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  • 1.
    Ankerfors, Caroline
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Gimåker, Magnus
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Glad Nordmark, Gunborg
    A comparative study of polyelectrolyte multilayers and other chemical dosage strategies: Effect on properties of paper sheets produced in laboratory scale using tap and mill process waters2018Report (Other academic)
    Abstract [en]

    In this study, the addition of up to four layers of PEM was studied and compared with the use of single-additions or dual-additions of the same chemicals with respect to their effect on strength and bulk properties of paper sheets produced in the laboratory. First, this was made under clean conditions, i.e. in tap water, to set a baseline for the performance. The systems studied were cationic/anionic polyacrylamide (CPAM/APAM), polyvinylamine/carboxymethyl cellulose (PVAm/CMC) and cationic starch/anionic polyacrylamide (CS/APAM).One of the main findings of the study was that with single-additions with increasing dosage levels of PVAm, CPAM or CS, the tensile strength index of the produced sheets increased at first, but the effect seemed to level off at higher dosages. By comparing the effect from single-addition of each cationic component to the effect of a polyelectrolyte multilayer (1-4 layers) of the same component together with an anionic component, it was found that significantly higher tensile strength could be reached with the PEM strategy for the combinations PVAm/CMC and CS/APAM. For CPAM/APAM, however, very little advantage of using a multilayering approach was seen.All measured variations in sheet density were small, although with some indications that the density was lower for sheets with PEM, medium for sheets made with a single-dosage strategy and highest for sheets made with the dual-addition strategies.The later part of this activity also addressed the influence from dissolved and colloidal substances (DCS) to investigate the possibilities of implementing the polyelectrolyte multilayering technique in practice by repeating some of the trial points of the CS/APAM system in mill process water. Firstly, this part of the study showed that PEMs can be successfully built in mill process waters. Further, it was found that although the adsorbed amounts might differ compared to in the cleaner system, the trends for the dosage strategies and their strengthening effects remained.

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  • 2.
    Ankerfors, Caroline
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Östlund, Ida
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Gimåker, Magnus
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Krochak, Paul
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Östlund, Catherine
    Hansen, Peter
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Holmqvist, Claes
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Johansson, Klas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Final Report for the Source-Efficient Paper and Board Making Research Programme Area2018Report (Other academic)
    Abstract [en]

    This is the final report for the Innventia/RISE Bioeconomy research programme area “Source-Efficient Paper and Board Making”, which was executed 2015-2017.The overall aim of the Source Efficient Paper and Board Making was to improve the resource efficiency in paper and board production. This was achieved by combining paper chemistry, paper physics and process technology. A particular goal was to reduce raw material consumption through the use of stronger materials or creation of bulk, which are needed to maintain bending stiffness and mechanical properties if the grammage is reduced. The work in the project has been carried out in laboratory scale and in pilot scale using the FEX pilot paper machine and the dynamic flow loop.

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  • 3.
    Arun Chaudhari, Ojas
    et al.
    RISE Research Institutes of Sweden, Built Environment, Infrastructure and concrete technology.
    Ghafar, AN
    RISE Research Institutes of Sweden.
    Zirgulis, Giedrius
    RISE Research Institutes of Sweden, Built Environment, Infrastructure and concrete technology.
    Mousavi, Marjan
    RISE Research Institutes of Sweden, Built Environment, Infrastructure and concrete technology.
    Fontana, P
    RISE Research Institutes of Sweden.
    Pousette, Sandra
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Ellison, T
    BESAB AB, Sweden.
    A Practical Construction Technique to Enhance the Performance of Rock Bolts in Tunnels2021In: Proc of ICTC 2021, 2021Conference paper (Refereed)
    Abstract [en]

    In Swedish tunnel construction, a critical issue that has been repeatedly acknowledged is corrosion and, consequently, failure of the rock bolts in rock support systems. The defective installation of rock bolts results in the formation of cavities in the cement mortar that is regularly used to fill the area under the dome plates. These voids allow for water-ingress to the rock bolt assembly, which results in corrosion of rock bolt components and eventually failure. In addition, the current installation technique consists of several manual steps with intense labor works that are usually done in uncomfortable and exhausting conditions, e.g., under the roof of the tunnels. Such intense tasks also lead to a considerable waste of materials and execution errors. Moreover, adequate quality control of the execution is hardly possible with the current technique. To overcome these issues, a nonshrinking/ expansive cement-based mortar filled in the paper packaging has been developed in this study which properly fills the area under the dome plates without or with the least remaining cavities, ultimately that diminishes the potential of corrosion. This article summarizes the development process and the experimental evaluation of this technique for the installation of rock bolts. In the development process, the cementitious mortar was first developed using specific cement and shrinkage reducing/expansive additives. The mechanical and flow properties of the mortar were then evaluated using compressive strength, density, and slump flow measurement methods. In addition, isothermal calorimetry and shrinkage/expansion measurements were used to elucidate the hydration and durability attributes of the mortar. After obtaining the desired properties in both fresh and hardened conditions, the developed dry mortar was filled in specific permeable paper packaging and then submerged in water bath for specific intervals before the installation. The tests were enhanced progressively by optimizing different parameters such as shape and size of the packaging, characteristics of the paper used, immersion time in water and even some minor characteristics of the mortar. Finally, the developed prototype was tested in a lab-scale rock bolt assembly with various angles to analyze the efficiency of the method in real life scenario. The results showed that the new technique improves the performance of the rock bolts by reducing the material wastage, improving environmental performance, facilitating and accelerating the labor works, and finally enhancing the durability of the whole system. Accordingly, this approach provides an efficient alternative for the traditional way of tunnel bolt installation with considerable advantages for the Swedish tunneling industry.

  • 4.
    Baison, J.
    et al.
    SLU Swedish University of Agricultural Science, Sweden.
    Zhou, Linghua
    SLU Swedish University of Agricultural Science, Sweden.
    Forsberg, Nils
    SLU Swedish University of Agricultural Science, Sweden.
    Mörling, Tommy
    SLU Swedish University of Agricultural Science, Sweden.
    Grahn, Thomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Olsson, Lars
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate.
    Karlsson, Bo
    Skogforsk, Sweden----.
    Wu, Harry
    SLU Swedish University of Agricultural Science, Sweden.
    Mellerowicz, Ewa
    SLU Swedish University of Agricultural Science, Sweden.
    Lundqvist, Sven-Olof
    RISE Research Institutes of Sweden. IIC, Sweden.
    García-Gil, Maria
    SLU Swedish University of Agricultural Science, Sweden.
    Genetic control of tracheid properties in Norway spruce wood2020In: Scientific Reports, E-ISSN 2045-2322, Vol. 10, no 1, article id 18089Article in journal (Refereed)
    Abstract [en]

    Through the use of genome-wide association studies (GWAS) mapping it is possible to establish the genetic basis of phenotypic trait variation. Our GWAS study presents the first such effort in Norway spruce (Picea abies (L). Karst.) for the traits related to wood tracheid characteristics. The study employed an exome capture genotyping approach that generated 178 101 Single Nucleotide Polymorphisms (SNPs) from 40 018 probes within a population of 517 Norway spruce mother trees. We applied a least absolute shrinkage and selection operator (LASSO) based association mapping method using a functional multi-locus mapping approach, with a stability selection probability method as the hypothesis testing approach to determine significant Quantitative Trait Loci (QTLs). The analysis has provided 30 significant associations, the majority of which show specific expression in wood-forming tissues or high ubiquitous expression, potentially controlling tracheids dimensions, their cell wall thickness and microfibril angle. Among the most promising candidates based on our results and prior information for other species are: Picea abies BIG GRAIN 2 (PabBG2) with a predicted function in auxin transport and sensitivity, and MA_373300g0010 encoding a protein similar to wall-associated receptor kinases, which were both associated with cell wall thickness. The results demonstrate feasibility of GWAS to identify novel candidate genes controlling industrially-relevant tracheid traits in Norway spruce. © 2020, The Author(s).

  • 5.
    Björk, Elisabeth
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Some key aspects on screening of chemical pulp to achieve a fine fraction – a literature review2020Report (Other academic)
    Abstract [en]

    This literature review focus on fibre length-based fractionation with screens to achieve a fine fraction, how fractionation results can be evaluated and on the influence of different screening parameters when using pressure screens. The design of the screen basket, and in particular the aperture size and shape, have a predominant effect on fractionation. Smaller aperture size leads to improved fractionation efficiency. Furthermore, it seems clear that screen plates with holes fractionate better than slotted, even when the slots are narrower than the hole diameter. Moreover, smooth screen plates are more efficient for fractionation, as contoured screen plates increase the fibre passage. For slotted screens the fibre passage ratio is affected by the fluid velocity through the aperture, while the fibre passage ratio for screen plates with small holes is independent of the fluid velocity. Microperforated screens, i.e. screens with holes with a diameter of less than 300 micrometre, are very efficient for fines fractionation in order to enrich the fines in the accept fraction.

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  • 6.
    Björk, Elisabeth
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. Mid University, Sweden.
    Bouveng, Mikael
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Vomhoff, Hannes
    Holmen, Sweden.
    Production of a fine fraction using micro-perforated screens2020In: Nordic Pulp & Paper Research Journal, Vol. 35, no 4, p. 611-620Article in journal (Refereed)
    Abstract [en]

    The objective for this work was to investigate the possibility to use a pressure screen equipped with a micro-perforated screen basket to produce a fine fraction from bleached chemical pulp. Trials were performed with unrefined bleached chemical hardwood pulp, and with unrefined and refined bleached chemical softwood pulp. The effect of feed concentration, feed flow, and volumetric fine fraction flow was evaluated. The difference between the fine fraction (i. e. the particles passing the screen) and the feed was analysed by studying the fibre morphology. The results showed that high feed concentration was positive for both the fine fraction concentration and the separation efficiency. A higher fine fraction concentration was also obtained when using hardwood pulp, which was explained by the shorter fibre length. Refining of the pulp prior to the fractionation proved beneficial, as a larger share of the refined pulp passed the screen, resulting in a twice as high concentration of the fine fraction when compared to unrefined pulp.

  • 7.
    Björk, Elisabeth
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Bouveng, Mikael
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Vomhoff, Hannes
    Engstrand, Per
    Use of fines-enriched chemical pulp to increase CTMP strength2021In: TAPPI Journal, ISSN 0734-1415, Vol. 20, no 4, p. 255-263Article in journal (Refereed)
    Abstract [en]

    In this study, fines-enriched pulp (FE-pulp)-the fine fraction of highly-refined kraft pulp-was benchmarked against highly-refined kraft pulp (HRK-pulp) as a strength agent in eucalyptus chemithermomech. pulp (CTMP). Both the FE-pulp and the HRK-pulp were produced from unbleached softwood kraft pulp, and equal amounts of those strength agents were added to the original CTMP, as well as to washed CTMP, where most of the fines had been removed. The effects of the added strength agents were evaluated with laboratory handsheets. The FE-pulp proved to be twice as effective as HRK-pulp. Both HRK-pulp and FE-pulp increased the strength of the CTMP handsheets. The bulk of the handsheets decreased, however, as well as the drainability. The addition of 5% FE-pulp resulted in the same strength increase as an addition of 10% HRK-pulp, as well as the same decrease in bulk and CSF. For the handsheets of washed CTMP, the strengths were not measurable; the CTMP lost the sheet strength when the CTMP-fines content was reduced through washing. The reduced strength properties were compensated for by the addition of chem. pulp fines that proved to be an efficient strength agent. The addition of 5% FE-pulp restored the strength values, and at a higher bulk and higher drainability.

  • 8.
    Björk, Elisabeth
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. Mittuniversity, Sweden.
    Bouveng, Mikael
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Vomhoff, Hannes
    Holmen AB, Sweden.
    Engstrand, Per
    Mittuniversity, Sweden.
    Use of fines-enriched chemical pulp to increase CTMP strength2021In: TAPPI Journal, ISSN 0734-1415, Vol. 20, no 4, p. 255-263Article in journal (Refereed)
    Abstract [en]

    In this study, fines-enriched pulp (FE-pulp)-the fine fraction of highly-refined kraft pulp-was benchmarked against highly-refined kraft pulp (HRK-pulp) as a strength agent in eucalyptus chemithermomechanical pulp (CTMP). Both the FE-pulp and the HRK-pulp were produced from unbleached softwood kraft pulp, and equal amounts of those strength agents were added to the original CTMP, as well as to washed CTMP, where most of the fines had been removed. The effects of the added strength agents were evaluated with laboratory handsheets. The FE-pulp proved to be twice as effective as HRK-pulp. Both HRK-pulp and FE-pulp increased the strength of the CTMP handsheets. The bulk of the handsheets decreased, however, as well as the drainability. The addition of 5% FE-pulp resulted in the same strength increase as an addition of 10% HRK-pulp, as well as the same decrease in bulk and CSF. For the handsheets of washed CTMP, the strengths were not measurable; the CTMP lost the sheet strength when the CTMP-fines content was reduced through washing. The reduced strength properties were compensated for by the addition of chemical pulp fines that proved to be an efficient strength agent. The addition of 5% FE-pulp restored the strength values, and at a higher bulk and higher drainability. Application: In this study, we show how the strength of a CTMP sheet can be improved by adding fine material from kraft pulp.

  • 9.
    Björk, Elisabeth
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. Mid Sweden University, Sweden.
    Vomhoff, Hannes
    Holmen, Sweden.
    Engstrand, Per
    Mid Sweden University, Sweden.
    Production of fines from refined kraft pulp by fractionation with micro-perforated screens2021In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 36, no 3, p. 456-Article in journal (Refereed)
    Abstract [en]

    The objective in this work was to obtain a fine fraction of kraft pulp, with as high concentration as possible, in a pilot-scale fractionation with micro-perforated screen baskets. The influence of screen basket surface, hole size, feed concentration, pulp type and refining segment design was investigated. The results showed that a smooth screen basket surface improved the fractionation efficiency of the unrefined pulp compared to a profiled screen basket, despite a larger hole size. A significantly higher fine fraction concentration was obtained when using refined hardwood pulp compared to when using softwood pulp, which was explained with its lower average fibre length and narrower and thus more flexible fibre fragments. The pilot trials also showed that the screening process could be operated at feed concentrations similar to those directly after a refiner, 30-40 g/l. This was demonstrated in a process layout with partial recirculation where a refiner and a micro-perforated screen basket were operated in series in pilot scale. 

  • 10.
    Brännvall, Elisabet
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Kulander, Ida
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Consequences in a softwood kraft pulp mill of initial high alkali concentration in the impregnation stage2020In: Nordic Pulp & Paper Research Journal, Vol. 34, no 1, p. 28-35Article in journal (Refereed)
    Abstract [en]

    Impregnation with high initial concentration is fast and efficient, leading to a homogeneous delignification in the subsequent cook, resulting in improved screened pulp yield. To obtain high initial alkali concentration, the white liquor flow needs to be significantly increased. The moisture content of the wood chips and the alkali concentration of the white liquor limit the initial alkali concentration of the impregnation liquor that can be reached. It is therefore of interest to evaluate the possibility to implement high alkali impregnation (HAI) industrially and the consequences this would have on the mill system. The effect of HAI on mass and energy balances in a kraft pulp mill has been studied using mill model simulations. The sensitivity to disturbances in important parameters for process control has been compared to impregnation scenarios used industrially. It was shown that high initial alkali concentration can be achieved on industrial scale by increased white liquor flow. HAI has a positive effect on recovery flows and reduces the need for make-up chemicals. The HAI concept is less sensitive to variations in process parameters, such as chip moisture and white liquor concentration, thus diminishing the risk of alkali depletion in chip cores.

  • 11.
    Brännvall, Elisabet
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Larsson, P Tomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Changes in the cellulose fiber wall supramolecular structure during the initial stages of chemical treatments of wood evaluated by NMR and X-ray scattering2021In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, p. 3951-3965Article in journal (Refereed)
    Abstract [en]

    The effect of initial stages of pulping of spruce, resembling prehydrolysis and alkaline cooking was studied using CP/MAS 13C-NMR, X-ray scattering, FSP and carbohydrate composition in order to study the impact of the pre-treatments on the fiber wall nanostructure. Removal of fiber wall components, hemicellulose and lignin, increased the fiber wall porosity and induced cellulose fibril aggregation. The effect of temperature and pH in the treatment on cellulose fibril aggregate size appears to be secondary. It is the removal of hemicellulose that has a profound effect on the supramolecular structure of the cellulose fiber wall. As the amount of hemicellulose dissolved from wood increases, the fibril aggregate size determined by NMR increases as well, ranging from 16 to 28 nm. Specifically, a good correlation between the amount of glucomannan in the fiber wall and the fibril aggregate size is seen. The lower the amount of glucomannan, the larger the aggregate size. Glucomannan thus seems to prevent aggregation as it acts as a very efficient spacer between fibrils. Elemental fibril size determined by NMR, was quite similar for all samples, ranging from 3.6 to 4.1 nm. By combining measurement methods, a more well-resolved picture of the structural changes occurring during was obtained. © 2021, The Author(s).

  • 12.
    Brännvall, Elisabet
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Rönnols, Jerk
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Analysis of entrapped and free liquor to gain new insights into kraft pulping2021In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, p. 2403-2418Article in journal (Refereed)
    Abstract [en]

    Most of our knowledge on kraft pulping comes from studies on dissolved lignin in the freely drainable black liquor and isolated residual lignin in pulp. However, entrapped liquor in the delignified chips has been shown to differ significantly from the free liquor. The present study has compared three liquor fractions: free, lumen and fiber wall liquor. The free liquor was obtained by draining the delignified chips, the lumen liquor was separated by centrifugation and the fiber wall liquor by subsequent leaching. The liquor in the fiber wall had the lowest concentration of lignin and hydrosulfide ions and the highest concentration of monovalent cations. The dissolved lignin in the fiber wall liquor had the highest molar mass and the highest content of xylan. The highest concentration of dissolved lignin was in the liquor filling the lumen cavities. The lignin in the free liquor had the lowest molar mass and the lowest content of lignin structures containing β-O-4 linkages and aliphatic hydroxyl groups. The lowest mass transfer rate of dissolved lignin was from the lumen liquor to the free liquor probably restricted by the tortuosity of the chip. 

  • 13.
    Brännvall, Elisabet
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Walter, Karin
    Nouryon, Sweden.
    Process modifications to obtain a prehydrolysis kraft dissolving pulp with low limiting pulp viscosity2020In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 35, no 3, p. 332-341Article in journal (Refereed)
    Abstract [en]

    Cellulose can be directly dissolved in cold alkali without derivatization. However, this requires low cellulose molecular weight, i. e. low pulp viscosity, preferably below 300 mL g−1. This can be achieved by for example acid or enzymatic hydrolysis of the dissolving pulp. However, it would be beneficial to manufacture pulp with sufficiently low viscosity without an additional treatment stage prior to dissolution. Unit processes in pulping can be operated in such a way as to reduce the molecular weight of cellulose. The approach of the study was to modify the conditions in unit pulping processes in order to obtain a low pulp viscosity of fully bleached prehydrolysis kraft pulp. A high charge of alkali in the oxygen delignification reduced the cellulose molecular weight significantly. Increased temperature, 120 °C compared to 98 °C, had also a significant effect on viscosity. By performing peroxide bleaching at acidic pH, the viscosity could be sufficiently reduced even when oxygen delignification was performed at lower temperature. However, for high brightness, a chlorine dioxide stage is needed.

  • 14.
    Carlsson, Raul
    et al.
    RISE Research Institutes of Sweden, Built Environment, Certification.
    Lorentzon, Katarina
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Rex, Emma
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Karpenja, Tatjana
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Davis, Jennifer
    RISE Research Institutes of Sweden.
    Edoff, Petra
    RISE Research Institutes of Sweden, Digital Systems, Industrial Systems.
    Research institute strengthens its LCA capacity by internal collaboration and data infrastructure2021In: Abstract book of 10th International Conference on Life Cycle Management, 2021Conference paper (Other academic)
    Abstract [en]

    Most of the research institutes that during the last years merged to create RISE Research Institutes of Sweden had previously developed unique ways of delivering LCA competence, services and data to Swedish industry and public sector. Thereby RISE holds a unique position to establish itself as a leader in the LCA field, in practical application areas such as lifestyle and sustainability analyses, scenario simulation and modeling, service innovation, and policy recommendations at different system levels. To put this in effect, the competence groups of the former separate institutes need to establish synergetic collaboration and operational infrastructure of knowledge, internal standards, and data sharing, as well as concerted LCA offerings. Recognizing the general explosion of interest for environmental assessments, such as carbon footprints, from industry, public sector and consumers, RISE now focuses its capacity to manage different types and formats of life cycle data for internal use as well as for customer offerings. The goal is to increase availability of the life cycle competence connected to RISE’s technical breadth, to provide synergized competence in support of sustainable transition to industry and society. During 2020 the first step towards this goal resulted in an internal shared view of RISE’s LCA offerings and common fundamental and flexible data documentation principles for all different life cycle data within RISE’s different life cycle competence groups. This is an achievement, considering that formats for data presentations within RISE ranges from aggregated carbon footprint results of per kg of products to ILCD European Product Environmental Footprints. During 2021 the RISE effort is dedicated to formation of a solid platform for generic life cycle data sharing, through common internal data exchange formats and interfaces towards customers, as well as a long-term governance, maintenance and competence supply for the synergetic collaboration.

  • 15.
    De San Pio, Ignacio
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Johansson, Klas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Krochak, Paul
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    A novel predictive method for filler coflocculation with cellulose microfibrils2020In: TAPPI Journal, ISSN 0734-1415, Vol. 18, no 11, p. 653-664Article in journal (Refereed)
    Abstract [en]

    Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

  • 16. De San Pio, Ignacio
    et al.
    Simons, Andrew
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources.
    Delgado, Luis Fernando
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Process Water Management for Sustainable Papermaking2022Conference paper (Refereed)
    Abstract [en]

    Some of the challenges in papermaking have been the same for many years, however the demands from the market are increasing continuously and, together with them, the challenges for the paper mills. We consider it is the time to put a lot of efforts together to help papermaking industry to comply with these new demands on a cost-effective way. When it comes to the wet-end chemistry and stock preparation this is a clear and actual challenge. Many developments have been done in developing green chemicals with higher efficiency, machine suppliers are improving the efficiency of each unit, fiber recovery and water cleaning technologies are also under continuous improvement, but the degree of implementation of those advances is still limited. From our perspective, a mindset change is needed, where all those developments are combined to improve the product properties and the process efficiency. Process waters have a very important role to play in that, and in this presentation, we will demonstrate the link and importance that keeping the process water components under control can give to the process. Those improvements were evaluated at lab scale, demonstrated at pilot scale and then implemented at mill level. We will show how the performance of the process chemicals is affected by the process water components, and the impact on the product quality. We will also describe the methods used to understand and evaluate those impacts and describe in a full-scale test how improving the process waters lead to energy savings and the possibility to improve the product performance. The designed methodology can be of use for: - Chemical suppliers, that need to evaluate and demonstrate the performance on challenging processes, such as closed water loop mills. - Companies looking to save water and energy, identifying the costs related to their actual water management and therefore the benefits to implement the right technologies. - Water cleaning technology suppliers that are nowadays not implemented in paper mills, that would be able to demonstrate the removal of the right contaminants and the potential savings that this technology can give to the specific mill. - Paper mills with challenges due to changes in their incoming water quality, or when there are increasing demands from the market that require adaptation of the process chemistry, unlocking possibilities for further development. 

  • 17.
    Edblad, Maria
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Jensen, Carl
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Oberrauter, Lisa-Maria
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Bergman, Penny
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Ett digitalt system för ökad källsortering och engagemang i offentlig miljö2022Report (Other academic)
    Abstract [en]

    As we cope with our society’s increasingly hectic pace, sales of fast food and "on-the-go" products have dramatically increased. This consumption has led to increasing amounts of waste packaging in the public environment. While littering is a visible problem so is the appropriate provision of waste bins. The vast majority of waste collected from the public environment is not sorted for material recycling. The purpose of the project was to test and evaluate a deposit-return-system on “on-the-go” single use packaging. A three-month test focused on coffee cups. A local marketing communications campaign provided consumers with information on how the packaging was to be recycled. Mini-recycling stations (paper, glass, plastic and ‘other’) were provided within a short walk. The numerous regular ‘unsorted’ waste bins remained in place during the test. When buying a coffee at participating cafes in Örnsköldsvik, between 1 June and 31 August 2021, consumers paid an additional 2 SEK. This deposit was refunded to the consumer when they recycled their coffee cup. This was done using a smartphone ‘app’ at one of the eight mini-recycling stations in the city center. It was also possible to get the refund at the conventional household packaging recycling stations in Örnsköldsvik. The evaluation considered three areas. Firstly, the extent consumers retrieved the deposit. In the test consumers retrieved the deposit about 10% of the time. The majority was refunded and recycled at conventional recycling stations where consumers normally recycle household packaging. Secondly, recycling levels and the purity of collected waste. The test demonstrated increased sorting and improved sorting quality. Of the paper coffee cups left at one of the eight mini-recycling stations, 90% were sorted in the correct fraction. Compared to other beverage paper cups of which 70% were sorted correctly. When considering the unsorted waste from the numerous regular waste bins, an overall recycling level of 56% of refundable coffee cups was achieved. This, together with the low share of coffee cups refunded, indicates that the proximity and convenience of disposal has a higher value than the need to recycle. Thirdly, acceptance among consumers and cafés. A deposit-return-system for on-the-go packaging was not crucial for increasing recycling in public environment. The participating and surveyed consumers were positive towards the project's aim to increase recycling of on-the-go packaging. They did not, however, appreciate the design of the app used in the project. Café owners varied in their perception of the digital deposit system. The main project conclusion is that a deposit-return-system for on-the-go packaging is not crucial for increased source sorting in public environments. This was an ambitious project testing consumer behavioral change. Örnsköldsvik’s city centre went from using bins without the possibility of recycling-to-recycling stations in public environments with the possibility to recycle coffee cups with a refund. While residents and visitors participated, there was limited marketing and only a three-month test period. As a consequence, results must be qualified by the relatively small data sets. That includes physical volumes of cups refunded and recycled, the number of respondents in interviews and surveys. Örnsköldsvik’s city centre has retained recycling stations following the project.

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  • 18.
    El Miri, N.
    et al.
    Mid Sweden University, Sweden.
    Heggset, Ellinor B
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Wallsten, Sara
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Svedberg, Anna
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Syverud, Kristin
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Norgren, Magnus
    Mid Sweden University, Sweden.
    A comprehensive investigation on modified cellulose nanocrystals and their films properties2022In: International Journal of Biological Macromolecules, ISSN 0141-8130, E-ISSN 1879-0003, Vol. 219, p. 998-1008Article in journal (Refereed)
    Abstract [en]

    In this work, we aimed to tune cellulose nanocrystals (CNCs) properties by introducing different functional groups (aldehyde, carboxyl, silane, and ammonium groups) on the surface through different chemical modifications. These functional groups were obtained by combining: the periodate oxidation with TEMPO-oxidation, aminosylation or cationization. CNCs produced and their films were characterized to elucidate their performances. The results showed that the properties of obtained CNCs varied depending on the grafted functionalities on the surface. The results reveal that after each modification a colloidal stability is preserved. Interestingly, Periodate oxidation of cellulose nanocrystals results in film components that interact through intra- and intermolecular hemiacetals and lead to films with a tensile strength of 116 MPa compared to the pristine CNCs, in contrast the subsequent modifications led to lower tensile strength. Of note, remarkable thermal stability has been achieved after modifications reaching a maximum of 280 °C. The oxygen barrier properties of the films after modifications varied between 0.48 and 0.54 cm3μm/(m2d*kPa) at 50 % RH. 

  • 19.
    Engquist, Isak
    et al.
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Isacsson, Patrik
    Linköping University, Sweden.
    Wang, Xin
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Fall, Andreas B.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Mengistie, Desalegn Alemu
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Calvie, Emilie
    Ahlstrom-Munksjo Research Center, France.
    Granberg, Hjalmar
    Linköping University, Sweden.
    Gustafsson, Göran
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Highly conducting nanographite-filled paper fabricated via standard papermaking techniques2020In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 12, no 43, p. 48828-48835Article in journal (Refereed)
    Abstract [en]

    Eco-friendly and cost-effective materials and processes to manufacture functional substrates are crucial to further advance the area of printed electronics. One potential key component in the printed electronics platform is an electrically functionalized paper, produced by simply mixing common cellulosic pulp fibers with high-performance electroactive materials. Herein, an electronic paper including nanographite has been prepared using a standardized and scalable papermaking technique. No retention aid was needed to achieve a conducting nanographite loading as high as 50 wt %. The spontaneous retention that provides the integrity and stability of the nanographite paper, likely originates partially from an observed water-stable adhesion of nanographite flakes onto the fiber surfaces. The resulting paper exhibits excellent electrical characteristics, such as an in-plane conductivity of 107 S/cm and an areal capacitance of 9.2 mF/cm2, and was explored as the back-electrode in printed electrochromic displays.

  • 20.
    Escamez, Sacha
    et al.
    Umeå University, Sweden.
    Robinson, Kathryn
    Umeå University, Sweden.
    Luomaranta, Mikko
    Umeå University, Sweden.
    Gandla, Madhavi
    Umeå University, Sweden.
    Mähler, Niklas
    Umeå University, Sweden.
    Yassin, Zakiya
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate.
    Grahn, Thomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Scheepers, Gerhard
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate.
    Stener, Lars-Göran
    Forestry Research Institute of Sweden, Sweden.
    Jansson, Stefan
    Umeå University, Sweden.
    Jönsson, eif
    Umeå University, Sweden.
    Street, N. R.
    Umeå University, Sweden.
    Tuominen, Hannele
    Umeå University, Sweden; SLU Swedish University of Agricultural Sciences, Sweden.
    Genetic markers and tree properties predicting wood biorefining potential in aspen (Populus tremula) bioenergy feedstock2023In: Biotechnology for Biofuels and Bioproducts, E-ISSN 2731-3654, Vol. 16, no 1, article id 65Article in journal (Refereed)
    Abstract [en]

    Background: Wood represents the majority of the biomass on land and constitutes a renewable source of biofuels and other bioproducts. However, wood is recalcitrant to bioconversion, raising a need for feedstock improvement in production of, for instance, biofuels. We investigated the properties of wood that affect bioconversion, as well as the underlying genetics, to help identify superior tree feedstocks for biorefining. Results: We recorded 65 wood-related and growth traits in a population of 113 natural aspen genotypes from Sweden (https://doi.org/10.5061/dryad.gtht76hrd). These traits included three growth and field performance traits, 20 traits for wood chemical composition, 17 traits for wood anatomy and structure, and 25 wood saccharification traits as indicators of bioconversion potential. Glucose release after saccharification with acidic pretreatment correlated positively with tree stem height and diameter and the carbohydrate content of the wood, and negatively with the content of lignin and the hemicellulose sugar units. Most of these traits displayed extensive natural variation within the aspen population and high broad-sense heritability, supporting their potential in genetic improvement of feedstocks towards improved bioconversion. Finally, a genome-wide association study (GWAS) revealed 13 genetic loci for saccharification yield (on a whole-tree-biomass basis), with six of them intersecting with associations for either height or stem diameter of the trees. Conclusions: The simple growth traits of stem height and diameter were identified as good predictors of wood saccharification yield in aspen trees. GWAS elucidated the underlying genetics, revealing putative genetic markers for bioconversion of bioenergy tree feedstocks. © 2023, The Author(s).

  • 21.
    Esteves, Claudia
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. KTH Royal Institute of Technology, Sweden.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Larsson, Per Tomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Pulp delignification and refining: impact on the supramolecular structure of softwood fibers2023In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 30, no 16, p. 10453-10468Article in journal (Refereed)
    Abstract [en]

    The effect on softwood fiber wall nanostructure of kraft cooking, oxygen delignification and refining was evaluated by X-ray scattering. A recently developed simulation method for modelling small angle X-ray scattering (SAXS) data was used to estimate the apparent average sizes of solids (AAPS) and interstitial spaces in the fiber wall (AACS). Fiber saturation point and wide angle X-ray scattering were also used to calculate the pore volume in the fiber wall and the crystallite size of the fibril, respectively. The experimental modelled SAXS data was able to give consistent values for each kraft-cooked and oxygen-delignified pulp. Kraft delignification seems to have the major influence on the fiber nanostructure modification, while oxygen delignification has little or no significant impact even for different kappa numbers. The particle sizes values were more stable than the cavities sizes and no significant differences were seen between different delignification processes, refining or delignification degree. Pulps evaluated after PFI-refining, showed an increase in the fiber wall porosity evaluated by FSP and an increase in the interstitial spaces in the fiber wall, while the crystallite size and the particle sizes were very little or not affected at all. 

  • 22.
    Esteves, Claudia
    et al.
    RISE Research Institutes of Sweden.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Sevastyanova, Olena
    KTH Royal Institute of Technology, Sweden.
    Evaluating the Potential to Modify Pulp and Paper Properties through Oxygen Delignification2020In: ACS Omega, E-ISSN 2470-1343, Vol. 5, no 23, p. 13703-13711Article in journal (Refereed)
    Abstract [en]

    The potential to modify pulp and paper properties by oxygen delignification was assessed by looking beyond the ordinary purpose of oxygen delignification. Pulps with the same kappa number were obtained by both pulping and the combination of pulping and oxygen delignification, and the mechanical and chemical properties were compared. The oxidation of pulp components leads to an increase in carboxylic acid groups in the fibers, resulting in a large influence on fiber swelling, seen as an increase in the water retention value and fiber saturation point. The introduction of charged groups appears to replace some of the morphological changes caused by refining and enhance the strength of fiber-fiber joints, generating pulps with better refinability and higher tensile strength. Oxygen delignification was able to improve the tensile index with 6% at the same sheet density and less refining energy, when the amount of total fiber charges was higher than 140 μekv/g.

  • 23.
    Esteves, Claudia
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Sevastyanova, Olena
    KTH Royal Institute of Technology, Sweden.
    The effects of high alkali impregnation and oxygen delignification of softwood kraft pulps on the yield and mechanical properties2022In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 37, no 2, p. 223-231Article in journal (Refereed)
    Abstract [en]

    This study investigated whether the yield improvement after high alkali impregnation (HAI) is maintained after oxygen delignification and whether the potential of oxygen delignification to increase the mechanical properties is affected by high alkali impregnation. The yield improvement achieved by high alkali impregnation (1 %) was preserved after oxygen delignification, particularly of glucomannan. The total fiber charge and swelling increased after oxygen delignification regardless of the type of impregnation in the cooking step. The tensile index improvement obtained by oxygen delignification was retained if this was preceded by high alkali impregnation. The stiffness index was higher and elongation slightly lower after HAI impregnation than after a standard (REF) impregnation. Fibers obtained through high alkali impregnation seem to be slightly less deformed and slightly wider than fibers obtained after a standard impregnation. 

  • 24.
    Esteves, Claudia
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Sevastyanova, Olena
    KTH Royal Institute of Technology, Sweden.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Differences and similarities between kraft and oxygen delignification of softwood fibers: effects on chemical and physical properties2021In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, no 5, p. 3149-3167Article in journal (Refereed)
    Abstract [en]

    The fiber properties after oxygen delignification and kraft pulping were studied by looking into the chemical characteristics and morphology. The effect of the two processes on the fibers was evaluated and compared over a wider kappa number range (from 62 down to15). Wide-angle X-ray scattering, nuclear magnetic resonance and fiber saturation point were used to characterize the fiber network structure. Fiber morphology and fiber dislocations were evaluated by an optical image analysis. The total and surface fiber charges were studied by conductometric and polyelectrolyte titrations. The fiber wall supramolecular structure, such as crystallinity, size of fibril aggregates, pore size and pore volume, were similar for the two processes. The selectivity, in terms of carbohydrate yield, was equal for kraft cooking and oxygen delignification, but the selectivity in terms of viscosity loss per amount of delignification is poorer for oxygen delignification. Clearly more fiber deformations (2–6% units in curl index) in the fibers after oxygen delignification were seen. Introduction of curl depended on the physical state of the fibers, i.e. liberated or in wood matrix. In the pulping stage, the fiber continue to be supported by neighboring fibers, as the delignified chips maintain their form. However, in the subsequent oxygen stage the fibers enter in the form of pulp (liberated fibers), which makes them more susceptible to changes in fiber form. Graphic abstract: [Figure not available: see fulltext.] © 2021, The Author(s).

  • 25.
    Esteves, Claudia
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Sevastyanova, Olena
    KTH Royal Institute of Technology, Sweden.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Differences and similarities between kraft and oxygen delignification of softwood fibers: effects on mechanical properties2021In: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 28, p. 3775-3788Article in journal (Refereed)
    Abstract [en]

    Charged groups in pulp have been shown to enhance the tensile strength of the paper produced from the pulp. Oxygen delignification introduces charged groups and it is of interest to determine how the delignification should be distributed between the cooking and the oxygen stage with respect to mechanical properties. A number of unbleached kraft cooked and oxygen delignified pulps within a wide kappa number range were produced and refined, and the effects of the refining on the morphology and mechanical properties were studied. The WRV correlated with the fiber charge and at a given fiber charge, kraft cooked and oxygen delignified pulps had the same WRV development in refining, although they had significantly different kappa numbers. The tensile strength development during refining depends on the fiber rigidity which is affected by the lignin content, the fiber charge and the chemical and mechanical processes used. Refining increased the curl of the kraft cooked pulps and decreased the curl of oxygen delignified pulps, irrespective of kappa number. A greater increase in tensile strength was seen for the pulps with a higher fiber charge and WRV, probably because of the greater degree of fibrillation achieved in the beating process. Despite the greater fiber deformation in the oxygen delignified pulps, the strength can be increased by a larger amount of charged groups and a greater swelling of the fibers. Graphic abstract: [Figure not available: see fulltext.] © 2021, The Author(s).

  • 26.
    Esteves, Claudia
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Sevastyanova, Olena
    KTH Royal Institute of Technology, Sweden.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden.
    The impact of bleaching on the yield of softwood kraft pulps obtained by high alkali impregnation: Bleaching and high alkali impregnation impact2022In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 37, no 4, p. 593-608Article in journal (Refereed)
    Abstract [en]

    High alkali impregnation (HAI) increases the total yield of softwood pulps following kraft cooking. This yield improvement is also maintained after oxygen delignification. This study evaluates how bleaching with either chlorine dioxide or hydrogen peroxide affects the final yield of samples obtained with standard and HAI. The chemical composition, viscosity, brightness, mechanical and morphological properties were studied. Compared to cooking after standard impregnation the yield improvement achieved by HAI was preserved in both types of bleaching sequences (2 % units for chlorine dioxide and 4 % units for hydrogen peroxide). The introduction of charged groups into the cellulose fibers was higher with hydrogen peroxide bleaching than with chlorine dioxide however, no significant impact was seen on the swelling or mechanical properties. The brightness was higher for the pulps bleached with chlorine dioxide compared with hydrogen peroxide. Hydrogen peroxide bleaching resulted in similar brightness development for both standard and HAI. Fibers bleached with chlorine dioxide had the highest curl index (16-17 %) compared to the fibers bleached with hydrogen peroxide (15 %). © 2022 the author(s)

  • 27.
    Françon, Hugo
    et al.
    KTH Royal Institute of Technology, Sweden.
    Wang, Zhen
    KTH Royal Institute of Technology, Sweden.
    Marais, Andrew
    KTH Royal Institute of Technology, Sweden.
    Mystek, Katarzyna
    KTH Royal Institute of Technology, Sweden.
    Piper, Andrew
    KTH Royal Institute of Technology, Sweden.
    Granberg, Hjalmar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Malti, Abdellah
    KTH Royal Institute of Technology, Sweden.
    Gatenholm, Paul
    Chalmers University of Technology, Sweden.
    Larsson, Per
    KTH Royal Institute of Technology, Sweden.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Ambient-Dried, 3D-Printable and Electrically Conducting Cellulose Nanofiber Aerogels by Inclusion of Functional Polymers2020In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, article id 1909383Article in journal (Refereed)
    Abstract [en]

    This study presents a novel, green, and efficient way of preparing crosslinked aerogels from cellulose nanofibers (CNFs) and alginate using non-covalent chemistry. This new process can ultimately facilitate the fast, continuous, and large-scale production of porous, light-weight materials as it does not require freeze-drying, supercritical CO2 drying, or any environmentally harmful crosslinking chemistries. The reported preparation procedure relies solely on the successive freezing, solvent-exchange, and ambient drying of composite CNF-alginate gels. The presented findings suggest that a highly-porous structure can be preserved throughout the process by simply controlling the ionic strength of the gel. Aerogels with tunable densities (23–38 kg m−3) and compressive moduli (97–275 kPa) can be prepared by using different CNF concentrations. These low-density networks have a unique combination of formability (using molding or 3D-printing) and wet-stability (when ion exchanged to calcium ions). To demonstrate their use in advanced wet applications, the printed aerogels are functionalized with very high loadings of conducting poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:TOS) polymer by using a novel in situ polymerization approach. In-depth material characterization reveals that these aerogels have the potential to be used in not only energy storage applications (specific capacitance of 78 F g−1), but also as mechanical-strain and humidity sensors. © 2020 The Authors. 

  • 28.
    Frisvad, Jeppe Revall
    et al.
    DTU Technical University of Denmark, Denmark.
    Jensen, Søren Alkaersig
    Danish National Metrology Institute, Denmark.
    Madsen, Jonas Skovlund
    Danish National Metrology Institute, Denmark.
    Correia, António L.
    KU Leuven, Belgium.
    Yang, Li
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Gregersen, S. K. S.
    DTU Technical University of Denmark, Denmark.
    Meuret, Youri
    KU Leuven, Belgium.
    Hansen, Poul Erik
    Danish National Metrology Institute, Denmark.
    Survey of Models for Acquiring the Optical Properties of Translucent Materials2020In: Computer graphics forum (Print), ISSN 0167-7055, E-ISSN 1467-8659, Vol. 39, p. 729-755Article in journal (Refereed)
    Abstract [en]

    The outset of realistic rendering is a desire to reproduce the appearance of the real world. Rendering techniques therefore operate at a scale corresponding to the size of objects that we observe with our naked eyes. At the same time, rendering techniques must be able to deal with objects of nearly arbitrary shapes and materials. These requirements lead to techniques that oftentimes leave the task of setting the optical properties of the materials to the user. Matching the appearance of real objects by manual adjustment of optical properties is however nearly impossible. We can render objects with a plausible appearance in this way but cannot compare the appearance of a manufactured item to that of its digital twin. This is especially true in the case of translucent objects, where we need more than a goniometric measurement of the optical properties. In this survey, we provide an overview of forward and inverse models for acquiring the optical properties of translucent materials. We map out the efforts in graphics research in this area and describe techniques available in related fields. Our objective is to provide a better understanding of the tools currently available for appearance specification when it comes to digital representations of real translucent objects.

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    fulltext
  • 29.
    Grahn, Thomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. Mälardalen University, Sweden.
    Conceptual Integration of Digitalization and Servitization as Means to Introduce the Circular Economy2022In: Advances in Transdisciplinary Engineering, IOS Press BV , 2022, Vol. 21, p. 304-315Conference paper (Refereed)
    Abstract [en]

    The Circular Economy (CE) can be implemented with different strategies. In this analysis, it is assumed that there is a desire to find a CE introduction strategy that leads to as rapid and environmentally friendly increase of resource-efficiency as possible. It is further assumed that an introduction strategy needs to take full advantage of other resource-efficiency concepts, societal trends, and developments. It is observed that the ongoing Digitalization and Servitization trends have been found to significantly affect each other, and as Digitalization impacts the possibility to make operations more resource-efficient, and Servitization means a change in the business model, it is assumed that those trends affect the incentives and possibilities for companies to develop Circular Solutions (CS) suitable for the CE, and that it is relevant to ask how. The purpose of this is to contribute to the development of a resource-efficiency concept that synthesizes Digitalization and Servitization, to contribute with suggestions on how to efficiently introduce the CE. It is asked; What measures may take advantage of the Digitalization and Servitization trends, and efficiently facilitate introduction of the CE? To find the answer a theory synthesis conceptual approach is used, and it is analyzed how Digitalization and Servitization trends can contribute to increasing resource-efficiency, and what implications these trends may have on a strategy for the development of CS and the introduction of the CE. The findings indicate that companies interested in enacting resource-efficiency measures and being important actors in the future CE, should have their main focus on business models that incentivizes development of CS, rather than on techniques that enables the development of CS. This further indicates that an efficient CE strategy should prioritize policies that give actors responsible for procurement and purchasing, incentives to 'servitize' their purchasing strategy. © 2022 The authors and IOS Press.

  • 30.
    Hagman, Anton
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Mechanical and repulpability assessment of four recycled demo streams, a study2023In: TAPPICon 2023 - "Rock the Roll: Unleashing the Harmonies of the Paper Industry", TAPPI Press , 2023Conference paper (Refereed)
    Abstract [en]

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

  • 31.
    Hagman, Anton
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Mechanical and repulpability assessment of four recycled demo streams, a study2023In: Rock the Roll: Unleashing the Harmonies of the Paper Industry, Cleveland, USA: TAPPI Press , 2023Conference paper (Refereed)
    Abstract [en]

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

  • 32.
    Hagman, Anton
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Rydefalk, Cecilia
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. KTH Kungliga Tekniska Högskolan.
    ZD – Directional Testing of Paperboard, Using Refined Methods to Revisit Out of Plane Properties2022In: TAPPICon 2022 Proceedings, 2022Conference paper (Refereed)
    Abstract [en]

    The ZD-tensile strength is tested by attaching the top and bottom sides of a paperboard to rigid blocks that are pulled apart. In a production laboratory the strength is recorded using a tape as an adhesive. In specialized laboratories a more thorough method is available that also measures the force-displacement curve of the sample. The advanced method involves laminating and gluing the paperboard sample to metal blocks which are mounted in a universal testing machine. 

    In this study the advanced ZD-tensile method was refined by removing the glue step and laminating the paperboard directly to the blocks. The new method was validated against the regular method with adequate results. The limits of the refined method were explored with regards to ZD-strength and paper/paperboard thickness. 

    In an attempt to unify the ZD-tensile and -compressive behaviour of paperboard, samples were laminated and tested in combined compression and tension testing. The compressive properties were compared to non-laminated samples. The laminated samples showed a different behaviour than the non-laminated samples. The flat slope seen in the initial part of the pure compression curve disappeared, replaced by a continuous response passing 0 N. The stiffness in this region resembled the response in tensile testing. 

  • 33.
    Hagman, Anton
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Trost, Thomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Perforations on Boxes - Technical Aspects2022Conference paper (Other academic)
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  • 34.
    Karpenja, Tatjana
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging. Digital Cellulose Center, Sweden.
    Granberg, Hjalmar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. Digital Cellulose Center, Sweden.
    Edberg, Jesper
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware. Digital Cellulose Center, Sweden.
    Ahniyaz, Anwar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Circularity of DCC materials – case study on three energy storage solutions2022Report (Other academic)
    Abstract [en]

    Due to growing concerns about the environmental impacts of fossil fuels and the capacity and resilience of energy grids around the world, engineers and policymakers are increasingly turning their attention to energy storage solutions1. In turn, the huge demand for materials for such storage systems will require a considerable energy input in extraction, processing and materials formulation, and new and sustainable electrochemical systems need to be developed2. Current report is the result of the exploration work where the circularity and environmental potentials of biobased energy storage solutions were analysed in the form of iterative interviews with stakeholders along the energy storage and packaging value chains, complemented by literature research. The work was performed within the scope of Digital Cellulose Center (DCC) research center3 in the sub-project 1 “Circularity of DCC materials” of the Theme 1: Design for a circular bioeconomy. Totally three systems were selected and analysed in the form of three respective case studies: • Case study I: Biobased battery (Chemical energy storage system) • Case study II: Biobased printed supercapacitor (Electrochemical energy storage system) • Case study III: Intelligent packaging (Chemical or electrochemical energy storage for fiber-based packaging) Each case study was put into the life cycle context where aspects such as legislation, circularity potential and potential environmental impact were discovered. The biobased battery for large-scale grid storage applications was classified as an industrial battery with collection rate requirement of 75% at end-of-life, of which 50% to be materially recycled. The biobased printed supercapacitor was classified as an electric and electronic equipment (EEE) with collection rate requirement of 65%, of which recovery and recycling / preparing for reuse targets vary between 55% - 85% depending on application. The material recycling target for the fiber-based intelligent packaging is 85% since being perceived as a paper-based packaging it would enter paper packaging recycling stream rather than entering the recycling stream of Waste electrical and electronic equipment (WEEE). In next steps of this exploratory journey, the compositions of the respective energy storage solutions were identified, including biobased content and recycling potential on the short- and long-term, compared to their benchmark solutions where possible. Today, the material recycling processes for batteries and WEEE are strongly economically driven: the material components that are considered as valuable by recyclers are mainly base metals (e.g., aluminium, steel) and to low extent critical raw materials (e.g., cobalt, nickel). The biobased energy storage solutions though do not contain any critical raw materials and use base metals to a less extent. This is a dilemma where the material value of the biobased, renewable materials (more sustainable materials by origin) is not favourable in the end-of-life processes of today and therefore will be lost (i.e., incinerated). A more balanced approach to such dilemma is urged in order to facilitate both economic and environmental incentives in the energy storage value cycles. Current Battery and WEEE directives do not promote the recycling of materials that are critical or have a high environmental burden, which in practice results in loss of those materials, not least due to lack of economy in recycling processes. Moreover, the legislation needs to be adapted in order to meet innovative development in the area. It can be relevant to introduce a cross-sectoral category ‘Biobased energy storage solutions’ in the upcoming legislation with the aim to encourage use of more abundant, biobased materials and thus decouple energy storage applications from use of critical raw materials.

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  • 35.
    Karpenja, Tatjana
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Wästerlid, Cecilia
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Granberg, Hjalmar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Beni, Valerio
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Guidelines for Green Electronics – Sustainability and Foresight: Introducing the concepts as a first step2022Report (Other academic)
    Abstract [en]

    The society is transitioning towards a circular economy and the Digital Cellulose Center (DCC) that develops green electronics may play an important role in it. The research within the DCC focuses on the topic of digital cellulose, where cellulose is combined with electroactive material, making it possible to develop electrically active cellulose products that can communicate with the digital world while remaining sustainable. This could mean entirely new types of active packaging solutions, able to sense and adapt to their surroundings, or paper rolls able to store energy from solar cells or wind power [1]. This document offers guidance for the DCC stakeholders on the choice of sustainable materials for green electronics, focusing on the two life cycle phases of a product: • Raw materials • End-of-life Since the DCC green electronics are still in the development stage, a future scenario analysis has been applied in order to envision the possible future outcomes. The DCC green electronics have been explored in two opposite future scenarios: • Stuck in the Mud – A business-as-usual scenario, where the year 2045 is more or less the same as year 2022. • Circular Dawn – Where the circular economy has become a new normal and the whole society is thriving in a resource-efficient, circular and biobased economy. The guideline contains a sustainability checklist adapted to the needs of the DCC stakeholders for more informed decision-making and for being able to drive the development towards a circular economy, i. e. the future scenario Circular Dawn.

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  • 36.
    Krochak, Paul
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Johansson, Klas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    De San Pio, Ignacio
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    The effect of contact time between CPAM and colloidal silica on the flocculation behavior in the approach flow2021In: TAPPI Journal, ISSN 0734-1415, Vol. 20, no 1, p. 39-47Article in journal (Refereed)
    Abstract [en]

    Multicomponent wet-end systems have become increasingly common in papermaking, with the objective of improving the retention-formation-dewatering relationship. It is quite common to use at least a cationic polymer, often in combination with an anionic microparticle. In some cases, a fixative is also used. However, there is still debate on the optimal implementation of these systems. In particular, optimizing the contact time of the cationic polymer prior to addition of the anionic microparticle is still poorly understood. In this work, we investigate the effect of the contact time of a cationic polyacrylamide (CPAM) prior to addition of colloidal silica on the flocculation response in a flowing fiber suspension. The effect of using a fixative is also investigated. Focused beam reflectance measurements (FBRM) are combined with zeta-potential measurements for optimizing the addition levels of a two- and three-component system, as well as for elucidating the effect of contact time on CPAM performance. Trials are then performed on a pilot scale flow loop, where the time between addition of these two components is varied and the resulting flocculation response is characterized using high-speed filming and image anal. techniques. It is shown that the efficacy of CPAM can be improved through use of a fixative and that a longer CPAM contact time may be beneficial in terms of immediate flocculation; however, hydrodynamic shear tends to dominate the flocculation response regardless of contact time due to floc rupture.

  • 37.
    Köhnlein, Maximilian
    et al.
    University of Borås, Sweden.
    Abitbol, Tiffany
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Osório Oliveira, Ana
    Karolinska Institute, Sweden.
    Magnusson, Mikael
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Adolfsson, Karin
    KTH Royal Institute of Technology, Sweden.
    Svensson, Sofie
    University of Borås, Sweden.
    Ferreira, Jorge
    University of Borås, Sweden.
    Hakkarainen, Minna
    KTH Royal Institute of Technology, Sweden.
    Zamani, Akram
    University of Borås, Sweden.
    Bioconversion of food waste to biocompatible wet-laid fungal films2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 216, article id 110534Article in journal (Refereed)
    Abstract [en]

    The fungus Rhizopus delemar was grown on bread waste in a submerged cultivation process and wet-laid into films. Alkali or enzyme treatments were used to isolate the fungal cell wall. A heat treatment was also applied to deactivate biological activity of the fungus. Homogenization of fungal biomass was done by an iterative ultrafine grinding process. Finally, the biomass was cast into films by a wet-laid process. Ultrafine grinding resulted in densification of the films. Fungal films showed tensile strengths of up to 18.1 MPa, a Young's modulus of 2.3 GPa and a strain at break of 1.4%. Highest tensile strength was achieved using alkali treatment, with SEM analysis showing a dense and highly organized structure. In contrast, less organized structures were obtained using enzymatic or heat treatments. A cell viability assay and fluorescent staining confirmed the biocompatibility of the films. A promising route for food waste valorization to sustainable fungal wet-laid films was established. © 2022 The Authors

  • 38.
    Larsson, Per Tomas
    et al.
    RISE Research Institutes of Sweden.
    Lindström, Tom S. C.
    RISE Research Institutes of Sweden, Materials and Production, Applied Mechanics.
    Glad-Nordmark, Gunborg
    RISE Research Institutes of Sweden.
    Ankerfors, Caroline
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Bulking method for chemical pulps and its effect on cellulose structure - A CP/MAS 13C-NMR Study2021In: TAPPICon LIVE, TAPPI Press , 2021, p. 460-464Conference paper (Refereed)
    Abstract [en]

    Cellulose-rich never-dried acetate grade Eucalyptus dissolving pulp was used to study the effects on the supramolecular structure of cellulose due to the addition of AlCl3 during drying from acidic conditions (pH 3.5). CP/MAS 13C-NMR was the analytical technique used for taking measures of the cellulose supramolecular structure. In this study AlCl3 was used as source of Al3+, but Al2(SO4)3 has been shown to give the same effect and it is believed that any salt of Al3+ will give the same effect. The presence of AlCl3 increased the average lateral fibril aggregate dimensions some 25% above that reached by the pulp dried without addition of AlCl3. The observed changes in cellulose supramolecular structure due to the addition of AlCl3 are large considering the low AlCl3 concentration that was used. No change in degree of crystallinity was observed as the result of drying, either with or without AlCl3 addition. Although the mechanism of action for AlCl3, causing the observed effects on the cellulose supramolecular structure, is currently not fully understood, the interpretation made was that the presence of AlCl3 increased the agglomeration of the cellulose that always take place during the first drying of cellulosic fibres. This can be seen as an increased degree of physical cross-linking in the cellulose network. 

  • 39.
    Löfgren, Cathrine
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Jensen, Carl
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Lindström, Annika
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Wickholm, Kristina
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Ökat resursutnyttjande av plastförpackningar från on-the-go produkter2020Report (Other academic)
    Abstract [sv]

    Projektet har identifierat behov, hinder och möjligheter för on-the-go förpackningar i hela värdekedjan. Aktuella krav och konsekvenser i gällande förpackningslagstiftning (Förordningen (2018:1462) om producentansvar för förpackningar, förordning (2016:1041) om plastbärkassar) och Avfallsförordning (2011:927) har inkluderats.

    Förslag på nya möjliga lösningar för minskad nedskräpning och för incitament att samla in och återvinna och återbruka fler förpackningar har arbetats fram genom workshops med relevanta aktörer i olika delar av värdekedjan.

    Tre koncept för en ökad materialåtervinning samt tre koncept för ökat återbruk av plastförpackningar från ”on-the-go”-produkter arbetades fram.

    Efter en urvalsprocess valdes ett koncept för ökad materialåtervinning (”Recycling generation and cities”) och ett koncept för ökat återbruk (Reuse generation) av plastförpackningar från ”on-the-go”-produkter för utvärdering.

    Det slutliga konceptet som togs fram för ökad materialåtervinning ger möjlighet till insamling och källsortering on-the-go, inom rimligt avstånd och med tydlig information om hur förpackningarna ska sorteras. Med pant som sporre för att återvinna. Det möjliggörs genom en app som dessutom underlättar för konsumenter att göra rätt. Appen laddas ner till konsumentens mobiltelefon i kombination med ett väl utbyggt källsorteringssystem på allmänna platser och med tydlig information på källsorteringsstationerna om hur förpackningarna ska sorteras. Ett digitalt pantsystem är förhållandevis billigt jämfört med dagens konventionella pantsystem, det skapar ekonomiska incitament för konsumenten att gå till en källsorteringsstation och som dessutom underlättar för konsument att göra rätt. Ett väl utbyggt källsorteringssystem med tydliga sorteringsinstruktioner ger också konsumenten möjlighet att inom rimligt avstånd kunna materialåtervinna sina förpackningar med höga materialåtervinningsnivåer och bra kvalitet på insamlat material som följd.

    Det slutliga konceptet för ökat återbruk bygger även den på en app som laddas ner till konsumentens mobiltelefon. Därefter registrerar konsumenten sig i appen och kan inhandla on-the-go mat i en flergångsförpackning i de restauranger och caféer etc som är anslutna till systemet och erbjuder dessa återbrukbara förpackningar. Efter förtäring ges information via appen till konsumenten om på vilka platser förpackningen kan återlämnas. Vid dessa platser scannas förpackningen med hjälp av mobiltelefonen och panten som betalades vid köptillfället betalas tillbaka.

    Under utvärderingen av koncepten analyserades:

    • Möjligheter för respektive koncept samt hur de kan realiseras

    • Hinder och hot för respektive koncept samt hur de kan övervinnas

    • Konsekvenser och ansvarsfrågan för respektive koncept

    • Potential för respektive koncept 

    Utvärderingen resulterade i att ett antal ”knutar" identifierades som kan uppstå i de olika delarna av värdekedjan. Lösningar som behövs för att konceptet ska fungera enligt aktörerna i värdekedjan identifierades samt potentialen med respektive koncept.

    Utvärderingen visar att det finns en stor potential för att konceptet för ökad materialåtervinning ska fungera då konceptet leder till:

    • Att förpackningar ses som en resurs

    • Minskad nedskräpning

    • Positiv PR för Varumärkesägare (inget skräp med namn)

    • Ökad resurseffektiv användning av råvaror

    • Ökad cirkularitet

    • Ökad materialåtervinning med renare fraktioner

     

    Vissa förutsättningar som krävs är t.ex. nytt sätt att samarbeta för olika aktörer, ändrade beteenden hos konsumenter, information, utbildning och ny digital lösning av pantsystem.

     

    För konceptet med återbruk finns en potential under vissa förutsättningar. Något som rekommenderas för att underlätta en uppstart av konceptet är t.ex. att starta konceptet inom ett begränsat område såsom en nöjespark. Ett sätt att börja bygga en beteendeförändring och en ökad acceptans för återbruk.

     

    Innan dessa koncept kan implementeras krävs att de testas i verklig miljö, vilket vi planerar göra i Örnsköldsviks stadskärna under sommaren 2020.

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  • 40.
    Marin, Gustav
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Hagman, Anton
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Nygårds, Mikael
    KTH Royal Institute of Technology, Sweden; BillerudKorsnäs, Sweden.
    Torsional and compression loading of paperboard packages: Experimental and FE analysis2023In: Packaging technology & science, ISSN 0894-3214, E-ISSN 1099-1522, Vol. 36, no 1, p. 31-44Article in journal (Refereed)
    Abstract [en]

    The present study investigates torsional and compressive loading of a paperboard package. Finite element (FE) analyses simulating the tests were performed to improve understanding of the stresses and deformations in the paperboard during loading. A simple experimental characterization of the necessary material properties could be performed to represent the multi-ply paperboard as a single-ply structure. The results from the single-ply model were compared with a laminate model, and the differences between the models were small. Comparing experimental and FE simulations of box compression and torsion showed that the FE models could accurately predict the response curves. However, in the simulations, there was an overprediction of the maximum compressive force and maximum torque, which was expected since geometrical imperfections and the heterogeneous internal structure of the material were not accounted for in the material model or the FE model. Local yield lines formed at the onset of non-linearities in the package load–displacement curves. Therefore, the strength of the paperboard affects the maximum compressive strength and maximum torque, and the bending stiffness of the paperboard only had a minor effect. When a first local maximum was reached, the number of FE that reached the failure stress increased exponentially. The simulations also showed that box compression was not an effect of package height, but higher packages had a lower maximum torque. © 2022 The Authors. 

  • 41.
    Marin, Gustav
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging. RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Nygårds, Mikael
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging.
    Box compression strength of packages in different climates2019In: 29th IAPRI Symposium on packaging, 2019: Serving society innovative perspectives on packaging, 2019Conference paper (Other academic)
    Abstract [en]

    Packages made of five folding box boards made on the same paperboard machinehave been analysed. The paperboards were from the same product series but had different grammage (235, 255, 270, 315, 340 g/m2) and different bending stiffness. Thepaperboards are normally used to make packages, and since the bending stiffnessand grammage varies the packages performance will be different. In this study, twodifferent load cases were defined and Box Compression Tests (BCT) were performedat different levels of relative humidity (30, 50, 70, 90 % RH) and were evaluated as afunction of moisture ratio.The result showed a linear relation between the box compression strength and themoisture ratio. In addition, when the data was normalized with the measurements forthe standard climate (50 % RH) and was evaluated as a function of moisture ratio, theresult indicated that the normalized box compression strength for all the paperboardsand both of the load cases could be expressed as a linear function of moisture, dependent of two constants a and b.Consequently, the study indicates that it is possible to estimate the Box compressionstrength at different climates of a package made of paperboard, by knowing the boxcompression strength for the standard climate (50 % RH and 23 °C) and the constantsa and b.

  • 42.
    Marin, Gustav
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Nygårds, Mikael
    BillerudKorsnäs, Sweden.
    Östlund, S.
    KTH Royal Institute of Technology, Sweden.
    Experimental quantification of differences in damage due to in-plane tensile test and bending of paperboard2022In: Packaging technology & science, ISSN 0894-3214, E-ISSN 1099-1522, Vol. 35, p. 69-Article in journal (Refereed)
    Abstract [en]

    Creasing is an essential process to convert paperboards into packages since it enables folding along well-defined lines. The creasing process relies on purpose-made damage that is initiated in the paperboard structure: delamination. However, creasing might also cause in-plane cracks, which must be avoided. In this laboratory study, three paperboards were creased at six different depths, respectively. Two mechanical tests were performed to characterize the creases at standard climate (23°C and 50% RH): 2-point folding, to examine the bending force and short-span in-plane tensile test to evaluate the strength. The results were normalized with the values for the uncreased boards, which gave the relative strength ratios: relative creasing strength (RCS) and relative tensile strength (RTS). When the relative strengths were evaluated against the normative shear strains, a creasing window was formed. This window has an upper limit given by the RTS values, corresponding to the in-plane cracks, and a lower limit given by the RCS values, corresponding to the delamination damage initiated in the paperboard during creasing. It was observed that both the RCS and RTS values exhibit a linear relation against normative shear strain. From this, it was concluded that performing tests at two creasing depths might be sufficient to estimate the lower, and upper, limits for the creasing window in future studies. Finally, the effect of moisture was investigated by creasing, folding and tensile testing at 23°C and 90% RH, which showed that moisture had no clear effect on the RCS or the RTS values. 

  • 43.
    Marin, Gustav
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Nygårds, Mikael
    RISE Research Institutes of Sweden.
    Östlund, S.
    KTH Royal Institute of Technology, Sweden.
    Stiffness and strength properties of five paperboards and their moisture dependency2020In: TAPPI Journal, ISSN 0734-1415, Vol. 19, no 2, p. 71-85Article in journal (Refereed)
    Abstract [en]

    Five commercial multiply folding boxboards made on the same paperboard machine have been analyzed. The paperboards were from the same product series but had different grammage (235, 255, 270, 315, 340 g/m2) and different bending stiffness. The paperboards are normally used to make packages, and because the bending stiffness and grammage varies, the performance of the packages will differ. Finite element simulations can be used to predict these differences, but for this to occur, the stiffness and strength properties need to be determined. For efficient determination of the three-dimensional properties in the machine direction (MD), cross direction (CD), and Z direction (ZD), it is proposed that the paperboard should be characterized using in-plane tension, ZD-tension, shear strength profiles, and two-point bending. The proposed setups have been used to determine stiffness and strength properties at different relative humidity (20,% 50%, 70%, and 90% RH), and the mechanical properties have been evaluated as a function of moisture ratio. There was a linear relation between mechanical properties and moisture ratio for each paperboard. When the data was normalized with respect to the standard climate (50% RH) and plotted as a function of moisture ratio, it was shown that the normalized mechanical properties for all paperboards coincided along one single line and could therefore be expressed as a linear function of moisture ratio and two constants. Consequently, it is possible to obtain the mechanical properties of a paperboard by knowing the structural properties for the preferred level of RH and the mechanical property for the standard climate (50% RH and 23°C).

  • 44.
    Marin, Gustav
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Nygårds, Mikael
    RISE Research Institutes of Sweden.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Elastic-plastic model for the mechanical properties of paperboard as a function of moisture2020In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 35, no 3, p. 353-361Article in journal (Refereed)
    Abstract [en]

    To verify a linear relation between normalized mechanical property and moisture ratio, in-plane tensile tests were performed on four types of paperboard from different manufacturers. Tensile properties were normalized with respect to the property at standard climate (50 % RH, 23 °C). Short-span Compression Tests were also performed to investigate if the relation was linear also for in-plane compression. The tests were performed at different relative humidity (20, 50, 70 and 90 % RH) but with constant temperature (23 °C) in MD and CD, respectively. The linear relation was confirmed for the normalized mechanical properties investigated. In fact, when also the moisture ratio was normalized with the standard climate, all paperboards coincided along the same line. Therefore, each mechanical property could be expressed as a linear function of moisture ratio and two parameters. Moreover, an in-plane bilinear elastic-plastic material model was suggested, based on four parameters: Strength, stiffness, yield strength and hardening modulus, where all parameters could be expressed as linear functions of moisture ratio. The model could predict the elastic-plastic behavior for any moisture content from the two parameters in the linear relations and the mechanical properties at standard climate.

  • 45.
    Marin, Gustav
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Nygårds, Mikael
    Billerud AB, Sweden.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Relations Between Material Properties And Performance Of Paperboard Packages2023Conference paper (Refereed)
    Abstract [en]

    With material properties as a starting point, this study focuses on analyzing the performance of a paperboard package. Torsional and compressive loading of a paperboard package have been investigated through physical experiments and finite element (FE) simulations, where an orthotropic linear elastic material model with a stress-based failure criterion was used. Comparing physical experiments and FE simulations of box compression and torsion showed that the finite element models could accurately predict the response curves. Additionally, the model was utilized to investigate which impact variations in moisture, bending stiffness, and crease quality had on packaging performance. The effect of moisture was examined through an established master curve, where the necessary mechanical properties could be expressed as linear functions of moisture ratio. The impact of creases was evaluated by varying previously established ratios (relative crease strength, RCS, tensile strength, RTS) for reducing the creases’ mechanical properties in the simulations. Furthermore, the results showed that the strength of the paperboard affects the maximum compressive strength and maximum torque. Still, the bending stiffness of the paperboard only had a minor effect on box compression strength. To conclude, the model accurately predicted how moisture, crease quality, and bending stiffness affected packaging performance.

  • 46.
    Marin, Gustav
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging. RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Nygårds, Mikael
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Papermaking and Packaging.
    Östlund, Sören
    KTH Royal Institute of Sweden, Sweden.
    Stiffness and strength properties of five paperboards and their moisture dependency2019In: International Paper Physics Conference 2019, Indianapolis, IN, USA, 5-8 May 2019: preprint proceedings, TAPPI Press, 2019, p. 14-29Conference paper (Other academic)
    Abstract [en]

    Research has been undertaken to characterise the in-plane and out-of-plane stiffness and strength properties of paperboards to enable data for use in determining constitutive parameters needed in finite element simulations. Paperboards with different bending stiffness were analysed, using five folding box boards of varying grammage (235, 255, 270, 315 and 340gsm). The stiffness and strength properties were determined at different relative humidity (RH), namely, 20, 50, 70 and 90%. As well as in-plane tensile test and out-of-plane tensile test, the short-span compression test (SCT) was carried out, together with bending stiffness test and double-notch shear test. The results revealed a linear relation between mechanical properties and moisture ratio for each paperboard. When the data were normalised with data for the standard climate (50% RH) and investigated as a function of moisture ratio, it was determined that the normalised mechanical properties for all paperboards coincided along one single line. Thus they could be expressed as a linear function of moisture ratio and two constants. It has been concluded that by knowing the structural properties for the preferred level of RH and the mechanical property for the standard climate, the mechanical properties of a paperboard could be obtained.

  • 47.
    Marin, Gustav
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Srinivasa, Prashanth
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Nygårds, Mikael
    BillerudKorsnäs, Sweden.
    Östlund, Sören
    KTH Royal Institute of Technology, Sweden.
    Experimental and finite element simulated box compression tests on paperboard packages at different moisture levels2021In: Packaging technology & science, ISSN 0894-3214, E-ISSN 1099-1522, Vol. 34, no 4, p. 229-243Article in journal (Refereed)
    Abstract [en]

    Finite element (FE) analyses can be used as a powerful tool in the package design process to study for instance stress and strain fields that arise during loading. An orthotropic linear elastic material model with a stress-based failure criterion was used to simulate box compression tests (BCTs) of a paperboard package in the FE solver LS-Dyna. Physical experiments were performed at 50%, 70%, and 90% relative humidity (RH). The input parameters required for the simulations were calculated based on material characterization at standard climate (50% RH and 23°C) and a linear relation between mechanical material properties and moisture ratio established in earlier studies. The result showed that it was possible to accurately predict the load–compression curve of a BCT when moisture was accounted for. Furthermore, it was found that modelling of the mechanical properties of the creases are important for capturing the stiffness response of the package. To conclude, it was possible to predict the box compression strength and the linear stiffness response prior to the peak in the load–compression response at relevant moisture levels, by using the previously established linear relationship between moisture ratio and material properties. In addition to the moisture ratio at the preferred moisture level, the only material properties required were the in-plane strengths and stiffnesses, and the out-of-plane shear moduli at standard climate. 

  • 48.
    Molloy, E
    et al.
    Measurement Standards Laboratory of New Zeal, New Zealand.
    Koo, A
    Measurement Standards Laboratory of New Zeal, New Zealand.
    Gevaux, L
    LNE-CNAM, France.
    Obein, G
    LNE-CNAM, France.
    Yang, Li
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Use of bidirectional transmittance distribution function measurements to determine transmittance haze2023In: Metrologia, ISSN 0026-1394, E-ISSN 1681-7575, Vol. 60, no 5, article id 055003Article in journal (Refereed)
    Abstract [en]

    Accurate and traceable measurements of transmittance haze are required for quality control in various different industries, such as optoelectronics, automobiles, and agriculture. Transmittance haze is defined as the fraction of light transmitted through a material that deviates from the incident beam by more than 2.5∘. Various documentary standards specify the use of an integrating sphere with a prescribed geometry for the measurement of transmittance haze. This paper uses goniometric measurements of the bidirectional transmittance distribution function (BTDF) to calculate transmittance haze according to the definition and demonstrates that the sphere-based realisation of transmittance haze specified in the documentary standards does not agree with the definition, with the difference being up to 20% for some samples. The BTDF measurements are also used to simulate the integrating sphere haze, allowing the sensitivity of the sphere haze to errors in the integrating sphere geometry to be calculated. 

  • 49.
    Moon, R. J.
    et al.
    USDA Forest Service, USA.
    Hensdal, C. L.
    Stora Enso Pulp & Paper Asia AB, Sweden.
    Beck, S.
    Calgary, Canada.
    Fall, Andreas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Costa, J.
    WebTech Pulp & Paper Technologies, Brazil.
    Kojima, E.
    Nanocellulose Japan, Japan.
    Abitbol, Tiffany
    EPFL Institute of Materials, Switzerland.
    Raghuwanshi, V.
    Monash University, Australia.
    Walker, C.
    University of Maine, USA.
    Batchelor, W.
    Monash University, USA.
    Setting priorities in CNF particle size measurement: What is needed vs. what is feasible2023In: TAPPI Journal, ISSN 0734-1415, Vol. 22, no 2, p. 116-137Article in journal (Refereed)
    Abstract [en]

    Measuring the size of cellulose nanomaterials can be challenging, especially in the case of branched and entangled cellulose nanofibrils (CNFs). The International Organization for Standardization, Technical Committee 6, Task Group 1—Cellulosic Nanomaterials, is exploring opportunities to develop standard methods for the measurement of CNF particle size and particle size distribution. This paper presents a summary of the available measuring techniques, responses from a survey on the measurement needs of CNF companies and researchers, and outcomes from an international workshop on cellulose nanofibril measurement and standardization. Standardization needs differed among groups, with Japanese companies mostly requiring measurements for product specification and production control, and other companies mostly needing measurements for safety/regula-tory purposes and for grade definitions in patents. Among all the companies, average length and width with percen-tiles (D(10), D(50), D(90)) were the most desired measurands. Workshop participants concurred that defining the location(s) on the CNF at which to measure the width and the length is an urgent and complex question. They also agreed that methods are needed for rapid particle size measurement at the nanoscale. Our recommendation within ISO is to start work to revise the definition of CNFs and develop sample preparation and measurement guidelines. It was also recommended that further research be done to reproducibly prepare hierarchical branched CNF structures and characterize them, develop automated image analysis for hierarchical branched CNF structures, and develop a classification system encompassing measurements at multiple size ranges from micro-to nanoscale to fully characterize and distinguish CNF samples. 00327-2022 

  • 50.
    Méhes, Gabor
    et al.
    Linköping University, Sweden.
    Vagin, Mikhail
    Linköping University, Sweden.
    Mulla, Mohammad
    Linköping University, Sweden.
    Granberg, Hjalmar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Che, Canyan
    Linköping University, Sweden.
    Beni, Valerio
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Crispin, Xavier
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Stavrinidou, Eleni
    Linköping University, Sweden.
    Simon, Daniel
    Linköping University, Sweden.
    Solar Heat-Enhanced Energy Conversion in Devices Based on Photosynthetic Membranes and PEDOT:PSS-Nanocellulose Electrodes2020In: Advanced Sustainable Systems, ISSN 2366-7486, Vol. 4, no 1, article id 1900100Article in journal (Refereed)
    Abstract [en]

    Energy harvesting from photosynthetic membranes, proteins, or bacteria through bio-photovoltaic or bio-electrochemical approaches has been proposed as a new route to clean energy. A major shortcoming of these and solar cell technologies is the underutilization of solar irradiation wavelengths in the IR region, especially those in the far IR region. Here, a biohybrid energy-harvesting device is demonstrated that exploits IR radiation, via convection and thermoelectric effects, to improve the resulting energy conversion performance. A composite of nanocellulose and the conducting polymer system poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is used as the anode in biohybrid cells that includes thylakoid membranes (TMs) and redox mediators (RMs) in solution. By irradiating the conducting polymer electrode by an IR light-emitting diode, a sixfold enhancement in the harvested bio-photovoltaic power is achieved, without compromising stability of operation. Investigation of the output currents reveals that IR irradiation generates convective heat transfer in the electrolyte bulk, which enhances the redox reactions of RMs at the anode by suppressing diffusion limitations. In addition, a fast-transient thermoelectric component, originating from the PEDOT:PSS-nanocellulose-electrolyte interphase, further increases the bio-photocurrent. These results pave the way for the development of energy-harvesting biohybrids that make use of heat, via IR absorption, to enhance energy conversion efficiency. 

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