The influence of log soaking temperature on surface quality and integrity performance of birch (Betula pendula Roth) veneer

Lathe check development and properties: effect of log soaking temperature, compression rate, cutting radius and cutting speed during peeling process of European beech (Fagus sylvatica L.) veneer

“…Similar values for beech were also obtained by Dupleix et al (2013). Interestingly, much higher decrease of lathe check depths was observed on birch (Dupleix et al 2013;Rohumaa et al 2016a), showing that soaking temperature has a much more significant effect on birch than on beech by decreasing the depth of checks by approximately 30-35% in the same range of temperature. The reason might lie in the different anatomical structure, where beech has much higher volume of rays (approx.…”

“…These findings also support the results obtained in this study, where the lathe checks will more favourably propagate along the rays (radial direction) at lower temperature ( Figure 6a) and will pass through the rays (Figure 6b) at higher temperature. This weaker plane caused by rays in radial direction will also explain the deeper checks compared to the results on birch wood obtained by Dupleix et al (2013) and Rohumaa et al (2016a).…”

“…The effect of soaking temperature seems to be not remarkable on lathe check interval (Figure 8a). However, comparing this study with other studies conducted under similar conditions (Dupleix et al 2013;Rohumaa et al 2016a), some interesting observations could be made. The results show that the rise of soaking temperature from 50°C to 80°C will have a decreasing effect on lathe check depths, which is approximately 15-20%.…”

“…One of these process stages is soaking, where the logs are commonly heated prior to peeling in order to soften the wood (Sellers 1985;Marchal et al 2009;Dupleix et al 2013) so as to obtain smoother veneer and minimise the severity of knife checks (Meriluoto 1965;Dupleix et al 2013). Generally, at higher temperature during peeling the formation of deep lathe checks will be reduced (Meriluoto 1965;Dupleix et al2013) and the integrity of the veneer will be improved (Rohumaa et al 2016a). The depth of checks and integrity of veneer have been shown to be critical factors affecting the bonding process (Rohumaa et al 2013(Rohumaa et al , 2014(Rohumaa et al , 2016b, but also have effect on veneer based products shape stability and mechanical properties (Blomqvist et al 2014;Pot et al 2015).…”

Study on the in-process measurements of the surface roughness of Douglas fir green veneers with the use of laser profilometer

“…Dundar et al (2008b) completed similar experiments and demonstrated that the soaking time increased the surface roughness of beech veneers peeled from heartwood. Rohumaa et al (2016) investigated the effect of the soaking temperature on the surface quality of birch veneers showing that too low soaking temperature (20 °C) causes high surface roughness of the loose side of veneers. Aydin et al (2006) carried out research on a similar subject showing that surface roughness of spruce veneers obtained from the log with a temperature of 52 °C was lower than when the log temperature was 32 °C.…”