By Shell Polymers on Nov 24, 2020
Compared to alternatives such as linear low-density polyethylene (LLDPE), HDPE film is significantly stiffer, which means that films can be made thinner while still running efficiently through packaging machines. From the consumer side of things, stiffer films also provide a thicker feel.
According to Polymer Pioneer, Dan Falla, HDPE is widely used in the packaging industry due a variety of traits such as moisture barrier, light weight, stiffness, low cost, durability, easy processing, etc.
Discover three key properties of HDPE that makes it ideal for protecting consumer packaged goods:
1. Moisture and Chemical Resistance
Polyethylene has a high compatibility rating with most chemicals and is resistant to strong acids and bases, as well as gentle oxidants and reducing agents. HDPE is an efficient moisture barrier in food packaging applications such as cereal and cracker packages. This trait reduces the moisture transmission rate, which helps increase the shelf life and reduce waste. It also helps protect other moisture sensitive products.
HDPE is also resistant to many organic substances, such as bacteria and fungi. Due to this characteristic, HDPE film can withstand repeated exposure to chemicals such as cleaning agents and protect its contents from contamination. While this trait makes HDPE ideal for extrusion applications like pipe, it also makes exceptional packaging for chemical liquids or highly-sanitized items.
Because of this characteristic, HDPE works well for a variety of protective packaging applications such as:
- Baked goods bags
- Produce bags
- Liquid packaging for household chemicals like laundry detergent
Additionally, because HDPE is chemical resistant, it withstands corrosion and is great for handling acids and alkalis. HDPE is also resistant to grease and oils. This makes it suitable for protective plastic film applications such as electronic goods packaging.
2. Higher Material Strength
HDPE has a high tensile strength², which is higher than other forms of polyethylene. This trait allows thin HDPE film to withstand extreme stress and hold quantities higher than its weight.
Consider garbage bags. They’re only a couple of ounces when empty, but they can hold 15+ pounds of trash. It also maintains its strength at low temperatures, which makes it useful for products like freezer bags. Whenever bags for bulky items such as food grains, cement, and fertilizer are needed, HDPE is the go-to material because of its incredible strength.
Thanks to these traits, HDPE excels in high-stress environments for applications such as:
- Garbage bags and liners
- Mulch film
- Grocery bags
In addition to its impressive tensile strength, HDPE is generally stiffer than other polyethylene films, making it more durable and giving it the ability to hold its shape. Enhancing the existing strength of HDPE, researchers from the University of Warwick and Queen Mary University of London devised a method for creating transparent polyethylene sheets that have a strength greater than aluminum with a lighter weight. This new processing technique supports protective glazing for phone display screens, windscreens, and visors in the automotive and aerospace industry.1
3. Affordable and Reusable
Compared to alternatives, polyethylene packaging is often a more economical option for consumer goods packaging. For plastic converters, it’s cheaper to produce. According to the American’s Chemistry Council, this is because “plastics are incredibly energy efficient to manufacture and lighter than alternative materials.” This benefits brand owners by reducing the weight of products, therefore reducing the cost of shipping.
The American Chemistry Council explained that just two pounds of plastic can deliver 10 gallons of a beverage. Three pounds of aluminum, eight pounds of steel, or over 40 pounds of glass is required to bring home the same amount of a beverage.”2 This makes it suitable for any packaging application looking to reduce packaging costs!
According to McKinsey, the use of flexible packaging in packaged goods is starting to grow in popularity.3 HDPE offers converters and brand owners with key advantages for making reliable flexible plastic packaging. Learn more about Shell Polymers’ polyethylene film expertise by reading about film expert Dan Falla’s polymer profile.4