We know that polythene is highly stable, mostly unreactive and versatile in a ton of applications. But how does it hold up in extreme environments? Well, its performance can be challenged by extreme conditions – high and low temperatures, and exposure to harsh environments, can cause polythene to come under stress. Let’s explore these extremes, and discuss ways that additives, design and engineering can help polythene perform in even the harshest of conditions.
Polythene in extreme temperatures and humidity
Polythene can endure a pretty broad range of temperatures – LDPE (the most common material for polythene films and bags) remains flexible in cold conditions and is able to function at temperatures as low as -40°C. For applications in freezing and sub-zero environments, cold-resistant additive agents need to be integrated into the masterbatch; without them, the material can become brittle over time. At the upper end of the temperature scale, polythene can withstand up to 90ºC, but prolonged exposure to extreme heat can cause deformation, degradation or total failure.
Polythene’s inherent resistance to moisture makes it an excellent choice for humid conditions. It can serve as a highly effective moisture barrier for packaging sensitive products in areas with high environmental humidity.
Hot, humid conditions are also generally very sunny – and UV light breaks polythene down over prolonged exposure. To combat this, additives like UV inhibitors can be added to prevent polythene from breaking down due to sun exposure.
By controlling the additives mixed in with the masterbatch (as well as the thickness and colour), polythene can be engineered to withstand punishingly harsh conditions; on land, at sea – and in space.
Applications in extreme environments
Research bases
On remote polar research bases, large teams have to live day to day – and polythene is essential for that. The number of people carrying out scientific research on the continent and its nearby islands ranges from approximately 4,800 during the summer to around 1,200 during the winter.
And during this time, food and supplies need to be transported over vast, inhospitably cold stretches. Equipment needs to be packaged and protected against these harsh conditions, too. Cold-resistant plastics like polythene ensure that essential supplies remain protected and functional despite the harsh climate. Sensitive electronic equipment can be packaged in polythene treated with anti static additives, for increased protection.
At sea
Keeping food fresh at sea has been a huge challenge since humans first built boats to explore the planet. In modern times, polythene has made this so much easier. But it’s not just useful for storing food and supplies.
Polythene is prominent in maritime applications thanks to its chemical resistance to seawater, and with UVI additives, its durability under continuous sun exposure. This means it can be used to protect devices and equipment that would otherwise be damaged by spray, or used as a temporary, reusable cover – and it can be used in marine biology to keep fish and other aquatic animals bagged for study, transport or release back into the wild.
In space
Polythene plays a crucial role in space missions, where it’s used to package and preserve food and other supplies. Its ability to maintain integrity under the vacuum and temperature extremes of space is essential for astronaut survival, plus its light weight makes it a prime material candidate for missions where every gram at launch counts.
Polythene is also being engineered for use as a primary building material in future spacecraft. It showcases excellent resistance and reflectivity to the radiation encountered in deep space – and it weighs far less than the current standard material, aluminium.
Emergency services
Polythene films with flame-retardant additives and advanced thermoplastic films have a high resistance to burning – useful for protecting equipment and people in hazardous situations. While the polythene will fail once it exceeds its maximum operating temperature, this is a far safer prospect than having it burst into flames.
Police use polythene bags for evidence and forensics, and armed forces frequently use it in the field on challenging assignments. Polythene is also used by medical professionals and paramedics, who often have to perform in extreme conditions; outdoors or otherwise.
Key failure points and how to address them
Despite all its strengths, polythene will fail under the most extreme conditions – especially in high temperatures with added mechanical stress. Engineering and additives can vastly improve this performance, far beyond the baseline.
The masterbatch can be blended with white coloured pellets to reflect sunlight (or infrared light in general), as well as UV inhibitors. Flame retardant additives can resist burning for longer. And during extrusion, polythene can be blown thicker to provide more resistance to mechanical stress.
The extrusion process can also be highly optimised for strength, by paying careful attention to the “grain”; by stretching the film in both directions while it’s rolled, the polymer chains are layered across each other – making the polythene film stronger.
Polythene’s adaptability makes it a preferred material for packaging and protection in extreme conditions. By understanding its properties and enhancing it with additives, polythene can meet the demands of challenging environments – from polar research bases and maritime applications, to space missions.
Learn more about the properties of polythene
Polythene for extreme applications
Talk to the polythene experts at NPF Packaging – and start your order for custom blended polythene. Get a quote now, or call us on 01773 820415 to find out more about our manufacturing and design process.
