T r i t h e r m
SPECIALIST IN HEATING & DRYING SINCE 1995
Thermal Wood Heat Treatment
THE PROCESS
Heat treatment is a chemical free treatment process. The process is carried out in stainless steel chamber and in an oxygen free atmosphere in the presence of steam. Treatment temperatures range from 160 to 220 degrees C.The chemical changes taking place in the wood during heat treatment is quite complex. Simply put , the hydroxyl (OH) groups of the cellulose chain and the sugars are broken up forming new water insoluble polymers. This results in the wood to be less hydrophilic and having less food for bacteria and fungi to feed on.
As a result, the treated timber becomes more durable, more stable and more beautiful . Heat treatment darkens and deepens the wood’s natural color, making it a competitive alternative to tropical hardwoods.
PROPERTIES OF HEAT TREATED TIMBER
- it absorbs less moisture making it very stable, the higher the treatment temperature
the higher the stability. Swelling and shrinkage reduced by 2 to 3 times for softwood
and 5-
10 times for hardwood. - wood becomes brittle, the higher the treatment temperature the more the brittleness.
- it is more resistant to rot and decay.
- not resistant to UV photo-
oxidation , needs coating with UV absorbers and Haline Light Stabilizer - strength reduced -
impact bending, shear, splitting and screw holding strength. - hardness increased but density loss by 15 to 20 %.
- wood shrinkage -
average 2 to 3 % in width ,1 to 2% in thickness. Overall volume loss is about 5%.
TRITHERM HEAT TREATMENT EQUIPMENT
MODEL VHT10 -
MODEL CHT -