The Use of Bio-Polyurethane Binder for the Development of Engineered Wood Composites
Sigitas Vėjelis, Agnė Kairytė, Saulius Vaitkus, Arūnas Kremensas
Abstract
Fiber hemp shives and biopolyurethane binder were used to create an engineered wood composite due to the synergistic properties of these materials. This study created engineered wood specimens using different ratios of biopolyurethane binder and hemp shives, which varied from 0.5 to 1.5. Different pressure levels were used when preparing the specimens, which were 1.5, 3.0, and 4.5 MPa. The formed engineered wood specimens showed that both the amount of binder and the level of pressure significantly influence the strength and moisture indicators, and different processes occur when increasing the amount of binder and the level of pressure. The research showed that the developed engineered wood composites had reached bending strength equal to 17 MPa, tensile strength equal to 7 MPa, and compressive stress equal to 11 MPa. In most cases, the strength index values were higher than those of various industrial-engineered wood products. Engineered wood was characterized by water absorption from 35 to 10%, and swelling in water varied from 26 to 10%. The flammability of the specimens, determined by the low-flame method, indicated that the specimens were flammable, but the expanded graphite used allowed for the creation of non-flammable specimens.