydrolysis of Lignocellulosic Wood Biomass……….203 Veronika Kotradyova, Slovak University of Technology, Faculty of Architecture, Slovakia; Alfred Teischinger, BOKU – University of Natural Ressources and Life Sciences, Austria

Tactile Interaction and Contact Comfort of Wood and Wood Materials………204 Peter Niemz, Katalin Kranitz and Walter Sonderegger; ETH Zurich, Switzerland

Effect of Natural Aging on Wood Properties……….214 Stephen Frybort and Thomas Krenke, Kompetenzzentrum Holz GmbH, Austria; Ulrich Müller, Deformation Analysis of Cutting Processes of Wood………222

5

Wood Panels Composites

Session Co-Chairs: Marius Barbu, Transilvania University of Brasov, Romania and Sergej Medved, University of Ljubljana, Slovenia

Marius Barbu, Axel M. Rindler, Pia Solt, and Thomas Schnabel; Salzburg University of Applied Sciences, Austria

The Use of Waste Leather in Wood-based Panels………..227 Marius Barbu, Günther Kain, Marius-Catalin Barbu, Alexander Petutschnigg, Bettina Hauser, and Michael Mazzitelli; Salzburg University of Applied Sciences, Austria

Bark-based Insulation Panels Made of Different Softwood Barks……….236 Ayfer Donmez Cavdar and Hulya Kalaycioglu, Karadeniz Technical University, Turkey; Ertugrul Casur, Kastamonu Integrated Wood Industry & Trade Company, Turkey; Fatih Mengeloglu, Kahramanmaras Sutcuimam University, Turkey

Some Properties of Fire Retardants and Sand Dusts of Medium Density Fiberboard Filled Wood Plastic Composites………..244 Kate Semple, University of British Columbia, Canada; Martin Smola, Fachhochschule Rosenheim, Germany; John Hoffman, FPInnovations, Canada; Gregory D Smith, University of British Columbia, Canada

Optimising the Stranding of Moso Bamboo (Phyllostachys pubescens Mazel) Culms Using a

CAE 6/36 Disk Flaker……….257 Ahmad Jahan-latibari, Islamic Azad University Karaj Branch, Iran; Fardad Golbabaei, Institute of Forests and Rangeland, Iran

The Potential Of Urban Wood Residues in Particleboard Production………270 Eike Alexander Mahrdt and Hendrikus W. G. van Herwijnen, Wood K Plus, Austria; Wolfgang Gindl-Altmutter,BOKU – University of Natural Resources and Applied Life Science, Austria; Wolfgang Kantner and Johann Moser,Metadynea Austria GmbH, Austria; Ulrich Müller, BOKU – University of Natural Resources and Applied Life Science, Austria

A New Analytical Method to Study UF Resin Distribution within Particle Boards………..278 Johann Trischler, Linnaeus University, Sweden; Dick Sandberg, Luleå University of Technology, Sweden; Thomas Thörnqvist, Linnaeus University, Sweden

Classifi cation of Lignocellulose Raw Materials Regarding Selected Material Properties and the Requirements of Three Competitors to Reveal Options for Alternative Use……….287 Christoph Wenderdel, Tino Schulz and Detlef Krug, Institut fuer Holztechnologie Dresden GmbH, Germany; Alf-Mathias Strunz, Papiertechnische Stiftung, Germany

Very Thin Medium Density Fibreboards (MDF) with Paperboard-like Properties as

Reusable Packaging Material………..296 Anna Ślęzak and Stanisław Proszyk, Poznan University of Life Sciences, Poland

Investigations upon Resistance of Surfaces Panel Elements Bonding by Artificial Veneers

from Hot Melt Adhesives………305 Min Niu, Fujian Agriculture and Forestry University, China; Olle Hagmanand Xiaodong (Alice) Wang, Luleå University of Technology, Sweden; Yongqun Xie, Fujian Agriculture and Forestry University, China

Fire Properties Improvement of an Ultralow Density Fiberboard………..312 Levente Dénes, Viktor Utassy, and Zsolt Kovács University of West Hungary, Hungary

Finite Element Modelling Simplifi cation of Paper Honeycomb Panels by a Substituting

6

Wood Construction & Structures

Session Co-Chairs: Arijit Sinha, Oregon State University, USA and Bohumil Kasal, Fraunhofer Wilhelm Klauditz Institute, Germany

Andreja Kutnar, University of Primorska, Slovenia; Anthonie Kramer, Arijit Sinha, and Andre Barbosa, Oregon State University, USA

Cross Laminated Timber Panels Using Hybrid Poplar………...321 Karol Sikora and Annette M. Hart, National University of Ireland, Ireland;Daniel O. McPolin, Queen’s University Belfast, UK

Durability of Adhesive Bonds in Cross-laminated Timber (CLT) Panels Manufactured………...323 Bryan Dick, North Carolina State University, USA; Miklos Horvath, Obuda University, Hungary; Perry Peralta, Phil Mitchell and Ilona Peszlen, North Carolina State University, USA; Weichiang Pang and Scott Schiff, Clemson University, USA; Robert White, U.S. Forest Products Laboratory, USA

Fire Performance of Adhesives Used for Southern Pine Cross-Laminated Timber………...332 Georg Stecher, Anton Kraler and Roland Maderebner, University of Innsbruck, Austria “Radiusholz” – Curved Cross-laminated Timber Elements………334 Marius Barbu and Josef Weissensteiner, Salzburg University of Applied Sciences, Austria; Timothy M. Young, University of Tennessee, USA

Cross Laminated Timber – Implementation of European Experiences in the USA………...342 Desmond Dolan, Mark McCaffreyand Annette Harte, National University of Ireland, Ireland A Hybrid Input-Output LCA Analysis of Timber Construction Products Produced in Ireland…….349 David DeVallance, Gregory Estep and Shawn Grushecky, West Virginia University, USA Spatial Analysis of Certified Wood Use in LEED Green Building Projects………..358 Jaromir Milch, Jan Tippner, Martin Brabecand Václav Sebera, Mendel University in Brno, Czech Republic

Experimental Verification of Numerical Model of Single and Double-Shear Dowel-Type

Joints of Wood………368

Energy, Fuels, Chemicals

Session Co-Chairs: Dave DeVallance, West Virginia University, USA and Margareta Wihersaari, Åbo Akademi University, Finland

Quy Nam Nguyen, Alain Cloutier, Alexis Achim, and Tatjana Stevanovic Université Laval, Canada Fuel Pellets from Low Quality Hardwood Trees: Raw Materials and Pelletization Characteristics..377 Robert Rice, University of Maine, USA; Evan Chatmas, New Page Paper Company, USA; Douglas Gardner and Adrian Van Heiningen, University of Maine, USA

Rapid Assessment of Pellet Ash Agglomeration Using Electrical Resistivity………...385 Bestani Benaouda and Benderdouche Noureddine, University of Mostaganem, Algeria

7

Wenliang Wang and Jianmin Chang, Beijing Forestry University, China; Liping Cai and Sheldon Q. Shi, University of North Texas, USA

Fast Pyrolysis of Wastes and Bio-refinery for Value-added Products………...397 Amy Falcon and Jingxin Wang, West Virginia University, USA

Optimizing Urea Concentration for Woody Biomass Pretreatment………...404 Richard Bergman and Hongmei Gu, US Forest Service Forest Products Laboratory, USA Life-cycle Inventory Analysis of Bio-products from a Modular Advanced Biomass

Pyrolysis System……….405 Md Sarwar Jahan, BCSIR, Bangladesh; Haitang Liu and Huiren Hu, Tianjin University of Science and Technology, China; Yonghao Ni, University of New Brunswick, Canada

Improvement of Furfural Production From Concentrated Pre- Hydrolysis Liquor (PHL) of a

Kraft-Based Hardwood Dissolving Pulp Production Process………416 Melanie Blumentritt and Stephen M. Shaler, University of Maine, USA

Electron Microscopic Study of Neat and Hot Water Extracted Aspen Wood by Means of

Selective Electron Dense Staining and Immunogold Labeling………..417 Milan Sernek and Matjaž ČOP, University of Ljubljana, Slovenia

Curing Kinetics of Spruce Bark Tannin-Based Foams………...425 Ru Liu and Jinzhen Cao, Beijing Forestry University, China

Some Physical and Mechanical Properties of Two-step Organo-montmorillonie Modified Wood Flour/Polypropylene Composites………...426 Michel Delmas, Bouchra Benjelloun-Mlayahand Nadine Tacho, University of Toulouse, France; Louis Pilato, Pilato Consulting, USA

Biolignin™, a Renewable and Efficient Natural Product for Wood Adhesives………....433

Advanced Wood and Polymer Composites

Session Co-Chairs: Rupert Wimmer, BOKU Vienna, IFA Tulln, Austria and Joris Van Acker, Ghent University, Belgium

Matthew Schwarzkopf and Lech Muszyński, Oregon State University, USA

Strain Distribution and Load Transfer in the Polymer-wood Particle Bond in Wood Plastic

Composites (WPCs)………434 Gloria Oporto, Tuhua Zhong, Jacek Jaczynski and Ronald Sabo West Virginia University, USA Microstructure, Mechanical, Thermal and Antimicrobial Properties of Hybrid Copper Nanoparticles and Cellulose Based Materials Embedded in Thermoplastic Resins……….441 Stephen Shaler, Nadir Yildirimand R. Lopez-Anid, University of Maine, USA

Cellulose Nanofibril (CNF) Reinforced Open Cell Foams - Application of Cubic Array

Foam Theory………...451 Sheldon Shi, Changlei Xia and Liping Cai, University of North Texas, USA

Vacuum Assisted Resin Transfer Molding Process for Kenaf Fiber Based Composites…………...459 David DeVallance and Nan Nan, West Virginia University, USA

Bio-based Carbon/Polyvinyl Alcohol Piezoresistive Sensor Material………...467 A. Emeran Neuhäuser and Hendrikus Van Herwijnen, Wood K Plus, Austria; Stefano D’Amico and Ulrich Müller, BOKU- University of Natural Resources and Life Sciences, Austria

8

Nadir Ayrilmis and Alperen Kaymakci, Istanbul University, Turkey; Turker Güleç, Artvin Çoruh University, Turkey

Mechanical Performance of Wood Plastic Composite Containing Decayed Wood………...482 Joris Van Acker, Imke De Windt, Wanzhao Li, and Jan Van den Bulcke, Ghent University, Belgium Moisture Dynamics of Plywood and Impact on Time of Wetness……….488 Yonggun Park, Yeonjung Han, Jun-Ho Park, Yoon-Seong Chang,

JuHee Lee, Sang-Yun Yang, Hwanmyeong Yeo, Seoul National University, Korea

Properties of the Wood Dried and Heat-treated by Superheated Steam………...489 Sheldon Shi, University of North Texas, USA; Jun Hua, Wei Xu, Guangwei Chen and Keqi Wang, Northeast Forestry University, China; Liping Cai, University of North Texas, USA

Correlation Between Fracture Fractal Dimension and Wood Shear Properties after

Hydrothermal Treatment………497 Roland Maderebner, Thomas Badergruberand Anton Kraler University of Innsbruck, Austria Artificially Aged Timber for Structural Components………510 Levente Dénes and Balazs Bencsik, University of West Hungary, Hungary

Modification of Wood by Organometallic Processes……….518

Poster Session and Student Poster Competition

Session Co-Chairs: Douglas Gardner, University of Maine, USA and Jozef Kúdela, Technical University in Zvolen

Turgay Akbulut and Zeki Candan, Istanbul University, Turkey

Low Formaldehyde-Emitting Wood Composites by Nanotechnology………...519 Abdulrazzak Raoof Alsulaiman, Mosul University, Iraq; Ahmed Younis Al-Khero,

Ministry of Agriculture/Ninavah Agricultural Directorate, Iraq

Phthalic Acid Unhydride for Wood Modification………..524 Ioannis Barboutis, Aristotle University of Thessaloniki, Greece; Charalampos Lykidis, Hellenic Agricultural Organization "Demeter"

The Effects of Bark on Fuel Characteristics of Some Evergreen

Mediterranean Hardwood Species………..533 Bogdan Bedelean, Cristina Olarescu, and Mihaela Campean, Transilvania University of Brasov, Romania

Predicting the Compression Strength Parallel to Grain of Heat Treated

Wood Using Artifi cial Neural Networks: A Preliminary Study………541 Richard Bergman, US Forest Service Forest Products Laboratory, USA

Life-Cycle Inventory Analysis of Cellulosic Fiberboard Production in

North America………542 Wayan Darmawan, Dodi Nandika, Yusram Massijaya, Abigael Kabe, Irsan Alipraja, Istie Rahayu, Bogor Agricultural University, Indonesia; Barbara Ozarska, University of Melbourne, Australia Lathe Check Characteristics of Fast Growing Sengon Veneers and

Their LVL Glue-Bond and Bending Strength………551 Levente Dénes, University of West Hungary, Hungary

9 Levente Dénes, University of West Hungary, Hungary

User-chair Interaction Analysis of Different Age Groups………..566 David DeVallance, West Virginia University, USA; Joshua Faulkner, University of Vermont Center for Sustainable Agriculture, USA; and Tom Basden, West Virginia University Extension, USA Use of Non-treated and Thermally-treated Biomass Media in Livestock

Heavy-use Areas to Reduce the Environmental Impacts of Agriculture………567 Tuncer Dilik, Istanbul University, Turkey

Surface Treatment, Layer Thickness and Surface Performance Relations

of Wood Materials………..568 Arsenio Ella, Emmanuel P. Domingo, and Florena B. Samiano, Forest Products Research and Development Institute, Philippines

Wood Anatomy of Naturally Grown Philippine Teak

(Tectona philippinensis Benth. & Hook. F)………574

Emine Seda Erdinler, Istanbul University, Turkey

Relations Between Varnish Type and Color Changes of Wood Material………..576 Tomasz Gałęzia, Pomorze Forest Inspectorate, State Forests National Forest Holding, Poland Comparing the Efficiency of Selected Methods of Logging Residue

Chipping for the Energy Purposes………...582 Peder Gjerdrum, Norwegian Forest and Landscape Institute, Norway

Woods and Wood through the Ages of Western Culture – our Wooden Heritage……….591 Galina A. Gorbacheva and Victor G. Sanaev, Moscow State Forest University, Russia; Anatoly V. Bazhenov, Institute of Solid State Physics of the RAS, Russia; Ivica Suchanova, Technical University in Zvolen, Slovakia

FTIR-Study of Thermally Treated Beech Wood………592 Eric Hansen, Oregon State University, USA

US Forest Sector Innovation During the Great Recession……….599 Alyson Wade, Arijit Sinha, and Chris Knowles, Oregon State University, USA

Industry Perspective on Wood as Structural Green Building Material………...600 Eva Haviarova, Purdue University, USA and Henry J. Quesada-Pineda, Virginia Tech, USA New Approach to Sustainability Education for Study Abroad Programs………..601 Eva Haviarova, Mesut Uysal, Carl A. Eckelman, Purdue University, USA

Furniture Design and Product Development Principles Considering

End-of-Life Options and Design for Environment Strategies………609 Salim Hiziroglu, Oklahoma State University, USA

Wood-Plastic Composite Made from Eastern Redcedar………617 Richard Hrčka, Pavol Halachan, Marián Babiak and Rastislav Lagaňa,

Technical University in Zvolen, Slovakia; Jan Tippner, Eva Troppová, and Miroslav Trcala, Mendel University in Brno, Czech Republic

Transverse Isotropic Material Thermal Properties Measurement………..622 Pavel Ihracký and Josef Kúdela, Technical University in Zvolen, Slovakia

10 David Jones, Mississippi State University, USA

Providing Wood Science Training to the Forest Products Industry or How Do You Provide Educational Programs to Employees with No Formal Education in Wood Science………..630 Abolfazl Kargarfard, Iran Research Institute of Forests & Rangelands, Iran;

Ahmad Jahan-Latibari, Islamic Azad University, Iran

Investigation of The Effect of Resin Consumption on The Properties of

Particleboard Made Using Cotton Stalks………631 Abolfazl Kargarfard, Iran Research Institute of Forests & Rangelands, Iran;

Ahmad Jahan-Latibari, Islamic Azad University, Iran

Investigation on the Influence of Nano-clay Addition on Mechanical

Properties of Soy Straw-polypropylene Composite………637 Walid Aboudi Kasir, Mosul University, Iraq

Using Pine And Oak Bark Tannin Extracts As An Adhesive For

Particleboards Production………...644 Alperen Kaymakcı, Istanbul University, Turkey

Effect of Wood Chemical Composition on Physical Properties of

Biocomposites………650 Chul-Ki Kim, Seoul National University, Korea

Improvement of Accuracy of Portable CT by Considering Penetrating

Depth in Wood………656 Seon-Hong Kim, Ga-Hee Ryu, and Su-Yeon Lee, Seoul National University, Korea; Mi-Jin Park, Korea Forest Research Institute, Korea; In-Gyu Choi, Seoul National University, Korea

Insecticidal Effect of Essential Oils from Abies Holophylla Maxim and

its Chemical Constituents against Dermatophagoides Farinae……….662

Kucuk Huseyin Koc, Istanbul University, Turkey

Abrasion, Surface Treatment and Glossiness Relations of Wood Material………...667 Suleyman Korkut and Zeki Candan, Istanbul University, Turkey

Surface Characteristics of Thermally Modified Plywood Panels………..674 Tomasz Krystofi ak, Stanisław Proszyk and Barbara Lis, Poznan University of Life Sciences, Poland Bio-friendly Systems for Finishing of Wooden Windows Elements……….676 Andreja Kutnar, University of Primorska, Slovenia; Frederick A Kamke, Oregon State University, USA; Emil Engelund Thybring, ETH Zurich EMPA, Switzerland

Sorption Properties of Viscoelastic Thermal Compressed (VTC) wood ………...677 Jin Heon Kwon and Seung-Hwan Lee, Kangwon National University, Korea; Nadir Ayrilmis, Istanbul University, Turkey; Tae Hyung Han, Kangwon National University, Korea

Effect of Microfibrillated Cellulose Content on the Bonding Performance

of Urea-formaldehyde Resin………..683 Ahmad Jahan Latibari and Hanieh Ghasemi, Islamic Azad University, Iran; Abolfazl Kargarfard, Institute of Forests and Rangeland, Iran

The Application of Canola Straw In the Reduction of the Particleboard Density……….691 Su-yeon Lee, Chang-Young Hong, Seon-Hong Kim, In-Gyu Choi; Seoul National University, Korea Biotransformation of Geraniol by Polyporus brumalis ……….697

11 Erni Ma, Beijing Forestry University, China

Dimensional Responses of Wood Subjected to Cyclic Temperature Changes………..701 Miroslava Mamoňová and Ladislav Reinprecht, Technical University in Zvolen, Slovakia Spectrophotometric Analysis of the Accelerated Aged Wood Treated

with Transparent Coatings for Exterior Constructions………...709 Carl Morrow and Thomas M. Gorman, University of Idaho, USA; David E. Kretschmann, USDA Forest Service, Forest Products Laboratory, USA

A Comparison of Latewood Measurements in Suppressed Douglas-fir………719 Leoš Mrenica, Technical University in Zvolen, Slovakia; Šmíra, P., Thermo Sanace Ltd., Czech Republic; Ihracký, P., Technical University in Zvolen, Slovakia; Nasswettrová, A., Thermo Sanace Ltd., Czech Republic; and Kúdela, J., Technical University in Zvolen, Slovakia

Pre-treatment of Surface of Old Wood Construction Elements with Dry Ice………727 Monika Muszynska, Tomasz Krystofi ak, Stanisław Proszyk, and Barbara Lis, Poznan University of Life Sciences, Poland

Silanes Adhesion Promoters Applied in Furniture Industry………..737 Abdollah Najafi , Islamic Azad University, Iran

Effect of Pretreatment of Rice Husk with Acetic Acid on Properties of Rice

Husk/HDPE Composites………744 Elisha Ncube, Copperbelt University, Zambia

Premature Failure of Creosote Treated Electricity Transmission Wood Poles in Zambia………….745 Conan O'Ceallaigh, Annette Harte, and Karol Sikora, National University of Ireland, Ireland; Daniel McPolin, Queens University Belfast, Ireland

Mechano-sorptive Creep in Reinforced Sitka Spruce……….…753 Jung-Kwon Oh, Jung-Pyo Hong, and Jun-Jae Lee, Seoul National University, Korea

Compressive Strength of Cross-laminated Timber Panel………...761 Sung-Jun Pang, Seoul National University, Korea

Accelerated Leaching Test for Estimating Service Life of Preservative

Treated Wood in Retaining Wall………769 Zoltán Pásztory, University of West Hungary, Hungary

Log Homes Mitigate the Global Warming……….773 Henry Quesada-Pineda, Edgar Arias, Robert Smith, Virginia Tech, USA

Case Study: “Exports of U.S. Hardwood Products:

Increasing Performance in Asia and Western Europe”………..774 Vladimír Račko and Ol’ga Mišíková, and Blažej Seman Technical University in Zvolen, Slovakia Effect the Indentation of the Annual Growth Rings in Norway Spruce

(Picea Abies L.) on the Shear Strength - Preliminary Study………..780 Peter Rademacher, Mendel University in Brno, Czech Republic; Ditriech Meier, Thünen Institute of Wood Research, Germany; Petr Pařil, Jan Baar, Pavel Sáblík, Petr Čermák, and Radim Rousek, Mendel University in Brno, Czech Republic

12

Péter Rébék-Nagy and Zoltán Pásztory, University of West Hungary, Hungary

CO2 Balance of Wood Wall Constructions Compared to Other Types of Wall………799 Roman Réh, Technical University in Zvolen, Slovakia; Marius C. Barbu, Salzburg University of Applied Sciences, Austria; and Ayfer D. Çavdar, Karadeniz Technical University, Turkey Non-Wood Lignocellulosic Composites……….801 Martin Riegler, Martin Weigl, and Ulrich Müller, Wood K Plus, Austria

The Role of Fibre Characteristics for Online Process Adaptation in the Manufacturing of MDF….806

Ildikó Ronyecz, Kristóf Mohácsi, and Zoltán Pásztory, University of West Hungary, Hungary Errors of Sampling Based Moisture Content Measurement of Wood………814 Matthew Schwarzkopf and Lech Muszynski, Oregon State University, USA

Quantitative Analysis of the Micromechanical Load Transfer in

Wood-Adhesive Bond Interphases……….815 Václav Sebera, Jan Tippner, Peter Rademacher, and Rupert Wimmer, Mendel University in Brno, Czech Republic

FE model of Oriented Strand Board Made By Two Different Geometry Generation Techniques…821 Franz Segovia, Pierre Blanchet, Costel Barbuta, and Robert Beauregard, Université Laval, Canada Aluminium Laminated Wood Composites: Optimal Manufactured Parameters………828 Milan Simek, Mendel University, Czech Republic

Development of Ready-to-Assemble Furniture Constructions………...837 Tomislav Sinković, Faculty of Forestry, Croatia

Defining of Wood Colour………...847 Nikolay Skuratov, Moscow State Forest University, Russia

Assessment of Drying Quality and Accuracy of Wood Processing………...856 Yaroslav Sokolovskyy, Ukraine National Forestry University, Ukraine

Mathematical Modeling of Timber Elastic-viscous-plastic Deforation in Drying Process…………865 Péter Szeles, Szabolcs Komán, and Sándor Fehér; University of West Hungary, Hungary Mitigation of End Shakes on Oak Saw Timber as a Result of Storage by

Applying Environmentally-friendly Methods………866 Radovan Tiňo, Zuzana Repanova, and Michal Jablonsky, Slovak University of Technology, Slovakia Activation of Wood Surfaces With Atmospheric Plasma Treatment……….876 Jan Tippner, Mendel University in Brno, Czech Republic

Probabilistic Numerical Analysis of Quasi-stationary Thermal Measurement of

Medium Density Fiberboard………...878 Johann Trischler, Linnæus University, Sweden; Dick Sandberg, Luleå University of Technology, Sweden

Integrating the Surface Treatment of Monocotyledons into Particleboard

Production Process to Provide a Substitute Raw Material……….887 Eva Troppová, Mendel University, Czech Republic

13

Inna Varivodina, Nikolai Kosichenko and Tamara Starodubtseva, Voronezh State Academy of Forestry and Technologies, Russia

Interconnection of Strength, Porosity and Microstructure of Hardwood………903 Oliver Vay, Kompetenzzentrum Holz GmbH, Austria; Johannes Konnerth, Alfred Teischinger, and Ulrich Müller, BOKU - University of Natural Resources and Life Sciences - Vienna, Austria

Cross Industry Innovation Process to Identify “New” Technologies for

Mechanical Wood Disintegration………...909 Xiping Wang, Steve Verrill, Eini Lowell, Robert J. Ross and Vicki L. Herian, US Forest Products Laboratory, USA

Acoustic Sorting Models for Improved Log Segregation………...915 Kyaw Ko Win, Seoul National University, Korea

Heart Rots Detection on the Nasis of Sonic Velocity Based on Transducer’s Angles Orientation...925 Sang-Yun Yang, Seoul National University, Korea

Analysis of High Frequency Dielectric Curing of Phenol-Resorcinol

Formaldehyde Resin used for Manufacturing Larch Glulam……….933 Hwanmyeong Yeo, Yeonjung Han, Yoon-Seong Chang, Sang-Yun Yang, Chul-Ki Kim, Gi-Young Jeong, Jun-Jae Lee, Seoul National University, Korea; Yeonjung Han, Yoon-Seong Chang, Sang-Yun Yang, and Chul-Ki Kim, Seoul National University; Gi-Young Jeong, Chunnam National University; Jun-Jae Lee, Seoul National University

Analysis of Laminar Yield for Manufacturing Cross Laminated Timber………..940 Hwanmyeong Yeo, Yoon-Seong Chang, and Jun-Ho Park, Seoul National University, Korea; Whi-Lim Son, Joo-Saeng Park, and Moon-Jae Park, Korea Forest Research Institute, Korea Half-Life and Carbon Stock of Harvested Wood Products (HWP)

Produced by Domestic Trees in Korea………...945 Ales Zeidler, Vlastimil Boruvka, Guillermo Garcia Mayoral, Czech University of Life Sciences Prague, Czech Republic

Wood Quality of Black Walnut Grown in Reclaimed Surface Mine in the Czech Republic……….951

Student Poster Competition

Adeyinka Saheed Adesope, Forestry Research Institute of Nigeria, Nigeria Effects of Particle Geometry on Dimensional Stability of

Bamboo-reinforced Cement Composites………957 Melanie Blumentritt, Sasha Howes and Stephen M. Shaler, University of Maine, USA

Life Cycle Assessment of Exported Torrefied Wood Pellets (TOP) from

Maine to the European Union……….958 Bryan Dick, North Carolina State University, USA

Changes in the Anatomy of Exposed Roots of Some Hardwood Species………..967

Charles Edmunds, North Carolina State University, USA

Thermo-mechanical Properties of Genetically Modified Populus trichocarpa……….968

Alexandra Himsel, Kompetenzzentrum Holz GmbH, Austria; Ulrich Müller, BOKU – University of Natural Resources and Applied Life Science, Austria; Hendrikus W. G. van Herwijnen,

Kompetenzzentrum Holz GmbH, Austria

Rheometer Method to Determine Factors Influencing Sticking Behaviour

14

Chloé Maury and Khalil Jradi, Université du Québec à Trois-Rivières, Canada; Claude Daneault, Canada Research Chair in Value-added Paper, Canada Study of Mechanical Properties of Composites Based on TEMPO-oxidized Cellulose

Gel and Silica Nanoparticles………..979 Zachary Miller, North Carolina State University, USA

Comparing Mechanical and Chemical Properties of Young Transgenic Black Cottonwood Trees Modified for Reduction of Specific Genes in Lignin Biosynthesis………980 Jimmy Thomas, The Rubber Board and University of Canterbury, New Zealand; David Anthony Collings, University of Canterbury, New Zealand

Novel Imaging and 3D rendering Techniques to Visualise Spiral Grain inPinus radiate…………984

15

Hardwood Research & Utilization Session

Session Co-Chairs: Rado Gazo, Purdue University, USA

Róbert Németh, University of West Hungary, Hungary

CT Scanning of Logs – Analysis and Optimization for

Better Utilization of Hardwoods

Rado Gazo, Juraj Vanek, Michel Abdul-Massih, and Bedrich Benes

Department of Forestry and Natural Resources, Purdue University

West Lafayette, Indiana, USA

Abstract

The mission of the Hardwood Scanning Center at Purdue University is to increase the global competitiveness of the United States hardwood industry and to conserve the hardwood resource by development of manufacturing technologies which will enable hardwood industry to “see inside a tree” and use this information to make better processing decisions.

The Hardwood Scanning Center partnered with Microtek, GmbH of Italy in the

development of an industrial grade log CT scanner. World’s first three industrial CT log scanners have been installed in last 12 months in mills around the world and we will briefly discuss their application. The Hardwood Scanning Center also developed

visualization and optimization software for the hardwood veneer and sawmill operations. This presentation will provide an overview of state-of-the-art in CT scanning of logs.

16

Decorative Veneer Properties of Black Walnut

(

Juglans nigra

L.)

Roman Réh

1

_{Associate Professor, Department of Mechanical Technology of Wood,}

Faculty of Wood Science and Technology, Technical University in Zvolen,

Zvolen, Slovak Republic.

reh@tuzvo.sk

Abstract

Black walnut (Juglans nigra L.) is an interesting species for wood processing worldwide and it can be fully recommended for the European woodworking industry as well. The quality of decorative veneer made from black walnut does not differ from the quality of the commonly used veneer for veneering in furniture industry when correct thickness is selected. In Europe selected introduced woody species suggest good perspectives in the coming years and the future quality and volume of the production may be secured providing systematic and intense tending of the forest stands takes place. Because of the shortage of the high quality traditional raw material for decorative purposes, it is the time to start to utilize the suitable minor trees from the European forests.

From the results of tests performed black walnut is an interesting species for veneering industry and the veneer thickness of 0.6 mm can be fully recommended for furniture industry and other purposes.

Black walnut is suitable for application in the furniture industry either as a replacement for some commonly used woody species or as a woody species widening the assortment of woody species utilized in furniture industry. The results obtained suggest that it is possible to recommend its cultivation in larger areas upon properly managed stands. It is still necessary to reach more accurate data on the nearest zoning and to realize a research of consumer market in the field of utilizing veneer made of black walnut.

Keywords: wood veneer, decorative veneer, properties of veneer, black walnut

Introduction

Potential products including decorative veneers can be manufactured from hardwoods that are considered as introduced (invasive) species (Brashaw et al. 2012). Because of the growth of veneer industries and the reduction of timber supplies of the well-known veneer species, the search continues for alternate species, either domestic or foreign. In screening

17

for new veneer species, it is helpful to know which factors are important for veneer use (Lutz 1971).

This paper includes the recommendations to use the species black walnut (Juglans nigra L.) for the production of decorative veneer and veneering. Black walnut is an important source of decorative veneer in the U.S.A. For Central European wood-processing industry is black walnut an introduced species. Black walnut has it specific interesting particularities: it is the only North American dark wood and in Europe it does not have any natural pests while growing.

Botanic name: Juglans nigra, L.

Family: Juglandaceae

Other names used for species: American walnut, Eastern black walnut

Black walnut is sought after for its great beauty and toughness. It is fairly straight grained but can be wavy with a course texture and a dark brown to purplish black color. Heartwood can range from a lighter pale brown to a dark chocolate brown with darker brown streaks. Color can sometimes have a grey, purple, or reddish cast. Sapwood is pale yellow-gray to nearly white. Figured grain patterns such as curl, crotch, and burl are also seen. Grain is usually straight, but can be irregular. Has a medium texture and moderate natural luster.

Black walnut is a hard, strong, heavy wood that weighs 600 - 660 kg.m-3 when seasoned. The wood requires care in drying to avoid checking and degradation. It has good shock resistance and is unusually durable. The timber works well with hand and machine tools, with a moderate blunting effect on cutting edges. It holds nails and screws well, and can be glued satisfactorily. Its workability is good and it glues well while holding it’s bending properties (Barbu et al. 2014). It accepts natural wood finishes extremely well and can be polished to a fine finish.

Materials and Methods

Raw material for this research has Slovak origin and it was taken from Arborétum Mlyňany. 12 veneer logs with a length of 140 cm and with a diameter of 29 – 32 cm were dipped for a period of 2 months at the water temperature 20 oC. Veneers were manufactured by off-center cutting in the Development workshops and laboratories of the Technical University in Zvolen. By means of interrupted off-center cutting new and interesting grains and textures of black walnut were obtained. Veneers with the thicknesses of 0.6, 0.7, and 0.8 mm were dried up to a moisture content of 10  1 % by drying at a temperature 100 °C.

Black walnut veneers were subjected to a number of technological test procedures. Our aim was to determine the most appropriate thickness of off-center cutting (eccentrically peeled) black walnut decorative veneer and values of optimal glue mixture spread which is needed for veneering technology.

18

Specific Glue Penetration to the Veneered Area. The glue penetration to the veneered area is usually determined on veneer specimens of the size of 250 x 300 mm. The most common construction material used is particleboard (thickness 16 mm) and we had to solve the proper glue amount (it was tested the range from 100 to 220 g.m-2 _{in the glue}

spread gradation of 10 g.m-2). The evaluation of the amount of glue penetrated on the veneer surface was done with the help of a net with mesh size of 5 x 5 mm. For each value of the glue spread ten specimens had been pressed and the penetration was evaluated in percentage of the total area.

Veneering with urea-formaldehyde glue was carried out under the following conditions:

- Press pressure: 0.6 MPa - Pressing temperature: 130 ° C - Pressing time: 4 min.

Moisture Absorption of Veneer. Essence of the moisture absorption determination of veneers is to determine the equilibrium moisture content of the test specimens during long-term storage of veneer sheets in an environment in which the desired temperature and the desired relative humidity of air exists. The test is conducted under the terms of the technical standard. The test specimens with the dimensions 50 x 50 mm in the number of 60 specimens were conditioned in a chamber at a relative humidity of 95 ± 2 % and at a temperature of 20 ± 2 °C for 30 days. After completion of the conditioning the weight of test specimens was determined with an accuracy of ± 0.01 g. The test specimens were then oven dried to zero moisture content at the temperature 103 ± 2 º C. Moisture absorption nw (%) was calculated according to the

formula:

100

.

n



where mw is specimen weight after conditioning and mo is specimen weight after oven

drying.

Tensile strength of veneers perpendicular to the grain. Test essence is to determine the tensile strength at maximum load which is exposed to the test specimen up to the failure of its strength perpendicular to the grain.

Results and Discussion

Specific Glue Penetration to the Veneered Area. Results of the specific glue penetration to the veneered area in dependence on the spread thickness are given in Table 1.

19

Table 1. Results of the Specific Glue Penetration to the Veneered Area in Dependence on the Spread Thickness

Veneer Thickness (mm) Glue Spread (g.m-2₎ 100 110 120 130 140 150 160 170 180 190 200 210 220 0.6 0.7 0.8 - - - - - - - - - - - - 0.022 - - 0.015 - - 0.019 0.010 - 0.051 0.020 - 0.030 0.040 0.003 0.066 0.063 0.001 0.093 0.100 0.073 0.256 0.103 0.116 0.586 0.563 0.146

The test results on glue penetration to the veneered area revealed no substantial glue penetration within the spread range 140 – 160 g.m-2, inclusive of followed thicknesses. Black walnut from the point of view of glue penetration to the veneered area proved good properties. In actually used spreads there is no danger of devaluation of the veneered elements. Glue spread 140 – 150 g.m-2 was proposed for particleboard.

Moisture Absorption of Veneer. Results of the moisture absorption test are given in Table 2.

Table 2. Statistical characteristics of moisture absorption of black walnut veneer

Thickness [mm] x Vx n [pcs] [%] 0.6 21.24 7.21 60 0.7 20.92 8.16 60 0.8 20.67 7.56 60

(x – Average value; Vx - Variation coefficient; n – Number of measurements)

The values of moisture absorption of black walnut veneers move within the minimum interval of 20 – 21 % and they are decreasing insubstantially with the increasing veneer thickness. The variation coefficient of all measurements is at an acceptable level. The value of moisture absorption is relatively low. However, it corresponds to the equilibrium moisture content determined from sorption isotherm for lower range of standard test conditions (22.20 %) according to DeBoer and Zwicker isotherm.

Tensile strength of veneers perpendicular to the grain. Results of tensile strength of veneers perpendicular to the grain are given in Table 3.

Table 3. Statistical characteristics of tensile strength of black walnut veneers perpendicular to the grain (w = 12 %)

Thickness [mm] x [MPa] Vx [%] n [pcs] 0.6 3.34 16.61 60

20

0.7 3.76 18.26 60

0.8 3.82 19.42 60

(x – Average value; Vx - Variation coefficient; n – Number of measurements)

The value of tensile strength of black walnut veneers perpendicular to the grain increases with the veneer thickness.

Tensile strength of black walnut veneers perpendicular to grain could be theoretically equal to the tensile strength of wood in the same direction. Experimental results have shown that the average strength of veneers is significantly lower than the strength of the wood. This difference increases with decreasing veneer thickness. Cracks play a negative role in the case of tensile strength of veneers, whose frequency depends to a large extent on the veneers production technology.

Most importantly in terms of the mechanical properties of decorative veneer is that veneer must withstand as compact as possible during handling. From this perspective, tensile strength of black walnut veneers perpendicular to the grain is decisive. Mechanical properties of decorative veneers are negligible after veneering.

Conclusions

Black walnut as an interesting species for veneer industry is fully recommended. The quality of veneer made from black walnut does not differ from the quality of commonly used veneer and thickness 0.6 mm can be recommended for furniture industry. Glue spread 140 – 150 g.m-2 was proposed for particleboard.

Selected introduced woody species suggest good perspectives in the coming years and the future quality and volume production may be secured providing systematic and intense tending of forest stands takes places. Black walnut is suitable for veneering of composites (particleboard, MDF) and it is suitable for application in the furniture industry either as a replacement for some commonly used woody species or as a woody species widening the assortment of woody species utilized in furniture industry.

The results obtained suggest that it is possible to recommend its cultivation in larger areas upon properly managed stands. It is still necessary to reach more accurate data on the nearest zoning in Central Europe and to realize a research of consumer market in the field of utilizing veneer made of black walnut.

References

Barbu M.C., Irle M., Reh R. (2014): Wood Based Composites, Chapter 1 in Aguilera A., Davim P., Research Developments in Wood Engineering and Technology. IGI Global. Engineering Science Reference. Hershey, PA, USA, pp.1-45.

21

Brashaw B. K., Ross R. J., Wang X., Wiemann M. C. (2012): Options for Urban Trees Infested by Invasive Species. University of Minnesota and U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, Madison., 96 p. http://spfnic.fs.fed.us/werc/finalrpts/09 -DG-087_2.pdf

Lutz J. F. (1971): Wood and Log Characteristics Affecting Veneer Production. Forest Service research paper, Forest Products Laboratory, Madison, WI, 1971, pp. 1-35. http://www.fpl.fs.fed.us/documnts /fplrp/fplrp150.pdf. http://www.fpl.fs.fed.us/documnts/usda/amwood/270bwaln.pdf http://www.lewislp.com/woodchar.asp https://www.osbornewood.com/woodtypes.cfm http://www.piecesofwood.com/woods.html http://www.wood-database.com/wood-identification/ Acknowledgements

The research described in the paper presented was supported by grant No. 01/0345/12 from the Slovak Grant Agency (Interaction of the Components of Wood and High Temperatures during Pressing of Wood Composites and its Effect on the Formation of Composites Avoiding the Chemical Changes in Composition of Pressed Wood Particles and Elimination of the Fire Risk). The author would like to thank the grant agency for the support of this research.

22

Distribution of the Equilibrium Moisture Content in

Four Hardwoods Below Fiber Saturation Point by

Magnetic Resonance Microimaging

Leandro Passarini – Cédric Malveau – Roger Hernández

Abstract

The magnetic resonance imaging (MRI) is one of most powerful and versatile technique for wood characterization. It is non-invasive, relatively fast and allows the visualization of water in wood structure over a wide range of moisture contents. The main objective of this work was to use the MRI technique to study liquid and bound water distribution in small wood samples under equilibrium moisture contents (EMC) below FSP. Two hardwood species from the Amazon rainforest, namely huayruro (Robinia coccinea

Aublet) and cachimbo (Cariniana domesticata (C. Martius) Miers), a plantation grown eucalyptus species (Eucalyptussaligna Smith) from Brazil, and a temperate species red oak (Quercus rubra L.) were used for this study. These species were chosen considering their diversity in terms of anatomical and physical properties. Desorption tests were carried out at 21°C in a single step procedure from full saturation state for huayruro, cachimbo, and red oak and from green condition for E. saligna. The EMC was reached under three desorption conditions (58, 76, and 90% RH). One sample was select to IRM test for each RH condition. Two images were obtained, one based on T2 times and another

based on 1H concentration. A scanning electron microscopy image was obtained for the same section scanned in order to help the MRI interpretation. The results showed that wood structure plays a major role in liquid water drainage and water diffusion. E. saligna

and red oak presented liquid water entrapped, respectively, in axial parenchyma and rays, even below FSP. For cachimbo and huayruro woods, all liquid water was drained at 90 % RH. For these two species, even at EMC, the images showed that bound water was not uniformly distributed in wood structure, concentrating mainly in rays for cachimbo and in fibers for huayruro. Therefore, water concentration varied according to the wood tissue, reveling that some tissues are more hygroscopic than others.

Keywords: magnetic resonance imaging, fiber saturation point, liquid water, wood hygroscopicity

Leandro Passarini

PhD student, Centre de recherche sur les matériaux renouvelables, Département des Sciences du bois et de la Forêt, Pavillon Gene-H. Kruger, 2425, rue de la Terrasse,

23 Cédric Malveau

Research assistant, Laboratoire de RMN, Département de Chimie, Université de Montréal, Pavillon Roger-Gaudry (PRG), 2900, boul. Édouard-Montpetit Montréal (Québec) H3T 1J4. Email : cedric.malveau@umontreal.ca

Roger Hernández

Professor, Centre de recherche sur les matériaux renouvelables, Département des Sciences du bois et de la Forêt, Pavillon Gene-H. Kruger, 2425, rue de la Terrasse, Université Laval, Québec, Qc, Canada, G1V 0A6. E-mail: roger.hernandez@sbf.ulaval.ca

24

Changes in the Anatomy of Exposed Roots of Some

Hardwood Species

Bryan Dick, Perry Peralta, and Ilona Peszlen

Abstract

Dendrogeomorphology, a subfield of dendrochronology, is a valuable tool for dating and estimating the rates of erosion and deposition of river banks, ephemeral channels,

hillslopes, landslides and other mass movements. By determining the initial year of root exposure, exposed tree roots offer a means of determining erosion rates for both riverine and hillslope processes. While dendrogeomorphology is a well-established field, there is very little information available to researchers and practitioners in the way of specific responses of hardwoods by genus or classification of anatomical structure. Macroscopic and microscopic indicators of the date or root exposure include; the occurrence of

eccentricity in growth rings, a transition of diffuse to ring porous arrangements of vessels (root-like to stem-like anatomy), a decrease in the size of vessels and fibers, fiber cell wall thickening, the occurrence of gelatinous fibers in tension wood and the occurrence of pith flecks (scarring and wound tissue). The observed macroscopic and microscopic changes in root wood anatomy of exposed roots of sugar maple (Acer saccharinum), slippery elm (Ulmus rubra) and common hackberry (Celtis occidentalis), water oak (Quercus nigra), green ash (fraxinus pensylvannica), water hickory (Carya aquatica), black willow (Salix nigra), and eastern cottonwood (Populus deltoids) will be presented. The difficulties associated with using some species will also be discussed, in order to assist with the planning of what is best used for future studies of soil erosion using exposed roots. Keywords: dendrochronology, dendrogeomorphology, exposed roots of hardwoods Bryan Dick, Ph.D. Student

bmdick@ncsu.edu

Perry Peralta, Associate Professor +1919-515-5731; Fax: +191-3513-3496 Perry_Peralta@ncsu.edu

Ilona Peszlen, Associate Professor +1-919-513-1265; Fax: +191-3513-3496 Ilona_Peszlen@ncsu.edu

Department of Forest Biomaterials North Carolina State University Campus Box 8005

25

Mechanical Properties of European Beech Wood (

Fagus

Silvatica

L.) after Microwave Drying in Comparison to

Naturally and Laboratory Oven-Dried Material

Wilfried Beikircher

_{– Christian Lux}

_{– Szabolcs Komán}

1

_{Senior scientist, University of Innsbruck, Department of Engineering}

Science - Timber Engineering Unit, Technikerstr. 13, 6020 Innsbruck,

Austria.

wilfried.beikircher@uibk.ac.at

2

_{Assistant, University of Innsbruck, Institute of Ion Physics and Applied}

Physics, Technikerstr. 25/3, 6020 Innsbruck, Austria, Innsbruck, Austria.

3

_{Associate Professor, University of West Hungary, Simonyi Károly Faculty}

of Engineering, Wood Sciences and Applied Arts,

Institute of Wood

Sciences, Bajcsy-Zs. u. 4.,

9400 Sopron, Hungary.

* Corresponding author

szabolcs.koman@skk.nyme.hu

Abstract

This aim of this study to investigate the effect of the microwave drying process on

mechanical properties of European beech (Fagus silvatica L.) in comparison to laboratory oven dried and natural dried material. The wood was dried in air at ambient temperature at about 20 °C, in a conventional laboratory oven at elevated temperatures at 103°C and in a microwave oven at two different power settings with target core temperatures of 65°C for the vacuum drying and at 100 °C for drying at atmospheric pressure. The drying experiments were performed at small clear wood specimens with the cross section of 30 mm and 500 mm in length, which were prepared for the mechanical tests. After drying, the mechanical properties as the three-point bending test, the compression strength parallel to the grain and the Brinell hardness were determined. The results of this systematic investigation show no influence by the microwave drying process on the mechanical properties as the modulus of rupture and the modulus of elasticity out of tree-point bending test and the compression strength parallel to the grain. The influence of drying rate and internal cracking affect the mechanical properties more as the drying process. Regarding the Brinell hardness some differences could be found within the artificial drying processes but in comparison to the natural dried Beech wood not at significant level.

Keywords: microwave wood modification, wood drying, mechanical properties, European beech (Fagus silvatica L.)

26 Introduction

The drying of wood can be a time and energy consuming process. The optimization of drying processes and the reduction of needed energy plays an important role in the

industry. Several methods for drying are used in the timber industry. These include drying the wood at elevated temperatures by using convectional kiln drying, which is the most common method, drying in radio frequency or microwave ovens, or a combination of the two. In timber drying, mechanical properties may be changed due to treatment

temperature and treatment duration. In general when increasing the kiln temperature, drying time is decreased and some timber properties are negative affected. The occurrence of cracks, case hardening and loss of mechanical properties and undesired colour changes are major problems in wood drying. Attention should be given on the control of drying conditions in order to avoid these forms of defects.

Although investigations on microwave drying of wood have been performed since the late fifties, this drying process is little used for industrial timber drying processes. A

comprehensive review on the drying wood with high frequency electric current is given by Resch (2009) [1]. Studies by many authors [2], [3], [4],[4] [5], [6], [7]and [8]

emphasize the advantages of microwave drying over convective drying.

A literature review where different drying methods and investigated wood species are presented is given by Oltean et al. (2011) [9]. This report deals with different temperature ranges and drying methods, but little information is available to quantifying the effect of the microwave drying method on the mechanical properties of the wood. In general mechanical properties at drying temperatures below 100 °C are not affected.

Investigations of different authors differ in the statements concerning the effect of the microwave drying process on mechanical properties of wood. As Hansson and Atti (2006)[10] found no change in the temperature range at 60-100 °C, Oloyede and Groomebridge (2000) [5] found up to 60 % lower strength properties. In comparison Taskini (2007) [8] found that microwave dried wood lead to higher strength as infrared and convectional drying processes. Due to these inconsistencies research work will be necessary for this topic and this study should support the actual knowledge.

In this study the changes in MOE, MOR and the compression strength parallel to the grain on European beech (Fagus silvatica L.) related to the drying process are investigated. In the present paper, the tests were carried out using laboratory size specimens with the dimensions of 30 x 30 x 500 mm. As target moisture content (MC) 12 % and 0 % was selected. Due to the small specimen size, short drying times were used and the results should therefore not be directly compared on full size specimens e.g. timber boards and beams.

Materials and Methods Drying experiments

In this study, freshly sawn European beech (Fagus silvatica L.) from upper Austria was used for the investigations. The raw material was prepared in the way to get twin samples for optimal comparison of the microwave drying effect. For having an adequate material range the starting material selected was out of six trees, presented sapwood and

27

three bars were cutted and from each bar one sample were randomly selected for the different drying processes (Figure 1). Because of the careful selection of the test series, with exception of the water stored material, the samples can be denoted as twin samples to generate meaningful results. The series TSA_100°C_12%_w and

MWA_100°C_12%_w are in between directly comparable, because there were twin samples, but this series were made out of other trunks as the other six series. For every test series 36 samples were used. All drying samples were prepared to the dimension of 30 x 30 x 500 mm. After cutting, the bars were sealed on both cross sections with epoxide adhesive, in order to prevent drying from the cross sectional ends. Due to the material from the sawn mill the starting moisture content (MC) varied between 28 to 35 %. For a more intense effect of the drying processes on material properties additional two series were prepared and stored in water before drying. Those two series had a mean starting MC of 51 % (Error! Reference source not found.).

Figure 1.Sample preparation

The methods applied were vacuum-microwave drying, microwave and laboratory oven drying under atmospheric pressure and natural dried material was used as reference material. The drying schedules are summarized in Error! Reference source not found..

Identification Description Starting MC (%) Target MC (%) Drying temp. (°C) Process time (h)

MWA_100°C_12% MW-drying under

ambient pressure 30 ±6 12 100 ± 2 3

MWA_100°C_0% MW-drying under

ambient pressure 28 ±5 0 100 ± 2 14

MWV_65°C_12% MW-drying under

vacuum (200mbar) 29 ±5 12 65 ± 2 4

MWV_65°C_0% MW-drying under

vacuum (200mbar) 34 ±4 0 65 ± 2 14

FLA_20°C_12% Natural-drying in the

storage room 35 ±6 12 20 ± 5

3.5 month TSA_100°C_0% Laboratory oven drying

under ambient pressure 35 ±6 0 103 ± 3 126

TSA_100°C_12%_w Laboratory oven drying

under ambient pressure 51 ±8 12 103 ± 3 51

MWA_100°C_12%_w MW-drying under

ambient pressure 51 ±8 12 100 ± 2 12.5

28 Experimental equipment

Drying experiments were carried out with laboratory MW-drying equipment (Figure 2). For the drying tests the first five Magnetrons of the MW-kiln were used. The laboratory plant is equipped with 12 spirally positioned magnetrons at the whole length of 3 m. Each magnetron has a maximum power of 800 W and the working frequency is 2.45 GHz. During the drying the core temperature was measured with a fiber optic sensor

(FOTEMP1 Fa. OPTOcon GmbH), which was inserted to the core of one of the samples. The surface temperature was measured with an infrared spectral pyrometer. The core temperature was used for the manual regulation of the intensity of the MW-power. The drying started by using 50 % of the MW-power and then the power was manually

regulated for holding the target core temperature. The core temperatures were regulated in the range of 100 ± 2 °C for the atmospheric drying process and 65 ± 2 °C for the vacuum drying process at 200 mbar.

Figure 2.Microwave laboratory equipment and position of the samples

For the comparison of the MW-dried timber, natural dried and in a laboratory oven dried samples were used. The natural dried material was stored in a storage room at about 15-25 °C until the MC of about 12 % was reached. The drying steps for the laboratory oven were 24 hours with 50 °C following of 24 hours with 80 °C and finally until the target MC was reached the temperature of 103 °C were settled. The different drying experiments were carried out to get final target moisture content of 12 % and 0 % (Table 1). With exceptions of the natural dried material, this was only dried at the target MC of 12%. After drying all samples were conditioned in a climate chamber at 20 °C and 65 % relative humidity prior to testing until constant moisture content was reached. Preparation of test specimens

The test material consisted of microwave dried, laboratory dried and natural dried control specimens according to the schedules described above. For the determination of the mechanical properties defect free specimens were produced after the drying at the final dimension of 20 x 20 x 360 mm for the bending tests and 20 x 20 x 60 mm for the compression strength and 20 x 20 x 30 mm for the Brinell hardness in radial and tangential direction.

29 Mechanical testing

The determination of the material properties were performed according to the Standards for small defect free wood samples. The material properties to be determined were: the density, the moisture content, modulus of elasticity and bending strength, compressive strength and Brinell hardness. The specified standards which were followed, as well as the devices and some remarks are presented in Error! Reference source not found.. The material tests were performed at the TVFA (Technische Versuchs- und

Forschungsanstalt) of the University of Innsbruck. All tests were performed after storage the material in a climate chamber at 20 °C and 65 % RH until the equilibrium moisture content (EMC) was reached.

Test Standard Devices Remarks

Density DIN 52182 (1976) digital measuring slide, balance

balance accurateness 0,001 g Moisture

content

DIN 52183 (1977) balance accurateness 0,001 g

Compression test

DIN 52185 (1976) Shimadzu Autograph AG-100 kN Testing Maschine

cross head speed 0,7 mm/min Three point

bending test

DIN 52186 (1978) Shimadzu Autograph AG-100 kN Testing Maschine

cross head speed 7 mm/min Brinell

hardness

EN 1534 (2000) Shimadzu Autograph AG-100 kN Testing Maschine

max. load 1000 N

Table 2. Details concerning the standards followed and devices used

Results and Discussion

The statistical processing of the data obtained is presented in Table 1, Table 1. Number of samples, mean values and standard deviation for the density, the MOR and MOE out of the three point bending test and Table 2. Number of samples, mean values and standard deviation for the density and the compression strength. For the drying processes carried out mean values were recorded between 107.13 and 126.72 MPa for MOR and from 12.27 to 13.08 GPA for MOE in the tree point bending test. In the case of compression tests parallel to the grain mean values of compression strength were recorded between 47.56 and 57.88 MPa. Remarkable lower values for the water stored material can be recognized for the compression strength s. Table 1. Number of samples, mean values and standard deviation for the density, the MOR and MOE out of the three point bending test. For the Brinell hardness in the radial direction HB 10/1000 mean values are between 34.03 to 38.44 N/mm² and for the tangential direction between 31.27 to 34.94 N/mm². After the drying macro cracks could be recognized within the water stored test series

(TSA_100°C_12%_w and MWA_100°C_12%_w). Those cracks influence the mechanical properties of the wood [11]. The testing results with lower values for the water stored material at about 9 % for the compression strength in comparison to natural dried material are in agreement to this. The reason for the cracks can be assumed as result of the drying rate as the similar processes were used as for the material with lower starting MC [12].