Polyethylene terephthalate, commonly abbreviated PET, PETE, is the most common thermoplastic polymer resin of the polyester family and is used in fibers for clothing, containers for liquids (soft drinks) and foods, thermoforming for manufacturing, and in combination with glass fiber for engineering resins.

The majority of the world’s PET production is for synthetic fibers (in excess of 60%), with bottle production accounting for about 30% of global demand. In the context of textile applications, PET is referred to by its common name, polyester, whereas the acronym PET is generally used in relation to packaging. Polyester makes up about 18% of world polymer production and is the fourth-most-produced polymer after polyethylene (PE), polypropylene (PP) and polyvinyl chloride(PVC).

While most thermoplastics can, in principle, be recycled, PET bottle recycling is more practical than many other plastic applications because of the high value of the resin and the almost exclusive use of PET for widely used water and carbonated soft drink bottling. PET has a resin identification code of 1. The prime uses for recycled PET are food-grade product, such as plastic bottle and food container, also non-food grade product, such as polyester fiber and strapping.



  • Water bottles tend to be lighter than carbonated bottles
  • Weights are averages across all brands in Hong Kong

*a contaminant in the HK mechanical recycling pathway


High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called “alkathene” or “polythene” when used for HDPE pipes.[1] With a high strength-to-density ratio, HDPE is used in the production of plastic bottles, corrosion-resistant piping, geomembranes and plastic lumber.

HDPE is commonly recycled, and has the number “2” as its resin identification code.

It is commonly used as containers for cleaning products, bulk food products – ketchups and the like, as well as for items like personal care products – shampoo’s and conditioners.



  • Weights may vary considerably as there is no standard size bottle