EPE Foam: Properties, Uses, and Methods of Recycling
What is EPE Foam?
EPE foam, or Expanded Polyethylene foam, is one of the most widely used plastics in production. What is polyethylene foam? It is a thermoplastic resin, which means that it can be melted by heating and cooled to form different shapes and objects.
What Are The Physical and Chemical Properties of EPE?
The physical and chemical properties of EPE foam are what give it its desirable characteristics. It is due to these properties that this plastic has avariety of applications in different industries such as EPE foam padding, EPE foam tube, and EPE foam sheet.
Physical Properties of EPE Foam
EPE foam is a harmless plastic and has no taste or odour.
It is a very popular material for packaging goods as it is light in weight and flexible. It has the ability to absorb shock and provide good cushioning to delicate objects.
EPE has a high weight to strength ratio and high thermal resistance. It can be heated and melted multiple times, and reshaped into other new objects due to the high EPE foam temperature range.
EPE foam is resistant to water, oils, and many chemicals. It is also a very good insulating material. EPE is available in different densities, according to its application or purpose.
Chemical Properties of EPE Foam
The chemical makeup of expanded polyethylene is similar to most plastics, and of the form (C₂H₄)nH₂. EPE is usually white in colour unless a dye or other colour pigment is added to it during the melting process.
EPE foam is also referred to as bead board in the plastic industry. It is a closed cell foam, which allows it to take up more volume and be light weight.
Is EPE Foam Recyclable?
Yes! This is probably one of the most important characteristics of foamed polyethylene due to the huge potential impact it can have on the environment.
Expanded polyethylene foam can be melted and reshaped into various shapes multiple times. This is due to its high thermal resistance properties that enable it to maintain its chemical structure even when subjected to high temperatures and turned into molten plastic.
This is a very important property of epe material that allows it to be reused and recycled, reducing the amount of plastic in the environment.
However, there are very limited number of companies who offer recycling EPE, contributing to a very low global recycling rate. It is crucial to either melt and recycle EPE or compact the plastic in order to prevent burning of EPE waste or adding to landfills.
Among the most common methods of recycling are reusing EPE or bonding and grinding of expanded polyethylene. Recycled EPE can be used for packaging material or as underlay for carpeting in large rooms.
Why Polyethylene is Not Biodegradable
The term in-biodegradable is used to describe polymers that do not break at any point to a natural, environmentally friendly conditions over biological processes.
A majority of plastics are non-biodegradable because plastic is widely used as it is cheap, durable and versatile.
However, certain conditions fasten the degrading process of polythene. They include: moisture, oxygen, sunlight, composting and biodegradation enhancement through reduction of the hydrophobic polymer, and an increase of hydrophilic properties.
However, it is still an environment-friendly material as it can be easily recycled into new objects like EPE foam insulation. EPE foam recycling is a fairly simple process, which involves heating it until it melts and then reshaping it or remoulding it.
How Is EPE Foam Made?
As with most types of foam such as expanded polypropylene foam (EPP foam), expanded polyethylene (EPE foam), is manufactured by the application of high pressure, heat, as well as a blowing agent in a pressurized chamber called an autoclave.
The molten foaming polyethylene material is then made into small plastic beads in a machine that uses water to cool and form the beads.
The resultant plastic beads are used as feed material and injected into specialized moulds under high heat and pressure to force the beads to melt and take the shape of the mould.
The manufacturing process of EPE foam is pretty straightforward, and mostly involves the use of high temperatures and pressures in a sealed and pressurized container.
The leftover EPE material that is in the form of beads or defective pieces, or even material that has seeped through the material, can be collected and fed back into the machine to produce whole new pieces.
This is how to make polyethylene foam and is the principle behind the recycling of EPE foam material as well.
How is EPE Processed?
EPE is usually processed by the following methods:
Cutting, trimming, hot forming, and laminating.
It can also be processed by other unique methods depending upon the application.
Usually, customers require the EPE foam to be customized to a certain size and shape. This could be when they need to tightly pack some objects and the EPE must be cut in the form of the object.
This is done by hot forming. Hot forming s usually done only in special cases where the quality of the finished product needs to be very high. Sometimes, EPE foam is laminated along with some other material and then cut and hot formed.
Is Polyethylene Environmentally Friendly?
Polyolefin materials (Polypropylene and Polyethylene) have the lowest environmental impact compared to other material, traditional or synthetic products.
Polyolefin is formed from natural polyolefin resins. It has good electrical properties, acids, alkalis, good chemical resistance to solvents, resistance to environmental stress and good durability.
Whenever you hear of plastic and environment, what comes in your mind is a picture of PVC (Poly Vinyl Chloride) binder lying in a landfill, toxic and unscathed, for a hundred years.
However, all plastics are not equal in this perspective. Fifty years ago, two new members of the polyolefin family were born; Polypropylene (PP) and Polyethylene (PE). The two plastics can do all the functions of the traditional glass, metal, paper or PVC.
They can be die-cut for presentations and packaging, printed on; foil embossed as well as perform all the functions of binders and other traditional types of information packaging.
PP and PE have a significant wear resistance and increased durability compared to traditional products such as paper. A distinct factor remains that EPE products are environmentally-friendly.
These are the environmental benefits of plastics Polypropylene (PP) and Polyethylene (PE):
- They are widely recycled
- They are biodegradable (they break down to hydrogen and carbon).
- They generate fewer waste products in disposal and production.
How to Calculate Density of EPE Foam?
To find out the density of EPE foam, you will need to first measure the weight, height, length, and width of the foam. The higher the density, the stronger and more durable the material is.
You can then calculate the density by using the formula:
Density = Weight / (Height * Length * Width)
It is important to know the density of EPE foam in case of certain application so that you can have an estimate of the kind of insulation or protecting the EPE foam can offer the object to be insulated/ protected.
Knowing the density of expanded polyethylene foam is not always required, but it can be important for more important applications.
What Are The Advantages of EPE Foam?
There are multiple advantages of EPE foam, which we will be listing down in this section:
1. Extremely Flexible:
EPE foam is a very flexible material compared to other forms of foam. EPE thus gives most protection for oddly shaped objects.
2. Superior Shock Absorbency:
The closed cell structure of EPE foam makes it able to withstand and absorb high amounts of shock or stress and provide good cushioning to the object it is covering.
3. Regains Form Easily:
Another advantage of expanded polyethylene is that it quickly regains its original shape after the source of stress or shock has been removed. It cannot be broken, fractured, crumbled, or shattered.
4. Resistance To Chemicals:
EPE foam is highly resistant to strong corrosive chemicals like solvents, acids and alkalis. This makes it suitable for providing a barrier or shield for extra protection while storing and handling these chemicals.
5. Resistance to Water/ Moisture:
The chemical structure of expanded polyethylene foam makes it almost impermeable. EPE therefore does not absorb water or allow it to pass through. It is thus used as water protection for materials.
6. Resistance to Static:
Some forms of EPE are highly resistant to static and thus do not attract dust and other tiny particles to its surface.
7. Insulation Properties:
EPE foam has very low thermal conductivity and thus offers the best insulation against heat.
8. Non Toxic And Food Safe:
EPE foam is non toxic, and thus can be used for food packaging. It is also resistant to the growth of microbes and fungi on its surface. It is odourless.
9. Ease of Handling:
EPE foam is fairly easy to use. It is easily cut, moulded, shaped and glued to other objects or to itself. It can easily be shaped into various objects without the use of expensive equipment or moulds.
10. Extremely Light Weight:
Although quite tough, EPE foam is very lightweight, thus making it easy to transport and handle. It can be used for a wide variety of applications due to this property.
11. Usable Temperature Range:
EPE foam can be used within the temperature range of 40 to 70 degrees without affecting its structure or any of its properties thus making it very suitable for a wide variety of applications that require heat or electrical insulation.
EPE foam can be dyed in a variety of colours, thus allowing for colour coding or purely aesthetic applications.
What Are The Applications of EPE?
Expanded polyethylene can be used for a large variety of applications such as the ones listed below:
EPE foam can be used for the protection of fragile and breakable items such as glass and glassware, scientific instruments, delicate parts of machinery, scratchable materials such as marble and granite, etc.
Expanded polyethylene is widely used for insulating air conditioners, pipes, heaters, etc.
EPE can be used for many applications in construction such as in joint fillers, water proofing, etc.
EPE is used in the making of life vests and other floatation devices.
EPE is used for making sports mats, yoga mats, shin guards, thigh guards, etc.
Are EPE Foam and EVA Foam Different?
EPE and EVA foams are very similar to each other as in they are both closed cell types of foam. EPE stands for expanded polyethylene, whereas EVA stands for ethylene-vinyl acetate. Together, they constitute the largest portion of the plastic industry.
Just like EPE, EVA also has high shock absorbing capabilities, insulating property, water and oil resistance, and is extremely flexible. Both types of plastic are used for similar purposes and are very cost effective.
However, there are a few differences when it comes to the inherent properties of the two plastics:
- EVA is tougher and more durable than EPE. The strength and density of EVA is almost five times that of EPE. However, since EVA lasts longer, it is slightly more expensive than EPE and is thus used exclusively for certain purposes.
- Although EVA is more resilient than EPE, EPE is still a favourable choice when it comes to manufacturing wrapping and packaging material.
- EPE has a lower thermal conductivity than EVA, which makes it a better insulator. It is used as insulating material for flooring, walls, and even ceilings.
- Both EPE and EVA have a wide range of applications in various industries, although EPE is much more favoured due to its cost effectiveness.
Every individual must research on the products they use for packaging goods and other uses to ensure they are not harmful to the environment. They do not produce toxic (like chlorine from PVC plastics) when burned. EPE foam is environmentally-friendly as it can be recycled and degraded under certain conditions.