Characteristics of the 3D-printed composite material in different raster orientations under thermal effects

In this study, polylactic acid (PLA) and thermoplastic polyurethane (TPU) were used to fabricate composite materials with different raster orientations by a 3D printing process. The idea of this study came from the fact that in nature, many plants have vertical or horizontal lines on their leaves or branches. The authors made use of the composite material of a material structure under a thermal effect to achieve the material concept. Finally, their characteristics were observed by applying a thermal effect, tensile tests (to evaluate toughness), and a dynamic mechanical analysis (tan δ to evaluate energy absorption). After a thermal effect (temperature) from a heat source was applied, it was found that the material exhibited negative Poisson's ratio (NPR) characteristic. A single material with two layers on 0⁰ raster orientation of a material in this study had the maximum tan δ (energy absorption), an NPR, and toughness regardless of the kind of material. Among the composite materials, 0° raster orientation of them also had a larger NPR, and the absolute value of Poisson's ratio decreased as the temperature increased. Highlights: The innovative two-layer composite material fabricated by 3D printing. The material characteristics with various raster orientations are discussed. PLA0 has the largest tan δ, toughness, and negative Poisson's ratio.