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  • 201.
    Granberg, Hjalmar
    et al.
    RISE, Innventia.
    Béland, Marie-Claude
    RISE, Innventia.
    Lindberg, Siv M.
    RISE, Innventia.
    Berthold, Fredrik
    RISE, Innventia.
    Vomhoff, Hannes
    RISE, Innventia.
    Wickholm, Kristina
    RISE, Innventia.
    Lindström, Mikael
    RISE, Innventia.
    It’s a bird! It’s a plane! It’s a super multimaterial!2015In: Paper Conference and Trade Show (PaperCon 2015), TAPPI Press, 2015, Vol. 1, p. 492-504Conference paper (Refereed)
    Abstract [en]

    Matching market demands and technological solutions is not always straightforward. In this article, we report on one material, a cellulose-PLA multimaterial, which was made on a full-scale pilot paper machine and adapted to five different market applications having specialized and often conflicting demands. The material can be injection molded, 3D-printed, hot pressed, treated as a textile, used in a laminate, or converted as a paper board, giving it a wide range of possible properties depending on how it is processed.The five application areas presented here were identified as gaps in the marketplace where seemingly conflicting needs were desired: opacity and transparency; compact for transport but having an expanded size during use; stiffness and flexibility; strength and light-weight; and durability and degradability. These properties are exemplified in a number of material and product demonstrators, illustrating how tailored solutions can give products with distinctly different personalities. The material can be made flexible and given movement as graceful as the wing of a bird or be processed to be strong and light-weight enough to be used in vehicles like airplanes. By having one material that is produced on a large scale, but then processed according to specific market demands and expectations, the gap between needing scale and needing scope is bridged.

  • 202.
    Granberg, Hjalmar
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging.
    Håkansson, Karl
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging.
    Fall, Andreas
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging.
    Wågberg, Pia
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging.
    Electroactive papers, films, filaments, aerogels and hydrogels to realize the future of bio-based electronics2019In: PaperCon 2019: Proceedings, TAPPI Press, 2019, article id PF4.1Conference paper (Other academic)
    Abstract [en]

    Research has been undertaken into the mixing of electroactive additives (EAA), for example, conducting polymers or particles, in five different cellulose structures and their further processing into electroactive papers and films. The cellulose structures considered included cellulose nanofibrils (CNF) hydrogels, CNG aerogels, CNF filaments, CNF films and cellulose papers. It has been demonstrated that the cellulose structure in combination with the electroactive polymer or particle, could be used to tailor numerous different properties. The cellulose could provide properties that support structural integrity, processability, ionic conductivity, shapeability and a large inner capacitive surface. The highly porous aerogel particles could be shaped using three-dimensional printed templates prior to freezing. The particles could be filled either with active material from the start before freeze-linking or filled with active material afterwards based on the layer by layer method. Electroactive paper could also be produced by adding the active component directly as a filler during papermaking, by adding CNF spun EA filaments cut into conveniently long staple fibres.

  • 203.
    Granberg, Hjalmar
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Sandberg, Mats
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Håkansson, Karl
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Pilot scale production of interactive zinc oxide paper and its multiple applicability2019In: PaperCon 2019: Proceedings, TAPPI Press, 2019, article id PF3.3Conference paper (Other academic)
    Abstract [en]

    A study has been made of the production of zinc oxide (ZnO) paper in a pilot paper machine. Bleached sulphate softwood pulp (70%) and bleached sulphate hardwood pulp (30%) were corefined. Cationic polyacrylamide (CPAM) was used as retention agent, while alkyl ketene dimer (AKD) was used as sizing agent for some samples. Some papers were screen printed with a conducting carbon-based ink to produce a photosensor device. Two methods were used to study the photocatalysis: immersing ZnO papers into kongo red dispersions or resazurin (Rz) based photocatalyst activity indicator ink and exposing the papers to ultraviolet (UV) light in a sunlight simulator. ZnO papers of approximately 60gsm were successfully produced on the pilot scale machine, which was run at a low speed (100m/min) and the retention of ZnO particles was good in all samples. The paper looked like an ordinary white printing paper product, but was a truly interactive material, exhibiting photoconductivity and enabling use as an excellent photosensor.

  • 204.
    Gustafsson, Jan-Erik
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Nygårds, Mikael
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Loading and deformation of cigarette packages2017In: 28th IAPRI Symposium on Packaging 2017: Proceedings / [ed] Martine E, 2017, p. 409-Conference paper (Other academic)
    Abstract [en]

    Research has been undertaken to investigate the deformation properties of cigarette packages subjected to different loads. Numerical simulation enables a hypothetical package produced from a hypothetical paperboard to be tested. A finite element model was implemented in the Abaqus system in order to calculate stresses and strains in the deformed packages. The model behaves as expected up to deformations with limited damage. The calculated initial slopes of the reaction force responses were generally in good agreement with the corresponding measured slopes, although the model had a nonlinear force response that was not found in the experimental data. Incorporating cohesive behaviour into the model would allow the elements to disconnect from each other. Statistical analysis of the couplings between the initial process responses and the material properties of the paperboards revealed that only the initial yield stress parameter significantly affected the slope.

  • 205.
    Gustafsson, Åsa
    et al.
    Stockholm University, Sweden.
    Hale, Sarah
    NGI Norwegian Geotechnical Institute, Norway.
    Cornelissen, Gerard
    NGI Norwegian Geotechnical Institute, Norway; NMBU Norwegian University of Life Sciences, Norway; Stockholm University, Sweden.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Gunnarsson, Jonas S.
    Stockholm University, Sweden.
    Activated carbon from kraft lignin: A sorbent for in situ remediation of contaminated sediments2017In: Environmental technology and innovation, ISSN 23521864, Vol. 7, p. 160-168Article in journal (Refereed)
    Abstract [en]

    A new type of activated carbon derived from Kraft lignin, separated from black liquor in the paper pulp process, was evaluated for its use as an alternative sorbent to commercial powdered activated carbons (AC) from anthracite (ACCOAL) or coconut (ACBIO) for remediation in situ of contaminated sediments. Two types of kraft lignins (KL): (1) softwood (SKL), (2) hardwood (HKL) were first evaluated for their sorption to PAHs using assays in water with passive samplers (POMs). Results showed that without further chemical modifications the two kraft lignins tested had lower sorption coefficients than commercial ACCOAL or ACBIO and are not good sorbents for remediation. Following these initial tests a new type of AC derived from softwood (ACSKL) was produced in the lab using activation with potassium hydroxide (KOH) (lignin:KOH, 1:3 by dry weight) and pyrolysis at 700 °C. Sorption properties of the new ACSKL was compared to the other ACs in water spiked with PAHs and in water with PAH-contaminated sediment. Sorption results were also compared to bioavailability measurements, using digestive fluid extraction (DFE) in vitro, a method that mimics the solubilization of contaminants that occurs in the gut of a sediment-ingesting invertebrate. ACSKL was found to have similar surface area, pore volume and sorption coefficients as ACCOAL and ACBIO and thus offers a new potential sorbent for remediation, based on a more renewable biomass-derived source than AC from coal. Sediment amendment with 1% AC-SKL reduced the bioavailability of larger PAHs on average by 54% (measured by DFE), and reduced pore water concentrations of ΣPAH by 80% (measured with passive samplers). Our results show that a new type of AC based on softwood kraft lignin, a renewable and locally produced biomass material, could be used as an alternative sorbent for sediment and water remediation provided it is produced in sufficient amount and at a competitive price compared to other traditional ACs.

  • 206.
    Gällstedt, Mikael
    et al.
    SIG Combibloc, Switzerland.
    Pettersson, Henrik
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Johansson, Therese
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Newson, William R.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Johansson, Eva
    SLU Swedish University of Agricultural Sciences, Sweden.
    Hedenqvist, Mikael S.
    KTH Royal Institute of Technology, Sweden.
    Film extrusion of Crambe abyssinica/wheat gluten blends2017In: Journal of Visualized Experiments, E-ISSN 1940-087X, Journal of Visualized Experiments, Vol. 2017, no 119, article id e54770Article in journal (Refereed)
    Abstract [en]

    Crambe abyssinica is a plant with potential for use in industrial (non-food) plant oil production. The side stream from this oil production is a high-protein crambe meal that has limited value, as it is not fit for food or feed use. However, it contains proteins that could potentially make it a suitable raw material for higher-value products. The purpose of this study was to find methods of making this side stream into extruded films, showing that products with a higher value can be produced. The study mainly considered the development of material compositions and methods of preparing and extruding the material. Wheat gluten was added as a supportive protein matrix material, together with glycerol as a plasticizer and urea as a denaturant. The extrudate was evaluated with respect to mechanical (tensile testing) and oxygen barrier properties, and the extrudate structure was revealed visually and by scanning electron microscopy. A denser, more homogeneous material had a lower oxygen transmission rate, higher strength, and higher extensibility. The most homogeneous films were made at an extruder die temperature of 125-130 °C. It is shown here that a film can be extruded with promising mechanical and oxygen barrier properties, the latter especially after a final compression molding step.

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  • 207.
    Hagman, Anton
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Evaluation of moulded pulp trays using compression test and novel twist test2019In: 29th IAPRI Symposium on packaging, 2019: Serving society innovative perspectives on packaging, 2019Conference paper (Other academic)
    Abstract [en]

    Within the industry there exists great experience of producing moulded pulp trays,this includes adjusting process parameters to achieve a consistent output from thetray making machines. However, the evaluation of the results is at this point based onhands on methods that ultimately relies on subjective opinions of what makes a goodtray. This includes visual inspection of the trays, as well as a twisting the trays by handto evaluate stiffness. Such methods might suffice to achieve a consistent output, butare not suited for structured development work, which requires objective measures.One obvious measurement is a compression test, like a box compression test. However, this test does not tell the whole story, and differs from the hands-on tests usedtoday. Because of this a twist test was developed to emulate the hands-on testingpresently used to assess the quality of moulded pulp trays. The test is performed in atensile tester, by putting the tray in a sample holder which supports two diagonal bottom corners while a beam is pressing against the opposite upper diagonal corners.This forces the tray to bend.Plotting the results from these two tests against each other, results in a practicalgraph that can be used to evaluate both pulp and process properties, as well as trayweights. This plot reveals that some information remains hidden if only compressiontests are performed.Finally, such a graph lends itself to define boundaries for what is an acceptable tray.

  • 208.
    Hagman, Anton
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Mechanical and repulpability assessment of four recycled demo streams, a study2023In: Rock the Roll: Unleashing the Harmonies of the Paper Industry, Cleveland, USA: TAPPI Press , 2023Conference paper (Refereed)
    Abstract [en]

    In this study, oriented lab-sheets were produced from four different streams of base material. The reference stream was a blend virgin hardwood and softwood fibers, 50% of each. The three other streams were made of recycled material. The first recycled stream was a pure stream of unused paperboard, corresponding to “clippings”. The second recycled stream was composed of a selection of used corrugated boxes as well as some test liner. The third and final recycled stream was made to match a “1.02 quality” and consisted of 30% each of the other recycled streams and 40% journal paper. The streams were assessed with respect to repulpability (rejects, yield, adhesiveness, and visual inhomogeneity). The lab-sheets produced from each stream were evaluated through extensive mechanical testing at standard climate 23°C and 50% RH. The tests included: tensile tests, SCT, ZD-tension and compression, BCT on converted boxes and bending. Tensile tests were also performed on dried out samples as well as samples that had been conditioned at 90% RH. The repulpability study indicated that all three recycled streams had a high yield, with low amounts of adhesiveness and inhomogeneities. The mechanical testing showed, as expected, that the sheets from all three recycled streams had, overall, much lower values for the measured properties then the sheets from the virgin stream. The sheets from the clippings-stream performed better from a mechanical perspective then the sheets from the other recycled streams which were quite similar in their performance. By testing three realistic but well-behaved recycled streams, a benchmark has been created which can be used as reference data for future assessments of recycled fibers from different sources. 

  • 209.
    Hagman, Anton
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Strength development during drying: possibilities with a different wet strength testing approach2019In: International Paper Physics Conference 2019, Indianapolis, IN, USA, 5-8 May 2019: preprint proceedings, TAPPI Press, 2019, p. 117-126Conference paper (Other academic)
    Abstract [en]

    A new method has been proposed for mapping the tensile behaviour of paper during drying without the need for large amounts of material. Three pulps were used to make handsheets: a long fibre pulp (softwood) and a short fibre pulp (hardwood), as well as softwood pulp mixed with microfibrillated cellulose (MFC). Comparative testing was undertaken with rewetted commercial blotting papers. Strips were produced from never dried laboratory sheets using die cutting and tested using pneumatic clamps typically used for short span tensile tests. Using the span length of 30mm, four sample points could be sequentially measured on each strip, enabling faster testing while using less material. It was found that the strength levels were different, but that the general behaviour was very similar for all three pulps. In addition, the strength increase associated with the addition of MFC was found to be present during the whole drying process. It has been concluded that the proposed new method could enable the differences between short and long fibre pulps to be examined, as well as to characterise the effect of addition of MFC.

  • 210.
    Hagman, Anton
    et al.
    KTH Royal Institute of Technology, Sweden; BiMaC Innovation, Sweden.
    Considine, J M
    USDA Forest Service, USA.
    Nygårds, Mikael
    RISE - Research Institutes of Sweden, Bioeconomy. BiMaC Innovation, Sweden.
    Stiffness heterogeneity of multiply paperboard examined with VFM2017In: Residual Stress, Thermomechanics & Infrared Imaging, Hybrid Techniques and Inverse Problems. Conference Proceedings of the Society for Experimental Mechanics Series (CPSEMS) vol. 9, 2017, 2017, Vol. 9, p. 151-159Conference paper (Refereed)
    Abstract [en]

    Mechanical heterogeneity of a multiply paperboard was characterized in uniaxial tension using DIC and VFM. The specimen was divided into three subregions based on axial strain magnitude. VFM analysis showed that the subregions had stiffnesses and Poisson’s ratio’s that varied in a monotonically decreasing fashion, but with the stiffness differences between subregions increasing with applied tensile stress. An Equilibrium Gap analysis showed improved local equilibrium when comparing a homogeneous analysis with the subregion analysis. Although only a single specimen was examined, results suggest that high stiffness regions provide only marginal improvement of mechanical behavior. The analysis also showed that even though the subregions themselves were non-contiguous, their mechanical behavior was similar.

  • 211.
    Hagman, Anton
    et al.
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    Nygårds, Mikael
    RISE, Innventia.
    Short compression testing of multi-ply paperboard, influence from shear strength2016In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, no 1, p. 123-134Article in journal (Refereed)
    Abstract [en]

    The influence of the through-thickness shear strength profiles on the short span compression test was examined. This was done both with experiments and finite element simulations on five industrial produced paperboards. It was concluded that the short span compression test is governed by in-plane stiffness and through thickness delamination. The delamination damage was in turn dependent on the local transverse shear strength and in-plane stiffness gradients. Furthermore, it was concluded that the pre-delamination mechanisms were elastic. Finally it was possible to alter the results from the test by altering the shear strength of the paperboard; this should be done uniformly over the entire middle ply of the board if an increased SCT value was what was sought after.

  • 212.
    Hagman, Anton
    et al.
    KTH Royal Institute of Technology, Sweden.
    Nygårds, Mikael
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Thermographical Analysis of Paper During Tensile Testing and Comparison to Digital Image Correlation2017In: Experimental mechanics, ISSN 0014-4851, E-ISSN 1741-2765, Vol. 57, no 2, p. 325-339Article in journal (Refereed)
    Abstract [en]

    The thermal response in paper has been studied by thermography. It was observed that an inhomogeneous deformation pattern arose in the paper samples during tensile testing. In the plastic regime a pattern of warmer streaks could be observed in the samples. On the same samples digital image correlation (DIC) was used to study local strain fields. It was concluded that the heat patterns observed by thermography coincided with the deformation patterns observed by DIC. Because of its fibrous network structure, paper has an inhomogeneous micro-structure, which is called formation. It could be shown that the formation was the cause of the inhomogeneous deformations in paper. Finite element simulations was used to show how papers with different degrees of heterogeneity would deform. Creped papers, where the strain at break has been increased, were analysed. For these paper it was seen that an overlaid compaction of the paper was created during the creping process. During tensile testing this was recovered as the paper network structure was strained.

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  • 213.
    Hagman, Anton
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy. BiMaC Innovation, Sweden.
    Timmermann, Brita
    Holmen-Iggesund, Sweden.
    Nygårds, Mikael
    RISE - Research Institutes of Sweden, Bioeconomy. BiMaC Innovation, Sweden.
    Lundin, Andreas
    Barbier, Christophe
    Billerud-Korsnäs, Sweden.
    Fredlund, Mats
    Stora Enso, Sweden.
    Östlund, Sören
    KTH Royal Institute or Technology, Sweden.
    Experimental and numerical verification of 3D forming2017In: 16th Fundamental research symposium, 2017, p. 3-26Conference paper (Refereed)
  • 214.
    Hagman, Anton
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Trost, Thomas
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Perforations on boxes: some fundamental facts2019In: 29th IAPRI Symposium on packaging, 2019: Serving society innovative perspectives on packaging, 2019Conference paper (Other academic)
    Abstract [en]

    The grocery retail industry is striving with low margins and an ever-increasing competition from e-commerce applications. Therefore, as a mean to save time, money andincrease the efficiency in the supply chain, perforated shelf-ready packages (SRP) hassince a long time been used. However, there is also problems related to this perforation; it weakens the transport packaging and makes it more sensitive to damage onthe way to the shelf. The current guidelines are focused on appearance of the box onthe shelf, e.g. how much of the product is seen and evenness of perforate edge, andnot on the mechanical properties of the box.Today there exist much knowledge about perforations inhouse in the die cutting industry. This knowledge is however unattainable for outsiders. Further the questionarises about how well founded said knowledge is. The scientific literature offers littleinformation about the basics of perforation and how it affects the mechanical properties of the board and box. This study is an attempt to build knowledge, useful toconverters and industrial users, in a systematic way.In this paper several different perforations patterns have been studied from a mechanical point of view. The experiments were designed to answer some basic questionsabout how different nick lengths and distances affects the strength of the perforatione.g. at different cut/uncut ratios. Among methods studied were tensile testing, bending stiffness, compression testing and edge compression test. The different methodswere compared regarding sensitivity to discriminate between different perforationpatterns and give a useful classification of the perforation.

  • 215.
    Hagman, Anton
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Trost, Thomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Perforations on different corrugated flute grades and their effect on packaging performance2023Conference paper (Other academic)
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  • 216.
    Hammar, Lars-Åke
    et al.
    RISE, STFI-Packforsk.
    Salmen, Lennart
    RISE, STFI-Packforsk.
    Sandberg, C.
    Sundström, L.
    The effect of process conditions on pulp quality development at low consistency refining of mechanical pulp - TMP2009In: 2009 International Mechanical Pulping Conference : proceedings: IMPC 2009, 2009, p. 182-185Conference paper (Refereed)
    Abstract [en]

    Low consistency refining (LC) as a second refining stage, after a HC-defibration is an energy-efficient process solution. This HC-LC concept has for some time been explored in pilot scale and shown promising results. However it is clear that in order to obtain an optimal development of pulp properties the LC-refining has to be optimized with regard to process conditions. In this study the effects of temperature, pH, and specific edge load in the LC-refining on the pulp quality were investigated. For this purpose a mobile LC refiner rig placed after a primary stage HC mill refiner in the Braviken Paper mill, Holmen Paper was used. The trials show that energy savings are possible with preserved properties in the production of mechanical pulp. High temperature, high pH and low specific edge load were indicated to be preferable for both the tensile index development and for preserving the fibre length of the pulp. An increased degree of refining developed as expected the tensile index but too high specific energy resulted in some fibre shortening.

  • 217.
    Hammar, Lars-Åke
    et al.
    RISE, Innventia.
    Salmen, Lennart
    RISE, Innventia.
    Sandberg, C.
    Sundström, L.
    The effect of process conditions on pulp quality development in low consistency refining of mechanical pulp - TMP2010In: Appita journal, ISSN 1038-6807, Vol. 63, no 5, p. 377-380Article in journal (Refereed)
    Abstract [en]

    High consistency (HC) defibration followed by secondary stage low consistency refining (LC) is an energy efficient process in mechanical pulping that has been explored for some time. In this study the effects of temperature, pH, specific edge load and specific energy on pulp quality have been investigated for LC refining using a mobile LC refiner rig placed after a primary stage HC refiner In the Braviken Paper mill. The trials showed that the specific energy consumption in production of mechanical pulp can be reduced with at least 15% with preserved pulp properties. High temperature, pH over 7 and low specific edge load were advantageous both for tensile index development and for preserving the fibre length of the pulp. The development of other pulp properties such as shives content and light scattering coefficient, as a function of freeness, were comparable for the second stage LC- and HC-refining.

  • 218.
    Hammar, Torun
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology.
    Peñaloza, Diego
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology.
    Hanning, Anne-Charlotte
    RISE Research Institutes of Sweden, Materials and Production, Product Realisation Methodology.
    Haatanen, Noora
    South-Eastern Finland University of Applied Sciences, Finland.
    Pakkasmaa, Juhana
    South-Eastern Finland University of Applied Sciences, Finland.
    Life cycle assessment of textile fibre-to-fibre recycling by cellulose carbamate technology2023In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 426, article id 139189Article in journal (Refereed)
    Abstract [en]

    The fashion industry faces major challenges in reducing its environmental impacts along the textile value chain, from fibre production, via various processing steps, use phase and to the end-of-life stage. A major challenge is how to shift from the current linear industry to a circular one, where textiles are both sustainably produced, and after the full life length, recycled into new fibres with high value applications. The aim of this study was to evaluate the environmental impacts of post-consumer textile fibre-to-fibre recycling by cellulose carbamate technology, in terms of climate impact, water scarcity impact, cumulative energy demand and land use impact. By performing life cycle assessment, it was shown that the chemically recycled cellulose carbamate fibre has a climate impact of about 2.2 kg CO2-eq per kg fibre, water scarcity impact of 1.6 m3 H2O-eq per kg fibre, cumulative energy demand of 90 MJ-eq per kg fibre and land use impact of about 92 Pt per kg fibre (when applying mass allocation of co-products). Hotspots identified during the fibre production technology were electricity use and production of sodium hydroxide. In a sensitivity analysis, it was shown that the choice of electricity has a major influence on the results, and by using a renewable electricity mix over an average Finnish electricity mix, the impact could be decreased for all impact categories, except when using bioenergy, which would increase the land use impact. Compared to primary fibres like viscose and conventional cotton, these impacts are in the lower to middle range, showing potential to lower environmental impacts when moving towards an increased amounts of recycled post-consumer textile fibre with high value applications, that can replace primary fibres. 

  • 219.
    Hansen, Peter H F
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Johansson, Klas
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Monitoring cross-thickness distributions of fines and CMF by dyeing and optical measurement2018In: PaperCon 2018: Shaping the future through innovation, TAPPI , 2018, article id FF3Conference paper (Refereed)
    Abstract [en]

    A methodology has been verified where the ZD-distribution of a component of the furnish (fines or CMF) can bemonitored. The component to be monitored was dyed using a direct azo-dye before addition to the furnish. Theproduced sheets were sectioned in cross-thickness direction by sequential heat-seal lamination and splitting, usingplastic pouches. The amount of dyed material in a split was monitored using thea* and L* parameters of the CIELabcolor space and the opacity, all measured simultaneously with a spectrophotometer. The value on the green-redaxis,a*, the lightness, L, and the opacity were combined into a new parameter, -a*L/opac. Two mechanisms forfines retention was observed by laboratory studies, mechanical retention by filtering process in the formed fiber weband chemical retention by agglomeration to the fibers.The methodology has recently been applied for monitoring cross-thickness distributions of either CMF or fines inpaper produced in pilot scale trials. For example, it was demonstrated, that the machine settings affected themechanisms for retention of fines in the fiber web during sheet forming and dewatering, with different distributionsof fines in the cross-thickness direction as result.

  • 220.
    Hedlund, Artur
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Structure of cellulose coagulated from different EmimAc-DMSO solutions2016Conference paper (Other academic)
  • 221.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Hagström, Bengt
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Untersuchungen zur Koagulation von Celluloselösungen / Investigations of coagulation of cellulose solutions2014Conference paper (Other academic)
  • 222.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Coagulation of cellulose solutions and controlling properties of regenerated cellulose materials2017In: Cellulosic material Properties and industrial potential: Final meeting in COST FP1205 / [ed] Monica Ek, 2017, p. 64-66Conference paper (Refereed)
  • 223.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF. Chalmers University of Technology, Sweden.
    Köhnke, Tobias
    RISE, Swerea, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Coagulation of cellulose-EmimAc-DMSO solutions studied in order to control properties of wet-spun cellulose fibers2016In: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives, 2016, p. 49-52, article id 15Conference paper (Other academic)
  • 224.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Theliander, Hans
    Chalmers.
    Coagulation Values of Cellulose-EmimAc-DMSO solutions and their precipitation-dissolution disparity2014In: Proceedings of the  4th Avancell conference: Creating Value from the Swedish Forest Resources, 2014, p. 15-21Conference paper (Other academic)
  • 225.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Theliander, Hans
    Chalmers University.
    Measurements of mass transport during coagulation of cellulose-EmimAc-DMSO solutions2015In: Proceedings of the 4th EPNOE international Polysaccharide Conference, 2015Conference paper (Other academic)
  • 226.
    Hedlund, Artur
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Structure of cellulosematerials coagulated from different EmimAc-DMSO solutions2015Conference paper (Other academic)
  • 227.
    Heggset, Ellinor B
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Strand, Berit L.
    NTNU Norwegian University of Science and Technology, Norway.
    Sundby, Kristin W.
    Borregaard, Norway.
    Simon, Sebastien
    NTNU Norwegian University of Science and Technology, Norway.
    Chinga-Carrasco, Gary
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Syverud, Kristin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI. NTNU Norwegian University of Science and Technology, Norway.
    Viscoelastic properties of nanocellulose based inks for 3D printing and mechanical properties of CNF/alginate biocomposite gels2019In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, no 1, p. 581-595Article in journal (Refereed)
    Abstract [en]

    Inks for 3D printing based on cellulose nanofibrils (CNFs) or mixtures of CNFs and either cellulose nanocrystals (CNCs) or alginate were assessed by determining their viscoelastic properties i.e. complex viscosity and storage and loss moduli (G′ and G″). Two types of alginates were used, i.e. from Laminaria hyperborea stipe and Macrocystis pyrifera. Shape fidelity of 3D printed grids were qualitatively evaluated and compared to the viscoelastic properties of the inks. The biocomposite gels containing alginate were post stabilized by crosslinking with Ca2+. Mechanical properties of the crosslinked biocomposite gels were assessed. The complex viscosity, G′ and G″ of CNF suspensions increased when the solid content was increased from 3.5 to 4.0 wt%, but levelled off by further increase in CNF solid content. The complex viscosity at low angular frequency at 4 wt% was as high as 104 Pa·s. This seemed to be the necessary viscosity level for obtaining good shape fidelity of the printed structures for the studied systems. By replacing part of the CNFs with CNCs, the complex viscosity, G′ and G″ were reduced and so was also the shape fidelity of the printed grids. The changes in complex viscosity and moduli when CNFs was replaced with alginate depended on the relative amounts of CNFs/alginate. The type of alginate (from either L. hyp. stipe or M. pyr.) did not play a role for the viscoelastic properties of the inks, nor for the printed grids before post stabilization. Replacing CNFs with up to 1.5 wt% alginate gave satisfactory shape fidelity. The effect of adding alginate and subsequent crosslinking with Ca2+, strongly affected the strength properties of the gels. By appropriate choice of relative amounts of CNFs and alginate and type of alginate, the Young’s modulus and rupture strength could be controlled within the range of 30–150 kPa and 1.5–6 kg, respectively. The deformation at rupture was around 55%. The alginate from L. hyp. stipe yields higher Young’s modulus and lower syneresis compared to M. pyr. This shows that the choice of alginate plays a significant role for the mechanical properties of the final product, although it does not influence on the viscoelastic properties of the ink. The choice of alginate should be L. hyp. stipe if high strength is desired.

  • 228. Henriksson, M.
    et al.
    Berglund, L. A.
    Isaksson, P.
    Lindström, Tom
    RISE, STFI-Packforsk.
    Nishino, T.
    Cellulose nanopaper structures of high toughness2008In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Biomacromolecules, Vol. 9, no 6, p. 1579-1585Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibrils offer interesting potential as a native fibrous constituent of mechanical performance exceeding the plant fibers in current use for commercial products. In the present study, wood nanofibrils are used to prepare porous cellulose nanopaper of remarkably high toughness. Nanopapers of different porosities and from nanofibrils of different molar mass are prepared. Uniaxial tensile tests are performed and structure - property relationships are discussed. The high toughness of highly porous nanopaper is related to the nanofibrillar network structure and high mechanical nanofibril performance. Also, molar mass correlates with tensile strength. This indicates that nanofibril fracture controls ultimate strength. Furthermore, the large strain-to-failure means that mechanisms, such as interfibril slippage, also contributes to inelastic deformation in addition to deformation of the nanofibrils themselves. © 2008 American Chemical Society.

  • 229. Hii, C
    et al.
    Gregersen, Ø
    Chinga-Carrasco, Gary
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Eriksen, Öyvind
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Toven, Kai
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Rosén, Fredrik
    RISE, Innventia.
    Vomhoff, Hannes
    RISE, Innventia.
    Quantification of the web structure in relation to process conditions during wet pressing and furnish composition2011In: / [ed] Hirn, U., 2011, , p. 2Conference paper (Refereed)
  • 230. Hii, C.
    et al.
    Gregersen, Ø.W.
    Chinga-Carrasco, Gary
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Eriksen, Öyvind
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    The effect of microfibrillated cellulose on the pressability of TMP and filler mixtures and on paper properties2012Conference paper (Refereed)
  • 231.
    Hii, Collin
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Gregersen, Øyvind Weiby
    NTNU Norwegian University of Science and Technology, Norway.
    Chinga-Carrasco, Gary
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Eriksen, Öyvind
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    The effect of MFC on the pressability and paper properties of TMP and GCC based sheets2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 2, p. 388-396Article in journal (Refereed)
    Abstract [en]

    Different qualities of microfibrillated cellulose (MFC) were blended with thermomechanical pulp (TMP) and ground calcium carbonate (GCC) filler. The addition of MFC reduced the drainage of the pulp suspension but improved strength properties. Wet pressing experiments showed that optimal use of MFC and filler could enhance the strength and optical properties without reducing the solids content after wet pressing. Field-emission scanning electron microscopy (FESEM) revealed that MFC adsorbed onto and contributed to the bonding of the filler particles and fibres. The MFC binds the filler-MFC-fines aggregates to the fibre network and partially filled the pore network. As a result, MFC addition increased the air resistance and internal bonding of the sheet.

  • 232.
    Hii, Collin
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Gregersen, Øyvind Weiby
    NTNU Norwegian University of Science and Technology, Norway.
    Chinga-Carrasco, Gary
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Eriksen, Öyvind
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    The effect of Newsprint furnish composition and sheet structure on wet pressing efficiency2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 4, p. 790-797Article in journal (Refereed)
    Abstract [en]

    The dewatering ability and wet sheet structure after pressing was studied using a dynamic wet pressing simulator in combination with electron microscopy and image analysis. Deinked pulp (DIP) that contains 5% ash dewaters more easily than thermo-mechanical pulp (TMP) when pressed with single roll pulse. The in-plane moisture flow (crushing) in DIP samples started at higher peak pressure and higher solids content compared to TMP samples. The TMP sample showed higher springback after wet pressing compared to DIP samples. When both TMP and DIP samples were designed to have a higher amount of small pores at the dewatering side surface layers, the samples with coarser TMP pulp could achieve similar dryness as DIP samples when pressed with higher nip pressure. In addition, the DIP samples with higher number of small pores in the outermost 10 μm thick surface layer in the dewatering side resulted in lower dryness after pressing with a single roll pulse. The effect of filler distribution in paper z-direction on dryness and sheet structure after wet pressing using an 8 milliseconds roll pulse was also studied. In this study the distribution of filler does not affect the maximum achievable dryness (41%) after wet pressing when the total amount of filler in the sheets remains constant, 13.5%. In addition, the samples with more filler in the dewatering layer dewater more easily and yield the maximum achievable dryness (40%) after wet pressing at lower nip pressure (2.5 MPa) when compared to samples made from TMP (36% at 4.4 MPa) and DIP pulps (40% at 4.9 MPa).

  • 233.
    Hii, Collin
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Gregersen, Øyvind Weiby
    NTNU Norwegian University of Science and Technology, Norway.
    Chinga-Carrasco, Gary
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Eriksen, Öyvind
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Toven, Kai
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    The web structure in relation to the furnish composition and shoe press pulse profiles during wet pressing2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 4, p. 798-805Article in journal (Refereed)
    Abstract [en]

    This study shows that wet-pressing TMP and DIP with a shoe press pulse may yield similar after-press solids, provided that an adequate shoe pulse length with similar pressure profile is applied. A wet web with more porous structure in the sheet dewatering (felt) layer seems to contribute to the increased dewatering during wet pressing. In addition, a shoe press pulse with high peak pressure at the end yields higher solids content after wet-pressing and higher bulk compared to a pulse with a peak pressure in the beginning. The increased dewatering during wet-pressing implies a reduction of steam consumption in the dryer.

  • 234.
    Hill, Jan
    et al.
    QualTech AB, Sweden.
    Johansson, Lars
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    Mörseburg, Kathrin
    RISE - Research Institutes of Sweden, Bioeconomy, PFI.
    ATMP pulping of Norway spruce: Pulp property development and energy efficiency2017In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, no 1, p. 70-86Article in journal (Refereed)
    Abstract [en]

    ATMP pilot refining trials on Norway spruce were conducted. The ATMP configuration consists of selective wood disintegration and targeted application of chemicals when defibration already is initiated in order to achieve energy-efficient final fibre separation and development. ATMP was compared to TMP and RTS. The TMP like character was maintained despite of differences in pre-treatment, chemicals and primary stage refining energies. The fractional composition of the pulps was, however, altered. Bauer McNett R14 fraction exhibited the largest differences followed by P200 fraction. Thus different process alternatives produced pulps with different fingerprints. The amount of the R14 fibres is important as these tend to cause surface roughness impairing printability. Regardless of strategy, the ATMP pulp properties at equal tensile index (44 Nm/g) were equal or superior to those achieved by TMP or RTS refining. The main difference was the required specific energy input, ranging from 1.71 (TMP) to 1.05 MWh/BDT (ATMP with bisulphite addition). Primary stage refining was explored from multiple trials with the same process configuration and chemistry. The higher the specific energy applied the better is the energy efficiency. Furthermore established refining theories appear inadequate in describing the differences between process alternatives with respect to energy efficiency and pulp property development.

  • 235.
    Holmberg, Pia
    et al.
    Acosense AB, Sweden.
    Bjärestrand, Annika
    RISE, Innventia.
    On-line monitoring of fiber properties: Listening in on the process in real-time2015In: Paper Conference and Trade Show (PaperCon 2015), TAPPI Press, 2015, Vol. 2, p. 859-871Conference paper (Refereed)
  • 236. Holmqvist, C.
    et al.
    Söderberg, Daniel
    RISE, Innventia.
    Drainage pressure oscillations during roll forming2010In: Paper Conference and Trade Show 2010, 2010, Vol. 3, p. 2354-2389Conference paper (Refereed)
    Abstract [en]

    In a roll-blade former the initial drainage is achieved by wrapping the tensioned fabrics over the roll surface. The dry line is located after the roll, and additional drainage is achieved in the blade section. This situation is referred to as partial roll forming. In order to study the dynamics of partial roll forming, pressure measurements have been made in the roll-blade former of the FEX pilot machine at Innventia in Stockholm. The measurements were performed using a fibre optic pressure measurement system. The results confirm that oscillatory flow behaviour is possible in industrial forming sections. The good agreement between the experimentally determined wavelengths of the oscillations and the theoretical analysis by Holm & Söderberg [1] strongly suggests that the oscillations are of capillary origin, and that they are controlled by a local dimensionless Weber number expressing the local balance between the momentum of the flow and the forces exerted by the fabric tension. Pressure gradients are capable of influencing the fibre web structure, and the gradients associated with the oscillations could hence be of significance to the forming process.

  • 237.
    Holmqvist, Claes
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Rosén, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy.
    Söderberg, Daniel
    KTH Royal Institute of Technology, Sweden.
    In-Situ Measurements of Stock Flow Conditions in the Twin-Wire Forming Zone2018In: PaperCon 2018: Shaing the future through innovation, TAPPI , 2018, p. 59-72, article id FF5.1Conference paper (Refereed)
    Abstract [en]

    In the present study, we report results from in-situ investigations of the forming process performed in the roll-bladesection of a pilot machine. Direct measurements of the drainage pressure along the forming zone were obtained usinga miniature fibre-optic pressure transducer inserted into the flow through the headbox jet. High-speed imaging oftracer particles using a transmitted light setup was performed to in an attempt to obtain direct measurements of thelocal stock speed. By replacing one section of a ceramic blade with a quartz glass piece, access was also obtained tothe region on top of the blade. The combined picture that emerges from these measurements is that the pressuredistribution and the velocity field along a twin-wire forming zone is significantly more complex than usuallyassumed, and that much remains to be understood about the dynamics of twin-wire forming.

  • 238. Honkalampi-Hämäläinen, U.
    et al.
    Bradley, E.L.
    Castle, L.
    Severin, I.
    Dahbi, L.
    Dahlman, Olof
    RISE, Innventia.
    Lhuguenot, J.-C.
    Andersson, M.A.
    Hakulinen, P.
    Hoornstra, D.
    Mäki-Paakkanen, J.
    Salkinoja-Salonen, M.
    Turco, L.
    Stammati, A.
    Zucco, F.
    Weber, A.
    von Wright, A.
    Safety evaluation of food contact paper and board using chemical tests and in vitro bioassays: Role of known and unknown substances2010In: Food Additives and Contaminants, ISSN 0265-203X, E-ISSN 1464-5122, Vol. 27, no 3, p. 406-115Article in journal (Refereed)
    Abstract [en]

    In vitro toxicological tests have been proposed as an approach to complement the chemical safety assessment of food contact materials, particularly those with a complex or unknown chemical composition such as paper and board. Among the concerns raised regarding the applicability of in vitro tests are the effects of interference of the extractables on the outcome of the cytotoxicity and genotoxicity tests applied and the role of known compounds present in chemically complex materials, such as paper and board, either as constituents or contaminants. To answer these questions, a series of experiments were performed to assess the role of natural substances (wood extracts, resin acids), some additives (diisopropylnaphthalene, phthalates, acrylamide, fluorescent whitening agents) and contaminants (2,4-diaminotoluene, benzo[a]pyrene) in the toxicological profile of paper and board. These substances were individually tested or used to spike actual paper and board extracts. The toxic concentrations of diisopropylnaphthalenes and phthalates were compared with those actually detected in paper and board extracts showing conspicuous toxicity. According to the results of the spiking experiments, the extracts did not affect the toxicity of tested chemicals nor was there any significant metabolic interference in the cases where two compounds were used in tests involving xenobiotic metabolism by the target cells. While the identified substances apparently have a role in the cytotoxicity of some of the project samples, their presence does not explain the total toxicological profile of the extracts. In conclusion, in vitro toxicological testing can have a role in the safety assessment of chemically complex materials in detecting potentially harmful activities not predictable by chemical analysis alone.

  • 239. Horvath, A.T.
    et al.
    Pelton, R.
    Larsson, Per Tomas
    RISE, Innventia.
    Wågberg, L.
    Effect of cross-linking fiber joints on the tensile and fracture behavior of paper2010In: Industrial and Engineering Chemistry Research, ISSN 08885885, Vol. 49, no 14, p. 6422-6431Article in journal (Refereed)
    Abstract [en]

    The tensile and fracture properties of cross-linked paper were investigated at low and high relative humidity by cross-linking the joints formed between fibers. Cationic acetal dextran served as a model cross-linking agent, as it can be prepared to adsorb specifically to the fiber surface. Thus, cross-linking occurs only in the joints between fibers. The kinetics of hydrolysis was investigated to optimize the stock preparation, such that the resulting aldehyde groups react as the paper is dried. The effect of the cross-link density on the tensile and fracture properties was studied by varying the amount of acetal groups adsorbed to the pulp fibers. At low humidity, cross-linking improved the tensile and fracture properties of paper, although lower cross-link densities yielded better properties. Cross-linking was not effective at high relative humidty, as the tensile strength and stiffness were not improved. However, the fracture properties were significantly improved.

  • 240.
    Hosseinaei, Omid
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy. RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Electrospun lignin-based carbon fibers for energy storage application2018In: The 8th Nordic Wood Biorefinery Conference: NWBC 2018 : proceedings / [ed] Hytönen Eemeli, Vepsäläinen Jessica, Espoo: VTT , 2018, p. 244-244Conference paper (Other academic)
  • 241.
    Hosseinaei, Omid
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Åkerström, Mårten
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Uhlin, Anders
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Tomani, Per
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Danielsson, Sverker
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Melt spun lignin-based carbon fiber from softwood kraft lignin: effect of lignin pretreatment and fiber conversion conditions2018In: The 8th Nordic Wood Biorefinery Conference: NWBC 2018 : proceedings / [ed] Hytönen Eemeli, Vepsäläinen Jessica, Espoo: VTT , 2018, p. 157-163Conference paper (Other academic)
  • 242.
    Huang, Hui
    et al.
    KTH Royal Institute of Technology, Sweden.
    Hagman, Anton
    KTH Royal Institute of Technology, Sweden.
    Nygårds, Mikael
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    Quasi static analysis of creasing and folding for three paperboards2014In: Mechanics of materials, ISSN 0167-6636, E-ISSN 1872-7743, Vol. 69, no 1, p. 11-34Article in journal (Refereed)
    Abstract [en]

    The creasing and folding behavior of three paperboards have been studied both experimentally and numerically. Creasing and folding studies were performed on strips in both the machine direction and the cross machine direction. A finite element model that mimicked the experimental creasing and folding setup was developed, and the creasing and folding behavior could be well predicted for all three paperboards. An experimental characterization scheme consisting of three experiments was proposed, and was shown to be sufficient to predict the creasing and folding behavior. For the whole paperboard the shear strength profiles in the through thickness direction was determined with the notched shear test. Each ply was laid free by grinding, and density measurements and in-plane tension tests were performed on the bottom, middle and top plies of each paperboard. Instead of assuming uniform properties in each ply, the shear strength profiles were used to map the measured properties in the through thickness direction. Numerical simulations were performed when the ply and interface properties of the paperboards were altered to follow different shear strength profiles. This was done in order to mimic different production strategies. It was shown that the interface strengths mainly influenced the folding behavior. Whereas altered the ply properties affected the creasing force needed.

  • 243.
    Hyll, Kari
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    Size and shape characterization of fines and fillers: A review2015In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 30, no 3, p. 466-487Article in journal (Refereed)
    Abstract [en]

    Many properties of fines and fillers are dependent on their size and shape. This review is on the literature on size and shape characterization of fines and fillers. It takes into account measurement techniques of particle width, length, equivalent diameter, area, and shape/morphology. The advantages and limitations of different methods are discussed. Measurement of other particles properties, e.g., optical, chemical or rheological, were not included in the review. Size and shape characterization methods can be roughly divided into gravimetric and non-gravimetric methods. Gravimetric measurements methods account for all particles in the sample, but give only indicative size and shape information. Non-gravimetric methods usually give more direct size and shape information, but only account for particles larger than the resolution of the instrument. Additionally, measuring both larger and smaller particles simultaneously is rarely possible. An implication is that current analysers fail to measure a larger share of the sample, for example fibrils, which have a high impact on product properties. Of the reviewed measurement techniques, flow microscopy had the highest potential. Based on instruments found in other application areas, possible developments for flow microscopes include multiwavelength illumination and sensors, fluorescent staining, and hydrodynamic focusing.

  • 244.
    Hyll, Kari
    et al.
    RISE, Innventia. KTH Royal Institute of Technology, Sweden.
    Björk, Elisabeth
    RISE, Innventia. Mid Sweden University, Sweden.
    Vomhoff, Hannes
    RISE, Innventia.
    Flow imaging characterisation of morphological changes of chemical pulp due to refining2016In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, no 3, p. 411-421Article in journal (Refereed)
    Abstract [en]

    The influence of the refining process on the morphological changes of a chemical softwood pulp was investigated. The Voith LR40 industrial-like laboratory low consistency refiner was used, where the pulp was refined with five refining segments with differences in bar widths, groove widths, and cutting angles. The refined pulp was characterized with a fibre analyser with a spatial resolution of approximately 4 μm/pixel and a wide size range. The fines fraction of the refined pulp was also characterized with an imaging flow cytometer with a spatial resolution of 0.33 μm/pixel and a narrower size range. The fibre analyser measurements showed that the mean length, width, and aspect ratio of the fines decreased monotonically with accumulated refining energy. The imaging flow cytometer with its higher spatial resolution showed little change in fines morphology with accumulated refining energy. The morphology of the fines was more dependent on the applied specific refining energy than the design of the refining segment. However, a segment with much finer grooves and bars, initially designed for hardwood, gave significantly less fibre shortening, fines generation, external fibrillation, kink, and fines that were more fibrillar, compared to the other segments.Grant: The authors of this work would like to thank Prof. Lars Mattsson, Thomas Grahn, and Eva Ålander for fruitful discussions. The discussions with Lorentzen & Wettre were of great assistance. The financial support of the Swedish Energy Agency and the Önnesjöstiftelsen to the PhD project, and of the Fibre and Stock Design research programme to this evaluation study is gratefully acknowledged.

  • 245.
    Hyll, Kari
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. King's College London, UK.
    Farahani, Farnaz
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Mattsson, Lars
    KTH Royal Institute of Technology, Sweden.
    Comparison of optical instruments for fines and filler characterisation2017In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, no 1, p. 97-109Article in journal (Refereed)
    Abstract [en]

    A laser diffractometer and three image-based instruments with spatial resolutions between 0.33 and 10 µm/pixel were compared through measurements on calibration spheres and fine fractions comprising pulp fines of various types, neat PCC filler, and a mixture of fines and fillers. The laser diffractometer was highly sensitive to the keyed in refractive index of the samples, which was calculated based on volume-based mixing rules. A high-resolution flow cytometer and a high-resolution fibre analyser were found to be complimentary for measurements on neat fines and fines/filler mixtures, and superior to the laser diffractometer. When measuring on fillers, the laser diffractometer performed as well as the high-resolution flow cytometer, which was capable of resolving single filler particles. The sizes of the calibration spheres were overestimated by the image-based instruments, and the measurement uncertainty was high. The uncertainty was mainly attributed to the unrestricted particle motion, and the low accuracy to the dissimilar optical properties of the calibration material, compared to fines. Thus, calibration materials with shape and optical properties more similar to fines should be developed.

  • 246.
    Hyll, Kari
    et al.
    RISE, Innventia.
    Vomhoff, Hannes
    RISE, Innventia.
    Mattsson, Lars H.
    KTH Royal Institute of Technology, Sweden.
    A method for measurement of the directional emittance of paper in the infrared wavelength range2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, no 5, p. 958-967Article in journal (Refereed)
    Abstract [en]

    A method for measuring the directional emittance of paper and board samples was developed. The available literature showed that the influence of temperature and observation angle on the emittance of dry and moist paper had not been investigated in detail. Methods adapted for such investigations were not available. In the developed method, the emittance of a sample is determined by comparing its infrared radiation with the radiation emitted from a reference surface with known emittance. In order to investigate the influence of the wavelength range, two cameras, operating in the mid-wavelength and long-wavelength infrared range, respectively, were used. The method allows for the adjustment of the directional emission angle in a range from 0° down to 80°, and variation of the sample temperature between 30°C and 100°C. A study was performed to evaluate the method. Here, the directional emittance of handsheets made from thermo-mechanical pulp was measured at different wavelength ranges, sample temperatures and emission angles. The obtained emittance values and trends were in agreement with previous experimental work and theoretical predictions. The emittance of the samples was also measured using Fourier-Transform Infrared spectroscopy. Given the methodological differences between the two measurement approaches, the results were in good agreement.

  • 247.
    Hyll, Kari
    et al.
    RISE, Innventia.
    Vomhoff, Hannes
    RISE, Innventia.
    Nygårds, Mikael
    RISE, Innventia.
    Analysis of the plastic and elastic energy during the deformation and rupture of a paper sample using thermography2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 2, p. 329-334Article in journal (Refereed)
    Abstract [en]

    Thermography has been used to quantitatively analyze the plastic and elastic energy during deformation of paper. Sack paper samples were subjected to uniaxial tensile testing until rupture occurred. The temperature of the sample was simultaneously recorded with an infrared camera. The mechanical energy invested in the deformation was determined based on the force and deformation data. The thermal energy that accumulated in the sample during testing was estimated using the temperature measurements. Here, special attention was put on using the correct emittance values for the sack paper by measuring it with a new method. When comparing exerted mechanical energy with released thermal energy up to the time of sample rupture, about 40% to 60% of the mechanical energy could be detected as thermal energy. The lacking share of heat was most likely lost due to cooling of the sample during the experiments, as a lower share of detected mechanical energy was obtained for longer experiments. When comparing the increase in thermal energy during rupture to the elastic energy stored in the sample, an agreement of better than 90% was found.

  • 248. Ibarra, D.
    et al.
    Köpcke, V.
    Larsson, Per Tomas
    RISE, Innventia.
    Jääskeläinen, A.-S.
    Ek, M.
    Combination of alkaline and enzymatic treatments as a process for upgrading sisal paper-grade pulp to dissolving-grade pulp2010In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 101, no 19, p. 7416-7423Article in journal (Refereed)
    Abstract [en]

    A sequence of treatments consisting of an initial xylanase treatment followed by cold alkaline extraction and a final endoglucanase treatment was investigated as a process for upgrading non-wood paper-grade pulps to dissolving-grade pulps for viscose production. Fivecommercial dried bleached non-wood soda/AQ paper pulps, from flax, hemp, sisal, abaca, and jute, were studied for this purpose. Commercial dried bleached eucalyptus dissolving pulp was used as reference sample. Sisal pulp showed the highest improvement in Fock’s reactivity, reaching levels nearly as high or even higher than that of eucalyptus dissolving pulp (65%), and a low hemicellulose content (3-4%) when was subjected to this sequence of treatments. The viscosity, however, decreased considerably. A uniform and narrow molecular weight distribution was observed by size exclusion chromatography. 13C nuclear magnetic resonance spectroscopy and Raman microspectroscopy revealed that the cellulose structure consisted of cellulose I.

  • 249.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Stenqvist, Björn
    Lund University, Sweden.
    Lund, Mikael
    Lund University, Sweden.
    Bergquist, Karl Erik
    Lund University, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Wernersson, E
    Tetrabutylammonium acetate/dimethyl sulfoxide  as a solvent for cellulose2017Conference paper (Other academic)
  • 250.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Stenqvist, Björn
    Lund University, Sweden.
    Lund, Mikael
    Lund University, Sweden.
    Bergquist, Karl Erik
    Lund University, Sweden.
    Olsson, Ulf
    Lund University, Sweden.
    Köhnke, Tobias
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Wernersson, E.
    Tetrabutylammonium acetate/dimethyl sulfoxide  as a solvent for cellulose2016Conference paper (Other academic)
2345678 201 - 250 of 602
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