An Approach to Improve Interface Healing in FFF-3D Printed Ultem 1010 Using Laser Pre-Deposition Heating

Fused Filament Fabrication (FFF) 3D printing has become an effective way to fabricate custom parts at low cost and fast speed. However, due to anisotropic properties of FFF 3D printed parts, their mechanical strength is unsatisfactory compared to those of parts made using traditional methods. To address this issue, an in-process laser local pre-deposition heating (LLPH) method is reported to increase thermal relaxation at inter-layer interface, for improvement of inter-layer adhesion, and therefore tensile strength in the build direction. The effect of laser power on tensile strength, and in-depth investigation of polymer relaxation, reptation and entanglement are presented. 178% increase in tensile strength and an isotropy value of 82.8% (build-direction strength divided by build-plane strength) were achieved. Isotropic behavior at inter-layer interface was observed using Scanning Electron Microscope.