PET (Polyethylene Terephthalate) and PETG (Polyethylene Terephthalate Glycol) are both thermoplastic polyesters, but they have some key differences due to the addition of glycol in PETG. Here's a breakdown:  

PET (Polyethylene Terephthalate)

• Properties:
  • High clarity and gloss  
  • Good chemical resistance  
  • Relatively rigid and strong  
  • Widely recycled (recycling code 1)  
• Applications:
  • Beverage bottles  
  • Food containers  
  • Packaging  
  • Fibers for clothing and carpets  

PETG (Polyethylene Terephthalate Glycol)

• Properties:
  • Excellent clarity and gloss (can be even higher than PET)  
  • Better impact resistance than PET  
  • More flexible than PET  
  • Good chemical resistance  
  • Easier to thermoform than PET
  • Recyclable, but not as widely as PET (recycling code 7)  
• Applications:
  • Packaging  
  • Medical devices  
  • 3D printing  
  • Displays and signs  

Key Differences:

• Flexibility: PETG is more flexible and less brittle than PET due to the addition of glycol.  
• Impact Resistance: PETG has better impact resistance than PET.  
• Thermoforming: PETG is easier to thermoform than PET, making it suitable for a wider range of applications.  
• Recycling: PET is more widely recycled than PETG due to its higher production volume and established recycling streams.  

In Summary:

• PET is a strong, rigid material with high clarity, making it ideal for applications like beverage bottles.  
• PETG is a more flexible and impact-resistant material with excellent clarity, making it suitable for applications like packaging, medical devices, and 3D printing.  

The choice between PET and PETG depends on the specific requirements of the application. If you need a rigid and strong material, PET is a good choice. If you need a more flexible and impact-resistant material, PETG is a better option.