With industry's growing focus on the rapid manufacturing (RM) of end-use products, rapid prototyping (RP) or layered manufacturing (LM) machines that were originally designed to build prototypes may now be required to build functional end-use products. To successfully accomplish the transition, the available materials utilized in RP must provide the performance required for RM. The specific technology used must also be capable of producing repeatable and reproducible parts in regards to mechanical and dimensional properties.
A design of experiments approach was performed to determine the effects of build orientation, aging, and pre-conditioning on the mechanical properties. To perform the investigations, sample parts were built on a 3D Systems Viper Si 2 stereolithography rapid prototyping machine. The two different build setups used in the study included 18 and 24 Type I specimens, respectively. The 18 specimen setup was performed to determine the effects of build orientation on mechanical properties. In addition, aging was analyzed at 4 days, 1 month, and 4 months with each aging condition also being analyzed under the environmental conditions of ambient, desiccant, and desiccant with 23±2°C and 50±5% relative humidity. The setup for 24 specimens analyzed the effects of an additional build orientation at 4 days ambient and 2 days conditioned at 23±2°C and 50±5% relative humidity. Results showed that build orientation (parts built flat, on an edge, or vertically) produced parts with statistically different mechanical properties as determined using measurements of Ultimate Tensile Strength and E Modulus. Statistical differences in mechanical properties were also found as a result of aging (the time between sample production and mechanical testing) and pre-conditioning (the storage conditions of the samples). These results as well as the implications of the results on extending RP to RM will be described.
