Experimental investigations on recycled polymeric composites developed by extrusion based 3D printing process

Abstract

The integration of continuous fibre reinforcement in recycled thermoplastic composites through material extrusion-based 3D printing (MEX 3D printing), or fused deposition modeling (FDM), aligns with the principles of Industry 4.0, presenting an innovative path for developing high-performance, sustainable materials. Continuous fibre-reinforced thermoplastic composites (CFRTPC) have consistently shown superior mechanical properties over short fibre-reinforced composites. The increased use of MEX 3D printing has generated high demand for thermoplastics, raising significant environmental concerns due to reliance on virgin polymers. Recycling thermoplastics for composite fabrication provides a viable solution, reducing waste and the environmental footprint associated with traditional plastic production. Thus, the primary goal of this research is to develop sustainable 3D printing filaments from recycled acrylonitrile butadiene styrene (ABS) waste, contributing to eco-friendly manufacturing without compromising material performance. In this work, a mixed feedstock approach was applied, blending recycled ABS (RABS) with virgin ABS (VABS) at weight ratios of 10-50%. The extruded filaments rheological and thermo-mechanical properties were studied to understand how varying temperatures impact the structural characteristics of ABS blends. Results showed that increasing the extrusion temperature from 190and#8451; to 195and#8451; led to significant material changes, particularly in the breakdown of styrene-acrylonitrile and butadiene within ABS. These changes resulted in strain hardening and enhanced stiffness in the material. Mechanical testing further revealed that a filament blend containing 60 wt.% RABS and 40 wt.% VABS demonstrated a Young s modulus of 2329 MPa, yield strength of 34.814 MPa, and ultimate tensile strength of 40.82 MPa values comparable to those of virgin ABS filament.