To a layman, PE and PET can be rather confusing; they are both thermoplastics and they both contain the word polyethylene in their names!
In this blog, we will list some basic differences as well as similarities in the structure, characteristics and apposite application of the two subsets of plastics.
Unlike PET, PE can vary in its crystalline structure that thus dictates the properties of the resin.
The most comparable type of PE to PET would be High Density Polyethylene (HDPE). Both PET and HDPE are very popular for manufacturing plastic bottles. The rigid structure, high strength and chemical resistance make them both great candidates for use in packaging of chemicals and perishable items.
Since PET is difficult to treat with plasticizers and so is BPA and phthalate-free, it is used to food and beverage containers.
Although the melting point of PET is higher than that of HDPE, it has a smaller range of temperature resistance and begins to weaken at a lower temperature than HDPE. HDPE can also withstand lower temperatures than PET.
On the flipside, PET offers better stress crack resistance as well as easier recyclability than HDPE.
|
|
Polyethylene |
Polyethylene terephthalate |
|
Family |
Polyolefin |
Polyester |
|
Monomers |
Homopolymer |
Copolymer |
|
|
|
|
|
|
High Density Polyethylene |
Polyethylene terephthalate |
|
Melting Point |
Lower |
Higher |
|
Tensile Strength |
Lower |
Higher |
|
Density |
Lower |
Higher |
|
|
|
|
PET is lightweight, transparent, pressure resistant and ideal for hot filled beverages like juices, dairy products, sports drinks, etc. Shopping bags, films to package foodstuff, FMCG product and electronic packaging are also manufactured using PET.
HDPE is used to package solid capsules and oral tablets, although PET is still usually the preferred choice. HDPE is commonly used to manufacture crates, barrels, cannisters and pressure pipes, a category that PET is not employed for.
Both plastic types are food-safe, durable and highly recyclable.
