Conference abstract, 2016
Comparative study on two tropical hardwoods thermally modified by Thermowood (R) and Thermovuoto (R) process
Pockrandt, Michael; Cuccui, Ignazia; Allegretti, Ottaviano; Uetimane, Ernesto; Terziev, NaskoAbstract
Thermally modified hardwood species, e. g. limba, is now being marketed in Europe for cladding and other external applications. The timber is supplied from West Africa and treated thermally in the EU. This approach opens very good possibilities for commercialisation of lesser-known tropical wood species that are hardly used nowadays. The objectives of the study were to treat thermally metil (Sterculia appendiculata) and neem (Azadirachta indica) timber originating from Mozambique under industrial conditions applying two well-recognized methods namely thermal treatment by steam (Thermowood (R)) and under vacuum (Termovuoto (R)). Matched boards were treated in industrial facilities under identical treatment conditions (temperature of 212 C, duration 3 h). Colour changes were characterised with CIELab method and it was proved that the thermal modification under vacuum generates lighter colour than that caused by steam treatment. Mass loss of the boards were measured; the difference was statistically significant for the mass loss being higher in Thermowood (R) process namely, 9.9% after vacuum and 14.1% after steam thermal treatment for metil and 12.1 and 14.2% for neem respectively. This probably can be explained by the fact that the applied vacuum removes partly the produced acetic acid from the material which catalyses sugar degradation. On the other hand, anatomical and chemical features may also play a significant role concerning the applied atmosphere. For instance, it should be noted that metil wood is more permeable than neem wood. In general the mass loss is an important predictor for the mechanical properties that are expected to be somewhat lower after thermal modification. Both thermal treatments showed good ability to mask fungal discolouration which is typical for the processing conditions in the tropics.Keywords
colour; fungal discolouration; mass loss; metil; neem; thermal modificationPublished in
Book title: Eco-efficient Resource Wood with Special Focus on Hardwoods: Sopron, 8-9 September 2016 : ProceedingseISBN: 978-963-334-291-6
Publisher: University of West Hungary
Conference
7th Hardwood Conference on Eco-Efficient Resource Wood with Special Focus on Hardwoods, SEP 08-09, 2016, Sopron, HUNGARYAuthors' information
Pockrandt, Michael
Eberswalde University of Applied Sciences
Cuccui, Ignazia
Consiglio Nazionale delle Ricerche (CNR)
Allegretti, Ottaviano
Istituto per la Valorizzazione del Legno e delle Specie Arboree (IVALSA-CNR)
Uetimane, Ernesto
Eduardo Mondlane University
Swedish University of Agricultural Sciences, Department of Forest Products
UKÄ Subject classification
Wood Science
URI (permanent link to this page)
https://res.slu.se/id/publ/117834