Download or read book Bondability of modified wood written by Alireza Bastani and published by Cuvillier Verlag. This book was released on 2016-06-30 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study investigates the bonding properties of modified wood by considering three different aspects: water related characteristics, mechanical performance and optical (fluorescence microscopy and X-ray micro-computed tomography) observation of adhesive penetration into modified wood structure. In recent years, the new wood modifications have become more commercially available in the market for both exterior and interior applications due to improved properties that modification can bring to the wood e.g. the improved biological durability, dimensional stability, hardness and weathering resistance of the wood as well as the environmentally friendly nature of the wood modification processes (Militz and Hill 2005). Besides these advantages, modification can affect some technological aspects of the wood such as its bonding performance. For example, it can alter the strength of adhesion as a result of changes in chemical, physical and structural characteristics of the wood. For example, the less polar and less porous modified wood surfaces can result in reduced adhesion due to formation of less free OH groups for bonding leading to poorer adhesive wetting of the wood surface and weaker chemical bonds between the two adherents (Hunt et al. 2007). As modified wood becomes a more demanded material for different applications, there is a need to study its bonding performance where the challenge is to bond different modified materials as their physical and chemical characteristics are substantially changed by modification. In this thesis, measurements of capillary water uptake, contact angle and surface energy were used to determine the water related properties and hydrophobic behavior of furfurylated (FA40 and FA70, which represent 65 and 75 % WPGs) and N-methylol melamine (NMM) (10, 20 and 30%) modified Scots pine and thermally treated Scots pine and beech (modified through an industrial scale vacuum press dewatering method at 195 and 210 °C). The capillary water uptake results indicated a considerable reduction of water uptake for all modifications in all directions both after short (24 h) and long contact times (168, 336 h). Contact angle measurement data revealed an increased hydrophobicity of modified wood. However, some exceptions were observed, mainly for thermally treated wood. Modifications provided radial and tangential surfaces with a non-polar character. Penetration of adhesives into the wood structure plays an important role in the production of glued wood-based panels and products by affecting the bond quality (Frihart 2005, Kamke and Lee 2007). The gross penetration of emulsion polymer isocyanate (EPI), polyurethane (PU) and polyvinyl acetate (PVAc) adhesives into modified wood, both with and without pressure, were determined by using fluorescence microscopy based on measurements of effective (EP) and maximum penetration (MP). Without application of pressure, the EP of EPI adhesive reduced after NMM modification and furfurylation (FA70) and also PU adhesive after NMM modification while the EP of PVAc adhesive increased into furfurylated and NMM modified (10 and 20%) wood. For thermally treated Scots pine, increasing the treatment temperature improved EP of all adhesives. Among used adhesives, PU penetrated much deeper into thermally treated wood for both treatment temperatures. Comparison of penetration of adhesive with and without pressure revealed that with the exception of EP of PU and EPI adhesives into NMM-modified wood and PVAc into thermally treated beech at 195°C, application of pressure led to rather different results as compared to the EP data when no pressure was applied. Visual observation and analysis of fluorescence microscopy photomicrographs provided more detailed information on modality of penetration. Due to the large and deep penetration of PU adhesive into thermally treated Scots pine observed in both studies (with and without pressure), the 3D pattern of penetration of this adhesive was obtained by X-ray micro- computed tomography indicating the pathways which were used by this adhesive for penetration. In another study, the bonding shear strength of the same modified wood materials glued with the same adhesives was also investigated. For all adhesives used, the shear strength significantly reduced after furfurylation and NMM modification of Scots pine samples, mainly due to the brittle nature of the wood after modification rather to the failure of the bondline. Bonding strength of both Scots pine and beech was also negatively affected by thermal modification and the bondline was found to be the weakest link in thermally modified wood. The EP of adhesives and the bondline thickness did not relate to the shear strength of all modified wood materials. It was indicated that the lower shear strength of modified wood could be attributed to other factors, such as the decreased chemical bonding or mechanical interlocking of adhesives, and the reduced strength of brittle modified wood substrate. The effect of two important bonding variables, wood moisture content and open assembly time on penetration of PU adhesive into thermally modified wood (195 and 210 °C) was also studied. The equilibrium moisture content (EMC) level of 8.6% was found to be the optimum for an effective penetration of PU adhesive in thermally modified Scots pine treated at 195°C. In most of the cases, penetration of PU adhesive did not change significantly by increasing the open assembly time, which suggested using a shorter open assembly time of 15 min than 30 min for bonding of thermally modified Scots pine with PU adhesive, in order to save time and reducing the production costs. For samples treated at both treatment temperatures and after shorter open assembly time, the highest MP values observed at moderate EMC levels of 8.6 and 8.2% and the lowest at the higher EMC levels of 13.2 and 12.5%. In another study, the effect of phenol formaldehyde (PF) treatment on bonding performance of beech glued with PVAc and phenol resorcinol formaldehyde (PRF) adhesives was also investigated. The results of both dry and wet conditions indicated higher shear strength for samples bonded with PRF than PVAc. With the exception of 25% PF treated wood bonded with PVAc, the PF modified wood can be glued with both adhesives satisfactorily under dry condition, while under wet condition only the 25% PF modified samples bonded with PRF provided acceptable bonding. For both adhesive systems, PF modification caused a reduction of adhesive penetration into wood structure, especially in the case of higher load treatment. The development of bonding strength of modified birch veneers glued with hot curing phenol formaldehyde (PF) adhesive was investigated in different pressing (20 s , 160s) and open assembly times (20s , 10 min). Generally, the bonding strength improved by extending the pressing time. In 20 s pressing, increasing assembly time did not change the bonding strength in most of the cases while at 160 s pressing, prolongation of assembly time developed a better bonding for controls, NMM modified and thermally treated veneers at 180°C. The combination of 10 min assembly time and 160 s pressing time provided the highest bonding strength for controls, NMM modified and thermally treated veneers at 180°C while furfurylated samples achieved the highest values in 20 s assembly and 160 s pressing times. In general, modification affected negatively the bonding performance of the veneers, especially for furfurylated and NMM modified samples. In General, the overall results obtained in this thesis showed that modified wood has lower bonding ability and performance than unmodified wood as result of the decreased water related properties, less penetration of adhesive into wood structure and decreased bonding strength after modification. However, the increased dimensional stability and low water uptake of modified wood might lead to better performance in long term.
Download or read book Wood Modification Technologies written by Dick Sandberg and published by CRC Press. This book was released on 2021-07-14 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes how to Improvement of wood products Describes Sustainable development Covers Environmental industrial processing
Download or read book Progress in Adhesion and Adhesives Volume 4 written by K. L. Mittal and published by John Wiley & Sons. This book was released on 2019-07-11 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: A solid collection of interdisciplinary review articles on the latest developments in adhesion science and adhesives technology With the ever-increasing amount of research being published, it is a Herculean task to be fully conversant with the latest research developments in any field, and the arena of adhesion and adhesives is no exception. Thus, topical review articles provide an alternate and very efficient way to stay abreast of the state-of-the-art in many subjects representing the field of adhesion science and adhesives. Based on the success of the preceding volumes in this series "Progress in Adhesion and Adhesives"), the present volume comprises 9 review articles published in Volume 6 (2018) of Reviews of Adhesion and Adhesives. The subject of these reviews fall into the following general areas: 1. Adhesion to wood and wood bonds 2. Adhesive joints 3. Adhesion in microelectronic packaging 4. Surface modification 5. Contact angle, wettability and surface free energy. The topics covered include: Adhesion phenomena in microelectronic packaging; adhesives for wood and lignocellulosic materials; adhesion to wood and lignocellulosic materials; adhesively bonded lap joints having bi-adhesive and modulus-graded bondlines; adhesion between compounded elastomers; applications of contact angle measurements in pharmaceuticals and foods; oxygen or ammonia plasma treatment of polyolefin surfaces; surface free energy determination of powders and particles; wood bonds; and dispersion adhesion forces between macroscopic objects.
Download or read book Wood Composites written by Martin P Ansell and published by Woodhead Publishing. This book was released on 2015-07-24 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent progress in enhancing and refining the performance and properties of wood composites by chemical and thermal modification and the application of smart multi-functional coatings have made them a particular area of interest for researchers. Wood Composites comprehensively reviews the whole field of wood composites, with particular focus on their materials, applications and engineering and scientific advances, including solutions inspired biomimetrically by the structure of wood and wood composites. Part One covers the materials used for wood composites and examines wood microstructure, and wood processing and adhesives for wood composites. Part Two explores the many applications of wood composites, for example plywood, fibreboard, chipboard, glulam, cross-laminated timber, I-beams and wood-polymer composites. The final part investigates advances in wood composites and looks at the preservation and modification of wood composites, environmental impacts and legislative obligations, nano-coatings and plasma treatment, biomimetic composite materials, the integration of wood composites with other materials and carbonized and mineralized wood composites. Comprehensively reviews the entire field of wood composites in a single volume Examines recent progress in enhancing and refining the performance and properties of wood composites by chemical and thermal modification and the application of smart multi-functional coatings Explores the range of wood composites, including both new and traditional products
Download or read book Digital Wood Design written by Fabio Bianconi and published by Springer. This book was released on 2019-02-24 with total page 1525 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores various digital representation strategies that could change the future of wooden architectures by blending tradition and innovation. Composed of 61 chapters, written by 153 authors hailing from 5 continents, 24 countries and 69 research centers, it addresses advanced digital modeling, with a particular focus on solutions involving generative models and dynamic value, inherent to the relation between knowing how to draw and how to build. Thanks to the potential of computing, areas like parametric design and digital manufacturing are opening exciting new avenues for the future of construction. The book’s chapters are divided into five sections that connect digital wood design to integrated approaches and generative design; to model synthesis and morphological comprehension; to lessons learned from nature and material explorations; to constructive wisdom and implementation-related challenges; and to parametric transfigurations and morphological optimizations.
Download or read book Adhesive Bonding written by Robert D. Adams and published by Woodhead Publishing. This book was released on 2021-07-02 with total page 828 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adhesive Bonding: Science, Technology and Applications, Second Edition guides the reader through the fundamentals, mechanical properties and applications of adhesive bonding. This thoroughly revised and expanded new edition reflects the many advances that have occurred in recent years. Sections cover the fundamentals of adhesive bonding, explaining how adhesives and sealants work, and how to assess and treat surfaces, how adhesives perform under stress and the factors affecting fatigue and failure, stress analysis, environmental durability, non-destructive testing, impact behavior, fracture mechanics, fatigue, vibration damping, and applications in construction, automotive, marine, footwear, electrical engineering, aerospace, repair, electronics, biomedicine, and bonding of composites. With its distinguished editor and international team of contributors, this book is an essential resource for industrial engineers, R&D, and scientists working with adhesives and their industrial applications, as well as researchers and advanced students in adhesion, joining, polymer science, materials science and mechanical engineering. Offers detailed, methodical coverage of the fundamentals, mechanical properties and industrial applications of adhesive bonding Enables the successful preparation of adhesives for a broad range of important load-bearing applications in areas such as automotive and aerospace, construction, electronics and biomedicine Covers the latest advances in adhesive bonding, including improved repair techniques for metallic and composite structures, cohesive zone modeling, and disassembly and recycling
Download or read book Progress in Adhesion and Adhesives written by K. L. Mittal and published by John Wiley & Sons. This book was released on 2015-07-27 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is based on the 13 review articles written by subject experts and published in 2014 in the Journal Reviews of Adhesion and Adhesives. The rationale for publication of this book is that currently the RAA has limited circulation, so this book provides broad exposure and dissemination of the concise, critical, illuminating, and thought-provoking review articles. The subjects of the reviews fall into 4 general areas: 1. Polymer surface modification 2. Biomedical, pharmaceutical and dental fields 3. Adhesives and adhesive joints 4. General Adhesion Aspects The topics covered include: Adhesion of condensed bodies at microscale; imparting adhesion property to silicone material; functionally graded adhesively bonded joints; synthetic adhesives for wood panels; adhesion theories in wood adhesive bonding; adhesion and surface issues in biocomposites and bionanocomposites; adhesion phenomena in pharmaceutical products and applications of AFM; cyanoacrylate adhesives in surgical applications; ways to generate monosort functionalized polyolefin surfaces; nano-enhanced adhesives; bonding dissimilar materials in dentistry; flame treatment of polymeric materials—relevance to adhesion; and mucoadhesive polymers for enhancing retention of ocular drug delivery.
Download or read book Wood Adhesives written by A. Pizzi and published by Routledge. This book was released on 2018-10-08 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: The perfect companion to the highly acclaimed Volume 1 of Wood Adhesives,Volume 2 presents stimulating discussions on technically and economically importantadhesives for wood bonding-covering their preparation and formulation, as well astechniques and suggestions for their application.Like its companion book, Wood Adhesives, Volume 2 provides up-to-date informationand analysis of new technologies and recent breakthroughs ... gives insightinto the relationship between adhesive chemistry and technical application . . . anddiscusses present and future trends likely to have considerable impact on the field.Elaborating upon general overviews presented in Volume 1, Wood Adhesives,Volume 2 includes a chapter on protein adhesives ... fills the gap on the chemistryof polyvinyl acetate wood adhesives ... contains a detailed discussion of formaldehydeemission ... and much more.A complementary and much needed follow-up to Volume 1, Wood Adhesives,Volume 2 is essential reading for wood technologists; adhesives and physicalchemists; forest products researchers; polymer scientists; chemical, mechanical, process,and civil engineers who must choose and apply wood adhesives; and advancedundergraduate and graduate students in the above disciplines.
Download or read book Wood and Fiber Science written by and published by . This book was released on 1983 with total page 904 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Wood Chemistry and Wood Composites written by Roger M. Rowell and published by CRC Press. This book was released on 2005-02-18 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: The degradable nature of high-performance, wood-based materials is an attractive advantage when considering environmental factors such as sustainability, recycling, and energy/resource conservation. The Handbook of Wood Chemistry and Wood Composites provides an excellent guide to the latest concepts and technologies in wood chemistry and bio-based composites. The book analyzes the chemical composition and physical properties of wood cellulose and its response to natural processes of degradation. It describes safe and effective chemical modifications to strengthen wood against biological, chemical, and mechanical degradation without using toxic, leachable, or corrosive chemicals. Expert researchers provide insightful analyses of the types of chemical modifications applied to polymer cell walls in wood, emphasizing the mechanisms of reaction involved and resulting changes in performance properties. These include modifications that increase water repellency, fire retardancy, and resistance to ultraviolet light, heat, moisture, mold, and other biological organisms. The text also explores modifications that increase mechanical strength, such as lumen fill, monomer polymer penetration, and plasticization. The Handbook of Wood Chemistry and Wood Composites concludes with the latest applications, such as adhesives, geotextiles, and sorbents, and future trends in the use of wood-based composites in terms of sustainable agriculture, biodegradability and recycling, and economics. Incorporating over 30 years of teaching experience, the esteemed editor of this handbook is well-attuned to educational demands as well as industry standards and research trends.
Download or read book Adhesives for Wood and Lignocellulosic Materials written by R. N. Kumar and published by John Wiley & Sons. This book was released on 2019-07-17 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is a comprehensive treatment of the subject covering a wide range of subjects uniquely available in a single source for the first time. A material science approach has been adopted in dealing with wood adhesion and adhesives. The approach of the authors was to bring out hierarchical cellular and porous characteristics of wood with polymeric cell wall structure, along with the associated non-cell wall extractives, which greatly influence the interaction of wood substrate with polymeric adhesives in a very unique manner not existent in the case of other adherends. Environmental aspects, in particular formaldehyde emission from adhesive bonded wood products, has been included. A significant feature of the book is the inclusion of polymeric matrix materials for wood polymer composites.
Download or read book Wood Handbook written by Forest Products Laboratory (U.S.) and published by . This book was released on 1987 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dividends from Wood Research written by and published by . This book was released on 1988 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Encyclopedia of Wood written by Agriculture and published by Simon and Schuster. This book was released on 2011-02-11 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Timber is one of our most precious, versatile, and vulnerable resources, so using it effectively is important. Knowing your material inside and out is the first step to doing just that. Read about the structure of wood itself, from growth rings to its chemical composition. Learn wood's physical and mechanical properties, including everything from elasticity to nuclear radiation. This extensive manual includes a section on stress grading as well as thorough descriptions of which fasteners to use and when. It has information on adhesive bonding, biodeterioration, control of moisture content, preservation, fire safety, specialty treatments, and much more. The Encyclopedia of Wood is an essential resource for builders, architects, engineers, and woodworkers.
Download or read book Bio based Wood Adhesives written by Zhongqi He and published by CRC Press. This book was released on 2017-05-25 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adhesive bonding plays an increasing role in the forest product industry and is a key factor for efficiently utilizing timber and other lignocellulosic resources. As synthetic wood adhesives are mostly derived from depleting petrochemical resources and have caused increasing environmental concern, natural product and byproduct-derived adhesives have attracted much attention in the last decades. Although adhesives made from plant and animal sources have been in existence since ancient times, increased knowledge of their chemistry and improved technical formulation of their preparation are still needed to promote their broader industrial applications. The primary goals of this book are to (1) synthesize the fundamental knowledge and latest research on bio-based adhesives from a remarkable range of natural products and byproducts, (2) identify need areas and provide directions of future bio-based adhesive research, and (3) help integrating research findings in practical adhesive application for maximal benefits. This book covers information on a variety of natural products and byproducts and the latest research on formulation, testing and improvement of the relevant adhesives in fifteen chapters written by an international group of accomplished contributors. This book will serve as a valuable reference source for university faculty, graduate students, research scientists, agricultural and wood engineers, international organization advocators and government agency regulators who work and deal with enhanced utilization of agricultural and forest products and byproducts.
Download or read book Wood Protection and Preservation written by Christian Brischke and published by MDPI. This book was released on 2020-12-10 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wood is an advantageous building material in many respects, but it is biodegradable and therefore requires protection when used in highly hazardous applications. This Special Issue comprises 19 papers by authors from 14 countries in Asia, North America and Europe. They represent a wide range of aspects related to wood protection and wood preservation, and give timely examples of research activities that can be observed around the globe. Several authors reported on the processes of thermal modification and different chemical wood modification techniques, which are among the latest alternative wood protection methods without the use of biocides. New preservatives and assessment methods of preservative-treated wood products are presented, as well as studies on the natural durability of wood, fire-retardant treated wood, the effect of concrete on wood durability and different novel surface modification techniques using plasma. In addition to biological durability, the mechanical properties, moisture performance, bonding properties, weathering stability and the corrosiveness of differently treated wood are investigated and reported within this Special Issue. Examples of research on fungal biology, service life planning with wood and test methodology are also included and complete the Special Issue.
