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Shrinkage: Shrinkage
is a reduction in the size of the amber due to a loss of moisture.
A sawlog shrinks towards the centre and along the annual-rings.
This means that planks that have the annual-rings at right-angles
to the face of the plank, and are close to the pith will shrink
a lot less than planks sawn from the outer part of the trunk
which have the annual-rings parallel to the face of the board.
From the illustration we can see that quarter sawing produces
the greatest amount of high quality timber. However, as you can
see, there is a lot of waste with this method, which makes the
timber expensive. Through & through sawing or tangential
sawing have a lot less waste but a greater percentage of the
boards will shrink and distort
By-products:
The waste from the conversion of timber is the sawdust and chippings.
Like the bark, which is gathered from the de-barking before the
sawing up of the logs, the sawdust and chip pings also have a
use. They are used in the production of particle boards: chipboard,
hardboard, fibre-board. |
