Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 68) Show all publications
Sjökvist, T., Blom, Å. & Wålinder, M. (2019). The infuence of heartwood, sapwood and density on moisture fuctuations and crack formations of coated Norway spruce in outdoor exposure. Journal of Wood Science, 65(45)
Open this publication in new window or tab >>The infuence of heartwood, sapwood and density on moisture fuctuations and crack formations of coated Norway spruce in outdoor exposure
2019 (English)In: Journal of Wood Science, ISSN 1435-0211, E-ISSN 1611-4663, Vol. 65, no 45Article in journal (Refereed) Published
Abstract [en]

The moisture sorption behaviour of wood strongly influences the durability of exterior-coated wood. Wood characteristics are known to influence the water sorption of uncoated wood. Despite this, the majority of the research on coated wood has been focused on the coating properties. This study aims to investigate the impact of heartwood, sapwood and density on the moisture content (MC) and crack formation of coated Norway spruce (Picea abies (L.) Karst.). Boards with film-forming coatings or a non-film-forming coating were exposed outdoors during 3 years. Crack development and the mass of the boards were recorded during this period. Heartwood and sapwood samples showed no differences in MC. Thus, a coating seems to reduce the differences in water sorption behaviour that is present in uncoated heartwood and sapwood spruce. The reduction is probably related to wetting properties and different sorption mechanisms, involving free and bond water diffusion. However, the low-density samples had significantly higher MC levels than the high-density samples. The high-density samples with a non-film-forming coating showed a higher number of cracks than those with lower density. Furthermore, sapwood samples had a remarkably high number of cracks when compared to the corresponding heartwood samples, despite a similar density and MC.

Place, publisher, year, edition, pages
Springer, 2019
Keywords
Exterior wood coatings, Alkyd, Acrylic, Water-borne coating, Growth ring width permeability, Weathering
National Category
Other Civil Engineering
Research subject
Civil and Architectural Engineering, Building Materials
Identifiers
urn:nbn:se:kth:diva-259998 (URN)10.1186/s10086-019-1825-1 (DOI)000486489400001 ()
Funder
Swedish Research Council Formas, EnWoBio 2014-172
Note

QC 20191004

Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-10-04Bibliographically approved
Peñaloza, D., Erlandsson, M., Berlin, J., Wålinder, M. & Falk, A. (2018). Future scenarios for climate mitigation of new construction in Sweden: Effects of different technological pathways. Journal of Cleaner Production, 187, 1025-1035
Open this publication in new window or tab >>Future scenarios for climate mitigation of new construction in Sweden: Effects of different technological pathways
Show others...
2018 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 187, p. 1025-1035Article in journal (Refereed) Published
Abstract [en]

A variety of climate mitigation strategies is available to mitigate climate impacts of buildings. Several studies evaluating the effectiveness of these strategies have been performed at the building stock level, but do not consider the technological change in building material manufacturing. The objective of this study is to evaluate the climate mitigation effects of increasing the use of biobased materials in the construction of new residential dwellings in Sweden under future scenarios related to technological change. A model to estimate the climate impact from Swedish new dwellings has been proposed combining official statistics and life cycle assessment data of seven different dwelling typologies. Eight future scenarios for increased use of harvested wood products are explored under different pathways for changes in the market share of typologies and in energy generation. The results show that an increased use of harvested wood products results in lower climate impacts in all scenarios evaluated, but reductions decrease if the use of low-impact concrete expands more rapidly or under optimistic energy scenarios. Results are highly sensitive to the choice of climate impact metric. The Swedish construction sector can only reach maximum climate change mitigation scenarios if the low-impact building typologies are implemented together and rapidly.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Building stock, Life cycle assessment, Low-carbon buildings, Climate scenarios, Biobased materials, Bioeconomy
National Category
Other Environmental Engineering
Identifiers
urn:nbn:se:kth:diva-230474 (URN)10.1016/j.jclepro.2018.03.285 (DOI)000432102500089 ()2-s2.0-85047457062 (Scopus ID)
Note

QC 20180613

Available from: 2018-06-13 Created: 2018-06-13 Last updated: 2018-06-13Bibliographically approved
Källbom, S., Altgen, M., Militz, H. & Wålinder, M. (2018). Sorption and surface energy properties of thermally modified spruce wood components. Wood and Fiber Science, 50(3), 346-357
Open this publication in new window or tab >>Sorption and surface energy properties of thermally modified spruce wood components
2018 (English)In: Wood and Fiber Science, ISSN 0735-6161, Vol. 50, no 3, p. 346-357Article in journal (Refereed) Published
Abstract [en]

The objective of this work is to study the water vapor sorption and surface energy properties of thermally modified wood (TMW) components, ie wood processing residuals in the form of sawdust. The thermal modification was performed on spruce wood components using a steam-pressurized laboratoryscale reactor at two different temperature (T) and relative humidity (RH) conditions, T = 150 degrees C and RH = 100% (TMW150), and T = 180 degrees C and RH = 46% (TMW180). A dynamic vapor sorption (DVS) technique was used to determine water vapor sorption isotherms of the samples for three adsorption-desorption cycles at varying RH between 0% and 95%. Inverse gas chromatography (IGC) was used to study the surface energy properties of the samples, including dispersive and polar characteristics. The DVS results showed that the EMC was reduced by 30-50% for the TMW samples compared with control samples of unmodified wood (UW) components. A lower reduction was, however, observed for the second and third adsorption cycles compared with that of the first cycle. Ratios between EMC of TMW and that of UW samples were lower for the TMW180 compared with the TMW150 samples, and an overall decrease in such EMC ratios was observed at higher RH for both TMW samples. The IGC results showed that the dispersive contribution to the surface energy was higher at lower surface coverages, ie representing the higher energy sites, for the TMW compared with the UW samples. In addition, an analysis of the acid-base properties indicated a higher KB than KA number, ie a higher basic than acidic contribution to the surface energy, for all the samples. A higher KB number was also observed for the TMW compared with the UW samples, suggested to relate to the presence of ether bonds from increased lignin and/or extractives content at the surface. The KB was lower for TMW180 compared with TMW150, as a result of higher modification temperature of the first, leading to cleavage of these ether bonds.

Place, publisher, year, edition, pages
Society of Wood Science and Technology, 2018
Keywords
Thermally modified wood, dynamic vapor sorption (DVS), inverse gas chromatography (IGC), Norway spruce, surface energy, acid-base properties
National Category
Other Engineering and Technologies
Identifiers
urn:nbn:se:kth:diva-232780 (URN)000439305600010 ()2-s2.0-85050353079 (Scopus ID)
Funder
Swedish Research Council Formas, EnWoBio 2014-172
Note

QC 20180803

Available from: 2018-08-03 Created: 2018-08-03 Last updated: 2018-08-24Bibliographically approved
Larsson, M., Wålinder, M. & Falk, A. (2018). Teleodynamic timber façades. Frontiers in Built Environment, 4, Article ID 37.
Open this publication in new window or tab >>Teleodynamic timber façades
2018 (English)In: Frontiers in Built Environment, ISSN 2297-3362, Vol. 4, article id 37Article in journal (Refereed) Published
Abstract [en]

This paper investigates ways in which weathering-related site conditions can be allowed to inform the design process in order to improve a building's geometry and performance. Providing a building design with the capacity to remember past experiences and anticipate future events can provide substantial gains to the architectural configuration and engineering of a timber façade. A new theory of architecture is outlined based on recent “teleodynamic” theories—a hypothesis about the way far-from-equilibrium systems interact and combine to produce emergent patterns. The proposed explanation considers nested levels of thermodynamic systems applied to an architectural context: “homeodynamic” operations that involve equilibration and dissipation of constraint combine to produce self-organising “morphodynamic” procedures that amplify and regularise site-specific constraining data streams. A teleodynamic design reconstitutes itself by combining morphodynamic processes so as to optimise its relationship to the past, present, and future. A novel teleodynamic design tool called Contextual Optimisation Workspace (COW) is assembled within the Grasshopper visual programming environment. The tool is used to carry out four experiments that combine to produce the teleodynamic design of an urban wooden façade, exemplifying an alternative framework for the design of wood-based structures. The first experiment investigates a variegated grid combining two distinct subdivision methods (an orthogonal grid and a Voronoi tessellation), transmuting one system into another. The second and third experiments focus on durability aspects of a wooden façade and devise strategies for how the effects of photochemical degradation and wetting due to driving rain might be minimised using the COW tool. The fourth experiment optimises the building for daylight based on an illuminance simulation. Using simulation and anticipation to add the advantages of site- and time-specific data streams as a design strategy can effectively suspend an algorithm-driven design iteration in time and space in order to allow it to be parametrically influenced by past or future events such as unique site and project conditions. The COW tool can be used to produce such teleodynamic designs.

Place, publisher, year, edition, pages
Frontiers Media S.A., 2018
Keywords
EnWoBio Pavilion, Façade, Multiple-objective optimisation, Preservation-treated wood, Teleodynamic architecture, Timber, Wooden structures
National Category
Civil Engineering
Identifiers
urn:nbn:se:kth:diva-252263 (URN)10.3389/fbuil.2018.00037 (DOI)2-s2.0-85064649322 (Scopus ID)
Note

QC20190607

Available from: 2019-06-07 Created: 2019-06-07 Last updated: 2019-06-07Bibliographically approved
Sedighi Moghaddam, M., Van den Bulcke, J., Wålinder, M. E. P., Claesson, P. M., Van Acker, J. & Swerin, A. (2017). Microstructure of chemically modified wood using X-ray computed tomography in relation to wetting properties. Holzforschung, 71(2), 119-128
Open this publication in new window or tab >>Microstructure of chemically modified wood using X-ray computed tomography in relation to wetting properties
Show others...
2017 (English)In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 71, no 2, p. 119-128Article in journal (Refereed) Published
Abstract [en]

X-ray computed tomography (XCT) was utilized to visualize and quantify the 2D and 3D microstructure of acetylated southern yellow pine (pine) and maple, as well as furfurylated pine samples. The total porosity and the porosity of different cell types, as well as cell wall thickness and maximum opening of tracheid lumens were evaluated. The wetting properties (swelling and capillary uptake) were related to these microstructural characteristics. The data show significant changes in the wood structure for furfurylated pine sapwood samples, including a change in tracheid shape and filling of tracheids by furan polymer. In contrast, no such changes were noted for the acetylated pine samples at the high resolution of 0.8 mu m. The XCT images obtained for the furfurylated maple samples demonstrated that all ray cells and some vessel elements were filled with furan polymer while the fibers largely remained unchanged. Furfurylation significantly decreased the total porosity of both the maple and pine samples. Furthermore, this was observed in both earlywood (EW) and latewood (LW) regions in the pine samples. In contrast, the total porosity of pine samples was hardly affected by acetylation. These findings are in line with wetting results demonstrating that furfurylation reduces both swelling and capillary uptake in contrast to acetylation which reduces mostly swelling. Furfurylation significantly increased the cell wall thickness of both the maple and pine samples, especially at higher levels of furfurylation.

Place, publisher, year, edition, pages
WALTER DE GRUYTER GMBH, 2017
Keywords
acetylation, cell wall thickness, furfurylation, hardwood, microstructure, porosity, softwood, sub-micron X-ray computed tomography, tracheid, wettability
National Category
Wood Science
Identifiers
urn:nbn:se:kth:diva-204696 (URN)10.1515/hf-2015-0227 (DOI)000394124800004 ()2-s2.0-85011867252 (Scopus ID)
Funder
EU, FP7, Seventh Framework Programme, 284181Swedish Research Council Formas, 2014-172
Note

QC 20170602

Available from: 2017-06-02 Created: 2017-06-02 Last updated: 2017-06-02Bibliographically approved
Falk, A. & Wålinder, M. (2016). Function and design of innovative bio-based products for the building sector. In: Structures and Architecture - Proceedings of the 3rd International Conference on Structures and Architecture, ICSA 2016: . Paper presented at 3rd International Conference on Structures and Architecture, ICSA 2016, 27 July 2016 through 29 July 2016 (pp. 93-101). CRC Press/Balkema
Open this publication in new window or tab >>Function and design of innovative bio-based products for the building sector
2016 (English)In: Structures and Architecture - Proceedings of the 3rd International Conference on Structures and Architecture, ICSA 2016, CRC Press/Balkema , 2016, p. 93-101Conference paper, Published paper (Refereed)
Abstract [en]

This paper will present a study of preconditions for competitiveness in a resource saving society. Preconditions for material suppliers and industry versus requirements from legislation and consumers means a balance, which can be difficult to manage. The paper is aiming for an analysis of the preconditions for property modification, innovation and marketing of biobased materials and products, and the paper deals with strategies to release the architectural potential of bio-based construction. 

Place, publisher, year, edition, pages
CRC Press/Balkema, 2016
Keywords
Architecture, Bio-based, Bio-based materials, Bio-based products, Building sectors, Material suppliers, Resource savings, Product design
National Category
Civil Engineering
Identifiers
urn:nbn:se:kth:diva-207550 (URN)2-s2.0-85014998126 (Scopus ID)9781138026513 (ISBN)
Conference
3rd International Conference on Structures and Architecture, ICSA 2016, 27 July 2016 through 29 July 2016
Note

Conference code: 177949; Export Date: 22 May 2017; Conference Paper; Funding details: 874/15, KTH, Kungliga Tekniska Högskolan; Funding text: This study is carried out as part of the EnWoBio - the Engineered Wood and Bio-based materials and products laboratory at KTH Building Materials, with funding from the Troëdsson’s foundation for scientific research (project number 874/15). QC 20170531

Available from: 2017-05-31 Created: 2017-05-31 Last updated: 2017-05-31Bibliographically approved
Sedighi Moghaddam, M., Heydarihamedani, G., Tuominen, M., Fielden, M., Haapanen, J., Mäkelä, J. M., . . . Swerin, A. (2016). Hydrophobisation of wood surfaces by combining liquid flame spray (LFS)and plasma treatment: dynamic wetting properties. Holzforschung, 70(6), 527-537
Open this publication in new window or tab >>Hydrophobisation of wood surfaces by combining liquid flame spray (LFS)and plasma treatment: dynamic wetting properties
Show others...
2016 (English)In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 70, no 6, p. 527-537Article in journal (Refereed) Published
Abstract [en]

The hydrophilic nature of wood surfaces is a major cause for water uptake and subsequent biological degradation and dimensional changes. In the present paper, a thin transparent superhydrophobic layer on pine veneer surfaces has been created for controlling surface wettability and water repellency. This effect was achieved by means of the liquid flame spray (LFS) technique, in the course of which nanoparticulate titanium dioxide (TiO2) was brought to the surface, followed by plasma polymerisation. Plasma polymerised perfluorohexane (PFH) or hexamethyldisiloxane (HMDSO) were then deposited onto the LFS-treated wood surfaces. The same treatment systems were applied to silicon wafers so as to have well-defined reference surfaces. The dynamic wettability was studied by the multicycle Wilhelmy plate method, resulting in advancing and receding contact angles as well as sorption behaviour of the samples during repeated wetting cycles in water. Atomic force microscopy (AFM) and Xray photoelectron spectroscopy (XPS) were employed to characterise the topography and surface chemical compositions and to elucidate the question how the morphology of the nanoparticles and plasma affect the wetting behaviour. A multi-scale roughness (micro-nano roughness) was found and this enhanced the forced wetting durability via a superhydrophobic effect on the surface, which was stable even after repeated wetting cycles. The hydrophobic effect of this approach was higher compared to that of plasma modified surfaces with their micro-scale modification.

Place, publisher, year, edition, pages
Walter de Gruyter, 2016
Keywords
contact angle (CA); dynamic wetting, hydrophobisation; hexamethyldisiloxane (HMDSO); liquid flame spray (LFS); multi-scale roughness; nano-sized metal oxide (TiO2); perfluorohexane (PFH); plasma polymerisation; superhydrophobicity; Wilhelmy plate method; wood.
National Category
Wood Science
Research subject
Chemistry
Identifiers
urn:nbn:se:kth:diva-175873 (URN)10.1515/hf-2015-0148 (DOI)000376680300006 ()2-s2.0-84973442118 (Scopus ID)
Funder
Swedish Research Council Formas, 2014-172
Note

QC 20161101

Available from: 2015-10-23 Created: 2015-10-23 Last updated: 2017-12-01Bibliographically approved
Tuominen, M., Teisala, H., Haapanen, J., Mäkelä, J. M., Honkanen, M., Vippola, M., . . . Swerin, A. (2016). Superamphiphobic overhang structured coating on a biobased material. Applied Surface Science, 389(December), 135-143
Open this publication in new window or tab >>Superamphiphobic overhang structured coating on a biobased material
Show others...
2016 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 389, no December, p. 135-143Article in journal (Refereed) Published
Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Biobased materialWoodCoatingPlasmaDepositionTitaniaNanoparticlePerfluorohexaneWettingSuperamphiphobicSuperhydrophobicSuperoleophobicWater repellencyOil repellencySelf-cleaning
National Category
Other Chemical Engineering
Identifiers
urn:nbn:se:kth:diva-260001 (URN)10.1016/j.apsusc.2016.05.095 (DOI)
Funder
Swedish Research Council Formas, EnWoBio 2014-172
Available from: 2019-09-24 Created: 2019-09-24 Last updated: 2019-09-24
Laine, K., Segerholm, K., Wålinder, M., Rautkari, L., Hughes, M. & Lankveld, C. (2016). Surface densification of acetylated wood. European Journal of Wood and Wood Products, 74(6), 829-835
Open this publication in new window or tab >>Surface densification of acetylated wood
Show others...
2016 (English)In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 74, no 6, p. 829-835Article in journal (Refereed) Published
Abstract [en]

The mechanical properties of wood can be improved by compressing its porous structure between heated metal plates. By adjusting the process parameters it is possible to target the densification only in the surface region of wood where the property improvements are mostly needed in applications, such as flooring. The compressed form is, however, sensitive to moisture and will recover to some extent in high humidity. In this study, therefore, acetylated radiata pine was utilised in the surface densification process in order to both reduce the set-recovery of densified wood and to improve the hardness of the acetylated wood. Pre-acetylation was found to significantly reduce the set-recovery of surface densified wood. However, after the second cycle the increase in set-recovery of acetylated wood was relatively higher than the un-acetylated wood. The acetylated samples were compressed by only 1 mm (instead of the target 2 mm), yet, the hardness and hardness recovery of the acetylated samples significantly increased as a result of densification. It was also discovered that rough (un-planed) surfaces may be surface densified, however, even if the surface became smooth to the touch, the appearance remained uneven.

Place, publisher, year, edition, pages
Springer, 2016
Keywords
Acetylation, Densification, Hardness, Recovery, Acetylated wood, Densified wood, Mechanical properties of wood, Porous structures, Process parameters, Property improvement, Surface densification, Surface region, Wood
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-195233 (URN)10.1007/s00107-016-1077-3 (DOI)000385208400005 ()2-s2.0-84976477767 (Scopus ID)
Note

QC 20161117

Available from: 2016-11-17 Created: 2016-11-02 Last updated: 2017-11-29Bibliographically approved
Ruponen, J., Kimpimäki, S., Rohumaa, A., Laine, K., Segerholm, K., Wålinder, M., . . . Hughes, M. (2016). Tensile-shear strength studies on self-bonded 2-ply birch veneer joint manufactured and tested by applying Automated Bonding Evaluation System (ABES) hot press. In: WCTE 2016 - World Conference on Timber Engineering: . Paper presented at 2016 World Conference on Timber Engineering, WCTE 2016, 22 August 2016 through 25 August 2016. Vienna University of Technology
Open this publication in new window or tab >>Tensile-shear strength studies on self-bonded 2-ply birch veneer joint manufactured and tested by applying Automated Bonding Evaluation System (ABES) hot press
Show others...
2016 (English)In: WCTE 2016 - World Conference on Timber Engineering, Vienna University of Technology , 2016Conference paper, Published paper (Refereed)
Abstract [en]

An Automatic Bond Evaluation System (ABES) hot press was employed to manufacture a self-bonded joint between two veneers of rotary-cut birch (Betula pendula Roth). The hot-pressing conditions were 220 °C and 5.0 MPa, with press times ranging from 180 s to 600 s with 60 s intervals. Additionally, the log-soaking temperature (20 °C and 70 °C) and the veneer initial MC (6% and 11%) were varied to study the effect on the tensile-shear strength of the joints. For one set, the surface properties were altered by acetone extraction. The samples were tested at 11% MC. However, one set was partly duplicated and tested at 6% MC, to study how the testing conditions influenced the bond strength. The maximum average tensile-shear strength was 3.3 MPa, observed after 600 s hot pressing. The studies also included bond-line micromorphology analysis by applying SEM combined with a micromachining surface preparation technique based on UV excimer laser ablation. It was also indicated that longer hot-pressing times, lower veneer initial MC and a lower testing MC resulted in increased tensile-shear strength. Acetone extraction decreased the bond strength with increased standard deviation. Finally, the highest single and average strengths were observed for veneers from higher soaking temperature.

Place, publisher, year, edition, pages
Vienna University of Technology, 2016
Keywords
ABES, Birch, Laser ablation, Self-bonding, SEM, Soaking temperature, Tensile-shear strength, Veneer, Ablation, Acetone, Bond strength (materials), Excimer lasers, Extraction, Hot pressing, Presses (machine tools), Scanning electron microscopy, Shear flow, Tensile testing, Thermal logging, Timber, Veneers, Self bonding, Tensile shear strength, Tensile strength
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-207528 (URN)2-s2.0-85010960673 (Scopus ID)9783903039001 (ISBN)
Conference
2016 World Conference on Timber Engineering, WCTE 2016, 22 August 2016 through 25 August 2016
Note

Conference code: 124667; Export Date: 22 May 2017; Conference Paper. QC 20170531

Available from: 2017-05-31 Created: 2017-05-31 Last updated: 2017-05-31Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9156-3161

Search in DiVA

Show all publications