3D Printing Optimization Using PETG Filament for Marine Applications

Additive manufacturing plays a crucial role in the rapid development of structural and functional components for autonomous vessels. The reliability of printed parts is strongly influenced by both material selection and printing parameters.

For this project, PETG (Polyethylene Terephthalate Glycol-modified) filament was selected and optimized to produce components that meet mechanical, environmental, and operational requirements for marine applications.

1. Material Selection: Why PETG Over PLA?

The choice of filament material significantly affects the durability and performance of 3D printed components, particularly for systems exposed to outdoor and marine environments.

Although PLA is widely used due to its ease of printing, it exhibits several limitations when applied to functional components on autonomous vessels. PETG was therefore selected as a more suitable alternative, offering a balanced combination of strength, durability, and environmental resistance.

1.1 Advantages of PETG Compared to PLA

PETG provides several key advantages over PLA for marine-oriented applications:

• Environmental Resistance
  PETG demonstrates superior resistance to moisture, UV exposure, and temperature fluctuations. PLA tends to soften and degrade under prolonged heat or humid conditions, whereas PETG maintains structural stability in outdoor environments.
• Mechanical Strength and Toughness
  Compared to PLA, PETG is less brittle and more impact-resistant. This makes it more suitable for components subjected to vibration, shock loads, or dynamic forces.
• Layer Adhesion
  PETG exhibits strong interlayer bonding when printed at appropriate temperatures, reducing the risk of delamination under mechanical loads.
• Chemical Resistance
  PETG shows better resistance to oils, fuels, and mild chemicals compared to PLA, making it suitable for marine and propulsion-adjacent components.

1.2 Limitations of PETG Compared to PLA

Despite its advantages, PETG also introduces certain trade-offs:

• Printability
  PETG requires more precise temperature tuning compared to PLA, which is more forgiving during printing.
• Surface Finish
  PLA typically produces a cleaner and stiffer surface finish. PETG may exhibit stringing if not properly configured.
• Dimensional Accuracy
  Due to its flexibility, PETG can show slightly lower dimensional precision for tight-tolerance parts.
• Moisture Sensitivity
  PETG is hygroscopic and absorbs moisture from the air, making filament storage more critical.

1.3 Material Selection Justification

While PLA is suitable for rapid prototyping and aesthetic components, its brittleness and poor environmental resistance limit its application in marine systems.

PETG was selected as the optimal compromise between:

• Mechanical toughness
• Environmental and moisture resistance
• Chemical durability
• Functional printability

This material choice supports long-term reliability and operational safety for autonomous vessel components.

2. Optimized PETG Printing Parameters

Through iterative testing and validation, the following printing parameters were identified as the most stable configuration for PETG filament used in this project.

2.1 Nozzle Temperature

The optimized nozzle temperature was set to 245 °C.

This temperature provides:

• Stable material flow
• Strong interlayer adhesion
• Improved mechanical integrity

Lower temperatures resulted in weak bonding, while higher temperatures increased stringing and surface artifacts.

2.2 Bed Temperature

The build plate temperature was set to 70 °C.

This configuration ensures:

• Reliable first-layer adhesion
• Reduced warping and edge lifting
• Stable thermal behavior during printing

2.3 Supporting Print Settings

To complement the temperature setup, additional parameters were applied:

• Moderate printing speed
• Controlled cooling fan usage
• Precise first-layer calibration

These settings improve print consistency and dimensional stability.

3. Environmental Factors Affecting PETG Printing

Environmental conditions play a significant role in PETG print quality and repeatability.

3.1 Humidity and Moisture

PETG absorbs moisture from the surrounding air. High humidity can cause:

• Bubbling during extrusion
• Rough surface finish
• Reduced layer adhesion

Filament should be stored in sealed containers with desiccants, especially in humid environments.

3.2 Ambient Temperature and Airflow

Uncontrolled airflow or rapid temperature changes may lead to:

• Layer separation
• Uneven cooling
• Dimensional inaccuracies

Maintaining a stable printing environment improves reliability.

3.3 Build Plate Cleanliness

Dust, oil, or residue on the build surface can reduce adhesion. Regular cleaning significantly lowers print failure rates.

4. Achieving Optimal Printing Results

The combination of PETG material selection, optimized printing parameters, and environmental control resulted in consistent and mechanically reliable printed components.

The finalized configuration—245 °C nozzle temperature and 70 °C bed temperature—represents a balanced setup that prioritizes strength, repeatability, and suitability for marine environments.

Conclusion

The use of PETG filament combined with carefully optimized printing parameters enables the production of durable and reliable 3D printed components for autonomous marine platforms.

By selecting PETG over PLA and refining the printing setup, this manufacturing strategy supports functional integration, rapid development, and long-term operational reliability.