Published on Tue Aug 15 2023 07:02:07 GMT+0000 (Coordinated Universal Time) by Alex

Prusa PETG: A Deep Dive into This Versatile 3D Printing Filament

Prusa PETG has become a staple in many 3D printing enthusiasts’ arsenals, lauded for its blend of strength, ease of use, and appealing aesthetics. This article will provide a comprehensive overview of Prusa’s PETG filament, covering its specifications, providing practical tips for successful printing, and evaluating its key performance attributes.

What is Prusa PETG?

PETG stands for Polyethylene Terephthalate Glycol-modified. This thermoplastic is a modified version of PET (the same material used in water bottles) with the addition of glycol during polymerization. This modification makes it less brittle and more suitable for 3D printing. Prusa Research, known for their high-quality 3D printers, also produces their own line of PETG filament, meticulously formulated for optimal performance on their machines and beyond.

Detailed Specifications:

• Material: Polyethylene Terephthalate Glycol-modified (PETG)
• Diameter: Typically 1.75mm ± 0.02mm (Standard)
• Spool Size: 1kg (Standard)
• Printing Temperature: 230-250°C (Recommended)
• Bed Temperature: 80-90°C (Recommended)
• Nozzle Size: Compatible with most common nozzle sizes (0.4mm recommended as a starting point)
• Density: ~1.27 g/cm³
• Tensile Strength: Varies slightly depending on print settings, typically around 50 MPa.
• Elongation at Break: Varies slightly depending on print settings, typically around 10-20%.
• Glass Transition Temperature (Tg): ~80°C
• Chemical Resistance: Good resistance to oils, greases, and many common solvents.
• Food Safety: Generally considered food-safe when printed with a clean nozzle and appropriately treated after printing (consult regulations in your region).
• Availability: Widely available through Prusa Research and authorized resellers.
• Price: Typically falls within the mid-range price point for PETG filaments.

Usage Tips for Optimal Printing:

• First Layer is Key: PETG requires good bed adhesion. Ensure your bed is clean and level. Use a glue stick or PEI sheet for optimal adhesion. Dial in your Z-offset carefully; the first layer shouldn’t be too squished or too far away.
• Temperature Control: The recommended temperature range is crucial. Experiment within this range to find what works best for your printer and environment. Higher temperatures can improve layer adhesion but may also lead to stringing.
• Cooling: PETG doesn’t generally require as much cooling as PLA. Start with 20-30% fan speed and adjust as needed. Excessive cooling can negatively impact layer adhesion.
• Print Speed: A moderate print speed is recommended, typically between 40-60 mm/s. Higher speeds can cause under-extrusion or warping.
• Retraction Settings: PETG is prone to stringing. Optimize your retraction settings to minimize this. Increase retraction distance and speed as needed. Use coasting and wiping settings to reduce stringing further.
• Enclosure (Optional): While not always necessary, an enclosure can help improve adhesion and reduce warping, especially for larger prints.
• Drying: PETG is hygroscopic, meaning it absorbs moisture from the air. If you notice issues like bubbling, popping, or poor layer adhesion, try drying your filament before printing. Use a dedicated filament dryer or place it in an oven at a low temperature (around 50°C) for a few hours.
• Avoid Over-Extrusion: PETG tends to be slightly more viscous than PLA. Ensure your extrusion multiplier is properly calibrated to prevent over-extrusion.
• Support Structures: PETG supports can be difficult to remove, so design your parts with minimal support requirements. Consider using breakaway support materials.

Evaluation of Prusa PETG:

Here’s an assessment of Prusa PETG across key attributes, rated out of 10:

• Print Quality: 9/10 - Produces smooth surfaces and detailed parts when properly tuned.
• Toughness: 8/10 - Offers good impact resistance and durability, superior to PLA.
• Flexibility: 6/10 - More flexible than PLA but less flexible than materials like TPU.
• Warping: 7/10 - Less prone to warping than ABS but can still occur, especially with larger prints.
• Adhesion: 8/10 - Excellent bed adhesion when printed on a suitable surface with the right settings.
• Moisture Sensitivity: 6/10 - Hygroscopic, requires proper storage and drying if exposed to moisture.
• Color Range: 7/10 - Offered in a decent range of colors, including transparent options.
• Temperature Range: 8/10 - Relatively wide printing temperature range allows for some flexibility in print settings.
• Odor & Fumes: 8/10 - Low odor compared to materials like ABS. Fumes are minimal but proper ventilation is still recommended.
• Spool Winding Quality: 9/10 - Excellent spool winding prevents tangles and ensures smooth feeding.

Overall Average Score: 7.9/10

Conclusion:

Prusa PETG strikes a good balance between ease of use, strength, and aesthetics, making it an excellent choice for a wide variety of 3D printing applications. While it may require some initial experimentation to dial in the optimal settings for your printer, the results are well worth the effort. Its durability and resistance to environmental factors make it suitable for both functional parts and decorative prints.

Written by Alex