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  • 1. Branström, J.
    et al.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Sandström, P.
    Ruel, K.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Compression wood in knots and the effect on surface roughness.2005In: proceedings from IMPC 2005, 2005Conference paper (Other academic)
    Abstract [en]

    The microstructural and ultrastructural characteristics of knot wood were examined and related to paper properties. Norway spruce (Picea abies) chips were laboratory fractionated and sorted into a knot containing assortment and a non knot containing reference assortment. The proportions of compression wood in these two assortments were then assessed and the two chip assortments refined in pilot refiners. The knot containing portion was divided into wood from the upper branch, wood from the lower branch compression wood and wood surrounding the branch. Fibres from the three knotwood portions and the reference chips were extracted and measurements were made of fibre properties including fibre length, fibre width and cell wall thickness. The two chip assortments were refined in a pilot plant and the surface properties of laboratory sheets were measured. The knot containing chips had adverse effects on several paper properties. However, no clear relationship was established between surface roughness and the presence of compression wood fibres in knot wood. (6 fig, 12 ref)

  • 2.
    Henshaw Osong, Sinke
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Olin, Håkan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engström, Ann-Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Development of CTMP-based nanofibrillated Cellulose /nanographite composites for paper applications2015Conference paper (Other academic)
  • 3.
    Henshaw Osong, Sinke
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Pettersson, Gunilla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    The use of cationic starch and microfibrillated cellulose to improve strength properties of CTMP-based paperboardManuscript (preprint) (Other academic)
  • 4.
    Höglund, Hans
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Pettersson, Gunilla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    A paper or paperboard product comprising at least one ply containing high yield pulp and its production method2018Patent (Other (popular science, discussion, etc.))
  • 5.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Effects of Reject Refining at High Temperature on TMP Fibre Properties2008Doctoral thesis, comprehensive summary (Other academic)
  • 6.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Gradin, P A
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Nyström, Staffan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Gullikson, Mårten
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Investigation of the z-direction strength properties of paper by use of acoustic emission monitoring2008In: Journal of Acoustic Emission, ISSN 0730-0050, Vol. 26, p. 23-31Article in journal (Refereed)
  • 7.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Gradin, Per
    Using acoustic emission monitoring to evaluate the through the thickness and in plane strength properties2009In: Proceedings - 2009 International Mechanical Pulping Conference, IMPC 2009, 2009, p. 298-303Conference paper (Refereed)
    Abstract [en]

    To shed some light on the deformation or damage processes active when paper made from carefully refined TMP long fibres and its fine material is loaded in the Z-direction and in-plane direction, specially designed grips with integrated acoustic emission sensors (AE sensors) were used to study the onset and progression of fracture. In this paper, experimental results from both Z-direction and in-plane tensile tests on three fractions of two TMP reject pulps are presented and discussed. Critical load, i.e. the load where fibre-fibre bonds starts to break, was shown to be approximately 80% of max strength and relatively independent of fine material content both in Z-direction and in-plane direction. In in-plan tensile fracture the fibre-fibre bonds are subjected to shear forces in contrast to loadings in through the thickness direction, where the bonds are loaded in a tensile mode. Addition of fines to the refined long fibre of the TMP reject has an evident effect of the bonds when loading in Z-direction, whereas the effect when loading in-plane is just marginal.

     

     

  • 8.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Gradin, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Isaksson, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Acoustic emission monitoring to evaluate the z-direction and in-plane strength properties of TMP reject fractionManuscript (Other academic)
  • 9.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Gradin, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Nyström, Staffan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Gulliksson, Mårten
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Investigation of the Z-direction strength properties of paper by use of acoustic emission monitoring2008In: 28th European conferance on acoustic emission testing, 2008, p. 238-243Conference paper (Other academic)
  • 10.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Hoglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Consolidation of fibre-fibre bonds in TMP and CTMP based papers2014In: Paper Technology, ISSN 0958-6024, Vol. 55, no 3, p. 6-10Article in journal (Other academic)
    Abstract [en]

    TMP and CTMP fibres are viscoelastic materials, which behave very differently at different temperatures and loading rates, should also be considered in papermaking. The positive effects of increased web temperature on dewatering and web consolidation (sheet strength) in pressing and drying of TMP/CTMP based papers have been known for some time. However, the effects of dry content during such conditions are less closely investigated. In this paper the effect of dry content on fibre-fibre bonds in consolidation of paper webs during press drying at high temperature is discussed. It is shown that the final paper strength is especially positively affected when a Z-directionalpressure is applied in the dryness range 50-75%.

  • 11.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Consolidation of fibre-fibre bonds in TMP and CTMP based papers2011In: PROCEEDING OF INTERNATIONAL MECHANICAL PULPING CONFERENCE 2011, 2011, p. 448-453Conference paper (Refereed)
    Abstract [en]

    TMP and CTMP fibres are viscoelastic materials, which behave very differently at different temperatures and loading rates, which should to be considered also in papermaking. The positive effects of increased web temperature on dewatering and web consolidation (sheet strength) in pressing and drying of TMP/CTMP based papers are well known since a long time. However, the effects of dry content during such conditions are less closely investigated. In this paper the effect of dry content on fibre-fibre bonds in consolidation of paper webs during press drying at high temperature is discussed. It is shown that the final paper strength is especially positively affected when a Z-directional pressure is applied in the dryness range 50%similar to 75 %.

  • 12.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Irreversible long fibre collapse at high temperature refining in a TMP system: Effects on fibre and surface properties2009In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 24, no 1, p. 19-24Article in journal (Refereed)
    Abstract [en]

    Effects on fibre and sheet properties of preheating to temperature well above the softening temperature of lignin in refining of spruce TMP reject were evaluated. This study indicates that an improved surface smoothness can be attained on TMP-based wood-containing papers through high-temperature reject refining. Under these conditions the degree of irreversible fibre collapse increased. Results from tests of the fibre-wall, fibre surface characteristics, pulp yield and sheet brightness show only marginal differences at high temperatures compared to standard reject refining. Experiments in which laboratory sheets were moistened showed that a high degree of irreversible fibre collapse correlates with surface smoothness.

  • 13.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Irreversible long fibre collapse at high temperature reject refining in a TMP system: Effects on fibre and surface properties2005In: Proceedings International Mechanical Pulping Conference Oslo 2005, 2005, p. 163-168Conference paper (Other scientific)
  • 14.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Irreversible long fibre collapse at high temperure reject refining in at TMP system - Initial studies.2003In: Proceedings from IMPC 2003, Quebec city, 2003Conference paper (Other scientific)
    Abstract [en]

    Irreversible Long Fibre Collapse at High Temperature Reject Refining in a TMP System

  • 15.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Moisture-Induced Surface Roughness in TMP Sheets.2007In: International Mechanical Pulping Conference 2007, TAPPI, TAPPI Press, 2007, Vol. 2, p. 718-729Conference paper (Other academic)
    Abstract [en]

    Favourable surface properties can be attained in softwood thermomechanical pulp (TMP)-based sheets, if most of the thick-walled long fibres are collapsed. Provided this can be done, a large amount of TMP can be used in highquality wood-containing papers, i.e., LWC or SC grades, without serious printability problems. It is known that the degree of fibre collapse during refining under standard TMP conditions is strongly related to the fibre wall thickness. However, the thickness of the thickest fibre walls cannot easily be changed by peeling actions in refining under standard TMP conditions in the CSF range of interest for news and magazine grades. Therefore, refining conditions obviously must be changed to enable the proper collapse of these fibres. Earlier studies (Norgren and Höglund, IMPC 2003 and 2005) have demonstrated that thick-walled fibres are more easily collapsed by reject refining after preheating to temperatures well above the softening temperature of lignin, i.e., high temperature conditions, than under standard conditions. If water is applied to the surface of a TMP-based paper during coating or printing, some fibres "decollapse", i.e., revert to their original shape. Earlier studies have demonstrated that decollapse is affected by both fibre wall thickness and fibre circumference (Norman and Höglund, IMPC 2003 and Norgren and Höglund, IMPC 2003). The present study evaluates the effects of moisture on sheets made of different Bauer-McNett (BMN) fractions, both individually and in combination. The pulps investigated are spruce TMP reject pulp made under reference and hightemperature conditions. The smoothness of laboratory sheets made of the BMN fractions were measured with PPS and with an optical scanning instrument, after moistening the sheets in environments of different relative humidities, i.e., 50-98%, to a sheet moisture content (MC) in approximately the 5-25% range. This was done to gain a better fundamental understanding of the conditions resulting in irreversible fibre collapse and of how combinations of types of fibres with different bonding abilities influenced the surface roughness. It is well known that the coarse, stiff, long fibres from the BMN >16 fractions cause surface roughness in dry sheets. However, this study indicates that the shapes of these fibres remain relatively unchanged when moisture diffuses into the sheet structure, i.e., the degree of decollapse is low. It also indicates that sheets including both coarse fibres and fibres from the middle fractions display the highest surface roughness values at a high MC. The fibres from the middle fraction rise easily, causing the greatest change in surface roughness when moisture is added to the sheet. The trials also indicate that fines contribute somewhat to increased surface roughness; when the degree of bonding in the sheet structure is increased, there is a risk that the whole structure or fibre flocks, instead of the individual fibres, may swell.

  • 16.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Moisture-induced surface roughness in TMP sheets2008In: Journal of Pulp and Paper Science (JPPS), ISSN 0826-6220, Vol. 34, no 3, p. 139-146Article in journal (Refereed)
    Abstract [en]

    The present study evaluates effects of moisture on sheet properties made different Bauer-McNett fractions from TMP, both individually and in combinations. It is well known that the coarse, stiff, long fibre fractions cause surface roughness in dry sheets. However, this study indicates that these fibres remain relatively unchanged when moisture diffuses into the sheet structure, i.e., the degree of decollapse is low. The fibres from the middle fraction rise easily, causing the greatest change in surface roughness when moisture is added to the sheet. Sheets including both coarse fibres and fibres from the middle fractions display the highest surface roughness values at a high moisture content. The trials also indicate that fines contribute to increased surface roughness: when the degree of bonding in the sheet structure is increased, there is a risk that the whole structure or the flocks, instead of the individual fibres, may swell.

  • 17.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bäck, R
    Irreversible long fibre collapse at high temperature TMP reject refining - initial studies2004In: Pulp & paper Canada, ISSN 0316-4004, Vol. 105, no 7, p. 47-51Article in journal (Refereed)
    Abstract [en]

    Effects of preheating temperature on energy consumption,fibre collapse and pulp quality in refining of spruce TMP reject material were studied. At preheating to temperatures well above the softening temperature of lignin thick-walled fibres were collapsed to a higher degree. Shives and fibres in the BMN +10 fraction were efficiently reduced. An increase in sheet density was obtained. Energy consumption was reduced, at a certain freeness level. This study indicates that an improved surface smoothness can be achieved as result of high temperature reject refining.

  • 18.
    Norgren, Sven
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Pettersson, Gunilla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    High strength papers from high yield pulps2014In: International Mechanical Pulping Conference, IMPC 2014, 2014Conference paper (Refereed)
    Abstract [en]

    The positive effects changing the present standard conditions regarding temperature and moisture content during pressing and drying in papermaking of high yield pulp furnishes, such as those from TMP and CTMP, has previously been reported in a series of studies at Mid Sweden University. In the current study, the effects of fibre surface modification by starch/CMC at press-drying conditions have been investigated. It is shown how the strength properties of sheets from HTCTMP, manufactured at very low electric energy consumption (approximately 600 kWh/ton), can be radically improved by several hundred percent at optimum papermaking conditions.

  • 19.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    A New Concept to Produce Nano-ligno-cellulose Materials by Means of High Pressure Homogenization2012Conference paper (Refereed)
  • 20.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Mechanical Properties of high-yield pulp handsheets, as affected by blends of Nano-ligno-cellulose2013Conference paper (Refereed)
  • 21.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    New Products based on Mechanical Pulps: Nano-ligno-cellulose (NLC)2013Conference paper (Refereed)
  • 22.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Nano-ligno-cellulose as strength enhancer in handsheets2013Conference paper (Other academic)
    Abstract [en]

    In recent years, there has been tremendous work in the research field of nanocellulose or microfibrillated cellulose but, very few scholars have envisioned the use of the low quality fibre fraction of mechanical pulps for the production of mechanical pulp based nanocellulose, referred to as nano-ligno-cellulose (NLC) in this paper. Today, it has been noticed by many that there has been an economic downturn in the pulp and paper industry and that this adverse situation could be somewhat alleviated by possibly searching for better products or by improving the material quality of existing products (papers and paperboards). This paper presents results related to paper strength properties based on testing of handsheets of pulp fibres blended with nanocellulose. The results indicate that the addition of nano-ligno-cellulose (NLC) to chemi-thermomechanical pulp (CTMP) fibres improved the z-strength property of laboratory sheets with only a slight effect in relation to the sheet density. Also the crill characterisation method was used to evaluate fibre size distribution. The measurement of crill is based on optical response of a suspension at two wavelengths of light; UV and IR. The UV light contains information on both the total fibres and the crill, while IR only contains information on fibres. Results showed that the crill value of NLC of CTMP correlated (linearly) fairly well with the homogenisation time.

  • 23.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Nano-ligno-cellulose from mechanical pulp fines2013Conference paper (Refereed)
  • 24.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Recent developments in nano-ligno-cellulose production and the crill characterization technique2014In: TAPPI International Conference on Nanotechnology for Renewable Materials 2014, TAPPI Press, 2014, p. 193-205Conference paper (Refereed)
  • 25.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Lundberg, Mathias
    PulpEye AB Örnsköldsvik Sweden.
    Reza, Mehedi
    Aalto University, School of Science and Technology, Aalto, Finland.
    Tapani, Vuorinen
    Aalto University, School of Science and Technology, Aalto, Finland.
    Qualitative evaluation of microfibrillated cellulose usingthe crill method and some aspects of microscopy2016In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 23, no 6, p. 3611-3624Article in journal (Refereed)
    Abstract [en]

    It has been a challenge to develop rapid online characterisation techniques for nanocellulose given the fibrillar structure of the nanoparticles. The crill optical analyser uses optical response signals in the infrared (IR) and ultraviolet (UV) wavelength ranges to evaluate the particle size properties of micro/nanofibrillar cellulosic materials. In this work, the crill analyser was used to measure the projected areas of UV and IR light sources by measuring the light blocked by nanocellulosic particles. This work uses the crill methodology as a new, simplified technique to characterise the particle size distribution of nanocellulosic material based on chemi-thermomechanical pulp (CTMP), thermomechanical pulp (TMP), and sulphite pulp (SP). In the first part, hydrogen peroxide pretreatment of CTMP and TMP in a wing mill refiner followed by high-pressure homogenisation to produce microfibrillated cellulose (MFC) was evaluated using the crill method. In the second part, TEMPO oxidation of CTMP and SP combined with high-shear homogenisation to produce MFC was studied using the crill method. With 4 % hydrogen peroxide pretreatment, the crill values of the unhomogenised samples were 218 and 214 for the TMP and CTMP, respectively, improving to 234 and 229 after 18 homogenisation passes. The results of the TEMPO method indicated that, for the 5 mmol NaClO SP-MFC, the crill value was 108 units at 0 min and 355 units after 90 min of treatment, a 228 % improvement. The CTMP and TMP fibres and the MFC were freeze dried and fibrillar structure of the fibres and microfibrils was visualised using scanning electron and transmission electron microscopy.

  • 26.
    Osong, Sinke H.
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Pettersson, Gunilla
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Còrdova, Armando
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Afewerki, Samson
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Alimohammadzadeh, Rana
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Processing of nanocellulose and applications relating to CTMP-based paperboard and foams2016In: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, p. 87-93Conference paper (Refereed)
    Abstract [en]

    Although remarkable success has been made in the production of nanocellulose through several processing methods, it still remain a challenge to reduce the overall energy consumption, to use green chemistry and sustainable approach in order to make it feasible for industrial production of this novel nanomaterial. Herein, we have developed a new eco-friendly and sustainable approach to produce nanocellulose using organic acid combined with high-shear homogenisation, made hydrophobisation of nanocellulose and cross-linked the modified nanocellulosic material. Also, TEMPO-mediated oxidised nanocellulose was produced in order to compare the processing route with that of mild organic acid hydrolysis. Freeze-dried 3D structure of TEMPO-derived nanocellulose foam materials made fi-om bleached sulphite pulp and CTMP, respectively. Further, there is growing interest in using nanocellulose or microfibrillated cellulose (MFC) as an alternative paper sfrength additive in papermaking, and in using chemi-thermomechanical pulp (CTMP) with high freeness in producing CTMP-based paperboard with high bulk properties. To achieve greater strength improvement results, particularly for packaging paperboards, different proportions of cationic starch (CS) or MFC can be used to significantly improve the z-strength, with only a slight increase in sheet density. Research in this area is exploring CS or MFC as potential strength additives in CTMP-based paperboard, which is interesting from an industrial perspective. The mean grammage of the CTMP handsheets produced was approximately 150 g m~, and it was found that blending CTMP with CS or MFC yielded handsheets with significantly improved z-strength, tensile index, burst index and other strength properties at similar sheet densities.

  • 27.
    Osong, Sinke Henshaw
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Dahlström, Christina
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Forsberg, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Andres, Britta
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engström, Ann-Christine
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Nanofibrillated cellulose/nanographite composite films2016In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 23, no 4, p. 2487-2500Article in journal (Refereed)
    Abstract [en]

    Though research into nanofibrillated cellulose (NFC) has recently increased, few studies have considered co-utilising NFC and nanographite(NG) in composite films, and, it has, however been a challenge to use high-yield pulp fibres (mechanical pulps) to produce this nanofibrillar material. It is worth noting that there is a significant difference between chemical pulp fibres and high-yield pulp fibres, as the former is composed mainly of cellulose and has a yield of approximately 50 % while the latter is consist of cellulose, hemicellulose and lignin, and has a yield of approximately 90 %. NFC was produced by combining TEMPO (2,2,6,6-tetramethypiperidine-1-oxyl)-mediated oxidation with the mechanical shearing of chemi-thermomechanical pulp (CTMP) and sulphite pulp (SP); the NG was produced by mechanically exfoliating graphite. The different NaClO dosages in the TEMPO system differently oxidised the fibres, altering their fibrillation efficiency. NFC-NG films were produced by casting in a Petri dish. We examine the effect of NG on the sheet-resistance and mechanical properties of NFC films. Addition of 10 wt% NG to 90 wt% NFC of sample CC2 (5 mmol NaClO CTMP-NFC homogenised for 60 min) improved the sheet resistance, i.e. from that of an insulating pure NFC film to 180 Omega/sq. Further addition of 20 (CC3) and 25 wt% (CC4) of NG to 80 and 75 wt% respectively, lowered the sheet resistance to 17 and 9 Omega/sq, respectively. For the mechanical properties, we found that adding 10 wt% NG to 90 wt% NFC of sample HH2(5 mmol NaClO SP-NFC homogenised for 60 min) improved the tensile index by 28 %, tensile stiffness index by 20 %, and peak load by 28 %. The film's surface morphology was visualised using scanning electron microscopy, revealing the fibrillated structure of NFC and NG. This methodology yields NFC-NG films that are mechanically stable, bendable, and flexible.

  • 28.
    Osong, Sinke Henshaw
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    An approach to produce nano-ligno-cellulose from mechanical pulp fine materials2013In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 28, no 4, p. 472-479Article in journal (Refereed)
    Abstract [en]

    Mechanical pulping, also called high-yield pulping processes, are pulping systems where a great deal of effort is taken with regards to the fractionation in screens and cleaners as well as to optimize process conditions to refine the rejected fractions. The fraction that is rejected for further treatment can vary from 10 to 50% depending on process strategy and final product which can be from printing paper, writing paper, paperboard middle layer and tissue. In practice, it is common that approximately 10% of the pulp fibres and also a large part of the fines fraction have properties that are unsatisfactory in relation to the final products. Part of the less useful fines fraction could instead be used to produce nano-ligno-cellulose (NLC) of high value either in the main product or used for completely different purposes.

    In order to study the potential of this concept, treatment of thermo-mechanical pulp (TMP) fines fractions were studied by means of homogenization. It seems possible to homogenize fine particles of thermo-mechanical pulp (1% w/v) to NLC. A corresponding fines fraction from bleached kraft pulp (BKP) was tested as a reference at 0.5% w/v concentration. This fines (BKP) fraction was very difficult to homogenize at a higher concentration (1% w/v). An explanation for this could be that the BKP fines have much higher cellulose content and lower charge level compared to the fines fraction of the hemicellulose and lignin-rich TMP. Fibre length-weighteddistribution plays a vital role with respect to both pressure fluctuations and clogging during treatment in the homogenizing equipment.

     

  • 29.
    Osong, Sinke Henshaw
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Paper strength improvement by inclusion of nano-ligno-cellulose to Chemi-thermomechanical pulp2014In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 29, no 2, p. 309-316Article in journal (Refereed)
    Abstract [en]

    So far, chemical pulp fibres have been utilized as conventional stock materials for nanocellulose production. The main aim of this work is to use stock materials from mechanical or chemi-thermomechanical pulping process to produce lignin containing nanofibres, which are referred to as nano-ligno-cellulose (NLC) in this study. The present study shows the influence on handsheets of chemi-thermomechanical pulp (CTMP) fibres blended with NLC. For comparison reasons, nanocellulose (NC) from bleached kraft pulp (BKP) was produced in a similar approach as NLC. Both the NLC and the NC were blended with their respective pulp fibres and their corresponding handsheets properties were evaluated with respect to sheet density. It was found that the handsheets of pulp fibres blended with NLC/NC improved the mechanical properties of handsheets with only a slight effect in relation to the sheet density. Improvements in strength properties of handsheets such as z-strength, tensile index, tear index, burst index, E-modulus, strain at break, tensile stiffness, air resistance were observed.

  • 30.
    Osong, Sinke Henshaw
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Processing of wood-based microfibrillated cellulose and nanofibrillated cellulose, and applications relating to papermaking: a review2016In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 23, no 1, p. 93-123Article, review/survey (Refereed)
    Abstract [en]

    As an emerging cellulosic nanomaterial, microfibrillated cellulose (MFC) and nanofibrillated cellulose (NFC) have shown enormous potential in the forest products industry. The forest products industry and academia are working together to realise the possibilities of commercializing MFC and NFC. However, there are still needs to improve the processing, characterisation and material properties of nanocellulose in order to realise its full potential. The annual number of research publications and patents on nanocellulose with respect to manufacturing, properties and applications is now up in the thousands, so it is of the utmost importance to review articles that endeavour to research on this explosive topic of cellulose nanomaterials. This review examines the past and current situation of wood-based MFC and NFC in relation to its processing and applications relating to papermaking.

  • 31.
    Osong, Sinke Henshaw
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Lundberg, M.
    PulpEye AB, Box 279, SE-891 26 Örnsköldsvik, Sweden.
    Hansen, P.
    INNVENTIA AB, Drottning Kristinas vag 61, Stockholm, Sweden .
    Development of nano-ligno-cellulose produced from mechanical pulp2014In: International Mechanical Pulping Conference, IMPC 2014, 2014Conference paper (Refereed)
    Abstract [en]

    The objective in this work was to develop a methodology for producing mechanical pulp based nano-ligno-cellulose (NLC) from fines fractions. Also there has been a great deal of enthusiasm to evaluate particle size distribution of NLC. In this work the crill characterisation technique was used. The crill values of TMP and CTMP based nano-ligno-celluloses were measured as a function of the homogenisation time. Results showed that the crill value of both TMP-NLC and CTMP-NLC correlated with the homogenisation time. Another objective was to utilise NLC as strength additives in paper and board grades. Laboratory sheets of CTMP and bleached kraft pulp (BKP), with the addition of their respective NLC, were made in a Rapid Kothen sheet former. It was found that handsheets of pulp fibres blended with NLC improved the z- strength and other important mechanical properties for similar sheet densities.

  • 32.
    Osong, Sinke Henshaw
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Lundberg, Mathias
    PulpEye AB, Box 279, SE-891 26 Örnsköldsvik, Sweden.
    Hansen, Peter
    INNVENTIA AB, Drottning Kristinas väg 61, Stockholm, Sweden.
    Crill: A novel technique to characterize nano-ligno-cellulose2014In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 29, no 2, p. 190-194Article in journal (Refereed)
    Abstract [en]

    The CrillEye is a technique for qualitatively assessing loose slender and fibrillar particles created during pulping. It has also been demonstrated that the crill measurement technique can easily be used to measure the degree of fibrillation of mechanical pulp based nano-ligno-cellulose (NLC). The measurement technique is based on an optical response of a suspension at two wavelengths of light; UV and IR. The UV light contains information on both fibres and crill, while IR only contains information on fibres. The resolution on the CrillEye module is based on optical response of the pulp and on an analogue signal analysis making it concentration independent. Characterization of particle-size distribution of nano-ligno-cellulose is both important and challenging. The objective of the work presented in this paper was to study the crill values of TMP and CTMP based nano-ligno-celluloses as a function of homogenization time. Results showed that the crill value of both TMP-NLC and CTMP-NLC correlated fairly well with the homogenization time.

  • 33.
    Pettersson, Gunilla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Sjöberg, Jessica
    SCA Östrand Mill, SE-86181 Timra, Sweden.
    Peng, Frank
    Stora Enso Res Ctr, SE-65637 Karlstad, Sweden.
    Hallgren, Hans
    Stora Enso Res Ctr, SE-65637 Karlstad, Sweden.
    Moberg, Anders
    Stora Enso Res Ctr, SE-65637 Karlstad, Sweden.
    Ljungqvist, Carl-Henrik
    Stora Enso Res Ctr, SE-65637 Karlstad, Sweden.
    Bergström, Jörgen
    SCA Östrand Mill, SE-86181 Timra, Sweden.
    Solberg, Daniel
    SCA Östrand Mill, SE-86181 Timra, Sweden.
    Strong and bulky paperboard sheets from surface modified CTMP, manufactured at low energy2015In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 30, no 2, p. 318-324Article in journal (Refereed)
    Abstract [en]

    A description is given regarding methods used to manufacture strong and bulky sheets from furnishes based on a broad range of surface modified CTMP qualities. Starch and CMC are adsorbed on the fibre surfaces using a multilayer or a MIX concept. It is shown that both the in-plane and out-of-plane strength for the CTMP based sheets after such surface treatment can be more than doubled at a maintained density. This can be utilized to improve bending stiffness or to reduce the basis weight in multi-ply paperboards.

  • 34.
    Pettersson, Gunilla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Sjöberg, J. C.
    SCA Östrand Pulp Mill, SE-861 81 Timrå, Sweden .
    Peng, F.
    Stora Enso Research Centre, SE-656 37 Karlstad, Sweden.
    Bergström, J.
    SCA Östrand Pulp Mill, SE-861 81 Timrå, Sweden .
    Solberg, D.
    SCA Östrand Pulp Mill, SE-861 81 Timrå, Sweden .
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Hallgren, H.
    Stora Enso Research Centre, SE-656 37 Karlstad, Sweden.
    Moberg, A.
    Stora Enso Research Centre, SE-656 37 Karlstad, Sweden.
    Ljungqvist, C. -H
    Stora Enso Research Centre, SE-656 37 Karlstad, Sweden.
    Strong and bulky paperboard plies from low energy CTMP2014In: International Mechanical Pulping Conference, IMPC 2014, 2014Conference paper (Refereed)
    Abstract [en]

    A description is given regarding methods used to manufacture strong and bulky sheets from furnishes based on a broad range of surface modified CTMP qualities. Starch and CMC are adsorbed on the fibre surfaces using a multilayer or a MIX concept. It is shown that both the in-plane and out-of-plane strength for the CTMP based sheets after such surface treatment can be more than doubled at a maintained density. This can be utilized to improve bending stiffness or to reduce the basis weight in multi-ply paperboards.

  • 35.
    Pettersson, Gunilla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Strong paper from spruce CTMP2016In: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, p. 229-233Conference paper (Refereed)
    Abstract [en]

    This study was carried out on sheets from spruce CTMP fibers, which are surface treated with a mix of cationic starch and CMC and blended with 20% bleach softwood chemical pulp fibers before handsheets were prepared in a Rapid Kothen sheet former, where the sheets were dried to 40-55% d.c. The sheets were pressed in a hot press nip in a pilot machine with adjustable pressure and heat. Both low and high nip pressure were used in combination with two different nip temperatures, 80 °C and 100 °C, to achieve sheets in a broad range of densities. The results show that remarkable improvements are possible, both in terms of tensile index (up to 85 kNm/kg) and compression strength, SCT, (up to 38kNm/kg) on the CTMP-based sheets under optimal conditions at papermaking, i.e. consolidate the sheet structure in a press nip at evaluated temperatures. It is evident from the current study that there is an as of yet unexploited potential in modifying the conditions of papermaking from spruce CTMP furnishes, which can be utilized for the manufacturing of papers with high requirements on strength and stiffness, e.g. packaging papers.

  • 36.
    Pettersson, Gunilla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Strong paper from spruce CTMP - Part I2017In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, no 1, p. 54-58Article in journal (Refereed)
    Abstract [en]

    This study was carried out on sheets from spruce CTMP fibers, which are surface treated with a mix of cationic starch and CMC and blended with 20% bleach softwood chemical pulp fibers before handsheets were prepared in a Rapid Köthen sheet former, where the sheets were dried to 40-55% d.c. The sheets were pressed in a hot press nip in a pilot machine with adjustable pressure and heat. Both low and high nip pressure were used in combination with two different nip temperatures, 80°C and 100°C, to achieve sheets in a broad range of densities. The results show that remarkable improvements are possible, both in terms of tensile index (up to 85 kNm/kg) and compression strength, SCT, (up to 38 kNm/kg) on the CTMP-based sheets under optimal conditions at papermaking, i.e. consolidate the sheet structure in a press nip at evaluated temperatures. It is evident from the current study that there is an as of yet unexploited potential in modifying the conditions of papermaking from spruce CTMP furnishes, which can be utilized for the manufacturing of papers with high requirements on strength and stiffness, e.g. packaging papers.

  • 37.
    Pettersson, Gunilla
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Norgren, Sven
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Höglund, Hans
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Engstrand, Per
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Low energy CTMP in strong and bulky paperboard plies2016In: Paper Conference and Trade Show, PaperCon 2016, TAPPI Press, 2016, Vol. 1, p. 556-564Conference paper (Refereed)
1 - 37 of 37
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