The impact of process parameters on mechanical properties of parts fabricated in PLA with an open-source 3-D printer

Antonio Lanzotti, Marzio Grasso, Gabriele Staiano, Massimo Martorelli

    Research output: Contribution to journalArticlepeer-review

    268 Citations (Scopus)


    Purpose - This study aims to quantify the ultimate tensile strength and the nominal strain at break (f) of printed parts made from polylactic acid (PLA) with a Replicating Rapid prototyper (Rep-Rap) 3D printer, by varying three important process parameters: layer thickness, infill orientation and the number of shell perimeters. Little information is currently available about mechanical properties of parts printed using open-source, low-cost 3D printers. Design/methodology/approach - A computer-aided design model of a tensile test specimen was created, conforming to the ASTM:D638. Experiments were designed, based on a central composite design. A set of 60 specimens, obtained from combinations of selected paramers, was printed on a Rep-Rap Prusa I3 in PLA. Testing was performed using a JJ Instruments - T5002-type tensile testing machine and the load was measured using a load cell of 1,100 N. Findings - This study investigated the main impact of each process parameter on mechanical properties and the effects of interactions. The use of a response surface methodology allowed the proposition of an empirical model which connects process parameters and mechanical properties. Even though results showed a high variability, additional ideas on how to understand the impact of process parameters are suggested in this paper. Originality/value - On the basis of experimental results, it is possible to obtain practical suggestions to set common process parameters in relation to mechanical properties. Experiments discussed in the present paper provide a variety of data and insight regarding the relationship among the main process parameters and the stiffness and strength of fused deposition modeling-printed parts made from PLA. In particular, this paper underlines the shortage in existing literature concerning the impact of process parameters on the elastic modulus and the strain to failure for the PLA. The experimental data produced show a good degree of compliance with analytical formulations and other data found in literature.

    Original languageEnglish
    Pages (from-to)604-617
    Number of pages14
    JournalRapid Prototyping Journal
    Issue number5
    Publication statusPublished - 17 Aug 2015


    • Central composite design
    • Nominal strain at break
    • Open-source 3D printers
    • Polylactic acid
    • Process improvement
    • Ultimate tensile strength


    Dive into the research topics of 'The impact of process parameters on mechanical properties of parts fabricated in PLA with an open-source 3-D printer'. Together they form a unique fingerprint.

    Cite this