This study proposes an electromagnetic shielding material sprayed with silver-coated copper powder (core-shell powder). The shielding properties of the material are analyzed in details section. Cross-sectional observation and sheet resistance measurement were used to determine the thickness and electrical conductivity of the electromagnetic shielding layer, which was generated by spray-coating; this aided in confirming the uniformity of the coating film. The results indicate that the electromagnetic interference shielding effectiveness increases when the silver-coated copper paste (core-shell paste) is used as the coating material rather than the conventional aluminum base. The proposed material can be used in various frequency ranges owing to the excellent shielding effectiveness of the core-shell paste used in this study. Further investigations on the optimized spray-coating type of electromagnetic shielding material are required based on the composition of the core-shell paste and the thickness of the coating film.

In this study, to improve the mechanical properties of polypropylene (PP) with the objective of developing a composite with ultra-high-molecular-weight polyethylene (UHMWPE) as a reinforcement, the mechanical properties of the composite material were investigated via numerical analysis and finite element analysis (FEA). Based on a mathematical approach, the modulus of elasticity, shear modulus, and Poisson’s ratio were calculated using a numerical model, and, through FEA with application of the homogenization method, the elastic properties were predicted, and the results were comparatively analyzed. In the future, it will be necessary to compare experimental and numerical analysis results to verify the findings of this study.

In this study, the characteristics of a composite material composed of polypropylene (PP) and ultrahigh molecular weight polyethylene (UHMWPE) are investigated. The elastic properties of the PP/UHMWPE composite material composed of short UHMWPE fibers with a low aspect ratio and long UHMWPE fibers with a high aspect ratio are compared and analyzed. In addition, the elastic properties of the PP/UHMWPE composite materials are calculated via finite element analysis and the Halpin–Tsai model by changing the volume fraction of the UHMWPE fibers. The results show that when UHMWPE fibers with a low aspect ratio and volume fraction are used, the results of the modulus of elasticity based on the finite element analysis are consistent with those obtained using the Halpin–Tsai model, although the fiber volume fraction of the UHMWPE fibers increases. Meanwhile, the deviation between the results yielded by both methods increases with the aspect ratio of the fiber. In terms of the shear modulus, the Halpin–Tsai model shows a linear trend. The results from the finite element analysis differ significantly from those of the Halpin–Tsai model owing to the random orientation of the UHMWPE fibers inside the fiber. Using a contour graph constructed based on the finite element analysis results, the aspect ratio and volume fraction of the UHMWPE fibers can be inversely calculated based on the elastic properties when synthesizing a PP/UHMWPE fiber composite. In future studies, the interfacial bonding properties of UHMWPE fibers and PP should be compared and analyzed experimentally.

In this study, we calculated the elastic properties of polypropylene composites mixed with ultrahigh-molecular-weight polyethylene (UHMWPE) fibers. We applied micromechanics models that use numerical analysis, conducted finite element analysis using the homogenization method, and comparatively analyzed the characteristics of polypropylene (PP) containing UHMWPE fibers as reinforcement. The results demonstrate that elastic properties improved as the volume fraction of UHMWPE fiber increased. It was confirmed that the fibers had anisotropic elastic properties due to the shape of the fibers. In addition, it is necessary to compare these findings with future experimental results to obtain data for developing UHMWPE–PP composites.

This study comparatively analyzed the behavior of elastic properties by aspect ratio of the ultra-high molecular weight polyethylene (UHMWPE) fibers that are added when creating a composite material of polypropylene and UHMWPE. The volume fraction (VF) of UHMWPE fibers added to polypropylene was fixed at 5%. The elastic properties were lumped for analysis according to the aspect ratio of the UHMWPE fibers oriented on the polypropylene matrix; they were analyzed using the Halpin–Tsai model, which involves a theoretical approach and finite element analysis based on the homogenization method. Finite element analysis was performed for fiber aspect ratios of 0.2 to 30 UHMWPE via the homogenization technique using the ANSYS Material Designer. For theoretical comparison, UHMWPE fiber aspect ratios of 0.2 to 100 were comparatively analyzed using the Halpin–Tsai model. When the aspect ratio of UHMWPE fiber was 0.2, it was calculated as 1518 MPa, and when the aspect ratio was 30, it was 2365 MPa, and it increased by 55.8%. As the aspect ratio increased, E22 and G12 converged to a constant value (1550 MPa). In the future, when the volume fraction of UHMWPE changes from 0 to 50%, a study must be conducted to analyze the predicted behavior of the elastic properties when the aspect ratio of the UHMWPE fiber changes.