Influence of Thermo-Mechanical Densification (TMD) on the Properties of Structural Sawn Timber (Pinus sylvestris L.)

Abstract

The article presents the results of thermo-mechanical densification tests conducted on Scots pine timber. The densification process was carried out in industrial conditions with a high-pressure press, which allowed flat compression of boards that were up to 2.5 m long. A phenomenon of elastic redeformations was observed in the densified boards after each pulse of compression. As a result of thermo-mechanical compression, the average timber moisture content dropped to 9%, and the average density increased by 13.5%, from the level of 547 to 621 kg/m3. As a result of thermo-mechanical densification, the strength class C of most Scots pine timber pieces improved. Most timber pieces that were subjected to thermo-mechanical densification have improved their strength class, C, by one (72.7% of the tested batch) or two C classes (3.6% of the batch under study).