There’s a lot to love about polyethylene. It’s been the most common plastic in the world for nearly one hundred years and renowned for its strength, stability, versatility, recyclability and countless applications in industry and daily life. You’ve probably encountered many products made of polyethylene today without even knowing it.
If you don’t know the details about polyethylene and what makes it great, there’s much to learn. The material is perfect for packaging. In a moment we will focus on what makes polyethylene stand out from other packaging options.
Learning more about polyethylene will give you the advantage when packaging your own products, whether you’re bringing a small business to life or looking for a competitive edge in your established industry. Let’s begin.
We Use It Daily. But What Is Polyethylene Plastic?
Polyethlyene (PE) is more than just a type of plastic you find in plastic bags.
When polyethylene polymer chains are extended to produce ultra high molecular weight polyethylene (UHMWPE), you’ve got one dense product with extremely long chains and a high tensile strength better than that of steel. Then there are other variants like medium-density polyethylene (MDPE) and ultra low-molecular weight polyethylene (MDPE).
It’s a thermoplastic polymer with a highly variable structure, allowing engineers to formulate unique materials for specific applications. It’s even resistant to acids and fading, though it does have a low melting point. The mechanical properties of PE depend on a variety of variables.
“Polymer” isn’t a word we hear often, but think of it as a network of repeating molecular units to create something bigger and better. Polymers can be natural, synthetic, a mix of both, and comprise a wide range of organic and industrial materials.
Just as cellulose and resin are polymers that occur in nature, lab-made materials like various types of rubber and plastics like polyethylene are man-made.
The concept may seem odd at first, but polymers are fairly straightforward once you understand the basic format: monomers connect in a specific order to form chains, which can be made into any shape, size, and dimension.
Polyethylene is the winning polymer to emerge in the last century, appearing in different grades and formations based on its chemical structure.
What Is Polyethylene Used For?
Looking at the properties of polyethylene and all its applications, it’s easy to see why this material is so widely used. Depending on the structure, polyethylene can be used in items ranging from food packaging to household items, industrial settings, and everywhere in between. It’s even used in bulletproof vests.
While some forms of polyethylene are ideal for lightweight packaging, plastic wrap and grocery bags, others are considered “heavy duty” and are better suited for manufacture water pipes, garbage containers, barriers, and other construction applications.
Finally, the most advanced types of polyethylene are designed for high-performance equipment, rivaling the strength of steel with far more agility and versatility.
Because there are so many types of polyethylene, the applications are almost unlimited, and engineers continue to push the boundaries of the material and find new uses.
How Is Polyethylene Plastic Made?
As with all synthetic polymer production, the manufacturing process starts with isolating monomers and then using specialized catalysts to jumpstart the reaction that leads to polymerization.
In the case of polyethylene, the monomer in question is ethylene, a hydrocarbon that takes the form of a colorless, flammable gas. Its hydrated form is ethanol, better known as alcohol, and both compounds are some of the world’s most widely produced materials overall.
Since ethylene is a monomer, it needs to undergo a process of polymerization to take the form of polyethylene. This is accomplished by introducing a material like titanium chloride or chromium oxide, which can be facilitated at scale.
The result is raw plastic material in the form of pellets or chips, which can then be melted down and reformatted into any design imaginable. Producers can make thin layered films and wraps, create thicker sheets and laminates, add barriers and safety features, and meet the exact specifications that companies require to make their products possible.
What Are the Different Types of Polyethylene?
Based on their packaging needs, companies will seek out different types of polyethylene — and there are plenty to choose from.
The most common form is the highly flexible low-density polyethylene (LDPE) made by applying high-pressure, which is used for basic films, lightweight baggies, and single-use wraps. Protective properties are minimal, but they get the job done in the short term and offer unmatched convenience.
One step up from that is linear low-density polyethylene (LLDPE), which has slightly higher strength and barrier properties for more advanced applications. This material is used for tougher films in the packaging industry, as well as bubble wrap, saran wrap, and stretch films.
High density polyethylene (HDPE) is tougher, with molecules more tightly packed together for improved tensile strength and chemical resistance. This material is used for intensive, high-volume packaging solutions like crates, large drums, and bulk containers.
At last, polyethylene can be further modified and improved in examples like cross-linked polyethylene (PEX) and biaxially oriented polyethylene terephthalate (BoPET) or Mylar. These are modern, highly optimized materials for maximum utility, lightweight feel, and endless customization options.
Polyethylene Versus Polypropylene
At a quick glance, polyethylene has much in common with its polymer cousin, polypropylene. Both materials follow a similar production process, but a few features set the two apart.
Visually, polypropylene is not see-through like polyethylene. Instead, it’s translucent and foggy, which makes it less suitable for items on store shelves. Polypropylene is also stiffer, more rigid, and less able to stretch compared to polyethylene.
In terms of pure strength and resistance, polypropylene is a great option, but falls short in key areas compared to the best modern polyethylene options.
What Are the Characteristics of Polyethylene?
Zooming in on the characteristics of polyethylene, we see why the material is universal.
Versatility is the number one trait that makes this a great packaging material, as entire packaging systems can be formulated from polyethylene of differing densities.
Consider a delicate product like a mechanical component that’s ready to be shipped. It can be wrapped first with a film of LDPE as a layer of defense from moisture and debris. Then, it can be placed in a specially formulated tray made from a higher density polyethylene to keep it in place.
That unit can then be protected by a polyethylene container, which is finally wrapped in an LLDPE film for extra barriers. The result is a package that protects from oxidation, heat, moisture, and will keep products intact for the whole journey.
Is Polyethylene (PE) Toxic?
Polyethylene can generate toxic gases during the polymerization process, but it’s safe to keep around the house and use for daily items. Even if you wrap food in polyethylene film, you have nothing to worry about when reaching for that snack later on.
What Are the Disadvantages of Polyethylene?
Quality polyethylene is nearly flawless when made correctly, but maintaining that consistency at scale is where problems can occur.
Some reports show that low-quality polyethylene can break down early or deteriorate during the recycling process, especially with foam products. This is a good reminder to always work alongside trusted packaging producers and stick with the best in the business.
PE vs. PET – Which Is Right for Your Packaging Needs?
Polyethylene terephthalates are solid forms of polyester, and rival polyethylene in packaging applications. PET plastics are better for stress crack resistance and pure physical strength, while PE is the superior gas and moisture barrier.
Both materials are also recyclable, but require different processes to achieve reusability. Keep this in mind when searching for recyclable packaging solutions for your brand.
Why Dymapak Is the Best Choice for Packaging
With a range of pouches, tins, cartons, and baggies, Dymapak is your best choice for packaging, using the best that polyethylene materials have to offer.
From recyclable PE to high-end BoPET laminates with child-resistant features, Dymapak can assess your brand’s needs and deliver what’s required to accomplish your packaging goals.
The world of polymers is fascinating to explore, with packaging solutions as just one facet of the field. Polyethylene is a time-tested material. Learn which materials suit your products best and then execute with precision.