| 1. |
- Hemmilä, Venla, 1987-, et al.
(författare)
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Bio-based adhesives for the wood industry - an opportunity for the future?
- 2013
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Ingår i: Pro Ligno. - Brasov : Publishing House of Transilvania University of Brasov. - 1841-4737 .- 2069-7430. ; 9:4, s. 118-125
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Tidskriftsartikel (refereegranskat)abstract
- This paper reviews the use of some of the new technologies that may be implemented in bio-based adhesives, e.g. carbohydrate polymers, proteins, tannins, lignins, and vegetable oils. In order to take a part of the market share, an adhesive should have low production costs, fulfil the environmental and health standards and give better properties than conventional synthetic adhesives. For large-volume wood products such as chipboard, it is essential to develop adhesives that enable the product to be cost competitive. Bio-based adhesives that are available and affordable for the wood industry suffer from three main problems: low moisture resistance, low reactivity and poor adhesive properties, and in several cases they are expensive compared to synthetic adhesives.
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| 2. |
- Hemmilä, Venla, 1987-, et al.
(författare)
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Lignin : an adhesive raw material of the future or waste of research energy?
- 2013
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Ingår i: Northern European Network for Wood Science and Engineering (WSE). - Hannover : Leibniz Universität. ; , s. 98-103
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Konferensbidrag (refereegranskat)abstract
- Lignin has been studied as an adhesive for more than 100 years, but there are only a few industrial applications. The reason for the current interest is the high availability and low price of lignin. Lignin is the main by-product of paper pulping processes and is typically burned as fuel. Being the natural glue in plants and having a phenolic nature makes lignins an attractive replacement for wood adhesives. An adhesive system for wood composites consisting mainly of lignin has yet to be developed. Lignin has less reactive sites in the aromatic ring than phenols, and the steric effects caused by the macromolecular structure further hinder its reactivity. The low reactivity leads to slow curing and causes problems in applications where the curing speed is a critical parameter. Modifications such as phenolation, methylolation, and demethylation have been shown to have a positive impact on the reactivity of lignin. This paper presents properties of particle boards produced using unmodified and oxidized Kraft lignin adhesives. The paper also describes recent research relating to lignin as a base for wood adhesive and discusses the possibilities for future research. The boards produced with unmodified and modified lignin adhesives under equivalent pressing conditions performed poorly compared to the reference board made with standard UMF adhesive. Oxidation at the correct pH level improved the adhesion of the boards compared with those based on unmodified lignin. Efforts to produce an industrially viable lignin-based adhesive system will continue, and promising combinations of modifications and alternative hardeners are being studied.
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| 3. |
- Rademacher, Peter, et al.
(författare)
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European co-operation in wood research From native wood to engineered materials : Part 3: engineered hybrid wood-based products
- 2017
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Ingår i: Pro Ligno. - Romania : Pro Ligno Foundation. - 1841-4737 .- 2069-7430. ; 13:4, s. 361-372
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Tidskriftsartikel (refereegranskat)abstract
- Forest-based industries have been continuously developing advanced processes, materials and wood-based solutions, to meet evolving demands and increase competitiveness. Engineered wood products (EWPs) constitute one emerging group of materials aiming at improved property profiles of wood, and provide desired shapes and functionality. In this paper, the main principles for different processes to soften wood and make it more flexible for bending and moulding, such as longitudinal compression, plasticization by water vapour and gaseous ammonia, and a dielectric heating technique, are discussed. Examples of implementation of these techniques for the production of wooden products are presented, and the use of reed canary grass, and a novel technique for embossment of hybrid particleboards are also further discussed.
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| 4. |
- Trischler, Johann, 1981-, et al.
(författare)
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An approach to estimate the productivity of various species on sites in Sweden by choosing individual climate and productivity values and the MIAMI-model with modifications.
- 2013
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The literature contains a large variety of bioclimate, climate, biometric models for estimating the production of different species or stands under specific conditions for a defined site, or general models giving a worldwide overview of a single species. Depending on the model used, the amount of input-data varies considerable and is often related to a large investment in time and money.The purpose of this study was to create a model to estimate the productivity of various species of interest for biomass production using only easy available input data defining the site conditions. Further, if the site-specific input-data is the same for all species, the model allows a comparison of different species on a single site. For this approach, the MIAMI-model of Lieth et al. was used as basic model with some modifications.This modified model differs from recently developed models regarding the combination of species-unspecific site data and the species-specific productivity data. As the site data change with geographical location, easy handling data are profitable. The species-specific data require more extensive investigation, but once established as a database they can be used for all sites without changes. Mean annual temperature and mean annual precipitation were chosen as site-defining data and the mean annual temperature of the native distribution area of each species in combination with the highest biomass production found in the literature were chosen as the species-specific data. This combination makes this model very efficient to estimate the productivity of various species on different sites once the database is established.This first version of the model is restricted to sites in Sweden where changes in soil and groundwater level are relatively small. Vegetation is then mainly controlled by energy input expressed for example as temperature or irradiation. As the maximum biomass production is estimated, lower nutrient and water supplies in the soil lead primary to a decrease in biomass production, but this negative impact can be influenced by culture and treatment such as fertilising which is common in conventional agriculture. When extended to other regions with a more Mediterranean climate, for example, the impact of soil, water-storage and distribution of precipitation has to be evaluated first and if necessary included in the model formulation.A validation of this model with data from the literature on the one hand and data estimated by another model on the other hand showed that it seems to be possible to use the model for purposed suggested here.
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| 5. |
- Trischler, Johann, 1981-, et al.
(författare)
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Challenges using annual plants as substitution for wood in particle-board production : Modification of reed canary grass
- 2013
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Ingår i: Northern European Network for Wood Science and Engineering (WSE). - Hannover : Leibniz Universität Hannover. ; , s. 104-109, s. 104-109
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Konferensbidrag (refereegranskat)abstract
- Forecasts show that, already in 2020, the European consumption of wood and wood fibre raw material can be as large as Europe’s combined forest growth increment. An increasing proportion of the forest raw material is expected to be used as fuel for heating, as propellant fuel or to generate electricity. This means an increasingly tight competition for wood between the board industry and the energy-conversion industry and a need for the board industry to find new raw material sources. High productivity in the boreal regions makes reed canary grass interesting as a raw material for several applications where wood is today the main raw material. One possible application is in board manufacture, e.g. as a substitute for wood in the core of multi-layer particleboards. The properties of reed canary grass must, however be modified to meet the industrial standards for particleboard production and for the mechanical properties of the boards. Alternatively, different adhesives can be chosen.The purpose of this paper is to present some pre-treatments and adhesives suitable for use when reed canary grass is used as core material in industrial particleboard production. An overview of different methods for pre-treatment and optional adhesives that can be used to increase the bonding properties of annual plants in the context of particleboard production is also presented. The bonding properties have been studied through mechanical tests and through light microscopy studies. Untreated and NaOH-pre-treated reed canary grass in combination with MUF, PVAc, Lignin, and PUR adhesives have been used in the tests.The results show that an adhesion suitable for particleboard production can be achieved with a NaOH-pre-treatment of the grass together with melamine urea formaldehyde (MUF), and especially PVAc and PUR adhesive. The adhesive system must, however, be optimized for industrial conditions.
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| 6. |
- Trischler, Johann, 1981-, et al.
(författare)
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Competitive strategies to wood production in Europe : A conceptional study
- 2017
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Ingår i: Pro Ligno. - : Pro Ligno Foundation. - 1841-4737 .- 2069-7430. ; 13:4, s. 586-593
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Tidskriftsartikel (refereegranskat)abstract
- Wood is a raw material with multifaceted properties making it useful for a diversity of industrial products. However, its primary production is restricted by environmental conditions and alternative land use. Forestry, as the main supplier of wood as raw material, is assumed to act strategically with regard to the market situation and to try, therefore, to provide the most beneficial mix of different assortments of wood. Changes in the supply of different assortments and their current value on the market are assumed to be closely related. Fluctuations in stock and market value affect the wood-using industry depending on the different assortments as raw material. The purpose of this study was to apply a concept of competitive strategies for market-driven goods to forest management in Europe, in order to derive information about the operational possibilities of forest management in specific market situations. For this purpose, Steinmann’s and Schreyögg’s concept of competitive strategies for market-driven goods was applied to forest management, in order to defining different competitive strategies for the production of different assortments of wood. The results show that different market strategies can be applied to forest management and that, even though the overall production is limited, forestry has quite a high flexibility regarding the competitive strategy used. The results also show possible impacts on the nature of forests due to changes in forest management.
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| 7. |
- Trischler, Johann, 1981-, et al.
(författare)
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Effect of temperature during vital gluten adhesive preparation and application on shear-bond strength
- 2018
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Ingår i: Journal of Adhesion Science and Technology. - : Taylor & Francis. - 0169-4243 .- 1568-5616. ; 32:4, s. 448-455
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Tidskriftsartikel (refereegranskat)abstract
- If protein-based adhesives are to become a competitive bio-based alternative to synthetic adhesives, the preparation and application methods have to be considerable improved to reduce process time and thereby improve the economy of the adhesive system. The purpose of this study was to investigate the impact of the temperature during preparation and application on the shear-bond strength of an adhesive based on vital gluten for use in wood applications. Vital gluten was used in its natural form and mixed with water of different temperatures (preparation temperature 0 °C or 20 °C), and applied on beech veneer at different temperature (application temperature –10, 20, 60 and 100 °C). Tensile shear-bond strength samples were prepared and tested according to EN 205. The results showed that an increase in veneer temperature during application of the adhesive led to a decrease in the shear-bond strength, but that the preparation temperature of the adhesive had no influence on the strength.
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| 8. |
- Trischler, Johann, 1981-, et al.
(författare)
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Reed canary grass as light-weight core in particle boards
- 2013
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Ingår i: Pro Ligno. - Brasov : Publishing House of Transilvania University of Brasov. - 1841-4737 .- 2069-7430. ; 9:4, s. 469-476
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Tidskriftsartikel (refereegranskat)abstract
- Particle boards are an important material for furniture production. In this sector, two tasks have had priority during recent years: to reduce the weight of the panels and to reduce the formaldehyde emission. As the production methods have been more or less the same for decades, these tasks have to be tackled by reducing or replacing the raw material in the board production.In this study, the possibility of replacing wood with reed canary grass (Phalaris arundinacea L.) to obtain a light-weight particle board has been studied. The boards studied were three-layered with a core of wood/reed canary grass particles and a surface of 100 % wood particles. A protein-based adhesive was tested as an alternative to a UMF adhesive to reduce the formaldehyde emission. Different combinations of densities between 250 and 450 kg/m3 were included in the study and no additional treatments were made to the raw materials.The results showed poor mechanical and swelling properties of all the tested boards regardless of the design. The main explanation of the poor properties is the poor wetting of the reed canary grass surface by the adhesives. A pre-treatment of the reed canary grass particles with steam, lipase enzyme or alkali is suggested to increase the wettability.
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| 9. |
- Trischler, Johann, 1981-
(författare)
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Strategic raw material supply for the particleboard-producing industry in Europe : Problems and challenges
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Particleboard was invented to increase the utilization of wood and it soon became an important core material for furniture production. Nowadays, other industries such as the pulp and papermaking industry and the thermal energy recovery industry claim the same type of raw material. This leads to increasing competition and higher prices than in the past when that kind of wood raw material was widely available and of low price. The particleboard-producing industry is therefore seeking opportunities to reduce the competition and ensure the future supply of lignocellulosic raw material for their products.The purpose of the work summarised in this thesis was to investigate the strategic supply of lignocellulosic raw materials for particleboard production and to evaluate alternatives for the supply of lignocellulosic raw material for particleboard production.To encompass the complex field of strategic raw material supply, several publications have considered different stages along the supply chain. These papers range from empirical studies to practical tests on a laboratory scale. In this thesis, some of the papers are linked together, building the base for the overall results.The results show that the task of increasing the supply of lignocellulosic raw material as primary raw material source is limited by several factors, but that improved product design coupled with a suitable recycling concept can greatly increase the availability of lignocellulosic raw material as a secondary source. Alternatively, the use of non-wood plants might be an opportunity to substitute wood as raw material but there are still some problems relating to the particle properties which must be overcome first.
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| 10. |
- Trischler, Johann, 1981-, et al.
(författare)
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The potential of available biomass for energy purposes under changing conditions of environment and industry
- 2015
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Ingår i: PAPERS OF THE 23RD EUROPEAN BIOMASS CONFERENCE. - : ETA-FLORENCE RENEWABLE ENERGIES. ; , s. 266-269
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Wood is a lignocellulosic raw material that is used for a diversity of industrial products. Besides the traditional uses of wood in the construction, pulp- and papermaking and furniture industries, the energy recovery industry based on renewable resources such as wood has been growing strongly during recent years. Like all resources, wood is available only in limited amounts and an increasing demand leads to greater competition among the wood-using industries. By defining a strategic cube it was possible to visualise the impact of the different parameters on the types of wood raw material available. Further, the method supported estimations of the changes inthe mix of wood raw materials when one or more of the parameters was changed. The results show that, in addition to the available land and to the climate conditions, the demands of the different sectors of wood-using industries have a strong impact on the amount of raw material available for energy purposes. Climate change and innovation or trends in the wood- using industries, for example, influence silvicultural management, and this then affects the mix of raw materials. The results challenge the studies estimating that large amounts of raw material available for energy purposes relate only to land.
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