Design and development of an environmentally controlled enclosure for a commercial 3D printer

The purpose of this study is to design and develop an environmentally controlled enclosure for commercial three-dimensional (3D) printers.

Computational fluid dynamics (CFD) simulations and experimental testing investigated various designs for environmentally controlled enclosures. CFD simulations provided the necessary information to select the optimal and feasible design, whereas experimental testing validated the CFD simulation results. An environmentally controlled environment allowed test samples to be printed at several relative humidity (RH) settings (20% RH, 50% RH and 80% RH). The test samples were characterized at both the macro and micro scales. The macroscale characterization was conducted using the static tensile testing procedure, while the microscale polymer material properties were determined using atomic force microscopy.

An environmentally controlled enclosure was designed and built to produce airflow in the print region with an average RH uniformity of over 0.70. Three batches of ASTM D638 standard test samples were printed at 20% RH (low RH), 50% RH (mid RH) and 80% RH (high RH). Macroscale characterization showed that the samples printed at lower humidity had statistically significantly higher tangent modulus, ultimate tensile strength and rupture strength. atomic force microscopy studies have also verified these results at the microscale and nanoscale. These studies also showed that a high humidity environment interacts with melted polylactic acid, causing additional surface roughness that reduces the strength of 3D-printed parts.

There is a need for stronger and higher-quality 3D-printed parts in the additive manufacturing (AM) market. This study fulfills that need by designing and developing an environmentally controlled add-on enclosure for the AM market.