# Parameter Optimisation in 3D Extrusion Printing of Polyhydroxybutyrate Using Design of Experiment Methodology

## TL;DR

This paper optimizes 3D printing parameters for polyhydroxybutyrate to improve the accuracy and reliability of printed structures for regenerative medicine.

## Contribution

A novel DoE-based optimization strategy for PHB extrusion printing is introduced, improving scaffold fidelity and process reliability.

## Key findings

- An optimized parameter set significantly improved the shape fidelity of PHB scaffolds.
- A regression model identified key printing parameters and their interactions affecting dimensional accuracy.
- Verification prints confirmed the effectiveness of the optimized conditions.

## Abstract

This study systematically optimised extrusion-printing parameters for polyhydroxybutyrate (PHB) using a Design of Experiment (DoE) approach to improve printability and construct fidelity. A five-factor DoE was conducted to evaluate the individual and interactive effects of printhead temperature, printing pressure, printing speed, bed temperature, and cartridge heating time on the dimensional accuracy of printed constructs. The resulting regression model enabled the identification of statistically significant main and interaction effects among processing variables. An optimised parameter set (printhead temperature 145 °C, pressure 150 kPa, speed 15 mm s−1, bed temperature 25 °C, and cartridge heating time 120 s) enabled the fabrication of PHB scaffolds with substantially improved shape fidelity, which was experimentally validated using verification prints. These results demonstrate that a DoE-based optimisation strategy provides a robust and efficient route for rationally tuning PHB extrusion-printing conditions, thereby enhancing process reliability for scaffold fabrication in regenerative medicine applications.