#2 is the resin identification number for High-density Polyethylene (HDPE). HDPE is a widely used plastic with applications in construction, food packaging, household items, toiletries packaging, etc.
Some experts believe, HDPE has the potential to be part of a sustainable economy. HDPE is repeatedly recyclable, and the quality of recycled HDPE (rHDPE) does not deteriorate drastically, making it reusable in making high-quality products.
HDPE or PEHD has certain chemical and physical properties which make it unique among other plastics. It is corrosion-resistant as well as non-toxic. The usefulness of this plastic is the primary reason why it’s so widely used, HDPE recycling cannot keep up with the demand for the product.
A complex list of reasons keep HDPE from becoming a truly sustainable product. This article will explain the ifs, whys, and hows of HDPE recycling. It will dive deep into the issues we face as a result of excess HDPE use, and what we can do now to make changes.
Is Plastic #2 recyclable?
Yes, HDPE or plastic #2 is 100% recyclable. In most cities, the curbside recycling system accepts HDPE as a recyclable item. In Europe, the recycling system is multi-stream, which means there are separate bins for glass, plastic, paper and cardboard, and metal. As you would guess, HDPE waste would go in the “plastics“
In North America, the recycling system is single-stream which means one bin collects all types of recyclable and this waste is sorted in a materials recovery facility (MRF). You can throw out all your HDPE waste into the bin along with any other recyclables.
What is HDPE?
High-density polyethylene (HDPE), a.k.a. PEHD is an extremely useful thermoplastic with many applications. It is made of a petrochemical called ethylene. HDPE is a transparent plastic that is extremely durable with high tensile strength.
It has a high melting temperature, which makes it more resistant to heat. It’s also resistant to acids and bases as well as corrosion from other chemicals.
These attributes make it a very versatile material with uses in making building materials, water piping, pavement and roof tiles, water and soda bottles, milk jugs, food containers, bottles to carry corrosive chemicals like acids and bases, ropes, shopping bags, etc.
Why is HDPE so widely used?
HDPE is a lightweight, durable plastic. Before recycling, it is graded according to the thickness of the plastic and, higher grade HDPE is usually thicker and
Lower-grade HDPE is thinner.
It is a lightweight material with a high weight to density ratio, in Layman’s terms, it means, it can carry many folds its weight without any damage. A 60g HDPE bottle can carry up to 8 pounds of liquids.
#2 Plastic is also non-toxic and heat resistant, because of this, this plastic is used to make reusable food containers that are microwave safe.
The tensile strength of HDPE is quite high, which makes it ideal for rope making. Tensile strength essentially is the property of a material that defines its elasticity. A material with high tensile strength can be stretched further without the material breaking or deforming. Meaning after the force exerted on it is removed, it goes back to its original shape.
The lightweight nature of HDPE makes it ideal as a replacement for heavier items, such as glass food containers, tiles, piping, etc.
Currently, pure HDPE products which are high grade are recyclable, and recycled HDPE can be used to make high-quality materials. HDPE is also used to make composite materials like tiles (mixed with crushed stone), or composite with wood.
These materials are still not recyclable, however, they are very durable, and can be made with recycled HDPE, which reduces the cost of production.
Why recycle #2 plastics?
As with most other plastics, #2 plastic is made of petrochemicals. These chemicals are sourced from fossil fuels Fossil fuel mining and the manufacturing of HDPE release huge amounts of carbon into the atmosphere.
Climate change is the greatest challenge of our generation and the generations to come, excess carbon in the atmosphere is leading to rising sea levels, unpredictable weather patterns, and hotter climates across the globe.
Moreover, the rapid depletion of fossil fuel reserves has the world scrambling to find alternative fuel sources. These reasons have prompted the world to find more sustainable systems where we reduce fossil fuel consumption and consequently reduce carbon emissions.
A system where the number 2 plastic is efficiently recycled reduces the amount of virgin HDPE made from fossil fuels. Besides reducing the use of raw materials by recycling, it also helps save energy and lowers carbon emission.
How to dispose of #2 plastic waste for recycling?
As you may know, all plastic should be cleaned properly before you send them in for recycling. These items must be cleaned of food waste, grease, chemicals before being recycled.
Contaminants remaining in the packaging are too hard to clean in recycling facilities, this is why dirty items are immediately thrown into the trash.
The recycling sign with the HDPE’s resin identification number will tell you which items are recyclable, however, it’s highly recommended you check your city, county, or municipality’s guidelines on what recyclables they accept.
The process of recycling HDPE:
HDPE is a thermoplastic, which means it can be melted and molded into new shapes. Like most other plastics, HDPE is also thermomechanically recycled.
The plastic is first moved to a materials recovery facility (MRF). Here these plastics are first put into bales. Then these are transported to recycling centers.
HDPE has multiple grades, these are based on the thickness of the plastic. Thicker plastics are better grades. After sorting, the plastic is thoroughly cleaned with water and detergent.
Then it’s shredded. Once shredded, the plastic is passed into an extruder which melts the plastic and then creates pellets out of them. These pellets are the final product which is then shipped to a manufacturing plant where they can be melted and molded into a variety of products.
HDPE can also be recycled chemically by a process called pyrolysis. In this process, shredded HDPE is heated in an oxygen deprived chamber in the presence of certain catalysts. This process breaks the plastic down into its monomer, ethylene.
Chemical recycling is currently very costly and very few companies have the infrastructure to perform this. Another product of chemical recycling is oil which can be used as a fuel.
Concerns regarding the sustainability of chemical recycling and HDPE in general have been raised. These matters are complex and require careful considerations.
The sustainability of #2 plastics:
No plastic currently is truly sustainable. Plastic number 2 is not an exception.
HDPE can be mechanically recycled up to 10 times before it’s quality deteriorates to the point it becomes post-consumer waste.
This means that sooner or later HDPE will end up in landfills or will be incinerated.
Plastic number 2 is not biodegradable and remains in the landfills for centuries. Which is why un-recycled HDPE is often incinerated.
Incineration is not considered a sustainable solution since it releases significant amounts of carbon into the atmosphere.
If we cannot find a way to stop or limit production of virgin HDPE from fossil fuels, we will never reach sustainability. Chemical recycling is a step in the right direction.
It has the potential to break down HDPE into its building blocks so HDPE can be remade from it.
This process can potentially make HDPE enter a closed-recycling-loop where no HDPE is from fossil fuels, it is simply recycled from waste HDPE. This is a lofty goal. Currently virgin HDPE is far too cheap for companies to look for alternatives.
Most companies will gravitate towards virgin HDPE because of its cheapness. Strict legislation is required to make a shift for recycled HDPE.
There still remains skepticism over whether shifting to recycled HDPE alone is enough. The main problem here is the wide use of this plastic. If the demand for plastic does not go down, all these changes will only bring about minimal difference. The main goal should always be to reduce and reuse.
HDPE is a widely used plastic and serves many purpose, with proper regulatory guidelines on its production and recycling, combined with lower demands can help it become a sustainable material.
HDPE or PEHD has certain chemical and physical properties which make it unique amongst other plastics. It is corrosion-resistant as well as non-toxic. The usefulness of this plastic is the primary reason why it’s so widely used, HDPE recycling cannot keep up with the demand of the product.
A complex list of reasons keeps HDPE from becoming a truly sustainable product. This article explains the ifs, whys, and hows of HDPE recycling. It dives deep into the issues we face as a result of excess HDPE use, and what we can do now to make changes.
Frequently Asked Questions (FAQs): Is #2 plastic recyclable?
What does the number 2 in #2 plastic refer to?
The numbers on a plastic container enclosed in circular arrows refer to the resin identification number of the plastic. Each number represents a different plastic type.
What is #2 plastic?
#2 plastic is known as high-density polyethylene (HDPE). It is made from a petrochemical named ethylene.
Is #2 plastic widely used?
Yes. It is a very common plastic used in a multitude of areas.
Is #2 plastic useful?
Yes, it is a very useful plastic. It is resistant to corrosive chemicals, heat, pressure, and has a high weight to density ratio. Additionally, it has a very high tensile strength and is very lightweight and non-toxic. These properties qualify it to be used for making a host of products from pavement tiles, underground water pipes, ropes, food containers, water bottles, plastic shopping bags, etc.
Is #2 plastic bad for the environment?
Yes, as things stand, more and more virgin HDPE is being made each day instead of recycling the already available post-consumer HDPE. This increases carbon emission, energy and fossil fuel expenditures, plastic waste, and air pollution.
Lastly, HDPE does not degrade and remains on the ground for centuries, overtime breaking down into smaller pieces of HDPE.
Is HDPE environmentally friendly?
No, not as things stand. It is not biodegradable, so it remains in landfills for centuries. With time it breaks down into smaller HDPE pieces. Animals near landfills or aquatic creatures ingest these small plastics, these lodge in their insides, and these creatures often die slow painful deaths.
Can you recycle HDPE?
Yes, it is recyclable. It is mostly recycled by a thermomechanical method, however, it is also recyclable by a chemical method where it is broken down to its base molecules.
How do you recycle HDPE plastic?
HDPE is recycled by a thermomechanical technique where the plastic is shredded, melted, and then turned into pellets.
Is HDPE biodegradable?
No, HDPE is not biodegradable. It can remain in landfills for centuries.
Is HDPE food safe?
Yes, it has a very high melting temperature and does not release toxic chemicals, making it ideal for reusable food containers.
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