Chapter 3 - The need for fused deposition modeling of composite materials

Abstract

Most commercial filaments for fused deposition modeling (FDM), aka fused filament fabrication (FFF), still consist in neat thermoplastics, with poly(lactic acid) (PLA), acrylonitrile butadiene styrene (ABS), polyamide (PA, “nylon”), polyethylene terephthalate (PET) and its glycol-modified version (PETG), and flexible thermoplastic elastomers (TPEs) being the most popular options. However, it is also possible to process thermoplastic-matrix composite filaments with FDM. Adding a functional filler provides the polymer matrix with new properties that can be tailored to match the assigned service requirements yielding functional active materials. Composite filaments with high filler loadings can be printed, debound and sintered into fully organic parts. After a detailed analysis of conventional mono-material filaments, this chapter summarizes the emerging trends in FDM of composite feedstocks. Ashby-like diagrams map out the mechanical properties of around 100 commercial filaments and help visualize the functional advantages and limitations of composite materials over mono-material feedstocks. Selected applications and case studies illustrate how composite materials with embedded functionality are already revolutionizing 3-dimentional (3D) printing by FDM in numerous high-tech industries, such as composites manufacturing, biomedicine and 3D pharming, as well as in everyday life.