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  • 1.
    Aldaeus, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    The Bioeconomy Research Programme 2018-20202018In: The 8th Nordic Wood Biorefinery Conference: NWBC 2018: proceedings / [ed] Hytönen Eemeli, Vepsäläinen Jessica, Espoo: VTT Technical Research Centre of Finland , 2018, p. 83-Conference paper (Other academic)
  • 2.
    Andersson, Sofia
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Bengtsson, Andreas
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy. KTH Royal institute of technology, Sweden.
    Åkerström, Mårten
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Sedin, Maria
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    The impact of inorganic elements on lignin‐based carbon fibre quality2018In: 15th European workshop on lignocelllulosics and pulp: Proceedings for poster presentations, 2018, p. 119-122Conference paper (Other academic)
    Abstract [en]

    The influence of inorganic elements on lignin ‐based carbon fibre (CF) quality was studied using sulphates of Na +, K+, Mg2+, Fe2+, Al3+. The metal sulphates were added to wet spun prefibres made from softwood kraft lignin (SKL):cellulose (70:30) and melt spun prefibres made from low molecular mass SKL. An increase in concentration from 0.1 w% to about 0.4 w% did neither affect the mechanical properties nor the morphology as observed by SEM. In contrast, metal sulphates added to the initial 0.45 w% to a total range 1.5 to 5.0 w%, was found detrimental to the melt spinning and to the final CF quality. Thus, the recommendation of <0.1 w% ash in kraft lignin may be exceeded, but more research is needed to establish the upper concentration limit.

  • 3.
    Bengtsson, Andreas
    et al.
    KTH Royal Institute of Technology, Sweden.
    Bengtsson, Jenny
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Sedin, Maria
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Improved yield of carbon fibres from cellulose and kraft lignin2018In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434XArticle in journal (Refereed)
    Abstract [en]

    To meet the demand for carbon-fibre-reinforced composites in lightweight applications, cost-efficient processing and new raw materials are sought for. Cellulose and kraft lignin are each interesting renewables for this purpose due to their high availability. The molecular order of cellulose is an excellent property, as is the high carbon content of lignin. By co-processing cellulose and lignin, the advantages of these macromolecules are synergistic for producing carbon fibre (CF) of commercial grade in high yields. CFs were prepared from precursor fibres (PFs) made from 70:30 blends of softwood kraft lignin (SW-KL) and cellulose by dry-jet wet spinning with the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) as a solvent. In focus was the impact of the molecular mass of lignin and the type of cellulose source on the CF yield and properties, while membrane-filtrated kraft lignin and cellulose from dissolving kraft pulp and fully bleached paper-grade SW-KP (kraft pulp) served as sources. Under the investigated conditions, the yield increased from around 22% for CF from neat cellulose to about 40% in the presence of lignin, irrespective of the type of SW-KL. The yield increment was also higher relative to the theoretical one for CF made from blends (69%) compared to those made from neat celluloses (48-51%). No difference in the mechanical properties of the produced CF was observed.

  • 4.
    Bengtsson, Andreas
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy. KTH Royal institute of technology, Sweden.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Conditions for the stabilisation of lignin-cellulose prefibres for carbon fibre production2018In: 15th European workshop on lignocellulosics and pulp: Proceedings for poster presentations, 2018, p. 111-114Conference paper (Other academic)
    Abstract [en]

    Stabilisation of the prefibre is a time-consuming step in carbon fibre (CF) production. In this paper the stabilisation condition of dry-jet wet-spun lignin-cellulose (LC) prefibres (70:30  t%) are reported. The impact of prefibre-impregnation by ammonium dihydrogen phosphate (ADHP) and various thermal conditions were evaluated by measuring the yield and mechanical properties of the final CFs. The addition of ADHP improved the CF yields from 32-40 wt% to 45-47 wt% but had a slight negative impact on the tensile modulus (TM) whereas no significant difference in tensile strength (TS) was observed. The absence of fibre fusion and glass transition temperature (Tg) indicate successful stabilisation of all prefibres. This implies possibilities of using short stabilisation times of LC prefibres in CF production.

  • 5.
    Brännvall, Elisabet
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Reimann, Anders
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    The balance between alkali diffusion and alkali consuming reactions during impregnation of softwood. Impregnation for kraft pulping revisited2018In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 72, no 3, p. 169-178Article in journal (Refereed)
    Abstract [en]

    The purpose of the impregnation stage is to ensure that cooking chemicals reach all parts of the chips. However, as alkali comes into contact with wood, reactions take place, which alter the paths available for ionic transport and dissolve wood components. The aim of the present study is to establish the most favorable impregnation conditions, which result in an even alkali concentration profile through the chip at a sufficiently high level without extensive yield losses due to peeling. Softwood chips were subjected to different impregnation conditions. The progress of impregnation was assessed by analyzing the concentration of hydroxide ions in the bound liquor inside wood chips and the release of acetic acid. The extent of undesired reactions was measured as the amount of carbohydrate degradation products formed and amount of wood dissolved. Increased temperature and time lead to more degradation of the carbohydrates during impregnation. At high temperature, the concentration of alkali in the bound liquor was lower due to higher alkali consumption in degradation reactions. The most favorable process is to perform impregnation at an elevated initial effective alkali (EA) for a short time. This resulted in an increased alkali concentration in the bound liquor within the chip without extensive carbohydrate degradation.

  • 6.
    Ehmcke, Gabrielle
    et al.
    Technical University of Munich, Germany.
    Pilgård, Annica
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials. Technical University of Munich, Germany.
    Koch, Gerald
    Thunene Institute of Wood Research, Gemany.
    Richter, Klaus
    Technical University of Munich, Germany.
    Topochemical analyses of furfuryl alcohol-modified radiata pine (Pinus radiata) by UMSP, light microscopy and SEM2017In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 71, no 10, p. 821-831Article in journal (Refereed)
    Abstract [en]

    Furfurylation is one of the wood modification techniques via catalytic polymerization of the monomeric furfuryl alcohol (FA) in the impregnated cell wall. Little is known about the topochemistry of this process. Brown rot degradation begins with lignin modification and therefore, the reactions between FA and lignin was one focus of this research. Furfurylated radiata pine (Pinus radiata) with three different weight percent gains (WPGs of 57%, 60% and 70%) after FA uptake was observed by cellular ultraviolet microspectrophotometry (UMSP) to analyze chemical alterations of the individual cell wall layers. Moreover, light microscopy (LM) and scanning electron microscopy (SEM) analyses were performed. The ultraviolet (UV) absorbance of the modified samples increased significantly compared to the untreated controls, indicating a strong polymerization of the aromatic compounds. Highest UV absorbances were found in areas with the highest lignin concentration. The UMSP images of individual cell wall layers support the hypothesis concerning condensation reactions between lignin and FA.

  • 7.
    Lie, Ewa
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Ålander, Eva
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Lindström, Tom
    RISE - Research Institutes of Sweden, Bioeconomy.
    Possible toxicological effects of nanocellulose: an updated literature study, No. 22017Report (Other academic)
    Abstract [en]

    This literature review covers open publications and reports on the subject of nanocellulose and its possible toxicological effects. There is currently a rather low number of peer reviewed articles on the subject. However, from the articles reviewed, caution of inhalation of nanocellulose would be recommended since in vivo tests have shown immunotoxicity effect on lungs even though residues of other production chemicals, biocides and endotoxins from bacterial contamination might affect the results.

  • 8.
    Lindberg, Anders
    et al.
    KTH Royal institute of technology, Sweden.
    Alfthan, Johan
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Pettersson, Henrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Flodberg, Göran
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Yang, Li
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Mechanical performance of polymer powder bed fused objects: FEM simulation and verification2018In: Additive manufacturing, ISSN 2214-8604, Vol. 24, p. 577-586Article in journal (Refereed)
    Abstract [en]

    Additive manufacturing (3D printing) enables the designing and producing of complex geometries in a layer-by-layer approach. The layered structure leads to anisotropic behaviour in the material. To accommodate anisotropic behaviour, geometrical optimization is needed so that the 3D printed object meets the pre-set strength and quality requirements. In this article a material description for polymer powder bed fused also or selective laser sintered (SLS) PA12 (Nylon-12), which is a common 3D printing plastic, was investigated, using the Finite Element Method (FEM). The Material Model parameters were obtained by matching them to the test results of multipurpose test specimens (dumb-bells or dog bones) and the model was then used to simulate/predict the mechanical performance of the SLS printed lower-leg prosthesis components, pylon and support. For verification purposes, two FEM designs for a support were SLS printed together with additional test specimens in order to validate the used Material Model. The SLS printed prosthesis pieces were tested according to ISO 10328 Standard. The FEM simulations, together with the Material Model, was found to give good estimations for the location of a failure and its load. It was also noted that there were significant variations among individual SLS printed test specimens, which impacted on the material parameters and the FEM simulations. Hence, to enable reliable FEM simulations for the designing of 3D printed products, better control of the SLS process with regards to porosity, pore morphology and pore distribution is needed.

  • 9.
    Lycken, Anders
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Rapport efter studie av automatisk sortering i justerverk samt av regelverken Nordiskt trä och EN 1611-12017Report (Other academic)
    Abstract [en]

    The project has two clear objectives: firstly to investigate the ability of the grading systems to optimize the value of production and, secondly, to investigate whether different grading rules are advantageous in different situations. Both studies have been carried out in cooperation with manufacturers and users of the systems.

    A study to investigate the ability of modern grading systems to optimize the value of the production in final grading stations has been performed. Pine and spruce, side boards and centre boards, have been studied in 15 studies with 15 sawmills and 5 different grading systems. One of the studies was a "method study" and is not included in the summaries. Therefore, 14 studies in the summary include 8 pine and 6 spruce studies, with both planks and boards, a total of 28 batches, with 100 to 200 timber pieces in each. A total of 4063 timber pieces were included. The sawmill's own grading rules and prices have been used. The system's decisions have been compared with a manual decision, with the help of caliper and measuring tape. Calculations of value and quality yield have been performed. All manufacturers have at least one study with 99% or 100% value yield, the quality yield’s "Equal" value of 93% or higher and "OK" value of 93% or higher. The median value of all studies is 98% for the value yield and 89% and 91% respectively for the two quality yield values.

    A functioning system, well-maintained and updated, with dedicated staff, should be able to achieve a 98% value and 95% quality yield.

    A simulation of the outcome of grading with the grading rules Nordic Wood (the Gray Book) and the SS-EN 1611-1 standard has been performed to see if there are any differences in yield. The simulation shows that in the vast majority of cases, it is more economically advantageous to use SS-EN 1611-1 than Nordic Wood. The rules are similar but different. For example, larger knots are in some cases allowed in SS-EN 1611-1 than in the corresponding grade in Nordic Wood.

    Which grading rule the sawmill will use depends on which customers you have, what requirements the customers have and the price for the products.

  • 10.
    Lycken, Anders
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Torstensson, Erik
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Engström, Jonas
    RISE - Research Institutes of Sweden, Bioscience and Materials, Agrifood and Bioscience.
    Lagnelöv, Oscar
    RISE - Research Institutes of Sweden, Bioscience and Materials, Agrifood and Bioscience.
    Söderberg, Andreas
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Förarlösa virkestruckar – en förstudie2017Report (Other academic)
    Abstract [en]

    This pilot study was initiated by the sawmill industry and aims to investigate the

    possibility of introducing autonomous vehicles in the form of forklift trucks for

    handling of timber packages at sawmills.

    The report presents the various levels of definition of autonomous vehicles, and in

    which activities we now can find examples of vehicles with varying degrees of autonomy.

    Various technical solutions to enable navigation and security for autonomous

    vehicles are presented as well as the security requirements of autonomous vehicles in

    different situations.

    To exemplify today’s and tomorrow’s use of forklifts, a sawmill’s package management

    is described, and a scenario for autonomous trucks is presented. Under that scenario,

    today’s six trucks are replaced with three or four driverless trucks. A brief economic

    calculation is made, describing the economic potential of driverless trucks. It shows

    that autonomous forklifts may be permitted to cost significantly more than conventional

    forklifts after the external security systems are installed, and still be profitable.

    The reason is mainly the personnel costs associated with running conventional forklifts.

    In conclusion, autonomous vehicles can be realized in the relatively near future in

    many industries. The sawmill industry is also expected to take advantage of the ongoing

    research and development. It is not least the economic parameters that weigh heavily

    pro an introduction of autonomous forklift trucks, while safety precautions can be a

    challenge.

    An intermediate step towards fully driverless forklift trucks can be a semi-autonomous

    solution, where the driver / operator manage a plurality of trucks by telemetry with

    manual assistance only when

  • 11.
    Markström, Emilia
    et al.
    Luleå University of Technology, Sweden.
    Kuzman, Manja K.
    University of Ljubljana, Slovenia.
    Bystedt, Anders
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Sandberg, Dick
    Luleå University of Technology, Sweden.
    Fredriksson, Magnus
    Luleå University of Technology, Sweden.
    Swedish architects view of engineered wood products in buildings2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 181, p. 33-41Article in journal (Refereed)
    Abstract [en]

    From a climate perspective, it could be advantageous to increase the use of wood products in buildings, but the use of sawn timber and engineered wood products (EWPs) in multi-storey buildings above two floors are a relatively new business (in Sweden since 1995) and there is a risk that wood as construction material is met with low awareness and high uncertainty by the construction sector. The purpose of this study was twofold: 1) to learn Swedish architects' views of using EWPs in buildings, and 2) to identify parameters that positively influence the likelihood that EWPs will be selected to a greater extent and the relative importance of those parameters. A survey was sent out to Swedish architects and 67 answers were received. The result indicates that architects in Sweden have a positive attitude towards EWPs in general and that the majority think that they will probably increase their use of these materials. Low impact on the environment, aesthetic appeal, and fast construction were the most common reasons stated for selecting EWPs. The Swedish architects have in general a moderate impact on the selection of materials, and the most common reason for not selecting EWPs was that other decision makers involved in the building projects prefer other materials. A lack of knowledge and information as well as uncertainties regarding the quality over time were other common reasons for not selecting EWPs. It was found that architects who had participated in building projects where EWPs had been chosen due to their low environmental impact and/or aesthetic appearance were more likely to state that they will increase their use of EWPs. The results also show that influence on material selection, knowledge of EWPs, experience of the use of EWPs, and the architect's own attitude to the use of EWPs affect the likelihood of an increased use.

  • 12.
    Meyer-Veltrup, Linda
    et al.
    Leibniz University, Germany.
    Brischke, Christian
    Leibniz University, Germany.
    Alfredsen, Gry
    The Norwegian Institute of Bioeconomy Research (NIBIO), Norway.
    Humar, Miha
    University of Ljubljana, Slovenia.
    Flæte, Per-Otto
    Norwegian Institute of Wood Technology, Norway.
    Isaksson, Tord
    Lund University, Sweden.
    Brelid, Pia L.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Westin, Mats
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Jermer, Jöran
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    The combined effect of wetting ability and durability on outdoor performance of wood: development and verification of a new prediction approach2017In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 51, no 3, p. 615-637Article in journal (Refereed)
    Abstract [en]

    Comprehensive approaches to predict performance of wood products are requested by international standards, and the first attempts have been made in the frame of European research projects. However, there is still an imminent need for a methodology to implement the durability and moisture performance of wood in an engineering design method and performance classification system. The aim of this study was therefore to establish an approach to predict service life of wood above ground taking into account the combined effect of wetting ability and durability data. A comprehensive data set was obtained from laboratory durability tests and still ongoing field trials in Norway, Germany and Sweden. In addition, four different wetting ability tests were performed with the same material. Based on a dose–response concept, decay rates for specimens exposed above ground were predicted implementing various indicating factors. A model was developed and optimised taking into account the resistance of wood against soft, white and brown rot as well as relevant types of water uptake and release. Decay rates from above-ground field tests at different test sites in Norway were predicted with the model. In a second step, the model was validated using data from laboratory and field tests performed in Germany and Sweden. The model was found to be fairly reliable, and it has the advantage to get implemented into existing engineering design guidelines. The approach at hand might furthermore be used for implementing wetting ability data into performance classification as requested by European standardisation bodies.

  • 13.
    Ong, Chee Beng
    et al.
    University of Bath, UK.
    Chang, Wen Shao
    University of Sheffield, UK.
    Ansell, Martin P.
    University of Bath, UK.
    Brandon, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Sterley, Magdalena
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Walker, Pete
    University of Bath, UK.
    Bench-scale fire tests of Dark Red Meranti and Spruce finger joints in tension2018In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 168, p. 257-265Article in journal (Refereed)
    Abstract [en]

    This study investigates the secondary failure of Malaysian Dark Red Meranti (Shorea spp.) and Spruce (Picea abies) finger joints in a glulam beam in a fire test using a bench-scale test set-up. Secondary failure is the occurrence of failure of the bond lines due to fire and the falling off of the outermost tension layers, exposing the uncharred inner layers to a sudden increase of fire intensity. The lack of published work and the difficulties in describing the behaviour of the finger joints after the secondary failure in a full-scale fire test has identified the need for a simple bench-scale method, incorporating the conditions of the standard fire test. This paper focusses on the performance of the finger joints which together with other defects such as knots and splits are generally the weakest component in the glulam beam. The finger joints were bonded with structural adhesives, specifically phenol resorcinol formaldehyde (PRF) and polyurethane (PUR). They were tested in tension to imitate the failure of finger joints on the tension side of a standard fire test of a glulam beam. Constant heat flux was introduced to the finger-jointed specimens to replicate the secondary failure of a glulam beam in the standard fire test. The results of this study indicate a relationship between the charring rate and density of the specimens, with higher density Dark Red Meranti showing lower charring rate compared to the lower density Spruce specimens. Factors such as constant heat flux as opposed to the time-increasing heat flux exposure and specimen size influenced the charring rate of the specimens. The char rate was measured at the early stages of the fire test, which is known to have higher values since the build-up of the charred layers was not sufficiently substantial to protect the inner unburnt wood. Overall, the bench-scale fire test set-up was able to differentiate the fire performance of the adhesives, with PRF showing better fire performance compared to the specimens finger-jointed with PUR adhesive. In addition, tensile tests at ambient temperature showed no significant difference in tensile strength between finger joints bonded with different adhesives for the same wood species. The tensile strengths of the finger joints bonded with different adhesives were influenced by the temperature profile through the joint. The proposed bench-scale fire test was used to compare the quality of the adhesives in a fire situation, specifically with respect to secondary failure. The PRF was selected as the reference adhesive.

  • 14.
    Pupure, LIva
    et al.
    Luleå University of Technology, Sweden.
    Varna, Janis
    Luleå University of Technology, Sweden.
    Jofe, Roberts
    RISE - Research Institutes of Sweden, Swerea, Swerea SICOMP. Luleå University of Technology, Sweden.
    Berthold, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Miettinen, Arttu
    Univrsity of Jyväskylä, Finland ; Paul Scherrer Institute, Switzerland ; .
    Mechanical properties of natural fiber composites produced using dynamic sheet former2018In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280Article in journal (Refereed)
    Abstract [en]

    Composites formed from wood fibers and man-made cellulosic fibers in PLA (polylactic acid) matrix, manufactured using sheet forming technique and hot pressing, are studied. The composites have very low density (due to high porosity) and rather good elastic modulus and tensile strength. As expected, these properties for the four types of wood fiber composites studied here improve with increasing weight fraction of fibers, even if porosity is also increasing. On the contrary, for man-made cellulosic fiber composites with circular fiber cross-section, the increasing fiber weight fraction (accompanied by increasing void content) has detrimental effect on stiffness and strength. The differences in behavior are discussed attributing them to fiber/ fiber interaction in wood fiber composites which does not happen in man-made fiber composites, and by rather weak fiber/matrix interface for man-made fibers leading to macro-crack formation in large porosity regions.

  • 15.
    Regnell Andersson, Sofia
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Rönnols, Jerk
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Aldaeus, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Jacobs, Anna
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Lignin Bimodality: Fact or Artefact?2018In: 15th European workshop on lignocellulosics and pulp: Proceedings for oral presentations, 2018, p. 97-100Conference paper (Other academic)
    Abstract [en]

    Size Exclusion Chromatography (SEC) of lignin poses many challenges. In numerous studies chromatograms of lignin show a bimodal molar mass distribution. Is this a true characteristic of lignin, is it caused by molecular associations or aggregations, or could it could be an artefact from using column combinations with porosities that do not match properly? To improve resolution and enable separation over a larger molar mass range, multiple columns with different porosities are often connected in series. If the porosities do not match properly, the result appears as a shoulder or bimodality in the chromatogram. To understand whether the bimodal distribution is a sample characteristic or an analyze artefact, we have used different columns, column combination and samples to see when the results is a bimodal distribution and when only one peak is formed. Results show that the bimodality of lignin can be an artifact originating from column mismatch. Using single porosity columns with a low molar mass cut-off should be avoided since it can cause false bimodality.

  • 16.
    Rönnols, Jerk
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Jacobs, Anna
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Aldaeus, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Recent advances in NMR spectroscopy of lignin and black liquor2018In: 15th European workshop on lignocellulosics and pulp: proceedings for oral presentations, 2018, p. 57-60Conference paper (Other academic)
    Abstract [en]

    This paper describes improvements in the methodology for NMR spectroscopic analysis of dissolved kraft lignins and black liquors, for structural analysis as well as for reaction monitoring. The described methodologies are variations and applications of non-uniform sampling (NUS) in 2D spectra and diffusion ordered spectroscopy (DOSY), with reduced experiment time and/or increased resolution and novel ways to track reactions through monitoring of diffusion of a reactant mixture.

  • 17.
    Rönnols, Jerk
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Jacobs, Anna
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Aldaeus, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Larsson, Tomas
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Digging in the structure and functionality of lignocellulosic raw material: from academic knowledge towards industrial applications2018In: The 8th Nordic Wood Biorefinery Conference: NWBC 2018 : proceedings / [ed] Hytönen Eemeli, Vepsäläinen Jessica, Espoo: VTT , 2018, p. 205-205Conference paper (Other academic)
  • 18.
    Scheepers, Gerhard
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Nilsson, Jonaz
    Linnéuniversitetet, Sweden.
    Johansson, Jimmy
    Linnéuniversitetet, Sweden.
    Mätning av ytspänningar i torkat gran med NIR2017Report (Other academic)
    Abstract [en]

    In sawmilling, a lot of timber properties are measured online in the sorting and grading of dried timber. This may include moisture content, shape, and a host of other parameters. An important wood property that cannot be measured online is drying stresses, although it is an important parameter for many customers. Since the destructive test methods for stress determination are time consuming, no high frequency routine measurement of the internal stresses is done.

    In literature, there are a few examples of near infrareds (NIR) capability to detect surface stresses along the fiber direction. There is also an example of stress measurements across the grain on a Japanese wood specie during drying, however, these measurements were always done on a tangential surface. It is unknown whether NIR prediction models can predict surface tension and stress measurements across the grain of dried Norway spruce with varying characteristics, i.e. material from different logs, heart- or sapwood, different year ring orientations, etc. If the technique cannot handle the variation in material properties, such as occurs in a sawmill environment, this means that a simple NIR measurement would not be sufficient to predict the surface tension in industry.

    This study investigated whether surface stresses in mechanically loaded as well as dried spruce samples with varying material properties can be predicted by NIR models. The measurement data from some mechanically loaded samples showed a correlation between the predicted and actual stress values, but many other samples showed no correlation. Moreover, the data for a single sample could show a good correlation, but the prediction could be at an incorrect stress level.

    As for the dried samples, NIR models were good at separating the conditioned and non-conditioned samples, but had no predictive power concerning the stress level. The models used to predict the stress level in mechanically loaded samples, were also used to predict the stress in the dried samples, but there was no correlation between the measured strain and the predicted stress level. Therefore, it is concluded that there are no clear indication that NIR measurements can be used in an industrial application for predicting the surface stress level of dried Norway spruce boards.

  • 19.
    Scheepers, Gerhard
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Olsson, Jörgen
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Lycken, Anders
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Grahn, Thomas
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Lundqvist, Sven-Olof
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Hagman, Olle
    Luleå Tekniska Universitet, Sweden.
    Hållfasthetsbestämning av virke med en NIR-kamera2017Report (Other academic)
    Abstract [sv]

    SP, Innventia och Luleås Tekniska Universitet har genomfört en förstudie där man undersökte om nära-infrarött (NIR) data kan bidra till säkrare hållfasthetsbestämning av virke. För att göra det behövdes förutom NIR-data, dels data som konventionellt används i sågverk för att göra hållfasthets-uppskattningar, dels referensdata från mekanisk provning.

    Följande data samlades in från 100 granplankor med dimensionen 3600*150*45 mm3:

    1. mått, vikt, och därmed densitet,

    2. egenfrekvenser via dynamisk excitering,

    3. högupplösta NIR-bilder på 2 flatsidor av varje planka,

    4. RGB och fibervinkeldata från flat- och kantsidorna,

    5. röntgentomografibilder,

    6. förstörande böjtestdata, med bestämning av lokal och global E-modul, och

    7. kvalitativ inventering av brottyp och kvistposition.

     

    Databasen är i sig en värdefull resurs och en god grund för fortsatt forskning och utveckling mot kun-skap och tillämpningar baserat på information som hittills inte utvärderats och nyttjats.

    Virkesegenskaper som påverkar hållfasthet, såsom tjurved, kunde identifieras och visualiseras. Andra egenskaper som är viktiga hållfasthetsindikatorer, såsom egenfrekvens och densitet, kunde predikteras med multivariata modeller baserade på NIR-spektraldata. Inledande modellförsök visar att det går att prediktera global E-modul med multivariata modeller baserade på NIR-spektraldata med ungefärlig samma precision som industriell hållfasthetsbedömning med dynamisk excitering. De NIR-data som användes i modelleringen var dock bara medelvärden över hela plankan. Därför finns det god potential för bättre prediktion med mer riktade variabler, som speglar de spatiala variationerna i varje planka, t.ex. runt kvistar, vilket blir ämnet för ett eventuellt fortsättningsprojekt.

    Projektet finansierades av Norrskogs Forskningsstiftelse, Stiftelsen Åforsk, Träcentrum Norr, och Södra Skogsägarnas Stiftelse för Forskning, Utveckling och Utbildning. Individer som medverkade i projektet inkluderar Gerhard Scheepers, Jörgen Olsson, Anders Lycken, Sven-Olof Lundqvist och Thomas Grahn (RISE Bioekonomi); och Olle Hagman (LTU). RemaSawco och JGA i Linneryd hjälpte också med insamlingen av fibervinkeldata.

     

  • 20.
    Sterley, Magdalena
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Noren, Joakim
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Liblik, Johanna
    Tallinn University of Technology, Estland.
    Brandon, Daniel
    Just, Alar
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. Tallinn University of Technology, Estland.
    Small-scale test method for the fire behaviour of woodadhesive bonds in CLT2018In: Book of abstracts of the final conference COST FP1404”Fire Safe Use of Bio-Based Building Products”, 2018Conference paper (Other academic)
    Abstract [en]

    There is an increasing use of cross laminated timber (CLT) in the building sector. CLT is a wood panel product made from layers of solid lumber boards. Each layer of boards is oriented perpendicular to adjacent layers and glued on the wide faces of each board. It has been recognised that different adhesive systems have different behaviour in fire; especially that delamination behaviour of CLT can be avoided by choosing a suitable adhesive system. The best method for evaluation of the delamination is a full‐scale fire test, but considering the high costs of such tests, it is of the utmost importance to develop small‐scale methods for evaluating the adhesive bond properties in fire. The intention is that such small‐scale methods should provide the same results as full‐scale tests. A new, smaller scale method for classifying adhesives with respect to  fire properties would also simplify  the planning of  full scale  tests. Previous  tested small‐scale method for evaluation of finger joints is presented in (1).  In this study, a small‐scale fire test methodology for evaluation of CLT adhesive bond performance in  fire  is  introduced  (2).  The  aim  was  to  demonstrate  an  easy  tool  to  distinguish  between  fire resistant adhesive bonds and non‐fire‐resistant bonds, especially with respect to delamination. The cone heater of a cone calorimeter was used to carry out the tests. Cone calorimeter in accordance with ISO 5660 is one of the most widely used bench‐scale instrument in fire research. This small‐scale  device  has  several  advantages  over  larger‐scale  tests  thanks  to  its  fast,  simple  and  cost‐efficient manner to investigate basic material properties.  

  • 21.
    Yang, Xuan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Berthold, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Berglund, Lars A
    KTH Royal Institute of Technology, Sweden.
    Preserving Cellulose Structure: Delignified Wood Fibers for Paper Structures of High Strength and Transparency.2018In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 19, no 7, p. 3020-3029Article in journal (Refereed)
    Abstract [en]

    To expand the use of renewable materials, paper products with superior mechanical and optical properties are needed. Although beating, bleaching, and additives are known to improve industrially produced Kraft pulp papers, properties are limited by the quality of the fibers. While the use of nanocellulose has been shown to significantly increase paper properties, the current cost associated with their production has limited their industrial relevance. Here, using a simple mild peracetic acid (PAA) delignification process on spruce, we produce hemicellulose-rich holocellulose fibers (28.8 wt %) with high intrinsic strength (1200 MPa for fibers with microfibrillar angle smaller than 10°). We show that PAA treatment causes less cellulose/hemicellulose degradation and better preserves cellulose nanostructure in comparison to conventional Kraft pulping. High-density holocellulose papers with superior mechanical properties (Young's modulus of 18 GPa and ultimate strength of 195 MPa) are manufactured using a water-based hot-pressing process, without the use of beating or additives. We propose that the preserved hemicelluloses act as "glue" in the interfiber region, improving both mechanical and optical properties of papers. Holocellulose fibers may be affordable and applicable candidates for making special paper/composites where high mechanical performance and/or optical transmittance are of interest.

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