Lighter is Better? Mechanical Properties of 3D Printed Plastics.

The 3D printing technology segment within advanced manufacturing is expected to be among the fastest growing technology sectors in the world. With the introduction of RepRap style machines, 3D printing has become affordable and by now is almost a household item, which explains at least partially its rapid growth. From a technological point of view, one of the most important aspects of 3D printing is rapid prototyping and printing functional parts or arbitrary shapes. For the latter it is particularly important to understand how filament selection and print settings effect the properties of 3D printed parts and how they compare to industrial standards. We 3D printed standard shapes with infill percentages ranging from 100% to 25% and determined their Young’s modulus through mechanical testing. As filament, we selected ABS (Acrylonitrile Butadiene Styrene), a widely used and well characterized plastic.  Careful analysis of our experiments allows us to isolate the effects of infill percentage. Our preliminary results show that the Young’s modulus does not vary linearly with infill as found previously but rather follows a power-law behavior. We will discuss the implications of this finding for 3D printing of functional materials and microstructural modeling of 3D printed plastics.