@misc{10333, abstract = {{The wood from oil palm trunks exhibits significant variations in distribution of structural tissue, density and elastomechanical properties across and along the trunk. Its reliable, safe, and economic usage for load-bearing purposes, such as glued laminated timber (GLT), requires a precise definition of its elastomechanical properties through appropriate strength grading procedures. Oil palm lumber is strength graded according to its density using an X-ray technique in which 50 % of the lamellas are ripped, graded, edge glued and therefore density homogenized, and 50 % are cut only according to their geometry. Lamellas are tested in tension parallel to the vascular bundles; combined GLT is produced from strength-graded lamellas and tested in bending parallel and compression parallel and perpendicular to the vascular bundles. The characteristic strength values for C10 and C14 according to EN 338 are achieved. A correlation between density and elastomechanical properties is estab-lished. GLT from density-homogenized lamellas achieve higher bending properties than from lamellas with a “natural” density gradient across the width.}}, author = {{Frühwald-König, Katja}}, booktitle = {{Timber for a livable future : World Conference on Timber Engineering : WCTE 2023 : 19-22 June 2023, Oslo, Norway }}, editor = {{Nyrud, Andres Q. and Malo, Kjell Arne and Nore, Kristine}}, isbn = {{9781713873297}}, keywords = {{Oil palm lumber, glue laminated timber, GLT, strength grading, elastomechanical properties}}, location = {{Oslo, Norway}}, pages = {{638--646}}, publisher = {{Curran Associates, Inc. }}, title = {{{Elastomechanical Properties of Glued Laminated Timber made of Strength Graded Oil Palm Lumber}}}, doi = {{https://doi.org/10.52202/069179-0087}}, year = {{2023}}, } @misc{10334, author = {{Frühwald-König, Katja}}, location = {{Olsberg}}, title = {{{Technische Eigenschaften der Birke und Einsatz im Ingenieurholzbau}}}, year = {{2023}}, } @misc{10335, author = {{Frühwald-König, Katja}}, title = {{{Die Holzbauinitiative der Bundesregierung}}}, year = {{2023}}, } @misc{10336, author = {{Frühwald-König, Katja and Wieland, Stefanie}}, booktitle = {{ 5. Aachener Holzbautagung 2023}}, location = {{Aachen}}, publisher = {{Aachen}}, title = {{{Wald im Klimawandel - Einsatz von Birke im Holzbau}}}, year = {{2023}}, } @misc{10602, abstract = {{The anatomical structure of oil palm wood is only to a limited extent comparable to common wood species used in construction. Typical for monocotyledons, the material is composed of high density vascular bundles and a parenchymatous tissue of lower density. In three experiment sets, the local and global moduli of elasticity (MOE) and the flexural strength of oil palm wood based GLT are determined using FEM and various influencing parameters are investigated in a sensitivity analysis. Furthermore, the application of densified tension lamellas is studied. The results of the modelling are compared with the results from mechanical tests. Significant differences, mainly attributed to the specific parameters of the selected material, are observed. The results of this preliminary study serve as a starting point for computer-aided optimisation and modelling of other oil palm-based products.}}, author = {{Hackel, Martin}}, booktitle = {{Timber for a livable future : World Conference on Timber Engineering : WCTE 2023 : 19-22 June 2023, Oslo, Norway }}, editor = {{Nyrud, Anders Q. }}, isbn = {{978-1-7138-7329-7}}, keywords = {{Oil palm wood, finite element method (FEM), GLT, modulus of elasticity, flexural strength}}, location = {{Oslo (Norwegen)}}, publisher = {{Curran Associates, Inc.}}, title = {{{FLEXURAL PROPERTIES OF OIL PALM WOOD BASED GLUE LAMINATED TIMBER USING FINITE ELEMENT METHOD}}}, doi = {{10.52202/069179-0088}}, year = {{2023}}, } @misc{10604, author = {{Hackel, Martin}}, booktitle = {{Computational methods in wood mechanics: CompWood 2023 : Dresden, Germany, 5-8 September 2023 }}, isbn = {{978-84-123222-7-9}}, location = {{Dresden}}, pages = {{83--85}}, publisher = {{International Center for Numerical Methods in Enginering (CIMNE), }}, title = {{{Numerical and Experimental Study of Flexural Properties of Cross-Laminated Timber (CLT) from Oil Palm Wood (Elaeis guineensis JACQ.)}}}, year = {{2023}}, } @misc{10605, author = {{Hackel, Martin}}, location = {{Werl}}, title = {{{Potenziale der Nutzung klimastabiler Holzarten}}}, year = {{2023}}, } @misc{10606, author = {{Hackel, Martin}}, location = {{Bilbao (Spanien)}}, title = {{{Smart Wood Center OWL}}}, year = {{2023}}, } @misc{10709, author = {{Frühwald-König, Katja}}, location = {{Arnsberg}}, title = {{{Wald im Klimawandel - Neue Holzarten für das Bauen mit Holz}}}, year = {{2023}}, } @misc{10786, abstract = {{The anatomical structure of oil palm wood is only to a limited extent comparable to common wood species used in construction. Typical for monocotyledons, the material is composed of high density vascular bundles and a parenchymatous tissue of lower density. In three experiment sets, the local and global moduli of elasticity (MOE) and the flexural strength of oil palm wood based GLT are determined using FEM and various influencing parameters are investigated in a sensitivity analysis. Furthermore, the application of densified tension lamellas is studied. The results of the modelling are compared with the results from mechanical tests. Significant differences, mainly attributed to the specific parameters of the selected material, are observed. The results of this preliminary study serve as a starting point for computer-aided optimisation and modelling of other oil palm-based products.}}, author = {{Hackel, Martin}}, booktitle = {{World Conference on Timber Engineering (WCTE 2023)}}, keywords = {{Oil palm wood, finite element method (FEM), GLT, modulus of elasticity, flexural strength}}, location = {{Oslo (Norwegen)}}, pages = {{647--656}}, publisher = {{World Conference on Timber Engineering (WCTE 2023)}}, title = {{{FLEXURAL PROPERTIES OF OIL PALM WOOD BASED GLUE LAMINATED TIMBER USING FINITE ELEMENT METHOD}}}, doi = {{10.52202/069179-0088}}, year = {{2023}}, } @misc{10874, author = {{Frühwald-König, Katja}}, location = {{Riyadh, Saudi-Arabien}}, title = {{{Mechanical Dewatering of Oil Palm Lumber to Reduce Costs and Improve Quality.}}}, year = {{2023}}, } @misc{10875, author = {{Frühwald-König, Katja}}, location = {{Riyadh, Saudi-Arabien}}, title = {{{Cross Laminated Timber (CLT) made of Oil Palm Wood (Elaeis guineensis JACQ.)}}}, year = {{2023}}, } @misc{8401, abstract = {{200 million m³ oil palm trunks per year are still a “waste by-product”. For generating added-value, material modelling and product optimization and therefore knowledge of the elastic properties are required. Apart from Young´s modulus parallel to the vascular bundles, the elastic properties of oil palm wood are not known. The applicability of ultrasonic testing (time of flight of three longitudinal, six shear and three quasi-shear wave measurements) for the characterization of all 12 elastic constants of oil palm wood hav-ing various densities was investigated under the assumption of an orthotropic material behavior. For the evaluation, the simplified uncorrected and the full stiffness inversion method were used. The lack of correlation between the density and the ultrasonic velocity when using flat transducers questions the applicability of this method for oil palm wood.}}, author = {{Frühwald-König, Katja and Faust, Benedikt}}, booktitle = {{Proceedings 22nd International Nondestructive Testing and Evaluation of Wood Symposium}}, location = {{Quebec City, Canada}}, pages = {{29--39}}, publisher = {{U.S. Department of Agriculture, Forest Service, Forest Products Laboratory}}, title = {{{Evaluation of Elastic Constants of Oil Palm Wood using Ultrasonic Measurement}}}, year = {{2022}}, } @misc{8926, author = {{Frühwald-König, Katja}}, location = {{Lichtenau/Westfalen}}, title = {{{Aktueller/künftiger Holzbedarf und Holzverwendung (stofflich und energetisch)}}}, year = {{2022}}, } @misc{8927, author = {{Wieland, Stefanie and Frühwald-König, Katja}}, location = {{Lichtenau/Westfalen}}, title = {{{Wald im Klimawandel - Neue Holzarten für das Bauen mit Holz}}}, year = {{2022}}, } @inbook{10593, abstract = {{Due to shorter rotation cycles compared to other palm species, oil palm wood has lower densities, a wider density range (150–600 kg/m3 dry), and a high moisture content. The moisture content varies, reversely to the density, with the highest values of up to 600% at the trunk core, especially at the top of the palm trunk. Kiln drying material with such low density, very high moisture content and high sugar and starch content is difficult and often produces drying defects such as cell collapse, cracks, and mold. Mechanical dewatering of wet oil palm lumber in an unheated double roller press reduces the water content and generates sugar-containing pressed water (sap) that could be used as a source for biochemicals. The share of mechanically removed water varied from 1 to >54% of the total water removed from wet to dry state (at 20 °C, 65% rh). Center boards from the top of the trunk had the highest dewatering rates while boards from the periphery at the bottom of the trunk (high density, low water content) showed the lowest.}}, author = {{Frühwald-König, Katja and Kölli, Nathan and Frühwald, Arno}}, booktitle = {{ Proceedings of 2nd World Conference on Byproducts of Palms and Their Applications }}, editor = {{Jawaid, Mohammad and Midani, Mohamad and Khiari, Ramzi}}, isbn = {{978-981-19-6194-6 }}, issn = {{2662-3161}}, location = {{Kuala Lumpur, Malaysia}}, publisher = {{Springer Nature Singapore}}, title = {{{Mechanical Dewatering of Wet Oil Palm Lumber Prior to Press-Drying}}}, doi = {{https://doi.org/10.1007/978-981-19-6195-3_2}}, year = {{2022}}, } @misc{10594, author = {{Hackel, Martin}}, location = {{Göttingen}}, title = {{{Elastic flexural properties of oil palm wood based glue laminated timber determined using the finite element method (FEM)}}}, year = {{2022}}, } @misc{10595, author = {{Hackel, Martin}}, location = {{Göttingen}}, title = {{{Elastic flexural properties of oil palm wood based glue laminated timber determined using the finite element method (FEM)}}}, year = {{2022}}, } @misc{10599, author = {{Hackel, Martin}}, booktitle = {{Aus der Praxis - für die Praxis : 26. Internationale Holzbau-Forum (IHF) / Forum Holzbau International ; Volume 3: Master Colloquium : December 1, 2022}}, isbn = {{9783906226507}}, location = {{Innsbruck (Österreich)}}, publisher = {{Forum Holzbau}}, title = {{{Investigation of Flexural Properties of Glued Laminated Timber Composed of Oil Palm Wood}}}, year = {{2022}}, } @misc{10600, author = {{Hackel, Martin}}, location = {{Innsbruck (Österreich)}}, title = {{{Investigation of Flexural Properties of Glued Laminated Timber Composed of Oil Palm Wood}}}, year = {{2022}}, } @inproceedings{6913, author = {{Frühwald, Arno and Frühwald-König, Katja and Loh, Yueh Feng}}, location = {{online}}, title = {{{Future Potential of Palm (Trunk) Fiber in Supplementing Timber: Quantities, Techniques, Challenges, Opportunities}}}, year = {{2021}}, } @inproceedings{6940, author = {{Frühwald-König, Katja}}, location = {{online}}, title = {{{Properties of Oil Palm Wood Relevant for Material Use}}}, year = {{2021}}, } @inproceedings{6941, author = {{Frühwald-König, Katja and Heister, Lena}}, location = {{online}}, title = {{{Grading of OP-Lumber – Techniques and Chances for Up-Grading Materials}}}, year = {{2021}}, } @inproceedings{6943, author = {{Heister, Lena and Frühwald-König, Katja}}, location = {{online}}, title = {{{GLT from Oil Palm Wood - Build-Up, Production and Elastomechanical Properties}}}, year = {{2021}}, } @inproceedings{6944, author = {{Frühwald, Arno and Frühwald-König, Katja}}, location = {{online}}, title = {{{Coconut Wood: Properties, Processing and Products}}}, year = {{2021}}, } @inproceedings{6945, abstract = {{Sustainable use of renewable raw materials is an important issue of policy and industry. Wood prices are rising because of increasing market demand while simultaneously forests are challenged through conservation issues, deforestation and hazards. The main reasons for deforestation are agriculture, infrastructure and wood harvesting. Oil palm plantations stock on former tropical forest land and cover some 25 Mio ha worldwide. They are replanted every 25 years due to reduced productivity. Using the available wooden trunk material of the cleared plantation not only makes sense in ecological terms but is also a big chance for economy and trade. Research over the last 30 years has led to several ideas in the use for products. The biggest challenge is the anatomical structure of palm wood which is different to coniferous or broadleaf trees. Hard vascular bundles are embedded in low-density parenchyma storage tissue with high moisture content. The soft and sponge-like parenchyma tissue can be compressed easily and a significant share of the water (mc up to 600 % based on dry wood) can be squeezed out. Through press drying, the volume of the parenchyma can be reduced and the wood density increases. Wood strength and stiffness are related to its density and can be improved by densification. TH OWL developed a four-step densification process for oil palm boards. Oil palm lumber was produced from oil palm trunks in a sawmill and then densified under defined conditions. The densification process includes (1) compression to remove a certain percentage of the palm sap, (2) plastification under heat and moisture to soften the wood, (3) hot compression to achieve the densification and remove more water, and (4) press-drying to dry and harden the material. A future perspective on how the laboratory tests could be scaled up to an industrial application with a possible machinery set-up is presented. }}, author = {{Kölli, Nathan}}, booktitle = {{6th International Conference on Process Technologies for the Forest and Biobased Products Industries PTF BPI 2021 }}, editor = {{Young , Timothy M. and Petutschnigg, Alexander }}, keywords = {{Oil Palm Wood, Densification, Drying}}, location = {{St. Simons Island, Georgia / USA}}, title = {{{Densification and Press-Drying of Wet Oil Palm Lumber}}}, year = {{2021}}, } @inproceedings{6946, author = {{Frühwald-König, Katja}}, location = {{Düsseldorf}}, title = {{{Mit Holzprodukten nachhaltig in die Zukunft bei veränderten Holzsortimenten}}}, year = {{2021}}, } @misc{10703, author = {{Frühwald-König, Katja}}, location = {{online}}, title = {{{Was kann Holz - außer klimafreundlich?}}}, year = {{2021}}, } @inproceedings{6947, author = {{Frühwald-König, Katja}}, location = {{Portoroz / Slowenien (online)}}, title = {{{Mechanical Properties versus Structure of Oil Palm Wood (Elais gueneensis Jacq.)}}}, year = {{2020}}, }