PolyEthylene Teraphthalate [PETG] for 3D Printing
Overview
PolyEthylene Terephthalate Glycol (PETG) is a popular 3D printing material known for its use in plastic bottles. In its original state, PET filament is colorless and crystal clear. However, its transparency can change with heating or cooling.
Advantages
- Durability: PETG is fairly hard and shockproof, making it ideal for lightweight items.
- Clarity: The material can achieve better clarity with thicker layer heights and controlled cooling.
- Thermoforming: PETG can be thermoformed and molded after being printed, providing versatility in post-processing.
- Flame Polishing: The material can be polished with a flame to enhance its finish.
- Ease of Printing: PETG is easy to print with and has a wide temperature range (160°C to 210°C).
Disadvantages
- Water Absorption: PETG can absorb moisture from the air, so it needs to be stored in a dry place.
- Temperature Sensitivity: PETG has specific requirements for printing temperatures and bed preparation to avoid printing issues.
Technical Specifications
- Compressive (Crushing) Strength: 55 MPa (8.0 x 10³ psi)
- Density: 1.3 g/cm³ (81 lb/ft³)
- Dielectric Constant (Relative Permittivity): 2.5
- Dielectric Strength (Breakdown Potential): 16 kV/mm (0.63 V/mil)
- Elastic (Young’s, Tensile) Modulus: 2.2 GPa (0.32 x 10⁶ psi)
- Flexural Modulus: 2.1 GPa (0.3 x 10⁶ psi)
- Flexural Strength: 77 MPa (11 x 10³ psi)
- Glass Transition Temperature: 81°C (180°F)
- Heat Deflection Temperature at 1.82 MPa (264 psi): 69°C (160°F)
- Heat Deflection Temperature at 455 kPa (66 psi): 73°C (160°F)
- Melting Onset (Solidus): 140°C (280°F)
- Refractive Index: 1.6
- Shear Strength: 62 MPa (9.0 x 10³ psi)
- Specific Heat Capacity: 1200 J/kg-K
- Strength-to-Weight Ratio: 41 kN-m/kg
- Tensile Strength: Ultimate (UTS): 53 MPa (7.7 x 10³ psi)
- Thermal Conductivity: 0.29 W/m-K
- Thermal Diffusivity: 0.19
- Thermal Expansion: 68 µm/m-K
- Water Absorption After 24 Hours: 0.2%
Material Properties for 3D Printing
- Printing Temperature: 210°C
- Flow Tweak: 0.9
- Bed Temperature: 75°C
- Bed Preparation: Apply two layers of glue stick
Additional Considerations
- Storage: Store PETG in a dry place to prevent moisture absorption, which can affect print quality.
- Print Quality: PETG offers good print quality with a balance of strength, clarity, and flexibility.
- Environmental Impact: While not biodegradable like PLA, PETG is recyclable and often made from recycled materials.
Comparison with Other Materials
- PLA: PETG has a higher impact resistance and flexibility compared to PLA but requires a higher printing temperature and more careful bed preparation.
- ABS: PETG offers similar strength to ABS but with better clarity and easier printing due to lower warping tendencies.
By understanding these properties and considerations, you can effectively use PETG in your 3D printing projects to achieve high-quality results with durable and versatile material.
PETG continues to be a versatile and popular choice for many 3D printing applications due to its durability, ease of use, and high-quality finish.