UNESCO resource kit - science and technology educa...

UNESCO Module 13: Materials made from wood - Teecher's Notes ------------
Page 2: To get a really even layer of fibres undisturbed by the effects of
pouring, the frame can be placed on a tray, the suspension of fibres poured in,
then the frame lifted up off the tray.
Page 3: If possible, actual samples should be available for students to examine.
Plywood has similar properties in each direction across a sheet but is, of course,
different across its thickness. Chipboard is the same in all directions. (It is
isotropic.) Students' own 2-ply can be made from thin sheets of balsa wood.
Page 4: A small can with a hole in the lid and small holes just above the base
can be used instead of a crucible. The gases coming from the hole in the lid
should be lit. When these change from yellow to blue they are mainly due to
carbon monoxide, and the charcoal making process is complete.
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