**Ana Pilar Valerga 1,\*, Moisés Batista 1, Jorge Salguero <sup>1</sup> and Frank Girot 2,3**


Received: 30 June 2018; Accepted: 28 July 2018; Published: 31 July 2018

**Abstract:** Additive manufacturing technologies play an important role in Industry 4.0. One of the most prevalent processes is fused deposition modelling (FDM) due to its versatility and low cost. However, there is still a lack of standardization of materials and procedures within this technology. This work aims to study the relationship of certain operating parameters and the conditions of poly(lactic acid) (PLA) polymer with the results of the manufactured parts in dimensional terms, surface quality, and mechanical strength. In this way, the impact of some material characteristics is analyzed, such as the pigmentation of the material and the environmental humidity where it has been stored. The manufacturing parameter that relates to these properties has been the extrusion temperature since it is the most influential in this technology. The results are quite affected especially by humidity, being a parameter little studied in the literature.

**Keywords:** FDM; additive manufacturing; PLA; material color; pigmentation; extrusion temperature; humidity
