PET, commonly known as the plastic used in soda and water bottles, is a widely recyclable and durable filament. Unlike PETG, it lacks glycol modifiers, which makes it less flexible but adds to its strength and rigidity. PET offers good mechanical properties and chemical resistance, making it suitable for more demanding applications.

  • Properties: Strong, chemical-resistant, low odor, slightly brittle.
  • Best For: Functional parts, mechanical components, containers, and applications needing high durability.
  • Toxicity and Food Safety:
    • During Manufacturing: PET production is less environmentally impactful than some other plastics due to its recyclability. However, producing raw PET still requires energy-intensive processes.
    • During Printing: PET emits relatively low VOCs during printing, making it a safe choice for indoor use with proper ventilation. Always print in a well-ventilated space to avoid inhaling any fumes.
    • Post-Printing: PET is food-safe in its pure form, though most filament manufacturers do not certify it as such. The safety depends on the quality and purity of the filament as well as the conditions under which it’s printed. Like other plastics, PET should only contact food if specifically marked as food-safe.
    • Recyclability: PET is one of the most widely recycled plastics, which makes it environmentally preferable if disposed of properly.

  • Advantages:

    • Durability: PET is strong and impact-resistant, suitable for functional parts that need to withstand wear.
    • Chemical Resistance: Resistant to a wide range of chemicals, making it ideal for containers and storage applications.
    • Low Odor: Emits minimal odor during printing, unlike ABS or other filaments.
    • Transparent Options: Available in transparent and translucent options, providing aesthetic flexibility.

  • Limitations:

    • Brittleness: PET can be more brittle than PETG, which may limit applications where flexibility is required.
    • High Heat Bed Requirement: A heated bed (70–80°C) is recommended to prevent warping and improve adhesion.
    • Hydroscopic: PET readily absorbs moisture from the air, which can impact print quality if not stored properly.

  • Print Settings:

    • Extruder Temperature: 230–250°C
    • Bed Temperature: 70–80°C
    • Print Speed: 30–60 mm/s
    • Cooling: Moderate cooling recommended to improve surface finish without compromising adhesion

  • Applications:

    • Mechanical Parts: Ideal for gears, brackets, and other parts that require strength and rigidity.
    • Containers: Often used for bottles, jars, and other containers due to its chemical resistance and transparency.
    • Medical and Lab Equipment: Sometimes used in medical applications due to its sterilization capability and durability (not typically in 3D-printed form unless certified).
    • Educational Projects: Durable enough for functional, low-stress applications.
  • Post-Processing:
    • Sanding and Polishing: PET can be polished to a smooth, glass-like finish, especially when transparent.
    • Glue and Bonding: Can be chemically bonded with adhesives designed for plastics.

PET is a durable and chemically resistant material with low toxicity, making it a good choice for containers, mechanical parts, and even certain educational or functional applications. While PET is theoretically food-safe, the printed product’s food safety depends on the filament’s purity and handling during printing.