Original scientific paper

https://doi.org/10.5552/drind.2018.1826

Evaluation of Dynamic Contact Angle of Loose and Tight Sides of Thermally Compressed Birch Veneer

Pavlo Bekhta orcid.org/0000-0002-4320-5247 ; Ukrainian National Forestry University, Lviv, Ukraine
Tomasz Krystofiak ; Poznan University of Life Sciences, Poznan, Poland
Stanislaw Proszyk ; Poznan University of Life Sciences, Poznan, Poland
Barbara Lis ; Poznan University of Life Sciences, Poznan, Poland

Abstract

Rotary-cut veneer is characterised by two sides, namely loose and tight surface, which have different properties. The information concerning dynamic contact angle behaviour of veneer sides plays an important role in efficient use of veneer. Therefore, the objective of this study was to investigate the influence of different compression temperatures and pressures on various wetting behaviour of loose and tight sides of birch veneer. Veneer sheets were compressed in a hot press at temperatures of 150 and 180 °C using seven pressure levels from 0.5 to 3.5 MPa. Wettability of loose and tight sides of thermally compressed veneer was evaluated by measuring the dynamic contact angle with distilled water. The results showed that thermal compression decreased the surface wettability of both loose and tight sides of the samples, especially for veneer samples compressed at a temperature of 180 °C. Tight side of the samples had lower wettability than loose side, even after thermal compression. Therefore, adhesive or any kind of finishing can be applied to both sides of thermally compressed veneer sheets without having any adverse influence on not only the bonding quality but also the whole finishing process.

Keywords

birch veneer; thermal compression; loose and tight sides; wettability; dynamic contact angle

Hrčak ID:

214112

URI

https://hrcak.srce.hr/214112

Publication date:

28.12.2018.

Article data in other languages: croatian

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