Characterization of shape memory polymer parts fabricated using material extrusion 3D printing technique

• Published in: Rapid prototyping journal Vol. 25; no. 2; pp. 322 - 331
• Main Authors: Garcia Rosales, Carlos Alejandro, Kim, Hoejin, Garcia Duarte, Mario F, Chavez, Luis, Castañeda, Mariana, Tseng, Tzu-Liang Bill, Lin, Yirong
• Format: Journal Article
• Language: English
• Published: Bradford Emerald Publishing Limited 04.03.2019; Emerald Group Publishing Limited
• Subjects: 3-D printers; Deformation; Deformation mechanisms; Design; Design of experiments; Experimental methods; Extrusion; Manufacturing; Material properties; Modulus of elasticity; Optimization techniques; Parameters; Polymers; Process controls; Process variables; Rapid prototyping; Ratios; Recovery; Research methodology; Rheological properties; Shape memory; Smart materials; Stress-strain curves; Stress-strain relationships; Temperature; Thermal energy; Three dimensional printing; Variables; Velocity; Material extrusion; 4D printing; Design of experiments; Shape memory polymer
• ISSN: 1355-2546; 1758-7670
• DOI: 10.1108/RPJ-08-2017-0157

Purpose Shape memory polymer (SMP) is capable of recovering its original shape from a high degree of deformation by applying an external stimulus such as thermal energy. This research presents an integration of two commercial SMP materials (DiAPLEX and Tecoflex) and a material extrusion (ME) printer to fabricate SMP parts and specimens. The material properties such as Young’s modulus of the specimens was examined as a process output. Furthermore, stress-strain curve, strain recovery, instant shape-fixity ratio, long-term shape-fixity ratio and recovery ratio of SMP specimens during a thermo-mechanical cycle were investigated. Design/methodology/approach The ME fabrication settings for the SMP specimens were defined by implementing a design of experiments with temperature, velocity and layer height as process variables. Findings It was found, according to main effect and iteration plots, that fabrication parameters have an impact on Young’s modulus and exist minimum iteration among variables. In addition, Young’s modulus variation of DiAPLEX and Tecoflex specimens was mostly caused by velocity and layer height parameters, respectively. Moreover, results showed that SMP specimens were able to recover high levels of deformation. Originality/value This paper is a reference for process control and for rheological properties of SMP parts produced by ME fabrication process.