The wood of mature individuals of conifers is constituted of two rather distinct
phases: heartwood and sapwood.
In the case of many tree species, the liguid and gas permeability of heartwood is
less than the permeability of sapwood.In some tree species, heartwood contains
chemical constituents inhibiting fungal activity.
These two properties make heartwood a material with a natural decay
resistance. Heartwood with significant extractives content also has a
greater stability of dimensions when subjected to varying humidity.
Wood products made of heartwood, or wood products with a high heartwood
content, may be produced in several ways. However, the production processes
can be made more efficient if the heartwood content of the logs is known.
It is difficult to measure heartwood content directly within a high-speed production
line at the sawmill. However, some kind of determination of the heartwood content
of individual logs is necessary for the diversification of the wood material since the
heartwood content significantly varies from tree to tree within a stand.
This invention comprises a cost-effective method of predicting the heartwood content
of indivdiual logs within a high-speed production line, as well as a sawmilling arrangement
for producing sawn goods of known heartwood content.
At this time, the method is proprietary. However, more information will be provided
soon. The following Figure shows the heartwood proportion of logs
as a function of a parameter which is easily measurable within a high-
speed production line.
