Investigation of thermo-mechanical shape memory signatures of 3D printed and Injection molded polymers

Abstract

This research paper investigates the shape memory signatures (SMSs) of SMPs fabricated by two different manufacturing processes, namely Fused Filament Fabricated (FFF) and Injection-molding (IM). The SMSs of each manufacturing route is first investigated by rating the thermophysical and thermodynamic properties of amorphous and semicrystalline-type shape memory polymers. Secondly, the capturing of SMSs is completed by a series of thermomechanical shape programming/recovery cycles on FFF printed specimens, and the results are correlated with the IM-produced samples of similar nature. Furthermore, the thermomechanical cycles are programmed at varying heating rates (1, 2, 3, and 5 °C min−1) to analyze their influence on shape memory behavior and cycling time. Results depict that an increase in induced pre-strain driven by small to large deformations (10% → 25%) in the elastic range leads to maximum shape memory performance and the highest performance was reported while heating at 2 and 3 °C min−1, respectively. Finally, the IM-produced samples showed slightly better shape recovery compared to the 3D-printed samples. The shape memory signatures of 3DP specimens are indeed up to 86% like the ones produced by injection molding, which is mostly governed by the distinct residual stress/strain induced during the two different manufacturing processes.