Polyester is a category of polymers that contain the ester functional group in their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET).Some of the most significant properties of Polyethylene terephthalate are:
Chemical Resistance: PET does not react with water or food which is one of the reasons it is used for consumable packaging.
Strength to Weight Ratio: PET is very strong for its lightweight.
Shatterproof: PET will not break or fracture. This makes it a great replacement for glass as a container.
Transmissivity: Polyethylene terephthalate is naturally transparent. That said, if high transmissivity is desired then plastics like Acrylic or Polycarbonate may be better choices.