Abstract
Interlaminar strength of extrusion-based additively manufactured parts is known to be weaker than the strength seen in the printed directions (X and Y). With Big Area Additive Manufacturing (BAAM), large parts lead to long layer times that are prone to splitting, sometimes referred to as delamination, between the layers. Fiber filled materials, such as carbon fiber reinforced ABS, are used to counter-act the effects of thermal expansion, but the fibers stay in-plane meaning that no fibers span from layer to layer, which helps counteract the weak interlaminar strength that causes splitting. A solution to this is a patent pending approach known as “z-pinning”. The process involves strategically positioning voids across multiple layers that will be backfilled with hot extrudate. This paper will explore the benefits and results of using “z-pinning” in large scale additive manufacturing.
