Fabrication and performance evaluation of a novel laminated veneer lumber (LVL) made from hybrid poplar

In this study, a fabrication method for laminated veneer lumber (LVL) was developed. The novel LVL (NLVL) was produced with poplar fibrosis veneers and phenolic formaldehyde. Some tests were conducted to evaluate the properties of the NLVL with different densities (ranging from 0.8 to 1.2 g cm⁻³), such as mechanical properties, water resistance and surface behavior. As a result of the data obtained from the tests, the mechanical properties and water resistance of the NLVL were observed to be superior to those values of the traditional LVL (TLVL) and could be used as engineering materials. In addition, the density played an important role in improving the properties of the NLVL. It can be concluded that the mechanical properties, surface wettability and roughness improved. Conversely, with regard to the surface energy, the calculations carried out by two models unanimously indicated that the total surface free energy declined dramatically on account of the densification process. Finally, the apertures of vessels and the fiber cells decreased with the density increasing. As a consequence, the penetration routes of moisture into the NLVL reduced significantly and in turn enhanced the water resistance.