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  • 251.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden (2017-2019), 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, Swerea, IVF.
    Wernersson, Erik
    Lund University, Sweden.
    Dissolution of cellulose in tetrabutylammonium acetate/dimethyl sulfoxide2016In: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives, 2016, p. 15-18, article id 1Conference paper (Other academic)
    Abstract [en]

    The dissolution of cellulose in tetrabutylammonium acetate (TBAAc)/dimethyl sulfoxide (DMSO) was studied combining experimental and simulation techniques. It was found that the dissolution limit at 40 °C corresponded to a molar ratio close to one acetate per cellulose anhydroglucose units. MD simulations suggested that the acetate ions bind to cellulose by dual hydrogen bonds. This effectively turns cellulose into a polyelectrolyte, attracting the bulky tetrabutylammonium (TBA+ ) counter ions, which prevent close contact between chains in the dissolved state. This hypothesis was tested by 1 Hand 13C-NMR spectroscopy, which confirmed that acetate forms hydrogen bonds to cellulose, and by diffusion NMR spectroscopy, which demonstrated a strong dynamic correlation between bound acetate and tetrabutylammonium in near-quantitative agreement with simulation. The present results suggest that offering hydrogen bonding to the acetate ions is the main driving force for dissolving cellulose and that the TBA+ counter ions form a diffuse layer around the acetate-decorated cellulose chains.

  • 252.
    Idström, Alexander
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Materials and Production, IVF.
    Gentile, Luigi
    Lund University, Sweden.
    Gubitosi, Marta
    Lund University, Sweden.
    Olsson, Carina
    RISE - Research Institutes of Sweden (2017-2019), 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 (2017-2019), Materials and Production, IVF.
    Bialik, Erik
    Lund University, Sweden.
    On the dissolution of cellulose in tetrabutylammonium acetate/dimethyl sulfoxide: a frustrated solvent2017In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 24, no 9, p. 3645-3657Article in journal (Refereed)
    Abstract [en]

    We have found that the dissolution of cellulose in the binary mixed solvent tetrabutylammonium acetate/dimethyl sulfoxide follows a previously overlooked near-stoichiometric relationship such that one dissolved acetate ion is able to dissolve an amount of cellulose corresponding to about one glucose residue. The structure and dynamics of the resulting cellulose solutions were investigated using small-angle X-ray scattering (SAXS) and nuclear magnetic resonance techniques as well as molecular dynamics simulation. This yielded a detailed picture of the dissolution mechanism in which acetate ions form hydrogen bonds to cellulose and causes a diffuse solvation sheath of bulky tetrabutylammonium counterions to form. In turn, this leads to a steric repulsion that helps to keep the cellulose chains apart. Structural similarities to previously investigated cellulose solutions in aqueous tetrabutylammonium hydroxide were revealed by SAXS measurement. To what extent this corresponds to similarities in dissolution mechanism is discussed.

  • 253.
    Ilanidis, Dimitrios
    et al.
    Umeå University, Sweden.
    Stagge, Stefan
    Umeå University, Sweden.
    Alriksson, Björn
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Jönsson, Leif
    Umeå University, Sweden.
    Factors affecting detoxification of softwood enzymatic hydrolysates using sodium dithionite2021In: Processes, ISSN 2227-9717, Vol. 9, no 5, article id 887Article in journal (Refereed)
    Abstract [en]

    Conditioning of lignocellulosic hydrolysates with sulfur oxyanions, such as dithionite, is one of the most potent methods to improve the fermentability by counteracting effects of inhibitory by-products generated during hydrothermal pretreatment under acidic conditions. The effects of pH, treatment temperature, and dithionite dosage were explored in experiments with softwood hydrolysates, sodium dithionite, and Saccharomyces cerevisiae yeast. Treatments with dithionite at pH 5.5 or 8.5 gave similar results with regard to ethanol productivity and yield on initial glucose, and both were always at least ~20% higher than for treatment at pH 2.5. Experiments in the dithionite concentration range 5.0–12.5 mM and the temperature range 23–110◦ C indicated that treatment at around 75◦ C and using intermediate dithionite dosage was the best option (p ≤ 0.05). The investigation indicates that selection of the optimal temperature and dithionite dosage offers great benefits for the efficient fermentation of hydrolysates from lignin-rich biomass, such as softwood residues. © 2021 by the authors. 

  • 254.
    Isacsson, Patrik
    et al.
    Linkoping University, Sweden.
    Jain, Karishma
    KTH Royal Institute of Technology, Sweden.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Chauve, Valerie
    Ahlstrom-Munksjö Research Center, France.
    Hajian, Alireza
    KTH Royal Institute of Technology, Sweden.
    Granberg, Hjalmar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Boiron, Lucie
    Ahlstrom-Munksjö Research Center, France.
    Berggren, Magnus
    Linköping University, Sweden.
    Håkansson, Karl
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Edberg, Jesper
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Engquist, Isak
    Linköping University, Sweden.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Production of energy-storage paper electrodes using a pilot-scale paper machine2022In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 10, no 40, p. 21579-21589Article in journal (Refereed)
    Abstract [en]

    The global efforts in electrifying our society drive the demand for low-cost and sustainable energy storage solutions. In the present work, a novel material concept was investigated to enable fabrication of several 10 meter-long rolls of supercapacitor paper electrodes on a pilot-scale paper machine. The material concept was based on cationized, cellulose-rich wood-derived fibres, conducting polymer PEDOT:PSS, and activated carbon filler particles. Cationic fibres saturated with anionic PEDOT:PSS provide a conducting scaffold hosting the activated carbon, which functions as the active charge-storage material. The response from further additives was systematically investigated for several critical paper properties. Cellulose nanofibrils were found to improve mechanical properties, while carbon black enhanced both the conductivity and the storage capacity of the activated carbon, reaching a specific capacitance of 67 F g−1. This pilot trial shows that “classical” papermaking methods are fit for the purpose and provides valuable insights on how to further advance bio-based energy storage solutions for large-scale applications.

  • 255.
    Jacobs, Anna
    RISE, STFI-Packforsk.
    How accurately can we determine the pulp carbohydrate composition?: comparison of results and reproducibility of different methods for carbohydrate analysis2005In: Chromatography in pulping and papermaking: Cost Action E41 : analytical tools with applications for wood and pulping chemistry, 2005Conference paper (Other academic)
  • 256.
    Jacobs, Anna
    RISE, STFI-Packforsk.
    MALDI mass spectrometry as a tool for hemicellulose characterisation2005In: Spectrometric techniques used for the analysis of carbohydrates, lignin and extractives: COST Action E41 : analytical tools with applications for wood and pulping chemistry., 2005Conference paper (Other academic)
  • 257.
    Jacobs, Anna
    et al.
    RISE, Innventia. RISE - Research Institutes of Sweden (2017-2019).
    Aldaeus, Fredrik
    RISE, Innventia.
    Lignin and hemicellulose characterization for the biorefinery2014Conference paper (Refereed)
  • 258.
    Jacobs, Anna
    et al.
    RISE, Innventia.
    Aldaeus, Fredrik
    RISE, Innventia.
    Lignin properties for the biorefinery, and their analytical challenges2015In: NWBC 2015: The 6th Nordic Wood Biorefinery Conference, Espoo: VTT , 2015, p. 203-204Conference paper (Refereed)
    Abstract [en]

    The lack of official standardised methods for lignin has meant that the results from analysis of lignin properties are largely dependent on which method or laboratory that is used. Therefore, relevant and harmonised analytical methods are essential to allow producers of biorefinery products to prepare specifications for their products and to improve the possibilities for systematic development of process and product. The current status of the most important methods for lignin characterisation has been evaluated together with method development or method adaption in order to meet the requirements for high-value lignin products.

  • 259.
    Jacobs, Anna
    et al.
    RISE, Innventia.
    Aldaeus, Fredrik
    RISE, Innventia.
    Chedid, Fadia
    RISE, Innventia.
    Molecular mass distribution of lignin from black liquor: methods comparison2014Conference paper (Refereed)
  • 260.
    Jacobs, Anna
    et al.
    STFI.
    Dahlman, Olof
    STFI.
    Absolute molar mass of lignins by size exclusion chromatography and MALDI-TOF mass spectroscopy2000In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 15, no 2, p. 120-127Article in journal (Refereed)
  • 261.
    Jacobs, Anna
    et al.
    STFI.
    Dahlman, Olof
    STFI.
    Characterization of the Molar Masses of Hemicelluloses from Wood and Pulps Employing Size Exclusion Chromatography and Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry2001In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 2, no 3, p. 894-905Article in journal (Refereed)
  • 262.
    Jacobs, Anna
    et al.
    STFI.
    Dahlman, Olof
    STFI.
    Persson, E.
    Simultaneous determination or uronic acid and neutral monosaccharide structural elements in wood and pulp2001In: 11th International Symposium on Wood and Pulping Chemistry, 2001, Vol. 1, p. 207-210Conference paper (Other academic)
  • 263.
    Jacobs, Anna
    et al.
    RISE, STFI-Packforsk.
    Klockare, Lisa
    RISE, STFI-Packforsk.
    Björklund Jansson, Marianne
    RISE, STFI-Packforsk.
    Quantification of different fibres in recycled pulp using NIR analysis2006In: Paper recycling technology, 2006Conference paper (Other academic)
  • 264.
    Jacobs, Anna
    et al.
    STFI.
    Larsson, Per Tomas
    STFI.
    Dahlman, Olof
    STFI.
    Distribution of Uronic Acids in Xylans from Various Species of Soft- and Hardwood As Determined by MALDI Mass Spectrometry2001In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 2, no 3, p. 979-990Article in journal (Refereed)
  • 265.
    Jacobs, Anna
    et al.
    STFI.
    Lundqvist, Jon
    Lund university, Sweden.
    Stålbrand, Henrik
    Lund university, Sweden.
    Tjerneld, Folke
    Lund university, Sweden.
    Dahlman, Olof
    STFI.
    Characterization of water-soluble hemicelluloses from spruce and aspen employing SEC/MALDI mass spectroscopy2002In: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 337, no 8, p. 711-717Article in journal (Refereed)
  • 266.
    Jacobs, Anna
    et al.
    STFI.
    Palm, Magnus
    Lund university, Sweden.
    Zacchi, Guido
    Lund university, Sweden.
    Dahlman, Olof
    STFI.
    Isolation and characterization of water-soluble hemicelluloses from flax shive2003In: Carbohydrate Research, ISSN 0008-6215, E-ISSN 1873-426X, Vol. 338, no 18, p. 1869-1876Article in journal (Refereed)
  • 267. Jamialahmadi, A.
    et al.
    Trost, Thomas
    RISE, Innventia.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    A proposed tool to determine dynamic load distribution between corrugated boxes2011In: Packaging technology & science, ISSN 0894-3214, E-ISSN 1099-1522, no 6, p. 317-329Article in journal (Refereed)
    Abstract [en]

    This paper summarizes the dynamic analysis of the interaction of corrugated boxes in transport using a pressure-mapping system. The dynamic contact forces on the contact area between boxes in both vertical and horizontal directions were measured, and the position of the instantaneous centre of force was traced, from which the pitch motion of boxes relative to each other was studied. The level-crossing diagrams of the contact forces show a Rayleigh distribution for the vertical contact and a Gaussian distribution for the horizontal contacts. The contact force and acceleration power spectral density from accelerometers and pressure-mapping system were compared. The results show that a pressure-mapping system is an interesting tool for the analysis of the dynamic performance of systems of corrugated boxes under different stacking and loading conditions.

  • 268.
    Janssen, Matty
    et al.
    Chalmers University of Technology, Sweden.
    Gustafsson, Eva
    Södra skogsägarna ekonomisk förening, Sweden.
    Echardt, Linda
    Södra skogsägarna ekonomisk förening, Sweden.
    Wallinder, Johan
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Wolf, Jens
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Life cycle assessment of lignin-based carbon fibres2019In: 14th Conference on sustainable development of energy, water and environment systems: (SDEWES), 2019Conference paper (Other academic)
    Abstract [en]

    Lignin-based carbon fibres may replace both glass fibres and fossil-based carbon fibres. The objective of this study was to determine the environmental impact of the production of lignin-based carbon fibres using life cycle assessment. The life cycle assessment was done from cradle to gate and followed an attributional approach. The climate impact per kg of lignin- based carbon fibres produced was 1.50 kg CO2,eq. In comparison to glass fibres, the climate impact was reduced by 32% and the climate impact of fossil-based carbon fibres was an order of magnitude higher. A prospective analysis, in which the background energy system was cleaner, showed that the environmental impact of lignin-based carbon fibres will decrease and outperform the glass fibres and fossil-based carbon fibres from a climate impact point-of-view. The constructed LCA model can be applied in further studies of products that consist of or use lignin-based carbon fibres.

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  • 269.
    Jansson, M.B.
    et al.
    RISE, Innventia.
    Aldaeus, F.
    RISE, Innventia.
    Reimann, A.
    RISE, Innventia.
    Ljungquist, P.
    RISE, Innventia.
    Schweinebarth, H.
    RISE, Innventia.
    Boklund, M.
    Extraction of bioactive chemicals in spruce wood residues2011Conference paper (Refereed)
  • 270.
    Jansson, Mikael B.
    et al.
    RISE, Innventia.
    Danielsson, Sverker
    RISE, Innventia.
    Saadatmand, Soheil
    KTH Royal Institute of Technology, Sweden.
    Edlund, Ulrica
    KTH Royal Institute of Technology, Sweden.
    Albertsson, Ann Christine
    KTH Royal Institute of Technology, Sweden.
    Upgrading of wood pre-hydrolysis liquor for renewable barrier design: A techno-economic consideration2014In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 21, no 3, p. 2045-2062Article in journal (Refereed)
    Abstract [en]

    A techno-economic assessment of an upgrading procedure and outtake of a pre-hydrolysate in a presumed dissolving pulp mill was performed. Pre-hydrolysis of spruce wood chips in pilot scale produced input data for energy and mass balances and was performed with and without subsequent membrane filtration to produce hydrolysate fractions rich in galactoglucomannan and with some lignin. The hydrolysate is a viable raw material for the production of renewable thin oxygen barrier films as demonstrated herein in the formulation of free standing films with very low oxygen permeability at both moderate and high relative humidities. Approximately 50,000 ton dry solid upgraded pre-hydrolysate suitable for production of oxygen barriers could be produced according to the presumed dissolving pulp mill producing about 500,000 air dry ton dissolving pulp per year and applying a liquor to wood ratio of 4:1. Utilization of the pre-hydrolysis liquor hence adds value to and realizes the dissolving plant as a biorefinery. A sensitivity analysis indicates that the market price of the upgraded pre-hydrolysate has the largest positive effect on the return on investment for separation and upgrading of a pre-hydrolysate. Increased investment cost and increased annuity factor show negative effects.

  • 271.
    Jansson, Mikael
    et al.
    RISE, Innventia.
    Berglin, Niklas
    RISE, Innventia.
    Olm, Leelo
    RISE, Innventia.
    Second generation ethanol through alkaline fractionation of pine and aspen wood2010In: Cellulose Chemistry and Technology, ISSN 0576-9787, Vol. 44, no 1-3, p. 47-52Article in journal (Refereed)
    Abstract [en]

    Pre-treatment studies on pine and aspen wood with alkaline fractionation were performed, the experimental results obtained being used as input for assessing the conversion of an existing pulp mill to ethanol and lignin production. By the LignoBoost process, the extracted lignin could be used in the lime kiln to replace fuel oil, while the lignin not needed in the lime kiln could be sold as a by-product. In addition to fuel applications, lignin could be used in a wide range of bio-based product applications, which would increase the value of the extracted lignin and increase the total revenues. A WinGEMS model was used to calculate mass and energy balances, and the results were used for an economic evaluation of the concept. The assessment indicated that the proposed alkaline concept would have reasonable production costs from both pine and aspen wood, comparable with the bioethanol produced from grain in Northern Europe today, i.e. about 0.45 ε/L ethanol (∌5 SEK/L). The production rate of a typical mill producing 1000 tonnes of pulp per day before conversion would be in the order of 140 000 m 3 of ethanol per year, as depending on the raw wood material. The corresponding lignin production would range from 25 000 to 63 000 tonnes per year. The use of alkaline delignification to produce a substrate with low lignin content for the enzymatic hydrolysis builds entirely on known and well-proven technology, yet it needs to be further developed. The process chain from enzymatic hydrolysis to ethanol is very similar to that used today for grain ethanol. Altogether, the technical risk should therefore be low.

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  • 272.
    Jetsu, Petri
    et al.
    VTT Technical Research Centre of Finland, Finland.
    Pöhler, Tiina
    VTT Technical Research Centre of Finland, Finland.
    Barraud, Vincent
    Soprema, France.
    Seppänen, Rauni
    Holmen, Sweden.
    Salmen, Lennart
    RISE, Innventia.
    Lecourt, Michael
    FCBA, France.
    Wood-based thermal insulation materials2016In: Proceedings of the 14th European workshop on lignocellulosics and pulp, 2016, Vol. 2, p. 341-345Conference paper (Other academic)
    Abstract [en]

    A research project has been undertaken with the aim of developing wood-based cellulosic thermal insulation panel material manufactured by foam forming with high performance and to explore the possibilities of creating a new bio-based cellulosic in-situ spray-on thermal insulation foam to replace traditional spray-on plastics insulation foams. Insulation boards were manufactured from 100% softwood and a mixture of softwood and microfibrillated cellulose (MFC). The foaming surfactant used was sodium dodecyl sulphate (SDS). The materials made of softwood and MFC mixtures were made by layering. The thermal conductivity behaviour of the boards was investigated. It has been demonstrated that by using foam forming technology, nanofibrillated cellulose and softwood kraft pulp, it was possible to create high bulk fibre networks with good thermal insulation properties that simultaneously had outstanding high air flow resistivity in relation to the total density of the material. The results obtained were affected by board density. Air flow decreased with board bulk density, due to higher tortuosity of fibrous structure. Air flow resistance increased with layering strategy, with MFC layer enhancing the performance of boards to limit air going across the board.

  • 273.
    Jiao, Fei
    et al.
    Linköping University, Sweden.
    Naderi, Ali
    BillerudKorsnäs, Sweden.
    Zhao, Dan
    Linköping University, Sweden.
    Schlueter, Joshua
    University of Kentucky, USA.
    Shahi, Maryam
    University of Kentucky, USA.
    Sundström, Jonas
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Granberg, Hjalmar
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Edberg, Jesper
    Linköping University, Sweden.
    Ail, Ujwala
    Linköping University, Sweden.
    Brill, Joseph
    BillerudKorsnäs, Sweden.
    Lindström, Tom
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy. RISE, Innventia.
    Berggren, Magnus
    Linköping University, Sweden.
    Crispin, Xavier
    Linköping University, Sweden.
    Ionic thermoelectric paper2017In: Journal of Materials Chemistry A, ISSN 2050-7488, E-ISSN 2050-7496, Vol. 5, p. 16883-16888Article in journal (Refereed)
    Abstract [en]

    Ionic thermoelectric materials, for example, polyelectrolytes such as polystyrene sulfonate sodium (PSSNa),constitute a new class of materials which are attracting interest because of their large Seebeck coefficientand the possibility that they could be used in ionic thermoelectric SCs (ITESCs) and field effect transistors.However, pure polyelectrolyte membranes are not robust or flexible. In this paper, the preparation of ionicthermoelectric paper using a simple, scalable and cost-effective method is described. After a compositewas fabricated with nanofibrillated cellulose (NFC), the resulting NFC–PSSNa paper is flexible andmechanically robust, which is desirable if it is to be used in roll-to-roll processes. The robust NFC–PSSNa thermoelectric paper combines high ionic conductivity (9 mS cm1), high ionic Seebeckcoefficient (8.4 mV K1) and low thermal conductivity (0.75 W m1 K1) at 100% relative humidity,resulting in overall figure-of-merit of 0.025 at room temperature which is slightly better than that for thePSSNa alone. Fabricating a composite with cellulose enables flexibility and robustness and this is anadvance which will enable future scaling up the manufacturing of ITESCs, but also enables its use fornew applications for conformable thermoelectric devices and flexible electronics.

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  • 274.
    Joffre, Thomas
    et al.
    Uppsala University, Sweden.
    Miettinen, Arttu
    University of Jyväskylä, Finland.
    Berthold, Fredrik
    RISE, Innventia.
    Gamstedt, Erik Kristofer
    Uppsala University, Sweden.
    X-ray micro-computed tomography investigation of fibre length degradation during the processing steps of short-fibre composites2014In: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 105, p. 127-133Article in journal (Refereed)
    Abstract [en]

    The mechanical properties of composites in the fibre direction are mainly attributed to the fibre slenderness, or aspect ratio. A trade-off between performance and processability is usually required, and dependent on the intended application. If the fibre length could be retained or not severely degraded during various processing steps towards the injection-moulded component, a stiffer and stronger composite product could be obtained. The processing steps for injection moulded wood-fibre composites here include: pulping, commingling, extrusion, pelletizing, and injection moulding. To tune the processing parameters systematically for retained fibre length, it would be useful to investigate the degradation of the original fibre length distribution throughout the processing chain. The fibre length degradation has been monitored by X-ray micro-computed tomography through the processing steps in wood pulp-fibre reinforced polylactide. A significant fibre-length degradation was found. In particular, the extrusion step was found to result in a drastic fibre length reduction.

  • 275.
    Johansson, Lars
    et al.
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Hill, J.
    Gorski, D.
    Axelsson, P.
    Improvement of energy efficiency in TMP refining by selective wood disintegration and targeted application of chemicals2011In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 26, p. 31-46Article in journal (Refereed)
  • 276. Johnson, J.
    et al.
    Andersson, C.
    Lestelius, M.
    Järnström, L.
    Rättö, P.
    Blohm, Erik
    RISE, Innventia.
    Some properties of flexographic printing plates and aspects of print quality2009In: Appita journal, ISSN 1038-6807, Vol. 62, no 5, p. 371-378Article in journal (Refereed)
    Abstract [en]

    The purpose of this research was to study the effects on print quality when the properties of the flexographic printing plate were changed in a systematic and controlled way. An attempt was made to identify plate parameters that govern good print quality. Coated paperboard was printed in a laboratory printing press using different plates, and print density and dot gain were determined. Essential parameters including mechanical, chemical, and morphological properties of the plate that led to good print quality were identified. The properties of the plates were characterised by means of profilometry, ESCA, contact angle measurements, durometer, and image analysis. The methods used to create printing plates with controlled material properties gave useful information about the ageing and wear of printing plates. The results showed that it was possible to systematically control the properties of the plate by changing the pre-press conditions. Application pressures and dot area influenced print quality. Small-scale roughness and long-scale roughness of the plate governed good print quality with respect to print density and dot gain It appeared that these printing plate properties affect the amount of ink transferred.

  • 277. Johnson, J.
    et al.
    Lestelius, M.
    Blohm, Erik
    RISE, STFI-Packforsk.
    Räättö, Peter
    RISE, STFI-Packforsk.
    Järnström, L.
    The interaction between water and liner and newsprint in flexographic CI-printing press2008In: Proceedings of the Technical Association of the Graphic Arts: TAGA, 2008, p. 267-284Conference paper (Refereed)
    Abstract [en]

    Printing with water-borne ink in a multicolor printing press subjects the substrate to water, because the water-borne ink contains water. The water in the ink can influence the surface properties, e.g. the roughness and compressibility, and can lead to dimensional changes. On the other hand, water derived from the ink can enhance or reduce some aspects of the final print quality depending on the properties of the substrate. In the present study, the manner in which the print quality of unsized paper substrates was influenced by pre-treatment with water and surfactant solution in flexographic printing was investigated. The experiment was designed to imitate the effects of multicolor printing using water-borne ink, since the water derived from the ink in an early printing unit influences the mechanical, dimensional and wettability properties of the paper and can thus influence the print quality in a later printing unit. This paper complements a previous paper, which showed a reduction of print mottle on a white top liner (with a low water absorptivity and wettability) when water and surfactant solution were applied just before the ink. The substrates investigated in the present paper were standard newsprint and a white top testliner, with high water absorptivity and wettability. The printing trials were performed in a central impression flexographic printing press using two of the six printing units. The first unit was used to apply water and a mixture of water and a surfactant and a second unit was used to transfer water-borne ink. The effects of water and surfactant pre-treatment were evaluated by measuring the print quality and the substrate properties. The pre-treatment by water and surfactant solution showed no effect on print mottle in the case of newsprint or testliner.

  • 278.
    Joseph, Prajin
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Opedal, Mihaela Tanase
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Moe, Störker
    NTNU Norwegian University of Science and Technology, Norway.
    The O-factor: using the H-factor concept to predict the outcome of organosolv pretreatment2021In: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823Article in journal (Refereed)
    Abstract [en]

    The H-factor, a parameter used extensively to analyze and predict the outcome of kraft pulping, is applied to organosolv pretreatment. The total solid yield after organosolv pretreatment fits well with the H-factor. The concept has been extended to apply to the individual biomass polymers using unique values for the activation energy for the depolymerization of the individual biomass polymers, giving the O-factor concept analogous to the P factor used for analyzing prehydrolysis kinetics. The results showed a linear relationship between ln(L0/L) and O-factor at an activation energy of 96 kJ/mol. The best linear fit for mannan and xylan degradation was obtained at O-factor activation energies of 104 kJ/mol and 142 kJ/mol, respectively, and the formation of furfural and 5-HMF gave a good linear fit using an O-factor activation energy of 150 kJ/mol. The O-factor is thus a useful concept for analyzing organosolv pretreatment when the temperature during pretreatment is not constant. © 2021, The Author(s).

  • 279.
    Jour, Pia
    et al.
    AkzoNobel Pulp and Performance Chemicals, Sweden.
    Lindgren, Karin
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Gutke, Katarina
    Akzo Nobel Pulp and Performance Chemicals, Sweden.
    ECF bleaching of eucalyptus kraft pulp: simulation of a mill with a high degree of closure2017In: International pulp bleaching conference / [ed] Colodette J L, Gomes F J B, Suprema Grafica e Editora , 2017, p. 106-110Conference paper (Other academic)
    Abstract [en]

    The composition of non-process elements (NPEs) in wood significantly affects the level of metals in the pulp in the bleach plant and contributes to the risk of forming precipitates. The possible degree of closure is often limited by calcium oxalate formation, mainly around the D0-stage, which can be prevented by increasing the temperature and/or decreasing the pH in this stage. This paper presents the effect of a decreased pH in the D0-stage when bleaching a eucalyptus kraft pulp as well as the influence it has on environmental parameters such as chemical oxygen demand (COD) and adsorbable organic halogens (AOX). The increased AOX measured when applying a low pH in the D0-stage was shown to be easily decomposed under process conditions. To be able to predict the effect on both the recovery cycle and the bleach plant itself as a consequence of increased closure of the bleach plant, a full mill simulation model (WinGEMS) was used based on a theoretical mill using the best available technology (BAT) in combination with data produced in laboratory trials. The model pulp mill was exclusively equipped with wash presses. According to the simulations, the effluent volume could be significantly decreased from 20.7 t/air dry tonne (ADt) pulp to 8.7 t/ADt in a D(EOP)DP sequence. Using a wood raw material with a calcium content of 520 mg/kg dry solids, no formation of calcium oxalate was predicted. However, for a wood raw material with a higher content, 800 mg/kg, calcium oxalate formation was likely to occur. By decreasing the final pH in the D0-stage from 3.0 to 2.5, formation of calcium oxalate could be avoided. At the effluent volume of 8.7 t/ADt, no fresh water was used in the bleach plant except for the water used for dilution of chemicals.

  • 280.
    Jour, Pia
    et al.
    Akzo Nobel Pulp and Performance Chemicals, Sweden.
    Lindgren, Karin
    RISE - Research Institutes of Sweden, Bioeconomy.
    Gutke, Katarina
    Akzo Nobel Pulp and Performance Chemicals, Sweden.
    Wallinder, Johan
    RISE - Research Institutes of Sweden, Bioeconomy.
    Decreased water usage in a softwood ECF bleaching sequence: full mill simulations2017In: TAPPI PEERS, November 5-8, 2017, Norfolk, Virginia, USA, TAPPI Press, 2017, p. 1681-1688Conference paper (Other academic)
  • 281.
    Jour, Pia
    et al.
    Akzo Nobel Pulp and Performance Chemicals, Sweden.
    Lindgren, Karin
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Gutke, Katarina
    Akzo Nobel Pulp and Performance Chemicals, Sweden.
    Walllinder, Johan
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Decreased water usage in a softwood ECF bleaching sequence: full mill simulations2018In: TAPPI Journal, ISSN 0734-1415, Vol. 17, no 6, p. 353-360Article in journal (Refereed)
    Abstract [en]

    In this study, an elemental chlorine free (ECF) bleach plant with a D0(EOP)D1(EP)D2 sequence was studied with the aim of identifying options for significantly decreasing (fresh) water usage in the bleach plant and decreasing the effluent volume. A base-case simulation model for a softwood kraft market pulp mill was made based on a reference model representing the best available techniques as well as data produced in an extensive  laboratory pulp bleaching study. This model was used to evaluate increased closure within the bleach plant and the recirculation of bleach plant effluent to the brownstock system and their effects on both the bleach plant and the recovery cycle. The results indicate that it is possible to reduce the fresh water consumption from 15 metric tons/a.d. metric ton in the base case to about 2 metric tons/a.d. metric ton, without increasing the carryover of chemical  oxygen demand (COD) to the pulp machine. Nonprocess elements in wood contribute to the levels of metals found in the bleach plant and thus to the risk of  precipitates such as calcium oxalate, barium sulfate, and calcium carbonate. The risk of precipitates forming is a key factor determining the possible degree of closure. In addition, chloride concentration in the black liquor is another important factor that is affected by recirculating bleach plant filtrate to the brownstock washer and by the grade of the sodium hydroxide used in the mill.

  • 282.
    Järnström, Lars
    et al.
    Karlstad university, Sweden.
    Javed, Asif
    Karlstad university, Sweden.
    Ulllsten, Henrik
    Karlstad university, Sweden.
    Rättö, Peter
    RISE - Research Institutes of Sweden, Bioeconomy.
    Lignin-containing coatings for packaging materials2017In: 28th IAPRI Symposium on packaging, 2017, p. 263-270Conference paper (Other academic)
  • 283.
    Kaldeus, Tahani
    et al.
    Wallenberg Wood Science Center, Sweden.
    Larsson, Per Tomas
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Biorefinery and Energy.
    Boujemaoui, Assya
    KTH Royal institute of technology, Sweden.
    Malmström, Eva
    KTH Royal institute of technology, Sweden.
    One-pot preparation of bi-functional cellulose nanofibrils2018In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882XArticle in journal (Refereed)
    Abstract [en]

    Herein, we present a route to obtain bi-functional cellulose nanofibrils (CNF) by a one-pot approach using an already established functionalisation route, carboxymethylation, to which a subsequent functionalisation step, allylation or alkynation, has been added in the same reaction pot, eliminating the need of solvent exchange procedures. The total charge of the fibres and the total surface charge of the nanofibrils were determined by conductometric and polyelectrolyte titration, respectively. Furthermore, the allyl and alkyne functionalised cellulose were reacted with methyl 3-mercaptopropionate and azide-functionalised disperse red, respectively, to estimate the degree of functionalisation. The samples were further assessed by XPS and FT-IR. Physical characteristics were evaluated by CP/MAS 13C-NMR, XRD, AFM and DLS. This new approach of obtaining bi-functionalised CNF allows for a facile and rapid functionalisation of CNF where chemical handles can easily be attached and used for further modification of the fibrils. Graphical abstract: [Figure not available: see fulltext.

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  • 284.
    Kalogiannis, Konstantinos G.
    et al.
    Center for Research and Technology Hellas, Greece.
    Stefanidis, Stylianos D.
    Center for Research and Technology Hellas, Greece; University of Western Macedonia, Greece.
    Michailof, Chrysoula M.
    Center for Research and Technology Hellas, Greece.
    Lappas, Angelos A.
    Center for Research and Technology Hellas, Greece.
    Sjöholm, Elisabeth
    RISE, Innventia.
    Pyrolysis of lignin with 2DGC quantification of lignin oil: Effect of lignin type, process temperature and ZSM-5 in situ upgrading2015In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 115, p. 410-418Article in journal (Refereed)
    Abstract [en]

    Thermal and catalytic pyrolysis of various types of lignin and their influence on the yield and the quality of the produced lignin oil were studied. Lignins originated from a mixture of pine and spruce wood (softwood), a mixture of birch and aspen wood (hardwood) and Eucalyptus Urograndis. High degree of deoxygenation of the bio-oil and maximum yield of value-added chemicals were the main targets of this work. 2DGC-ToFMS analysis was used for the qualitative and quantitative characterization of the lignin oils. Softwood lignin was found to be the most attractive feedstock and high yields of a mixture of phenolic compounds were detected in all cases. High char production was also evident for all types of lignins accounting for almost 50% of the original feedstock. The use of a commercial ZSM-5 catalyst was extremely beneficial for the process, enhancing deoxygenation at higher oil yields compared to thermal pyrolysis. Depending on the nature of the lignin, guaiacyl or syringyl groups were dominant in the oils and it was found that process optimization, involving lignin, catalyst selection and temperature could significantly improve the process efficiency.

  • 285.
    Kamal Alm, Hajer
    et al.
    RISE, Innventia.
    Ström, Göran
    RISE, Innventia.
    Schoelkopf, Joachim
    OMYA Deveopment AG, Switzerland.
    Ridgway, Cathy
    OMYA Deveopment AG, Switzerland.
    Gane, Patrick A. C.
    OMYA Deveopment AG, Switzerland; Aalto University, Finland.
    Ink adhesion failure during full scale offset printing: causes and impact on print mottle2015In: Journal of Print and Media Technology Research, ISSN 2223-8905, E-ISSN 2414-6250, Vol. 4, no 4, p. 257-284Article in journal (Refereed)
    Abstract [en]

    The printing plate used in offset lithography is designed to accept ink on image areas and reject ink on non-image areas. In order to reject ink in conventional offset, fountain solution is needed to form a weak boundary layer between the plate and the ink. Paper and coated paper in particular are designed to accept ink and absorb ink oil and fountain solution. The latter is often transferred to the paper surface through the rubber blanket and its absorption or subsequent displacement is essential for final ink transfer to the surface. There are strong demands on the uniformity of the paper surface, including in respect to absorptivity, both in structure and chemistry, in order to gain a print of high quality. If this is not the case, the ink film thickness may be non-uniform; subsequently, ink adhesion may even fail completely, leaving white spots on the paper surface in the print. This gives rise to print mottle, a severe print quality defect. The aim of this paper was to study the quality of prints from a full scale offset printing trial made on pilot coated paper, with attention given to ink-surface adhesion. Seven calcium carbonate pigment based coatings with different contents of pigment  dispersing agent were included in this study. The work showed that a moderate over-dosage of dispersant significantly increased the ink adhesion failure and print mottle, mainly on prints from the later print units and especially at high fountain feed levels. These findings demonstrate the fundamental impact of fount level, surface chemistry and coating  formulation on ink adhesion and thus also print mottle.

  • 286.
    Kamel, H.
    et al.
    RISE, STFI-Packforsk.
    Ström, Göran
    RISE, STFI-Packforsk.
    Schoelkopf, J.
    Gane, P. A. C.
    Characterization of ink adhesion failure; effect of pre-dampening of carbonate containing coatings2008In: TAPPI Advanced Coating Fundamentals Symposium Proceedings, TAPPI Press, 2008, p. 228-241Conference paper (Refereed)
    Abstract [en]

    To attain an improved knowledge about ink adhesion during offset printing we have developed a laboratory procedure to measure adhesion failure between ink and coated paper during ink setting. This paper describes the technique and a special case, where a normal coating and a coating with excess dispersing agent, in the form of sodium polyacrylate, have been printed. Characterization of the areas where the adhesion had failed at the pull-off points after tack testing was done by determining "white" spots in the retained print using image analysis. The "white" spots represent areas where ink has detached from the coating after contact with a rubber coated cylinder. This area is referred to as adhesion failure area (AFA). A minimum in AFA at the point of maximum in tack force was found for both coatings where the print was applied onto dried coating. When the coatings, however, were pre-damped, AFA increased on the normal coating over a short time period, independent of the dampening level. For the coating with excess dispersant, on the other hand, the higher dampening level strongly increased the AFA. The strong impact of excess dispersing agent in this work may be explained by a number of related effects, including increased polarity of the coating surface, and an associated moisture layer, and an effective reduction of fine pores due to water-swelling polyacrylate that blocks these pores.

  • 287.
    Karlholm, Ingeli
    et al.
    RISE, STFI-Packforsk.
    Lindgren, Karin
    RISE, STFI-Packforsk.
    Water-soluble kraft lignin products through sulphomethylation2008In: 2008 Nordic Wood Biorefinery Conference - Proceedings: NWBC 2008, 2008, p. 207-208Conference paper (Refereed)
  • 288.
    Karlsson, Pernilla
    et al.
    KTH Royal Institute of Technology, Sweden.
    Pendergraph, Samuel
    KTH Royal Institute of Technology, Sweden.
    Larsson, Per Tomas
    RISE, Innventia.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Cellulose model probes for unraveling the swelling behavior of wood fibres2016In: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives, 2016, p. 33-34, article id 8Conference paper (Other academic)
  • 289.
    Karlsson, Rose-Marie Pernilla
    et al.
    KTH Royal Institute of Technology, Sweden.
    Larsson, Per Tomas
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy. KTH Royal Institute of Technology, Sweden.
    Hansson, Per
    Uppsala University, Sweden.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Thermodynamics of the Water-Retaining Properties of Cellulose-Based Networks2019In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 4, p. 1603-1612Article in journal (Refereed)
    Abstract [en]

    Noncrystalline cellulose-based gel beads were used as a model material to investigate the effect of osmotic stress on a cellulosic network. The gel beads were exposed to osmotic stress by immersion in solutions with different concentrations of high molecular mass dextran and the equilibrium dimensional change of the gel beads was studied using optical microscopy. The volume fraction of cellulose was calculated from the volume of the gel beads in dextran solutions and their dry content and the relation between the cellulose volume fraction and the total osmotic pressure was thus obtained. The results show that the contribution to the osmotic pressure from counterions increases the water-retaining capacity of the beads at high osmotic pressures but also that the main factor controlling the gel bead collapse at high osmotic strains is the resistance to the deformation of the polymer chain network within the beads. Furthermore, the osmotic pressure associated with the deformation of the polymer network, which counteracts the deswelling of the beads, could be fitted to the Wall model indicating that the response of the cellulose polymer networks was independent of the charge of the cellulose. The best fit to the Wall model was obtained when the Flory-Huggins interaction parameter (χ) of the cellulose-water system was set to 0.55-0.60, in agreement with the well-established insolubility of high molecular mass β-(1,4)-d-glucan polymers in water.

  • 290.
    Karlström, Katarina
    et al.
    RISE, Innventia.
    Sjögren, Birger
    RISE, Innventia.
    Kulander, Ida
    RISE, Innventia.
    Sulphur-free process for dissolving pulp2014Conference paper (Refereed)
  • 291.
    Karlström, Katarina
    et al.
    RISE, Innventia.
    Sjögren, Birger
    RISE, Innventia.
    Vorwerg, Waltraud
    Fraunhofer Institute for Applied Polymer Research IAP, Germany.
    Volkert, Bert
    Fraunhofer Institute for Applied Polymer Research IAP, Germany.
    Sulphur-free cooking for value added cellulose2014In: Cellulose Chemistry and Technology, ISSN 0576-9787, Vol. 48, no 9-10, p. 781-786Article in journal (Refereed)
    Abstract [en]

    To study sulphur- and chlorine-free processes to produce pulps for triacetylation and preparation of films for LCD screen application was one of the aims in the EU project AFORE. It was shown possible to produce pulp suitable for triacetylation from Eucalyptus globulus chips with pre-hydrolysis soda cooking and a single oxygen delignification step. Pre-hydrolysis with water at elevated temperatures extracts wood components, mainly hemicelluloses and the wood matrix is opened to facilitate alkaline pulping. After a severe pre-hydrolysis extracting some 25% of the wood raw material, a subsequent soda cook reduces the lignin content to about 1%. The oxygen delignification step produces a pulp with low lignin content, kappa no 1.4, and low hemicelluloses content, < 2 wt% xylose. The resulting cellulose had high molar mass and produced highly transparent triacetate solutions. It was also possible to produce a transparent cellulose triacetate film by solution casting with good physical properties without using plasticizer. The process also results in a sulphur-free black-liquor suitable for lignin separation by the LignoBoost process. The resulting lignin is of high purity with low hemicelluloses content.

  • 292. Kihlman, M.
    et al.
    Aldaeus, F.
    RISE, Innventia.
    Chedid, F.
    RISE, Innventia.
    Germgård, U.
    Effect of various pulp properties on the solubility of cellulose in sodium hydroxide solutions2012In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, no 5, p. 601-606Article in journal (Refereed)
  • 293.
    Kihlstedt, Annika
    et al.
    RISE, Innventia. RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Lindberg, Siv M
    RISE, Innventia.
    Lindström, Annika
    RISE, Innventia.
    Pousette, Sandra
    RISE, Innventia.
    Material identity in a packaging context2014Conference paper (Refereed)
    Abstract [en]

    Package design includes a number of considerations ranging from protecting the content to conveying the brand image. The aim of this study was to gain a deeper understanding on how Swedish consumes perceive product packaging attributes, with a special emphasis on in which way packaging material (carton, paper plastic), and structural design (folding carton, paper bag, standing pouch and plastic bag), have an emotional impact on consumers' evaluation of the product and packaging. Assessing the appearance and effectiveness of a packaging system is often confounded by branding, why it is important to separate the brand influence from the attributes of the packaging system. Thus, in the experimental part, packaging prototypes of different structural design and materials were manufactured in order to present commercial cereal brands in different types of packaging. The research involved a combination of qualitative and quantitative methods, comprising (i) focus groups on cereal (muesli) packaging; (ii) a mock-up study of four muesli packaging types: transparent plastic bag, carton box, paper bag, and a resalable stand-up plastic pouch; and (iii) a questionnaire on environmental attitudes to packaging materials. Fourteen respondents participated in the focus groups and 20 in the mock-up study. Result show that the paper bag and the carton box were perceived to be the most environmentally friendly packaging material. Heavy ink usage on paper bags and carton boxes can however raise concern regarding the environmental impact. Introducing functionality and good print quality can cause preferences to divert to an alternative packaging material. In the mock-up study the standing pouch was the most liked package type regardless of brands. Functional reasons (protect, re-closable etc.) and appearance reasons (nice print, nice colours) was claimed for giving this package high ratings.

  • 294. Kirabira, J. B.
    et al.
    Jonsson, S.
    Drotz, Mattias
    RISE, STFI-Packforsk.
    Karathanasis, Michael
    RISE, STFI-Packforsk.
    Norman, Bo
    RISE, STFI-Packforsk.
    Properties of super-calendered (SC) paper filled with Mutaka kaolin, Uganda2009In: Paper Technology, ISSN 0306252X, Vol. 50, no 1, p. 11-16Article in journal (Refereed)
    Abstract [en]

    The experts from Makerere University (Mak) and the Royal Institute of Technology (KTH) evaluated three mineral deposits for the production of fireclay refractories in Uganda and found that the Mutaka kaolin deposit in Uganda is of extraordinary quality. Ten tons of raw kaolin was mined at the Mutaka deposit and shipped in a container to STFI-Packforsk, Sweden. The kaolin was first dry sieved in a shaker to remove sand, mica and large particles. The sieved material was mixed with fresh water to a dry content of 15% and hydrocycloned to separate and remove coarse particles. The paper machine trials were carried out at STFI-Packforsk on the EuroFEX paper machine. The results indicate that the potential of exploiting the Mutaka kaolin deposit for paper filling is high. Paper filled with Mutaka clay resulted in a slightly lower opacity, however, with an optimized particles size distribution, this could be improved.

  • 295.
    Koppolu, Rajesh
    et al.
    Åbo Akademi University, Finland; VTT, Finland.
    Lahti, Johanna
    Tampere University, Finland; VTT, Finland.
    Abitbol, Tiffany
    RISE Research Institutes of Sweden. École Polytechnique Fédérale de Lausanne, Switzerland.
    Aulin, Christian
    École Polytechnique Fédérale de Lausanne, Switzerland; Holmen Iggesund, Sweden.
    Kuusipalo, Jukka
    Tampere University, Finland.
    Toivakka, Martti
    Åbo Akademi University, Finland.
    Tailoring the performance of nanocellulose-based multilayer-barrier paperboard using biodegradable-thermoplastics, pigments, and plasticizers2023In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882XArticle in journal (Refereed)
    Abstract [en]

    In this work a multilayer barrier paperboard was produced in a roll-to-roll process by slot-die coating of nanocellulose (microfibrillated cellulose or carboxymethylated cellulose nanofibrils) followed by extrusion coating of biodegradable thermoplastics (polylactic acid, polybutylene adipate terephthalate and polybutylene succinate). Hyperplaty kaolin pigments were blended in different ratios into nanocellulose to tailor the barrier properties of the multilayer structure and to study their influence on adhesion to the thermoplastic top layer. Influence of a plasticizer (glycerol) on flexibility and barrier performance of the multilayer structure was also examined. Water vapor permeance for the multilayer paperboard was below that of control single-layer thermoplastic materials, and oxygen permeance of the coated structure was similar or lower than that of pure nanocellulose films. Glycerol as a plasticizer further lowered the oxygen permeance and kaolin addition improved the adhesion at the nanocellulose/thermoplastic interface. The results provide insight into the role played by nanocelluloses, thermoplastics, pigments, and plasticizers on the barrier properties when these elements are processed together into multilayer structures, and paves the way for industrial production of sustainable packaging. © 2023, The Author(s).

  • 296.
    Krochak, Paul
    RISE Research Institutes of Sweden, Bioeconomy and Health. Packforsk, Sweden.
    Rethinking the Packaging System2022In: TAPPICon Conference 2022, TAPPI Press , 2022Conference paper (Refereed)
  • 297.
    Krochak, Paul
    et al.
    RISE, Innventia.
    Athley, Karin
    RISE, Innventia.
    Björk, Elisabeth
    RISE, Innventia.
    Norman, Bo
    RISE, Innventia.
    Achieving maximum filler retention by improving mechanical and chemical retention2013Conference paper (Refereed)
  • 298.
    Krochak, Paul
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health.
    Bjärestrand, Annika
    RISE Research Institutes of Sweden, Bioeconomy and Health.
    Upgrading of recycled pulp quality by fractionation and selective refining2022In: TAPPICon Conference 2022, TAPPI Press , 2022Conference paper (Refereed)
    Abstract [en]

    Sustainability pressure on the packaging industry has increased considerably in recent years, with stricter regulation on recyclability and waste management along with heightened consumer awareness on the environmental impact of packaging. One critical measure that must be taken is to increase the recycling rates of all fiber-based packaging placed on the market, where in the EU this requirement has been set to at least 85% by the year 2030. Similar trends are being observed world-wide. This is creating an increased demand for using recycled fibre in packaging materials and with it an increased need for methods to ensure the quality of recycled fibre and final product performance. This trend also creates a risk for the availability of high-quality recycled fibre but also potential contamination of recycled fibre streams with other, low-quality materials, and producers may be forced to work with lower quality recycled materials in the future. This study investigates possible routes for upgrading recycled fibre quality through combined fractionation and refining strategies. A recycled pulp for containerboard was fractionated in pilot scale using a pressure screen and hydrocyclones. The pulp was first fractionated using a micro-perforated screen basket into a long fibre fraction and short fibre fraction, after which hydrocyclone fractionation was made on each screened fraction. Hydrocyclone fractionation of the screen short fraction resulted in a fine fraction with fibrillar fines and a coarse fraction containing low bonding fines, fibre fragments and ash. Hydrocyclone fractionation of the screen long fibre fraction was split into a fine fibre fraction containing good bonding fibres and fines and a coarse fibre fraction with coarse low bonding fibres. The coarse long fibre fraction was then upgraded through refining to a strength level comparable to the good bonding fine fraction, but with an energy input of only 24 kWh/t calculated on the entire pulp. This selective refining of the coarse long fibre fraction resulted in an improvement of the total pulp strength by 20 % when the pulp fractions were mixed back together in the same proportions as they had been separated. Strength was improved further when the low bonding short coarse fraction with high ash content was removed. 

  • 299.
    Krochak, Paul
    et al.
    RISE, Innventia.
    Fasci, Giuseppe Carmini
    KTH Royal Institute of Technology, Sweden.
    Norman, Bo
    RISE, Innventia.
    Prahl Wittberg, Lisa
    KTH Royal Institute of Technology, Sweden.
    Bridging chemical dosage, mixing quality, and variability in paper sheets2015In: TAPPI Journal, ISSN 0734-1415, Vol. 14, no 5, p. 311-320Article in journal (Refereed)
    Abstract [en]

    In the first part of this work, a series of paper production trials were performed on a forming experimental (FEX) pilot machine to investigate the distribution of additives in the final product. In these trials, a blue color was dosed into the stock before the headbox instead of a retention aid. Fine paper sheets were produced using twin-wire forming. Visual inspection of the sheets revealed surprisingly high levels of variability of the blue color. In the second part, the effect of different dosage nozzle configurations on downstream mixing quality of a single-component, polyacrylamide retention aid was studied using two-phase computational fluid dynamics. A non-Newtonian model for this phase was implemented using rheological parameters obtained through a combination of numerical and experimental analysis. Dosage was made into a turbulent pipe flow under typical industrial approach flow conditions. The effect of the number of dosage points, impingement angle, dosage location, and dosage speed on mixing uniformity was investigated qualitatively and quantitatively. Results from these studies indicate the existence of optimal dosage configurations and point toward strong coupling between chemical addition strategy, mixing quality, and chemical variability in final products. Application: Mills can gain valuable information, including dosage nozzle configuration and dosage conditions, for optimizing mixing of retention aids in the approach flow during paper production.

  • 300.
    Krochak, Paul
    et al.
    RISE, Innventia.
    Fasci, Giuseppe Carmini
    KTH Royal Institute of Technology, Sweden.
    Norman, Bo
    RISE, Innventia.
    Prahl Wittberg, Lisa
    KTH Royal Institute of Technology, Sweden.
    Bridging chemical dosage, mixing quality and variability in paper sheets2013Conference paper (Refereed)
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