What Is Polyethylene Resin?

A plastic bag made with polyethylene.
Polyethylene is a very strong plastic and can be found in bulletproof vests.
Polyethlene items can be recycled.
High density polyethylene is widely used to make plastic bottles for milk, soda and other beverages.
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  • Originally Written By: Janet Roberts
  • Revised By: C. Mitchell
  • Edited By: C. Wilborn
  • Last Modified Date: 12 November 2015
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Polyethylene resin is a type of themoplastic that’s commonly used in the manufacture of things like plastic shopping bags, packaging, certain tubing and machine parts, and even a number of toys. It’s a flexible chemical composite that’s relatively inexpensive to manufacture and widely accessible. The “resin” part of the name is mostly in reference to the substance’s viscosity. It is made up of complex chains of ethylene monomers, which are small molecules that combine together in repeating patterns to form larger compounds known as polymers. Manufacturers and researchers typically heat the polymers in order to activate and manipulate them, though at room temperature most are solid and will almost always keep their shape. Some occur naturally, but most of those used in commercial applications are the result of synthetic manufacturing. There are many variations, and most of them can be recycled. Not all communities have recycling programs, though, and in most places plastics end up in landfills and elsewhere in the environment anyway. Plastics in the polyethylene family don’t biodegrade, and a number of environmental activists have voiced concerns about the continuing manufacture of products that use these materials.


Understanding Resins Generally

A resin, at least in science, is usually a thick liquid made up of complex polymers. Tree sap is a common natural example. Some polyethylenes occur naturally like this, typically as a byproduct of petroleum burning or pooling and evaporating off. More commonly, though, it’s created synthetically in a laboratory. The resins can be poured into molds or combined with other materials to fix their form, then they are either heated or cooled in order to form a solid.

At room temperature they tend to be very stable, and are often used for foods and beverages for this reason. Most consumers never see the plastic in its resin form. Perhaps for this reason, it’s simply referred to as “polyethylene” in most circumstances.

From a Chemical Perspective

Ethylene is a hydrocarbon that carries the chemical formula C2H4. Polyethylene resin has a formula of C2nH4n+2, where “n” is the number of monomers that combined through the process of polymerization to form this chain. The process of polymerization turns the ethylene into a thermoplastic resin.

Primary Types

There are two types of resin, natural and synthetic. Natural resin is a hydrocarbon that is secreted by plants and other natural earth processes. As its name signifies, synthetic resin is manufactured through a process called esterification. It is a chemical process involving an alcohol and an acid, which form a hydroxyl compound called ester. Both natural and synthetic resins are materials with high viscosity that are capable of hardening at a certain temperature.


This sort of resin has a number of variations, with names such as high density polyethylene (HDPE), low density polyethylene (LDPE), very low density polyethylene (VLDPE), and so forth, based on density and crystallinity. Due to these different compositions, this resin has numerous uses in the home and in various industries. During the manufacturing process, the resin is injected into machines with specific pressure and temperature settings. The hardening property of resin helps to set the raw material as required.

Recycling and Environmental Issues

PE, the abbreviation for polyethylene, is normally marked to indicate that plastic packaging or a plastic product was made from a resin. It also has the three arrow signs to indicate that it can be recycled. Most of the polyethylene products manufactured around the world end up in the ocean or landfills, however. With more than 60 million tons of the material being produced annually all over the world, the usage of polyethylene resin has become a serious environmental issue.

Studies are being carried out in many parts of the world to produce biodegradable polyethylene resin to overcome the environmental issue. In terms of polyethylene usage, recent medical research has indicated the possibility of using HDPE to create implants for facial deformities. Cross linking of ultra high molecular polyethylene (UHMWPE) is also being considered to improve the problem of wear on current total joint replacement devices.


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Discuss this Article

Post 8

I think it's great that more people are conscious of recycling plastics, but I often wonder how safe polyethylene resin is.

I keep hearing studies about not storing things in plastic and that using glass or stainless steel is much better.

I used to put drinking water in plastic containers and place them in the freezer so my water would stay cold for a longer period of time.

Then I read somewhere where this was not a good thing to do because of chemicals being released from the plastic.

Most toys are probably made with this material and most babies put these in their mouths all the time.

Hopefully the biodegradable polyethylene resin products will be available soon and maybe they will be safer to use on a long term basis.

Post 7

I think we would be overwhelmed if we realized how many plastic water bottles end up in a landfill or are simply tossed away without thinking about it.

While there have been some great strides made toward recycling plastics like this, I know many people who don't do it.

Where we live, they provided us with a green bin to pick up recycled material every other week. We weren't given a choice and the small fee is added on to our water bill every month.

Every one of my neighbors has one of these green bins, but there are only a few of us who use them on a consistent basis.

Those who don't put their bin out to be collected are probably just throwing these plastics in with the rest of their trash and not recycling them at all.

Post 6

@StarJo - I have several of the reusable shopping bags that I keep in the back of my car. They are available at the checkout stands of most places where I buy groceries.

My problem is I forget to use them even though I leave them in my car. I think I need to leave them up in the front seat or come up with some other way to use them on a regular basis.

Does anybody have any good suggestions for this?

Most of the time I don't think about them until I am ready to load my groceries that are already in the plastic bags.

Using the fabric bags is a much better way to shop than getting several plastic shopping bags every week. Many times they only put 1 or 2 items in one bag and it seems like such a waste.

Post 5

We are not allowed to put the plastic shopping bags in with the recycling material they pick up at our house.

I have always been curious about this and have wondered what is the best way to recycle these plastic bags.

I use many of them again for other purposes, but always have way more than I need. I find myself throwing them away with the rest of the trash even though I know there must be a better way to recycle them.

As far as the other plastics I have, I always check the bottom of the bottle looking for the arrow signs so I know I can recycle it.

Post 4

My dad has some polyethylene resin tubing covering some of his computer wires. He told me that it is so great at resisting cracking and tears from overuse, and it lasts longer than other types of tubing.

He also said it is the same type of tubing used in some types of equipment in restaurant kitchens. It won’t leak, and nothing from the surrounding area can permeate or leech into it.

I believe my dentist even uses this type of tubing on his gas lines. I know that when I was coming off of my high from the nitrous oxide and he had switched me to pure oxygen, I saw that the tubing looked just like the kind on my dad’s computer wires.

Post 3

@OeKc05 - I understand using the plastic bags as trash bags, but have you ever considered recycling the ones you don’t need? I’ve started doing this, and I feel a lot better about having to bring home all that plastic now.

The grocery store that I use has a bin where you can put your used plastic bags. I bring mine back with me every week and put them in there to be recycled.

I live out in the country, and we don’t have any recycling pickup. This is one of the few ways I get to recycle, and I’m glad to get rid of all the extra plastic bags that would otherwise be littering my house.

Post 2

It’s weird to think of a resin being used to make shopping bags. When I think of a resin, I picture a thick, syrupy substance.

I take home many more plastic shopping bags than I would like every week after grocery shopping, but I keep them around and get at least one more use out of them. I use them as small garbage bags in the little trash cans in the bathroom and bedrooms, but they do get thrown out with the trash when the can is full.

I also use them to carry items with me when I go on a picnic or a road trip of some sort. They are great for keeping wet swimsuits in, because they keep the moisture from leaking out onto my car seat.

Post 1

I would like to ask, is it possible to find polyethylene in liquid solution?

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