What is PET?
PET is the acronym for Polyethylene Terephthalate and it forms part of the polyester family. This material is a plastic used to make one of the most common containers - the plastic bottle. PET is globally recognised as a safe and recyclable material to store food and drink as well as non-food products. It is used as packaging for a wide variety of contents due to the durability of the material as well as its ability to be easily recycled. PET is lightweight which makes it easy for transport, and shatterproof which protects its contents.
PET is popular because it provides a sound oil barrier that helps with chemicals attacking the plastic. PET can also be very clear plastic and can look like glass once set to its desired shape. PET can also be colour matched to be any colour.
PET bottles do not have as high of a temperature resistance (less than 55°C) as HDPE. PET containers can also handle cold temperatures of about -40°C.
What is HDPE?
High Density Polyethylene (HDPE) is a thermoplastic polymer made from petroleum. Much like PET, it is also used in a variety of applications such as shampoo bottles, cutting boards and piping. HDPE is known for being a very strong and durable plastic with high-impact resistance and melting point.
HDPE is engineered to be low maintenance, safe and long-lasting. It is also easily meltable and moldable - it will remain rigid in very high temperatures which is a bonus, however once it reaches its melting point, you can easily mould and manipulate the plastic into whichever application you would like. HDPE also resists told, mildew and rotting making it the ideal material for underground piping used to deliver water. Moreover, the material is virtually impervious to most common chemicals, water, solvents, acids, detergents, and cleaning fluids. HDPE bottles and containers also are able to withstand colder and freezing temperatures very well (-78,89°C) and higher temperatures moderately well near 75°C.
Best of all this material is also easily recyclable, which makes it a great option for a cost-effective and environmentally friendly and responsible material.
Differences between PET and HDPE
Opacity
The most obvious difference between the two is the opacity of the material. PET is typically transparent which means you can see through it completely, whereas HDPE is translucent which means that it looks opaque from a distance but it also allows you to see the fill level of your product through the material at a close distance.
Barriers
PET plastic is strong, yet lightweight and flexible; with it greatly resembling glass in appearance. It acts as a strong barrier against water vapour, gas, oil, alcohol and dilute acids, making it the perfect packaging option for food and drink where preventing product contamination is essential.
On the other hand, HDPE is tough and rigid, with a finish of a natural milky colour. The strength of the material means that it is very difficult to crack the plastic and makes it an appropriate packaging choice for food and drink, as well as chemicals and industrial cleaning products.
Recyclability
When it comes to recycling, there isn’t much of a difference between the two plastics. PET plastic can be recycled into a variety of new materials, including fabrics and new food packaging, whilst HDPE can be turned into garden furniture, bins and pipes!
Just remember the code for PET is 1 and the code for HDPE is 2.
EXAMPLES
PET: Water bottles, soft and fizzy drink bottles, food pots, oven ready trays, preserve jars, carpet, clothing, industrial strapping, rope, automotive parts, fibrefill for winter jackets and sleeping bags, construction materials, protective packaging.
HDPE: Milk bottles, chemical drums, jerrycans, children’s toys, household and kitchenware, cable insulation, carrier bags, cutting boards, some shoe parts, cereal box liners.
