General Thermo RedPine
Thermal modiﬁcation of wood is a chemi-cal-free process whereby wood is heated in a stainless steel kiln to tem-peratures between 180 C and 230 C. This results in a perma-nent change in the chemical composi-tion of the wood, giving improved durability and performance. At its simplest level, the change is similar to the caramel-izing of heated sugar which also alters the colour and chemistry of the original substance.
Compared to kiln-dried wood, the equilibrium moisture content of thermally modiﬁed wood is permanently 40-50% lower, thanks to the crystal-lization of the wood’s hemi-cellulose. The lower equilibrium moisture content means a reduction in tangential and radial swelling, which improves the wood’s dimensional stability. Thermal modiﬁca-tion also reduces permeability, which lowers the ﬁnishing and adhesive requirements. Based on the increased stability and the removal of the extrac-tives in the wood, which prevents sap stain, perfor-mance against paint ﬂaking also improves.