Surface Quality of Planed Beech Wood (Fagus sylvatica L.) Thermally Treated for Different Durations of Time

Lidia Gurau, Mark Irle, Mihaela Campean, Mihai Ispas, Julia Buchner

Abstract


Thermally treating wood improves its dimensional stability and durability. The chemical changes brought about by a heat treatment also affect the mechanical properties of wood. Consequently, a heat treatment also influences how a wood surface responds to machining. This study examined the impact of heat treatments at 200 C between 1 h and 6 h on the subsequent surface quality of planed beech wood (Fagus sylvatica L.). The new approach was that surface quality was assessed by following a tested method from previous research regarding the measuring and evaluation recommendations meant to reduce the biasing effect of wood anatomy, Also, a large number of roughness parameters were used for interpretation of the combined effect of processing and wood anatomy after filtering the data with a robust filter. Among those, Rk is the parameter that is least biased by wood anatomy and that best expresses the effect of processing alone. Electron micrographs were taken to visually assess the resultant surfaces. The results showed a gradual increase in processing roughness, as distinctively measured by Rk, which increased with longer durations of the treatment. Vessel cavities were deeper than those caused by processing and that influenced, among other parameters, Ra, which is most commonly used in literature to assess surface quality. The ray tissue, especially, exhibited both greater pull-out of fibers and a sort of plasticization with increased treatment time. The length of the thermal treatment reduced surface waviness. The results also showed that it was necessary to calculate the roughness parameters to differentiate between two similar surfaces rather than relying on visual and tactile assessments alone.

Keywords


Surface quality; Surface roughness; Thermally treated wood; Treatment duration; Roughness parameters; Microscopic images

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Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126