High processing temperatures are required to consolidate powders via additive manufacturing (AM) to form high quality, functional parts with minimal material waste. Repeated exposure at elevated temperatures causes degradation in unused polymeric powders leading to poor part performance when later reused, thus limiting powder recyclability. This project focuses on the development of a novel process christened Reactive Binder Jetting (RBJ) capable of forming solid, three-dimensional (3D) composite parts without a need for lasers or similar high temperature elements. RBJ consolidates polymeric powder at low temperature (≤ 60 °C) via strong covalent bonding between particulates following the selective deposition and penetration of a highly reactive two-part binding system composed of polyurethane (PU). A modified commercial inkjet printer equipped with a custom dual-printhead, and integrated powder bed system is used to facilitate the production of 3D composite structures which exhibit functional properties within a single part. Excellent customisation and control of part functionality is demonstrated by the versatility of the PU binding system and accompanying deposition strategies. Further work will focus on the low temperature manufacture of multi-functional, non-load bearing parts composed of different powders and reactive ink combinations. Thus, RBJ not only offers a unique, cost-effective method for fabricating net-shape polymer parts with tailored properties but also has potential to generate multi-material composite parts from a wider range of material classes.

Additive manufacturing (AM) of functional composite structures via reactive binder jetting (RBJ) using a highly reactive two-part binding system

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.