Original scientific paper

https://doi.org/10.5552/drvind.2019.1918

Influence of Natural Surface Ageing on Bonding Quality of Thermally Modified Oak and Beech Wood

Vjekoslav Živković ; University of Zagreb, Faculty of Forestry, Zagreb, Croatia
Gustav Gabrek ; University of Zagreb, Faculty of Forestry, Zagreb, Croatia
Goran Mihulja ; University of Zagreb, Faculty of Forestry, Zagreb, Croatia

Abstract

This paper presents the influence of natural surface ageing in indoor conditions on bonding quality of thermally modified wood used in structural laminated products. Two unmodified and thermally modified wood species were used for the experiment: oak and beech. Samples were planed and glued with MUF adhesive 2 hours, 1, 2, 6, 10, and 18 days after planing. Properties of laminated beech and oak beams, namely shear strength, delamination and contact angle, were measured in order to detect 1) suitability of wood species for lamination process and 2) influence of extended storage time after planing on properties of laminated wood. Generally, both native and thermally modified beech exhibited better results of shear strength and delamination and had lower contact angles compared to oak and thermally modified oak. Results of the delamination test (total delamination) indicate time dependence of surface ageing. Both unmodified and thermally modified beech may be successfully laminated at least up to 2 days after planing, whereas neither oak nor thermally modified oak are suitable for lamination process due to excessive delamination. Results of delamination may be related to contact angle measurements. Shear strength of glue lines did not show any influence on natural surface ageing. However, whereas beech and thermally modified beech samples exhibited almost the same values of the shear strength regardless of the duration of surface ageing, there is an obvious difference in shear strength of oak and thermally modified oak samples.

Keywords

bonding; delamination; modified wood, shear strength; surface ageing

Hrčak ID:

225636

URI

https://hrcak.srce.hr/225636

Publication date:

27.9.2019.

Article data in other languages: croatian

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