| AVS 66th International Symposium & Exhibition | |
| Manufacturing Science and Technology Group | Thursday Sessions |
| Session MS-ThP |
| Session: | Manufacturing Science and Technology Poster Session |
| Presenter: | Li Song, Aichi institute of technology, Japan |
| Correspondent: | Click to Email |
Indispensable 3D printing technique in manufacturing has made us an important unavoidable problem until now. It is unquestionably laminated interfacial existence in molded products. The problem become obviously that the strength of printed products in a vertical direction for printing direction is extremely weaker than the strength with along direction about almost same strength of original filament. The reason is absolutely clear for existence of laminated interfaces with a heterogeneous structure.
In this study, we tried to chanllenge an innovative improvement method of the excellent laminated interface strength which is the ultimate purpose to obtaine conventional products with strength of the bonding force with uniformization of the upper layer and the structure. We tried to create a new 3D printer by installing a compact halogen spot heater attached to one direction at the extruder of the FDM 3D printer with commercially black PLA filament as our first step. We consructed our original system in conjunction with the extruder with spot optical heating on fabricating lower layer interfaces due to change semi-melted state of already fabricated solid satate molded object during modeling. This effect contributes to the homogenization of the interface organization that is improvement of the interface strength.
In this study, it is great important to optimize optical radiation conditions of halogen spot heater due to change lower layer state to semi-melt again while maintaining the shape of the solidified lower layer part, while maintaining the shape of a product. Through trial and error, Optimum conditions of geometric placement of the devices and the irradiation temperature of 393 K estimated using a thermocouple. In order to evaluate a change of the interface strength by a tension test more definitely, we loaded perpendicularly in the laminated direction.
We showed great results that the tensile strength of typical specimen increased from 27 MPa to 34 MPa, and the surface smoothness drastic increase from Ra of 24 to 11 simultaneously by a mild fusion effect by the heat. Both surprisingly results was supported by the fracture surface observations. Using laser microscope, the microstructure of the unheated fracture surface was broken at the specific layer, but that of of heated product was observed at complex layers. These results were attributed to the interfacial texture homonigetion because of optimal semi-meltirized under layers.
The above-mentioned result makes the great effectiveness of the laminate spot heating method at the same time of molding heating remarkable clear.