Polyethylene vs Polypropylene: What’s the Difference?

When it comes to plastic bags, you really have two basic choices: polyethylene or polypropylene plastic. Which is better? Ultimately, it just depends on your needs. The most obvious difference is that polyethylene bags are opaque plastic, while polypropylene bags are completely clear.

But deciding which type of plastic packaging is right involves more than just how clear the actual plastic is. So, what is the difference between polyethylene and polypropylene? How do you know which one is right for you? Are there any major distinctions you should be aware of? Knowing about polypropylene-polyethylene differences is key to ensuring you get the best plastic bag for your products and needs.

Honestly, understanding polypropylene vs polyethylene is actually pretty easy. The biggest thing to remember is that while they’re both plastic bags, they aren’t typically used for the same products or purpose. Meaning, these two types of plastic most times won’t be used interchangeably.

Polyethylene is the most widely available type of plastic out there. It’s translucent or opaque, with a slight haze to it, making it a good option for when you want a bag that‘s got protective qualities. You can still see the items inside, but the details of the contents won’t be quite as clear.
Polypropylene, on the other hand, is crystal clear, so they’re ideal for food or medical items.

Even though these bags may seem fairly similar at first glance, when deciding on polypropylene versus polyethylene, and when trying to figure out which plastic packaging you actually need, you want to look at more complex factors than just these basic aesthetics.

If you need help deciding on polypropylene vs polyethylene, read on, as we cover all the pros and cons of each, so you’ll feel like an expert when you’re selecting your plastic bags.

Polyethylene (PE)

What is polyethylene plastic? It’s a strong, flexible material that’s resistant to rips and tears. Polyethylene is ideal for heavy-duty packaging applications. It has a semi-transparent quality, which makes it the perfection option if you’re looking for a plastic bag that’ll serve as a protective material.

For example, museums and archivists often use polyethylene plastic to protect important items from sun damage. This is also the bag type frequently used by comic book stores and collectors for the same protective reasons. Since sunlight fades images and text, unprotected exposure to sunlight can cause books and other artwork to lose value over time.

Commonly used polyethylene plastics include:

• High density polyethylene (HDPE) – Known for a high strength-to-density ratio. Commonly used in banners, bottle caps, food storage and more.
• Low density polyethylene (LDPE) – Not reactive at room temperature. Commonly used in juice and milk cartons, six pack rings, plastic wraps, electronic and computer packaging and more.
• Polyethylene terephthalate (PET) – Most common thermoplastic polymer resin. Commonly used in clamshell packaging, plastic bottles, yarn, microfiber towels/clothes and more.

Other Advantages of Polyethylene Bags

Polyethylene bags have some great qualities, including:

• Flexible
• Durable
• Tear-resistant
• Dulls the details of the product(s) inside
• Low static charge
• Good electrical insulation
• Soft and flexible
• Resistant to dirt, dust and colder temperatures
• 100% pure material

Disadvantages of Polyethylene Bags

There are some drawbacks to polyethylene, especially when looking at polyethylene versus polypropylene. Some of the bigger differences include:

• Lower melting point than polypropylene
• Less rigid and resistant to chemicals than polypropylene
• Higher cost than polypropylene

Polypropylene (PP)

Polypropylene offers a high degree of clarity, which makes it optimal for showcasing products like fresh foods. It provides a protective barrier without compromising visibility. Additionally, since it prevents evaporation or exposure to bacteria, polypropylene helps to preserve products.

It’s these qualities and more that make polypropylene perfect for those items that need to stay clean and visible, such as medical or dental equipment and food items.

Other Advantages of Polypropylene Bags

Polypropylene bags are:

• Light weight
• Resistant to cracking and organic solvents
• Compliant with all FDA and USDA recommendations
• Useful with food
• Incredibly strong, flexible, and has a high melting point
• Protective against vapor, moisture, and dirt
• Less expensive than polyethylene

Disadvantages of Polypropylene Bags

Just like polyethylene, there are some negatives to polypropylene. Keep in mind if you’re debating polypropylene vs polyethylene, polypropylene is:

• Less flexible than polyethylene
• Non-protective against light

Pick the Right Plastic Material with Paper Mart!

Before making a decision about polypropylene vs polyethylene, consider budget, products and the efficient delivery of your products to the customers.

If you have products that do not require protective measures, price may end up being the deciding factor. Polyethylene is generally more expensive due to the purity of the material and the protection it provides. If you find a quality source, you may be able to stock up on either type of plastic packaging at minimal or greatly reduced costs.

Polyethylene versus polypropylene – which bags are right for you? Check out Paper Mart’s wide selection of polyethylene bags and polypropylene bags today.