No abstract

Wood-polyvinyl chloride (PVC) composites were prepared using industrial wood particles used for manufacturing three-layer particleboards. The effect of particle size (0.25-0.5, 0.5-1, 1-2, and 2-4 mm) on the mechanical properties of the composites was investigated. The effect of cross-section size (4 × 10, 6 × 15 and 8 × 20 mm 2 ) of composite pieces made by an injection moulding method was also studied. Both the particle size and specimen crosssection area significantly influenced these properties. The tensile and flexural properties as well as the impact strength in general increased with increasing particle size, and decreased with increasing cross-section size. Einfluss von industrieüblichen Holzspanabmessungen auf die mechanischen Eigenschaften von Holz-PVC-VerbundwerkstoffenZusammenfassung Holz-PVC-Verbundwerkstoffe wurden unter Verwendung industrieüblicher Holzspäne, wie sie zur Herstellung von dreischichtigen Spanplatten eingesetzt werden, hergestellt. Der Einfluss der Spangröße (0,25-0,5, 0,5-1, 1-2 und 2-4 mm) auf die mechanischen Eigenschaften der Verbundwerkstoffe sowie der Einfluss der Querschnittsgröße (4 × 10, 6 × 15 and 8 × 20 mm 2 ) der mittels Spritzgusstechnik hergestellten Verbundwerkstoffe wurde

Particles derived from milling three-layer particleboards, with sizes from 0.5 to 3 mm, were used for making composites with polypropylene by an injection moulding method. Maleated polypropylene was used as a coupling agent. The objective of this study was to evaluate the mechanical and physical properties of the composites made from particleboard and polypropylene with respect to the content of particles derived from particleboard and coupling agent addition. Properties of the composites did not differ significantly from those of composites with virgin industrial wood particles used for manufacturing particleboards. Moreover, these properties were comparable with the properties of typical wood-plastic composites with wood flour. Particles derived from milling particleboards have proved to be an effective alternative wood component of wood-plastic composites.

Wooden glued constructions require touch-free monitoring of destructive processes, especially in adhesive bonds that are most exposed to failure. The objective of the investigations was to describe failure processes in the adhesive bond of wood joints, in particular to determine their initiation, propagation, and destruction. The acoustic emission (AE) method was employed as the carrier of information about changes occurring in glued joints, whereas the numerical method was applied to determine values of distribution of tangential stresses generated in adhesive bonds. The acoustic phenomena examined were described using the AE cumulative counts. The authors analysed acoustic signals generated in loaded wooden and plastic overlap samples glued together using polyethyl methacrylate glue as well as in solid samples. On the basis of the acoustic emissions obtained, it was possible to establish characteristic places and stages of escalating structural defects generated from bonds of adhesive joints. This was utilised later on, in conjunction with results of numerical calculations, to determine correlations occurring between the AE cumulative counts and generated tangential stresses. Dependencies established in this way were used to determine characteristic points during the propagation of destructive phenomena of wood adhesive joints. The results obtained proved that it was possible to predict the development of the destruction of wood adhesive joints on the basis of observations of the increasing AE cumulative counts of acoustic signals in combination with tangential stresses determined using the finite elements method.

No abstract