This paper presents results obtained for the development of a wood-polymer composite (WPC) based on polypropylene (PP) reinforced by olive wood fibers (OWF). The effect of the wood flour content and its chemical fiber treatment (amino-silane) on the mechanical properties of the WPC was studied by ultrasonic methods and mechanical tensile test. The elastic properties of the studied PP/OWF compositions are discussed and both of the mentioned evaluations give similar tendencies even if the characterization methods are somewhat different. As a result, the increase of the fiber content and the addition of the amino-silane coupling agent is shown to improve the rigidity of composite materials. Eventually, a correlation factor between the estimated Young's moduli is established between the ultrasound values (for ε < 0.05%) and mechanical values (for 0.05 < ε < 0.25%). Ultrasound measurements are discussed as an alternative method for the elastic properties evaluation.

This study applies the Taguchi method to investigate the relationship between the ultimate tensile strength, hardness and process variables in a squeeze casting 2017 A wrought aluminium alloy. The effects of various casting parameters including squeeze pressure, melt temperature and die temperature were studied. Therefore, the objectives of the Taguchi method for the squeeze casting process are to establish the optimal combination of process parameters and to reduce the variation in quality between only a few experiments. The experimental results show that the squeeze pressure significantly affects the microstructure and the mechanical properties of 2017 A Al alloy.

In this paper, the influence of process parameters on the ductility during squeeze casting of 2017 A wrought aluminum alloy is studied. The Taguchi method of design of experiments was employed to optimize the process parameters and to increase the elongation percent. A 3-factor, 3-level casting experiment is conducted by Taguchi L 9 orthogonal array through the statistical design method. Then, the input parameters are considered here including squeeze pressure, melt temperature, and die preheating temperature with three levels. The optimum casting parameters to acquire higher ductility were predicted, and the individual importance of each parameter was evaluated by examining the signal-to-noise (S/N) ratio and analysis of variance (ANOVA) results. The optimum levels of the squeeze pressure, melt temperature, and die preheating temperature were found to be 90 MPa, 700, and 200°C, respectively. The ANOVA results indicated that the squeeze pressure has the higher statistical effect on the elongation percent, followed by the melt temperature and die preheating temperature. Optical microscopy and scanning electron microscopy (SEM) analysis were used to discuss the effect of pressure levels on the microstructure and the fracture characterization of the investigated alloy.

Considerable interest has been shown in the development of biocomposite films for food packaging in recent years. In this study, biocomposite films based on polylactic acid (PLA) were prepared with varying levels of olive wood flour (OWF) (0, 1, 3, 5, and 10 wt%) using the solvent casting method. To achieve better dispersion, 2% ethanol was added during the casting of the biocomposite films. The effect of OWF content on the physicochemical and mechanical properties of the PLA films was investigated. Interaction between the OWF cellulose and the PLA matrix was revealed by FTIR spectroscopy analysis, and the addition of ethanol was found to be suitable for better dispersion of OWF, which resulted in decreased agglomeration rate in the biocomposites. The biocomposite films with the addition of 1% of OWF (OW1) exhibited the best dispersion, thermal stability, and tensile strength, with a gain of 31.07% (29.65 ± 6.6 MPa) and an increase in Young’s modulus of 15% (1199.18 ± 98 MPa). It was demonstrated that the properties of the PLA/OWF biocomposites make them suitable for green applications, including as film packaging for food products.

In additive manufacturing, fused deposition modelling (FDM) is one of the most often-used technologies. Polylactic Acid (PLA) is the most frequently applied polymer for prototyping or for real uses. This study mainly focuses on the mechanical properties of PLA parts printed with filament exposed to UV light to mimic the effect of recycled filament. Three radiation periods were studied, respectively, 24 h, 48 h and 72 h. Tensile tests were carried out to characterize the influence of building orientation (On flat/on-edge) and raster angles (0°, 45°, 90°, 0°/90°, −45°/+45°). Failure modes were also discussed. Printed specimens were subjected to water absorption to assess the mechanical properties in real application. Generally with the same raster angle, the interlayer structure of specimens manufactured in on-edge orientation has greater adhesion than the specimens in flat orientation. The results show that mechanical properties are lower in case of flat building orientation and the raster angle has the same trend in both orientations. Elsewhere, edge orientation exhibited lower water absorption thanks to the inwall that protected the printed part. UV radiation enhances the interface between printed layers for the lower period. The mechanical properties were affected by the degradation of the bulk material in the direction of 90°.