# Tensile and Structural Performance of Annealed 3D-Printed Polymer Composite Impellers for Pump-as-Turbine Applications in District Heating Networks

## TL;DR

This study evaluates 3D-printed polymer composites for turbine impellers in heating systems, finding that annealing improves their strength and heat resistance.

## Contribution

The study introduces the use of annealed ePAHT-CF15 as an optimal material for high-temperature turbine impellers in district heating networks.

## Key findings

- Annealing ePAHT-CF15 significantly increased tensile strength and Young’s modulus.
- ePAHT-CF15 showed superior thermal stability and rigidity at high temperatures.
- Annealed ePAHT-CF15 is the best material for 3D-printed turbine impellers in heating systems.

## Abstract

This study investigates the mechanical performance of three temperature-resistant 3D-printable polymer composites for turbine impellers used in district heating networks for pressure reduction. Using fused deposition modeling (FDM), tensile strength and deformation of ASA-X CF10, PA6-GF30, and ePAHT-CF15 were evaluated at temperatures representative of real operating conditions (60–130 °C). These polymer composites were systematically tested, with particular emphasis on annealed ePAHT-CF15. Results demonstrated that annealing significantly improved mechanical performance, yielding higher tensile strength, Young’s modulus, and reduced deformation. Structural analyses confirmed that ePAHT-CF15, particularly when annealed at 200 °C, exhibited superior thermal stability and rigidity, making it the optimal material choice for high-temperature turbine impeller applications. These findings support the design of 3D-printed composite impellers for pump-as-turbine applications in district heating systems, where high stiffness and heat resistance are required.