Polyethylene
Polyethylene, or polythene, abbreviated as PE, refers to ethylene polymers. They are made from resins that come mainly from petroleum that undergoes a catalysing process. PE is the most common type of plastic, accounting for 100 million tonnes or about one third of all plastics produced in 2020. It makes up around 29% of demand in Europe, making it the number 1 most widely used type of plastic on the continent.
There are two different types:
- LDPE (low-density polyethylene)
Soft objects are usually made from LDPE. It is used to produce films and plastic bags, rubbish bags, flexible containers in contact with food, etc.
- HDPE (high-density polyethylene)
Rigid products are generally made from HDPE. It is used to manufacture bottles and packaging for cleaning and cosmetic products, sturdy containers, toys, etc.
PE is derived from petroleum, but we have also had green polyethylene (BIO-PE), for a few years, which is polymerised from ethylene derived from ethanol obtained by fermentation of sugar cane.
Pros
Polyethylene is strong and very resistant to shocks, even when cold. It is also resistant to abrasion, corrosion and oxidation. PE is very easy to handle and transform and is robust in the face of temperature variations and contact with many different liquid chemicals (known as chemical inertia). It can be treated in different ways for different types of look/finish: mirrored, smooth, rough, grained, etc. Items of all sizes and volumes can be produced, as it is very malleable.
It does not degrade and has zero toxins, making PE a preferred material for food use. Its properties offer a wide range possibilities of use, from rigid to flexible, from translucent to opaque, and it can also easily be dyed.
Cons
As it is derived from fossil resources, PE is a polluting material, from its production to its recycling.
Polyethylene has low resistance to oxidising agents. Due to surface oxidation or physical degradation, PE can even lose its hydrophobic properties. At the same time, although this material is robust, it is still at risk of cracking under very high pressure.
Its resistance to heat varies depending on what type it is. LDPE, used to manufacture plastic bags, does not withstand high temperatures. HDPE on the other hand can withstand high temperatures up to 80°C. This factor must therefore be taken into account depending on the product you wish to develop.
As for recycling, only HDPE can be recycled (via thermal recycling), provided that it has not been mixed with other materials.
We can make your next PE items, but we can also offer you in particular new recycled or non-fossil-derived materials to help you reduce your environmental footprint. Feel free to contact us to discuss your future project.