effect of printing parameters on the shape transformation of 3d printed petg

In this research, for the first time, highly controllable self-coiling and tensile shape memory behaviors of the 3d printed (poly-ethylene terephthalate glycol) petg thermoplastic structures, as a novel shape memory polymer (smp), are introduced. the results showed that the maximum printing-induced pre-strain of the petg is stored in the first printed layer. manipulating the infill printing direction of the 3d printed petg strip provides different controllable shape transformation modes, including bending and spiraling. the wall effect experiments indicated that the shape transformation related to the infill pattern weakens by increasing the wall size. employing a cross printing pattern resulted in the strip’s more intense self-spiraling behavior, making the final shape transformation mode less influenced by the wall size. the shape transformation of the planar rectangular surfaces printed with single and cross printing patterns caused a self-tubing shape transformation in half and full tubes, respectively.