Bonding performance of wood of fast-growing tree species eucalyptus (Eucalyptus grandis) and radiata pine (Pinus radiata D.Don) with polyvinyl acetate and emulsion polymer isocyanate adhesives
Laen...
Kuupäev
2022
Kättesaadavus
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Estonian University of Life Sciences
Abstrakt
Fast-growing imported plantation tree species have become an available wood resource
for Europe’s wood industry in the last decades. This sustainable alternative may reduce the gap
between the increasing demand for and decreasing supply of the local tree species. The aim of
the study was to evaluate the performance of eucalyptus (Eucalyptus grandis) and radiata pine
(Pinus radiata D.Don) wood in face-bonding with polyvinyl acetate (PVAc) and emulsion
polymer isocyanate (EPI) adhesive for the production of non-structural semi-finished glued
laminated timber members for window manufacturing. Test specimen preparation and testing
were performed according to European standards. Tensile shear strength and wood failure
percentages were determined as bonding performance indicators for 3 adhesives and 3 selected
bonding parameters (pressure, pressing time and adhesive spread) in 27 variations after boiling
the specimens in water. According to the results, the bonding variables influence the glue-line
tensile shear strength and wood failure percentages. Bonding pressure and pressing time were
evaluated as the most significant factors influencing shear strength of bonded joints. For all
bonding variations the average level of shear strength from 3.45 to 5.23 MPa were reached for
PVAc adhesive and from 3.78 to 9.65 MPa for EPI adhesives. Both EPI adhesives provide higher
performance compared to PVAc adhesive. In the case of bonding fast-growing tree species, the
highest shear strength values were achieved using the lowest pressure of 0.8 MPa, adhesive
spread from 150 to 180 g m-2 and longest pressing time of 40 min. Based on the general
evaluation of the results, it can be stated that the wood of eucalyptus and radiata pine bonded with
both EPI adhesives presents great potential for non-structural semi-finished glued laminated
timber member production, especially for the use in humid conditions.
Kirjeldus
Received: July 11th, 2021 ; Accepted: December 5th, 2021 ; Published: January 25th, 2022 ; Correspondence: janis.iejavs@e–koks.lv
Märksõnad
bonding, EPI, Eucalyptus grandis, fast-growing wood, Pinus radiata D.Don, PVAc, articles