The effect of 3D printing parameters on the shape memory properties of 4D printed polylactic acid circular disks: An experimental investigation and parameters optimization

Abstract

Additive manufacturing (AM) using Fused deposition modeling (FDM) is one of the advanced fabrication processes which allows for fabricating sophisticated parts with high speed and low cost. Four-dimensional (4D) printing is a novel technology that emerged with the addition of time dimension to three-dimensional (3D) printing of smart materials. In this technology, the structure that 3D printed transforms over time, leading to deformation. The primary purpose of the 4D printing process is to control deformation type and amount during the process, but little research has been done on the controllability of the 4D printing process. This study presents a model to control the amount of deformation by examining the effect of FDM printing method parameters on polylactic acid (PLA) material using response surface methodology (RSM) for the first time. These parameters include layer height, print speed, nozzle temperature, and bed temperature. The results showed that the effect of the parameters on the height of the recovered conical shape were printing speed, layer height, bed temperature, and nozzle temperature, respectively. In the following, using the central composite design (CCD), high-order models were predicted to calculate the process control conditions, i.e., control the type and amount of deformation with a minor error compared to the experimental results. The maximum amount of conical deformation with a height of 17.63 mm was obtained by achieving optimal printing conditions. With the help of controllability obtained from the effective parameters, two shapes, such as a bowl and a straw hat, were created.