Mar 29 2019
Wood products like outdoor furniture and facades can have an extended service life if they get painted. Their durability is not just affected by the paint but also by the characteristics possessed by the wood. Studied variables included the density and also whether the wood was made up of sapwood, the outer part of a tree, or of heartwood, the inner part of a tree.
Tinh Sjökvist, doctor in forestry industry production systems, holding a lecture. (Image credit: Linnaeus University)
This was studied by Tinh Sjökvist in a recent dissertation from Linnaeus University. Her research highlights that heartwood possessing low density is capable of providing the finest durability for coated spruce panel outdoors.
I found no difference in the water sorption between coated heartwood and coated sapwood of spruce. However, there is less mould growth on panels of heartwood than on panels of sapwood. And if you want as little crack formation as possible, you should use wood with low density.
Tinh Sjökvist, Doctor, Forestry Industry Production Systems, Linnaeus University
Based on her research, Sjökvist has come up with two conclusions: wood is an intricate material and the phenomena that are measured can be dependent on several different factors. For example, it has long been believed that the amount of water absorbed by spruce wood relies on the extent of porosity of the wood.
I have discovered that water sorption is also affected by the chemical characteristics of the wood, through the fact that the surface tension of the water is changed by the spruce’s so-called extractive substances. This is something that I will continue to carry out research on.
Tinh Sjökvist, Doctor, Forestry Industry Production Systems, Linnaeus University