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Hybrid LVL panels made of eucalypt and pine woods decayed by white-rot fungus

Delucis R., Herrera R., Melo R., Muller M., Labidi J., Gatto D.

Drewno : prace naukowe, doniesienia, komunikaty

2018

vol. 61, nr 201

165--176

LVL panels have been employed for structural purposes on a large scale, replacing not only solid wood, but also other materials, due to their high mechanical properties combined with an ecological appeal. This study aimed to investigate the degradation which occurred in hybrid LVL panels composed of pine and eucalypts woods from fast-growing plantations, layered as six different combinations of five veneers. In order to evaluate the behaviour of the panels underwater immersion, some samples were subjected to an ageing process performed prior to mycological tests. For characterization, mass loss, colourimetric properties (CIELAB method) and Janka Hardness were the used parameters. The results indicated that the panels made with adjacent eucalypts veneers were more susceptible to water immersion. The panels made with pine veneers as cores showed lower hardness. The hybrid panels combined high durability and good water resistance.

Characterization of thermally modified wood at different industrial conditions

Herrera R., Krystofiak T., Labidi J., Llano-Ponte R.

Drewno : prace naukowe, doniesienia, komunikaty

2016

vol. 59, nr 197

151--164

In this study European ash wood (Fraxinus excelsior L.) was modified at 192ºC and 202ºC in Thermo-Drewno®, Poland; and at 212ºC in Termogenik®, Spain. After modification, samples were characterized by wet chemistry according to standard methods (TAPPI) and by instrumental methods (FT-IR); in addition, surface and physical properties were measured (density, acidity, moisture, water uptake, contact angle, colour) in order to quantify changes due to treatment and temperature. The results showed that chemical composition of modified wood presents a gradual variation according to the heating regime, regardless of the industrial process applied; the greatest differences were obtained in treatment at 212°C compared to untreated wood. Furthermore, the density (< 0.68 g·cm-3) of modified wood decreased proportionally to treatment temperature. Colour measurements showed proportional changes to darker colours depending on the treatment temperature. On the other hand, some physical properties did not vary significantly between treatments, obtaining similar values of contact angle (97°-99°) and of moisture content (<7%).