sh. mahboubizadeh

The use of polymeric binders in the fabrication of ceramic parts by extrusion-based 3D printers is considered to be one of the key elements that, in addition to providing a suitable suspension paste for the addition of ceramic particles, directly affects the controllability of their flow behavior and ultimately their printability. To this end, the present research investigated the effect of simultaneously adding different polyvinyl alcohol binders with different debinding temperatures to alumina pastes. Because of the high viscosity of the alumina at high percentages by weight, its printability is difficult for this reason, and the device can be damaged during the printing process. In addition, the density and strength properties of the printed parts suffer from a decrease in printability quality. For this purpose, the effects of hybrid binder systems on the additive manufacturing of alumina components were investigated, evaluating three different compositional ratios (25/75, 50/50, and 75/25) to identify the optimal formulation. The experimental results show that strategic selection of binder proportions significantly improves both the rheological properties critical for extrusion-based printing and the structural integrity of sintered components. Accordingly, it was observed that the sample with the highest PVA ratio with lower debinding temperature showed the best printability, but the strength and density properties of the cured samples of the equal binder combination sample were the highest.

The fabrication of polypropylene composites using various types of reinforcements to improve the mechanical properties has received much attention in recent years. In this paper, enhancing the mechanical properties of polypropylene composites by adding different classes of natural and synthetic particle and fiber reinforcements were reviewed. Accordingly, it was found that the fabrication of polypropylene composites leads to an increase either in the strength of samples and corresponding mechanical properties. Moreover, surface modification and processing reinforcements, especially natural fibers via chemical and physical methods were studied. The results show an increase in the adhesion of reinforcements surface inside the polypropylene, which results in strength enhancement and improving the mechanical properties of polypropylene composites. The evidence from this study points towards the idea that the increased use of modified natural fibers in polylropylene composites and those natural or synthetic reinforcements which form hybrid composites provide promising research topics in the future.