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  • 1.
    Andersson, Sofia
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Bengtsson, Andreas
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy. KTH Royal institute of technology, Sweden.
    Åkerström, Mårten
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Sedin, Maria
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    The impact of inorganic elements on lignin‐based carbon fibre quality2018In: 15th European workshop on lignocelllulosics and pulp: Proceedings for poster presentations, 2018, p. 119-122Conference paper (Other academic)
    Abstract [en]

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

  • 2.
    Ankerfors, Caroline
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Gimåker, Magnus
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Östlund, Ida
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Polyelectrolyte Multilayers and Other Dosage Strategies: Effects on Properties of Paper Sheets Produced in Pilot Scale Using MillProcess Waters2018In: PaperCon 2018: Shaping the future through innovation, TAPPI , 2018, article id PA3.3Conference paper (Other academic)
  • 3.
    Bengtsson, Andreas
    et al.
    KTH Royal Institute of Technology, Sweden.
    Bengtsson, Jenny
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Olsson, Carina
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Sedin, Maria
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF.
    Theliander, Hans
    Chalmers University of Technology, Sweden.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Improved yield of carbon fibres from cellulose and kraft lignin2018In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434XArticle in journal (Refereed)
    Abstract [en]

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

  • 4.
    Björk, Elisabeth
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Bouveng, Mikael
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Vomhoff, Hannes
    Holmen AB, Sweden.
    Fines-enriched pulp as a strength agent in a CTMP middle ply2018In: PaperCon 2018: Shaping the future through innovation, TAPPI , 2018, article id PA5.2Conference paper (Refereed)
    Abstract [en]

    The objective of this pilot scale trial, was to evaluate fines-enriched pulp (FE-pulp) as a strength agent in amiddle ply of a board product.A typical CTMP-based middle ply was produced on the FEX pilot paper machine. The stock consisted of CTMP,refined hardwood and softwood pulp, and filler. FE-pulp as strength agent was compared with glue pulp, ahighly refined chemical pulp. FEX sheets and hand sheets made of pulp mixtures were evaluated. Also, thedewatering and pressing conditions on the paper machine were compared.The results confirmed the results of earlier experiments with handsheets; FE-pulp used as strength agent showedto be twice as efficient as glue pulp regarding strength properties without impairing the bulk. Further, thedewatering conditions and press dryness's on the paper machine was comparable at these additions. Thus, allthese results imply that addition of FE-pulp can replace the double amount of glue pulp as a strength agent.

  • 5.
    Björk, Elisabeth
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Bouveng, Mikael
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Vomhoff, Hannes
    Holmen AB, Sweden.
    Production of pulps with an extremely high fines content for use as strength agent2018In: PaperCon 2018: Shaping the future through innovation, TAPPI , 2018, article id PA5.1Conference paper (Refereed)
    Abstract [en]

    The objective was to optimize the production of fines-enriched pulp (FE-pulp) from chemical pulp.The first trial was a continuous production of FE-pulp with unbleached and bleached never-dried softwood. Thepulp was refined using a JC00 equipped with SF filling, and screened with a micro-perforated screen basket with250 μm diameter holes, but the produced FE-pulp got low concentration, below 3 g/l.The second trial aimed at optimised conditions, using dried bleached softwood. Three fillings, microbar, AA andFF were evaluated in a JC01 refiner, where microbar was most energy efficient. Microbar and AA reachedtargeted FE-pulp concentration, 10 g/l. The refined pulps were screened with different hole diameters, where, asexpected, larger hole diameters resulted in higher concentration but also lower fines content in the FE-pulps.The last trial, the microbar filling was evaluated for never-dried softwood pulp, unbleached and bleached. Now,the refining of unbleached softwood gave 3 times more fines per kWh/ton compared with first trial.These trials demonstrated the importance of the right refining conditions regarding effect of refiner and type offilling to achieve glue-pulp with high enough fines content. With the right conditions, it was possible to produceFE-pulp with high concentration at moderate energy consumption.

  • 6.
    Edlund, Ulrica
    et al.
    KTH Royal Institute of Technology, Sweden.
    Lagerberg, Tove
    Ålander, Eva
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Admicellar Polymerization Coating of CNF Enhances Integration in Degradable Nanocomposites2018In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602Article in journal (Refereed)
    Abstract [en]

    A water-based one-pot synthesis strategy for converting cellulose nanofibrils (CNF) into a hydrophobic and processable biopolymer grade is devised. CNF was chemically modified through admicellar polymerization, producing fibrils coated with fatty acrylate polymers. The proposed modification targets a change in the interfibrillar interactions and improved CNF compatibility with a degradable plastic composite matrix, poly(butylene adipate-co-terephthalate), PBAT in composites prepared by melt extrusion. CNF had a clear reinforcing effect on PBAT, increasing Young's modulus by at least 35% and 169% at 5 and 20% (w/w) CNF content, respectively. However, unmodified CNF showed aggregation, poor adhesion in the matrix, and severely impaired the ductility of PBAT. CNF modified by admicellar polymerization was homogeneously dispersed in the PBT matrix and showed significantly better preservation of the elongation properties compared to unmodified CNF, especially at 5% (w/w) addition level.

  • 7.
    Erlandsson, Johan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Françon, Hugo
    KTH Royal Institute of Technology, Sweden.
    Marais, Andrew
    KTH Royal Institute of Technology, Sweden.
    Granberg, Hjalmar
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Cross-Linked and Shapeable Porous 3D Substrates from Freeze-Linked Cellulose Nanofibrils.2018In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602Article in journal (Refereed)
    Abstract [en]

    Chemically cross-linked highly porous nanocellulose aerogels with complex shapes have been prepared using a freeze-linking procedure that avoids common post activation of cross-linking reactions and freeze-drying. The aerogel shapes ranged from simple geometrical three-dimensional bodies to swirls and solenoids. This was achieved by molding or extruding a periodate oxidized cellulose nanofibril (CNF) dispersion prior to chemical cross-linking in a regular freezer or by reshaping an already prepared aerogel by plasticizing the structure in water followed by reshaping and locking the aerogel into its new shape. The new shapes were most likely retained by new cross-links formed between CNFs brought into contact by the deformation during reshaping. This self-healing ability to form new bonds after plasticization and redrying also contributed to the mechanical resilience of the aerogels, allowing them to be cyclically deformed in the dry state, reswollen with water, and redried with good retention of mechanical integrity. Furthermore, by exploiting the shapeability and available inner structure of the aerogels, a solenoid-shaped aerogel with all surfaces coated with a thin film of conducting polypyrrole was able to produce a magnetic field inside the solenoid, demonstrating electromagnetic properties. Furthermore, by biomimicking the porous interior and stiff exterior of the beak of a toucan bird, a functionalized aerogel was created by applying a 300 μm thick stiff wax coating on its molded external surfaces. This composite material displayed a 10-times higher elastic modulus compared to that of the plain aerogel without drastically increasing the density. These examples show that it is possible to combine advanced shaping with functionalization of both the inner structure and the surface of the aerogels, radically extending the possible use of CNF aerogels.

  • 8.
    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.

  • 9.
    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 Institutet of Sweden, Sweden.
    In-Situ Measurements of Stock Flow Conditions in the Twin-Wire Forming Zone2018In: PaperCon 2018: Shaing the future through innovation, TAPPI , 2018, 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.

  • 10.
    Javed, Asif
    et al.
    Karlstad University, Sweden.
    Rättö, Peter
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging. Karlstad University, Sweden.
    Järnström, Lars
    Karlstad University, Sweden.
    Ullsten, Henrik
    Karlstad University, Sweden.
    Crack analysis of barrier coatings based on starch and starch-PVOH with and without plasticizer2018In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 2, p. 336-347Article in journal (Refereed)
    Abstract [en]

    Barrier coatings based on starch and starch-PVOH plasticized with glycerol and without plasticizer were applied to two different paperboard substrates, a triple coated board and duplex board, in order to investigate the tendency for cracks to develop in the barrier coating layers during creasing and folding. Tensile properties of films based on the starch and starch-PVOH blend were determined to investigate the relationship between the flexibility of the films and the cracking in the barrier coating layers. Furthermore, the oxygen transmission rate through the barrier-coated paperboard was measured before and after creasing and folding. The oxygen transmission rate through the barrier-coated samples was over the measurable range i. e. OTR > 10000 cm 3 / m 2 day\text{OTR}>10000\hspace{0.1667em}{\text{cm}}^{3}/{\text{m}}^{2}\hspace{0.1667em}\text{day} after creasing and folding, which indicated failure in the barrier coating layers. Optical microscopy revealed small cracks in the barrier coating layers, probably related to an increase in flexibility of the barrier coating layers. It was observed in scanning electron micrographs that cracks in the barrier coating layers seemed to follow the fibers when the barrier coating was applied on the rear side of the duplex board. Scanning electron micrographs and surface profiler images revealed that cracks in the barrier coating layers might have originated from the mineral coating layer when the starch and starch/PVOH coating layers were applied on the mineral-coated side of the triple coated board. An increase in the thickness of the barrier coating layer did not seem to increase the resistance to failure.

  • 11.
    Javed, Asif
    et al.
    Karlstad University, Sweden.
    Ullsten, Henrik
    Karlstad University, Sweden.
    Rättö, Peter
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging. Karlstad University, Sweden.
    Järnström, Lars
    Karlstad University, Sweden.
    Lignin-containing coatings for packaging materials2018In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 3, p. 548-556Article in journal (Refereed)
    Abstract [en]

    The mechanical properties and chemical stability in water of self-supporting films made from aqueous solutions of starch and lignin, and the barrier properties of paperboard coated with solutions of these polymers have been studied. The dissolution of starch from the starch-lignin films in contact with the model liquids was decreased significantly when lignin was added to the starch films. The addition of ammonium zirconium carbonate (AZC) to the formulations as a crosslinking agent substantially increased the storage modulus of the starch-lignin films, which indicated that crosslinking had occurred. The addition of AZC to the formulations also led to a decrease in dissolution of both starch and lignin from the starch-lignin films in contact with model liquids. The effect of AZC on the water stability of the films was greater when the pH of the starch-lignin-AZC solution was adjusted with ammonia rather than NaOH. The addition of NH4Cl solution as a presumed catalyst to the recipe when the pH adjustment was performed with NaOH did not improve the effect of AZC on the water stability of the films. The water vapour transmission rate of the coated paperboard decreased slightly when AZC was added to the coating formulation.

  • 12.
    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.
    Yu, Shun
    KTH Royal Institute of Technology, Sweden.
    Pendergraph, Samuel Allen
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Pettersson, Torbjörn
    KTH Royal Institute of Technology, Sweden.
    Hellwig, Johannes
    KTH Royal Institute of Technology, Sweden.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Carbohydrate gel beads as model probes for quantifying non-ionic and ionic contributions behind the swelling of delignified plant fibers.2018In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 519, p. 119-129, article id S0021-9797(18)30200-5Article in journal (Refereed)
    Abstract [en]

    Macroscopic beads of water-based gels consisting of uncharged and partially charged β-(1,4)-d-glucan polymers were developed to be used as a novel model material for studying the water induced swelling of the delignified plant fiber walls. The gel beads were prepared by drop-wise precipitation of solutions of dissolving grade fibers carboxymethylated to different degrees. The internal structure was analyzed using Solid State Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance and Small Angle X-ray Scattering showing that the internal structure could be considered a homogeneous, non-crystalline and molecularly dispersed polymer network. When beads with different charge densities were equilibrated with aqueous solutions of different ionic strengths and/or pH, the change in water uptake followed the trends expected for weak polyelectrolyte gels and the trends found for cellulose-rich fibers. When dried and subsequently immersed in water the beads also showed an irreversible loss of swelling depending on the charge and type of counter-ion which is commonly also found for cellulose-rich fibers. Taken all these results together it is clear that the model cellulose-based beads constitute an excellent tool for studying the fundamentals of swelling of cellulose rich plant fibers, aiding in the elucidation of the different molecular and supramolecular contributions to the swelling.

  • 13.
    Knapic, Sofia
    et al.
    Universidade de Lisboa, Portugal.
    Grahn, Thomas
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Lundqvist, Sven-Olof
    RISE - Research Institutes of Sweden, Bioeconomy.
    Pereira, Helena
    Universidade de Lisboa, Portugal.
    Juvenile wood characterization of Eucalyptus botryoides and E. maculata by using SilviScan2018In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, no 2, p. 2342-2355Article in journal (Refereed)
    Abstract [en]

    The wood properties of 6-year-old Eucalyptus botryoides and Eucalyptus maculata point towards a possible aptitude for solid-wood end uses. Samples from E. botryoides and E. maculata were characterized regarding within-tree variation in wood density, radial and tangential fibre width, fibre wall thickness, fibre coarseness, microfibril angle, and stiffness based on SilviScan measurements taken radially from the pith outwards at varying stem height levels. The mean values of the studied wood properties for E. botryoides and E. maculata were, respectively: density 507 kg m-3 and 695 kg m-3, radial fibre width 17.4 Όm and 17.2 Όm, tangential fibre width 16.7 Όm and 16.9 Όm, fibre wall thickness 1.8 Όm and 2.5 Όm, fibre coarseness 161.2 Όgm-1 and 212.9 Όgm-1, microfibril angle 15.5° and 14.7°, and stiffness 9.6 GPa and 12.1 GPa. The variation in wood stiffness was explained to a large extent by microfibril angle and wood density variations. The results of the scans, along with the wood variability, indicated that both species should be considered for solid wood products or pulp production.

  • 14.
    Krochak, Paul
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Norman, Bo
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Practical Aspects of Retention Aids Addition on Web Structure Variability2018In: PaperCon 2018: Shaping the future throuch innovation, 2018, article id FF3.2Conference paper (Refereed)
    Abstract [en]

    In this work, we report on a series of pilot scale production trials investigating the effect of addition location, dosage velocity ratio and dilution level of a single component retention system (CPAM) on filler retention, formation and in-plane web structure uniformity for a fine paper grade. Specifically, we considered addition levels (500 g/t and 1000 g/t), dosage velocity ratios (2 and 4.5), and pre-dilution (300x and 600x) and addition location (before and after the headbox pump). The in-plane distribution of fibre and filler material in the final product was then mapped in high resolution over 10m paper samples using moveable radiation emitters and detectors.It was shown that addition of CPAM before the headbox pump resulted in a reduction in filler retention and poor formation in the final product. The addition velocity ratio was shown to have only minor influence on retention, formation and web structure variability. However, low CPAM dilution levels resulted in a high degree of variability in the distribution of filler and fibre including streakiness. Moreover, at low dilution levels, the in-plane distribution of filler was highly correlated to that of the fibres. By optimizing the dilution level and addition location, conditions could be established to reduce CPAM addition levels without adversely affecting retention or product variability.

  • 15.
    Lindberg, Anders
    et al.
    KTH Royal institute of technology, Sweden.
    Alfthan, Johan
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Pettersson, Henrik
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Flodberg, Göran
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Yang, Li
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Mechanical performance of polymer powder bed fused objects: FEM simulation and verification2018In: Additive manufacturing, ISSN 2214-8604, Vol. 24, p. 577-586Article in journal (Refereed)
    Abstract [en]

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

  • 16.
    Lo Re, Giada
    et al.
    KTH Royal Institute of Technology, Sweden.
    Spinella, Stephen
    NYU Tandon School of Engineering, US.
    Boujemaoui, Assya
    KTH Royal Institute of Technology, Sweden.
    Vilaseca, Fabiola
    University of Girona, Italy.
    Larsson, Per Tomas
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy. KTH Royal Institute of Technology, Sweden.
    Adås, Fredrik
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Berglund, Lars A.
    KTH Royal Institute of Technology, Sweden.
    Poly(ϵ-caprolactone) Biocomposites Based on Acetylated Cellulose Fibers and Wet Compounding for Improved Mechanical Performance2018In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 6, no 5, p. 6753-6760Article in journal (Refereed)
    Abstract [en]

    Poly(ϵ-caprolactone) (PCL) is a ductile thermoplastic, which is biodegradable in the marine environment. Limitations include low strength, petroleum-based origin, and comparably high cost. Cellulose fiber reinforcement is therefore of interest although uniform fiber dispersion is a challenge. In this study, a one-step wet compounding is proposed to validate a sustainable and feasible method to improve the dispersion of the cellulose fibers in hydrophobic polymer matrix as PCL, which showed to be insensitive to the presence of the water during the processing. A comparison between unmodified and acetylated cellulosic wood fibers is made to further assess the net effect of the wet feeding and chemical modification on the biocomposites properties, and the influence of acetylation on fiber structure is reported (ATR-FTIR, XRD). Effects of processing on nanofibrillation, shortening, and dispersion of the cellulose fibers are assessed as well as on PCL molar mass. Mechanical testing, dynamic mechanical thermal analysis, FE-SEM, and X-ray tomography is used to characterize composites. With the addition of 20 wt % cellulosic fibers, the Young's modulus increased from 240 MPa (neat PCL) to 1850 MPa for the biocomposites produced by using the wet feeding strategy, compared to 690 MPa showed for the biocomposites produced using dry feeling. A wet feeding of acetylated cellulosic fibers allowed even a greater increase, with an additional 46% and 248% increase of the ultimate strength and Young's modulus, when compared to wet feeding of the unmodified pulp, respectively. 

  • 17.
    Mojzes, Akos
    et al.
    Széchenyi István University, Hungary.
    Trost, Thomas
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Vörösköi, Kata
    Széchenyi István University, Hungary.
    Drop Performance of Dangerous Goods Packages in the Aspect of Parcel Delivery Standards2018In: Packaging: Driving a sustainable future, 2018, p. 569-577Conference paper (Refereed)
    Abstract [en]

    Requirements for dangerous goods packaging are well known, whatever version are used. The testing circumstances are strictly defined for each transportation method (road, rail, air, sea). But nowadays it is becoming a practice that courier express operators transport dangerous goods as single package. This parcel delivery method means a higher risk for all kind of logistics participants. By this service the packages are delivered fast, but handled more roughly than in comparison to LTL (less than truckload) or FTL (full truck load). Naturally, the parcel delivery sector uses its own suitability testing methods, which are also well defined. These procedures are coming from various standards such as ASTM, ISTA or corporate (FedEx) standards.This paper compares the most common parcel delivery testing conditions concerning the drop test requirements of DGR (Dangerous Goods Regulation) using packaging such as paper bag, corrugated fibreboard box, steel drum and plastic jerrycan, respectively. Then the test results were analyzed to present the differences.

  • 18.
    Nordström, Bengt
    et al.
    SCA, Sweden.
    Hermansson, Lennart
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Effect of machine speed on formation and strength efficiency in twin-wire roll forming of never-dried unbleached softwood kraft pulp2018In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 2, p. 271-278Article in journal (Refereed)
    Abstract [en]

    There is a constant drive to increase machine speed in the production of kraftliner and most other major paper grades, but the separate effect of the machine speed on the paper properties has been unclear. The effect of machine speed in twin-wire roll forming of never-dried unbleached softwood kraft pulp was evaluated here in a pilot machine investigation by examining three machine speed levels (500, 750, and 1000 m/min) over a series of jet-to-wire speed differences. Similar headbox consistency and draw from wire section to winding were employed at the different machine speed levels. An increase in the machine speed had a favorable effect on formation and Z-strength efficiency over a wide range of jet-to-wire speed differences, whereas the machine speed had an insignificant effect on tensile strength efficiency and tensile stiffness efficiency. For all properties, the overall shape of the jet-to-wire speed difference curve remained similar when changing the machine speed.

  • 19.
    Nordström, Bengt
    et al.
    SCA R&D Sundsvall, Sweden.
    Hermansson, Lennart
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Effect of softwood kraft fiber coarseness on formation and strength efficiency in twin-wire roll forming2018In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 2, p. 237-245Article in journal (Refereed)
    Abstract [en]

    It has been unclear how fiber coarseness affect formation and the utilization of furnish strength in the machine-made paper (strength efficiency). In this work, the effect of softwood kraft fiber coarseness on formation and strength efficiency in twin-wire roll forming was examined in a pilot machine investigation. A reduction in softwood kraft fiber coarseness from 0.21 to 0.17 mg/m, associated with a reduction in fiber grammage from 6.2 to 5.2 g/m2, was found to have no significant effect on formation at the point of minimum shear during dewatering. The insignificant effect of reduced coarseness can be interpreted as the net result of two effects, namely, an increase in the number of fiber layers at a given grammage (favorable) and an increase in the flocculation tendency (unfavorable). While the effect of coarseness was negligible at the point of minimum shear, coarser fibers enabled larger improvement in formation through the jet-to-wire speed difference. In correspondence to the insignificant effect on formation, fiber coarseness had a negligible effect on tensile strength efficiency and Z-strength at the point of minimum shear. The larger improvement in formation through the jet-to-wire speed difference for the coarser fibers was reflected in a favorable effect on Z-strength efficiency.

  • 20.
    Odeberg Glasenapp, Astrid
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Sundin, Maria
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Nordlinder, Johanna
    Swedish patent- and registration office, Sweden.
    Berthold, Jesper
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Alfthan, Johan
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Water-free bonding of corrugated board2018In: Packaging: Driving a sustainable future / [ed] Wang S-W, 2018, p. 608-616Conference paper (Refereed)
    Abstract [en]

    The "water-free bonding of corrugated board" concept focuses on thedevelopment, waste management and market potential of a new corrugated board production method. It has earlier been shown that by integrating PLA into paper, certain mechanical properties of corrugated board papers can be enhanced. These enhanced papers have been used for producing corrugated board. Corrugated board is usually produced by gluing the corrugated board paper layers with a starch suspension. This process is reducing the mechanical paper strength and is also energy consuming, as the water added by the starch suspension in the process has to be evaporated. In this study, two new water-free joining techniques for corrugated board have been investigated: PLA-welding, which melts the inherent PLA of the paper to create a bond and using PLA as an adhesive. Both techniques have shown promising results and are recommended for further investigation, however, replacing starch glue with PLA seems to be a solution closer to the market. For the material to fit in a future circular economy it is important that the waste is managed in a way that is sustainable for the environment and the society. Repulp ability testing in combination with literature studies indicate that the new material would be possible to recycle, and that the new material could function in every step described in the EU Waste Framework Directive.

  • 21.
    Ratke, Christine
    et al.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Terebieniec, Barbara K
    SLU Swedish University of Agricultural Sciences, Sweden.
    Winestrand, Sandra
    Umeå University, Sweden.
    Derba-Maceluch, Marta
    SLU Swedish University of Agricultural Sciences, Sweden.
    Grahn, Thomas
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Schiffthaler, Bastian
    Umeå University, Sweden.
    Ulvcrona, Thomas
    SLU Swedish University of Agricultural Sciences, Sweden.
    Özparpucu, Merve
    Swiss Federal Institute of Technology (ETH Zürich), Switzerland.
    Rüggeberg, Markus
    Swiss Federal Institute of Technology (ETH Zürich), Switzerland.
    Lundqvist, Sven-Olof
    RISE - Research Institutes of Sweden, Bioeconomy.
    Street, Nathaniel R
    Umeå University, Sweden.
    Jönsson, Leif J
    Umeå University, Sweden.
    Mellerowicz, Ewa J
    SLU Swedish University of Agricultural Sciences, Sweden.
    Downregulating aspen xylan biosynthetic GT43 genes in developing wood stimulates growth via reprograming of the transcriptome2018In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 219, no 1, p. 230-245Article in journal (Refereed)
    Abstract [en]

    Xylan is one of the main compounds determining wood properties in hardwood species. The xylan backbone is thought to be synthesized by a synthase complex comprising two members of the GT43 family. We downregulated all GT43 genes in hybrid aspen (Populus tremula × tremuloides) to understand their involvement in xylan biosynthesis. All three clades of the GT43 family were targeted for downregulation using RNA interference individually or in different combinations, either constitutively or specifically in developing wood. Simultaneous downregulation in developing wood of the B (IRX9) and C (IRX14) clades resulted in reduced xylan Xyl content relative to reducing end sequence, supporting their role in xylan backbone biosynthesis. This was accompanied by a higher lignocellulose saccharification efficiency. Unexpectedly, GT43 suppression in developing wood led to an overall growth stimulation, xylem cell wall thinning and a shift in cellulose orientation. Transcriptome profiling of these transgenic lines indicated that cell cycling was stimulated and secondary wall biosynthesis was repressed. We suggest that the reduced xylan elongation is sensed by the cell wall integrity surveying mechanism in developing wood. Our results show that wood-specific suppression of xylan-biosynthetic GT43 genes activates signaling responses, leading to increased growth and improved lignocellulose saccharification.

  • 22.
    Rättö, Peter
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Dahlman, Olof
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Junel, Kristina
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Pilot coating with a hemicellulose-based barrier2018In: PaperCon 2018: Shaping the future through innovation, TAPPI , 2018, article id FF1.3Conference paper (Refereed)
    Abstract [en]

    A hemicellulose-based barrier formulation was produced from wood chips to pilot coating application in a bladecoater. The development process is described from a project planning point of view with network plan and decisionpoints.Different hemicelluloses were produced and compared in the research laboratory. Oxygen barrier properties fromfilms and rheology of water suspensions were evaluated for different laboratory produced hemicelluloses originatingfrom wood chips or from kraft pulps. The viscosity at low and high shear rates were evaluated. From these results,hemicellulose produced from birch wood chips was chosen.Hemicellulose was then produced at in kg quantities. The hemicellulose was produced employing pre-hydrolysistreatment of birch wood chips. The concentration of hemicellulose pre-hydrolyses was increased from 3.3% to11.5% by membrane filtration. The barrier properties of the hemicellulose coated material were evaluated inlaboratory scale. A pre-coating was also evaluated in laboratory scale.Trials were performed at Iggesund PaperBoard in their pilot scale coater. A pre-coating was applied during the firstday, and the hemicellulose-based coating was applied on the second day. The pilot trials went well without anylarger obstacles. Quick barrier evaluations showed that the hemicellulose-based barrier coating had a good greaseresistance even if the coating consumption during the trials indicated a low application grammage.

  • 23.
    Scheepers, Gerhard
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Olsson, Jörgen
    RISE - Research Institutes of Sweden, Built Environment, Building Technology.
    Lycken, Anders
    RISE - Research Institutes of Sweden, Bioeconomy, Biobased Materials.
    Grahn, Thomas
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Lundqvist, Sven-Olof
    RISE - Research Institutes of Sweden, Bioeconomy, Biorefinery and Energy.
    Hagman, Olle
    Luleå Tekniska Universitet, Sweden.
    Hållfasthetsbestämning av virke med en NIR-kamera2017Report (Other academic)
    Abstract [sv]

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

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

    1. mått, vikt, och därmed densitet,

    2. egenfrekvenser via dynamisk excitering,

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

    4. RGB och fibervinkeldata från flat- och kantsidorna,

    5. röntgentomografibilder,

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

    7. kvalitativ inventering av brottyp och kvistposition.

     

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

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

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

     

  • 24.
    Thorman, Sofia
    et al.
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging. Karlstad University, Sweden.
    Ström, Göran
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Gane, Patrick A. C.
    Omya Internatioanl AG, Switzerland ; Aalto University, Finland.
    Impact of non-uniform water absorption on water-interference print mottle in offset printing2018In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 33, no 1, p. 150-163Article in journal (Refereed)
    Abstract [en]

    Print mottle is a serious and yet common print defect in offset printing. An imbalance between the feed of fountain solution and the ability of the paper substrate to absorb and transport this water away from the surface can cause moisture/water interference problems. In the study presented here, we have investigated the uniformity of aqueous absorption and coating structure of pilot-coated papers with different types and dosages of dispersants and linked this to print mottle and uncovered areas (UCA). In earlier studies, the print quality of these papers indicated that a moderate addition of excess dispersant caused ink refusal, ink-lift-off (ink-surface adhesion failure) and water-interference mottle when printing at elevated fountain feed. In the present study, we have shown that a majority of the samples with uneven water/moisture absorption and an uneven burn-out reflectance tended to have more severe printing problems related to surface-moisture/water.An aqueous staining technique was used to characterise the absorption non-uniformities. This method has been developed previously with focus on absorption of flexographic water-based inks but can clearly give relevant information also for offset printing, when it comes to moisture/water interference mottle. .

  • 25.
    Ye, Xinchen
    et al.
    KTH Royal Institute of Technology, Sweden.
    Junel, Kristina
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Gällstedt, Mikael
    SIG Combibloc, Sweden.
    Langton, Maud
    SLU Swedish University of Agricultural Sciences, Sweden.
    Wei, Xin-Feng
    KTH Royal Institute of Sweden, Sweden.
    Lendel, Christofer
    KTH Royal Institute of Sweden, Sweden.
    Hedenqvist, Mikael S.
    KTH Royal Institute of Sweden, Sweden.
    Protein/Protein Nanocomposite Based on Whey Protein Nanofibrils in a Whey Protein Matrix2018In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 6, no 4, p. 5462-5469Article in journal (Refereed)
    Abstract [en]

    This article describes nanocomposite films with separately grown protein nanofibrils (PNFs) in a nonfibrillar protein matrix from the same protein starting material (whey). Tensile tests on the glycerol-plasticized films indicate an increased elastic modulus and a decreased extensibility with increasing content of PNFs, although the films are still ductile at the maximum PNF content (15 wt %). Infrared spectroscopy confirms that the strongly hydrogen-bonded β-sheets in the PNFs are retained in the composites. The films appear with a PNF-induced undulated upper surface. It is shown that micrometer-scale spatial variations in the glycerol distribution are not the cause of these undulations. Instead, the undulations seem to be a feature of the PNF material itself. It was also shown that, apart from plasticizing the protein film, the presence of glycerol seemed to favor to some extent exfoliation of stacked β-sheets in the proteins, as revealed by X-ray diffraction.

  • 26.
    Östlund, Catherine
    RISE - Research Institutes of Sweden, Bioeconomy, Papermaking and Packaging.
    Towards total production monitoring of basis weight and moisture2018In: PaperCon 2018: Shaping the future through innovation, TAPPI , 2018, article id CS3.2Conference paper (Refereed)
    Abstract [en]

    Measurement methods using infrared (IR) camera techniques have been developed and evaluated, both in laboratorystudies, online on the FEX pilot paper machine, and at paper mills. The large advantage with the methods we developedfor applying the high-speed IR cameras on the paper machine is the ability to cover the whole width of the machine toview temperature changes over a longer period of time. The temperature changes can then be correlated to processvariations (i.e. moisture or material distribution) to obtain the local basis weight variation, to achieve more detailedinformation for an optimisation of the process.

1 - 26 of 26
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