Effect of printing parameters on the tensile strength of FDM 3D samples: a meta-analysis focusing on layer thickness and sample orientation

3D printing is an interesting and growing field in many areas. Despite advantages, several issues regarding the quality and strength of products have remained unresolved. Among these issues are the effects of printing process parameters on the mechanical properties of a printed object. In this study, the effects of the layer thickness and print orientation on the tensile strength of FDM-printed samples were considered. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, eligible studies in major databases were found. The pooled effect size, heterogeneity and publication bias were assessed using statistical analysis. Results showed that increasing layer thickness might reduce the tensile strength of FDM-printed samples up to 20%, while increasing the printing angle of the sample on the build platform decreased the tensile strength to about 12%. Furthermore, adjusting extruder temperature to higher values and printing speeds to lower values might reduce the heterogeneity of results between studies. In conclusion, when enhanced tensile strength is required, it is recommended to focus mainly on the layer thickness than printing orientation, adjust lower layer thickness and orient the model parallel to the build platform.