Dissertations in Forestry and Natural Sciences

Taneli Väisänen: Effects of Thermally Extracted Wood Distillates on
the Characteristics of Wood-Plastic Composites
less the same after 48 hours even though there was an increase
in the values for all the materials. After 48 hours of immersion,
LG containing 8 wt% of hardwood distillate had absorbed
approximately 20% less water than unmodified LG.
Accordingly, the difference between the unmodified LG and LG
with 1 wt% of hardwood distillate was about 10%.
The addition of softwood distillate did not decrease water
absorption of the WPCs to the same extent as hardwood
distillate even though water absorption decreased as a function
of the distillate content (Figure 14). The difference between
water absorption of LG and LG + SWD20 was approximately
16% whereas no difference was observed between LG and LG
with 1 wt% of distillate.
Study IV also shows that the difference in the water
absorption values between LG and distillate-treated LGs
decreased after 48 hours of immersion. The WPCs containing
softwood distillate absorbed more water between 24 and 48
hours of immersion than those containing hardwood distillate.
0.55
0.5
HWD, 24h
SWD, 24h
HWD, 48h
SWD, 48h
Moisture content (wt%)
0.45
0.4
0.35
0.3
0.25
0 5 10 15 20
Distillate content (wt%)
Figure 14. Moisture content of the WPCs after 24 and 48 hours of water
immersion in studies III and IV. HWD = hardwood distillate, and SWD = softwood
distillate.
90 Dissertations in Forestry and Natural Sciences No 222