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Advisor(s)
Abstract(s)
Paraffin has been used throughout the ages as surface protection of wood. Its use by
impregnation to improve resistance to biodegradation is recent. This study was intended to
determine the improvements of main mechanical properties of wood with this treatment. The wood
used in the tests was healthy wood of Pinus pinaster Ait. The wood was impregnated with paraffin
at different levels, using a hot-cold process, with dry and moist wood, with 2h in a hot bath at
160°C and 10 or 30 min in a water bath at 70°C. Weight gain, bending strength and bending
stiffness (MOE) were determined using a universal testing machine by a 3 points essay. The
Janka hardness was also determined. As expected, the moist wood absorbed more paraffin with
weight gains between 72% and 100%. The dry wood presented weight gains between 46% and
51%. The bending strength (MOR) increased with the increase in paraffin, reaching a 39%
increase compared to untreated wood for wood with a weight gain of about 80%. In relation to
MOE, there was also an increase, but smaller, reaching about 13% for wood with a weight gain
around 80%. The Janka hardness increased significantly with the weight gain, reaching about
40% for wood with 80% weight gain. In conclusion the impregnation should not be made with
completely dry wood and, in addition to the known resistance to biodegradation; the treatment
also improves several mechanical properties like bending strength, bending stiffness and
hardness which might increase the wood value
Description
Keywords
mechanical properties paraffin Pinus pinaster wood modification