Effect of Insertion of Controlled Composition Gradient Layer on Mechanical Characteristics of Composite Specimens Made by FDM Type 3D Printer Equipped with Co-axial Extruder

Abstract

The purpose of this study is to investigate the effects of insertion of controlled composition gradient layer on mechanical characteristics of composite specimens made by Fused Deposition Modeling(FDM)type ３D printer equipped with co-axial extruder. The tensile characteristics of composite filaments made from Poly-Lactic Acid(PLA)and Glycol-modified PolyEthylene Terephthalate(PETG) , in which compositions were varied from each other, were investigated. Test results showed that the tensile characteristics of composite filament could be controlled by changing the volume fraction of PLA／PETG. Sandwiched composite specimens having different numbers of composition gradient layers were fabricated to investigate the bending characteristics. Bending test results showed that when composition gradient layer was introduced to a sandwiched composite specimen, the energy absorption until failure increased while bending strength and modulus were almost same. The effects of inserting controlled composition gradient layer on interlayer adhesion strength under shear and tensile load were also investigated. Interlayer adhesion test revealed that the observed interlayer shear／tensile strength was improved by inserting the composition gradient layer to avert the adhesion between different polymers.