Numerical Simulation of a Core-Shell Polymer Strand in Material Extrusion Additive Manufacturing

Area of Science:

• Materials Science
• Polymer Engineering
• Additive Manufacturing

Background:

• Material extrusion additive manufacturing (ME-AM) is a novel technique for producing core-shell polymer structures.
• ME-AM offers enhanced mechanical properties and dimensional accuracy compared to traditional 3D printing methods.
• Optimizing operating parameters is crucial for achieving desired quality in 3D-printed products.

Purpose of the Study:

• To identify optimal operating parameters for 3D printing core-shell polymer strands using ME-AM.
• To achieve complete encapsulation of the core polymer within the shell polymer.
• To maximize the volume fraction of the core polymer in the final printed strand.

Main Methods:

• Numerical simulations utilizing computational fluid dynamics (CFD).
• Modeling the deposition flow controlled by three dimensionless parameters: diameter ratio (d/D), normalized gap (t/D), and velocity ratio (V/U).
• Analyzing cross-sections of deposited strands to evaluate encapsulation and morphology.

Main Results:

• The study identified specific operating parameters that lead to successful core-shell strand formation.
• Complete encapsulation of the core material by the shell material was achieved under optimal conditions.
• The shape and size of the printed strand were significantly influenced by the selected parameters.

Conclusions:

• Optimal operating parameters for ME-AM core-shell polymer printing were determined.
• A diameter ratio (d/D) of 0.7, a normalized gap (t/D) of 1, and a velocity ratio (V/U) of 1 are recommended.
• These parameters ensure high core volume fraction and complete encapsulation for improved 3D-printed polymer products.