Recent headlines have highlighted the mounting plastic waste problem we have globally. It is thought by experts, the amount of plastic waste present in our oceans will triple within the next 20-years. If we continue to recycle at our current rate, we will only reduce the volume by 7%. 
 
The use of synthetic or man-made plastics such as polyethylene is causing more issues as these materials are notoriously harder to break down and recycle via the usual avenues. Polyethylene is the most common plastic material in circulation as it is used for food packaging, plastic bottles and other such products, demonstrating the sheer abundance of this material that goes largely unrecycled. 
 
Our reliance on such single-use and film plastics for the packaging of everyday products is having a detrimental impact on our oceans and planet. While some plastics take several years to decompose, others break down fairly quickly but introduce another issue when they produce microplastics in their place. 
 
These microplastics and their impact on the environment is an understudied area, but scientists have confirmed some of the devastating effects of inhaling or ingesting these plastic particles. Estimates range from there being 12tn to 125tn of the particles present on our earth. 
 
With that said, it is naturally imperative that we increase our recycling efforts, and so in this blog, we are going to take a look at the two primary methods of plastic decomposition. We are going to explore the processes themselves and then take a look at the pros and cons of both the mechanical method of recycling plastics and the chemical method. 
 
As technology is continually advancing, more and more avenues open for us in the plastic recycling business. For instance, researchers are already on the lookout for bacteria that can decompose polyethylene - our main offender - either partially or wholly. 
 
If you are interested in learning about current efforts - and limitations - to plastic recycling, read on!
 
Mechanical Recycling: 
 
The mechanical method - also known as ‘chop and wash’ - is the process we most often think about when it comes to recycling. This method involves the cutting up of plastics into small pieces and then decontaminating those pieces so they can be melted down and used again. This process is one we might most commonly associate with circular economies: the idea that our plastic products can be reused or regenerated in some way. 
 
Fairly obviously, the mechanical process, then, involves plastics that we know can be reliably recycled, such as acrylic that can be continually reformed. This process does require substantial knowledge about which dyes and additives can be added to plastics without them using their recyclability. 
 
The mechanical process does mean that the plastics retain their molecular structure and so can only be reformed in certain ways. This method is not that flexible and only has a limited number of benefits as a result. 
 
In addition to this, there is legislation in place that limits what plastics generated from the mechanical recycling method can be used for. For instance, the European Food Safety Organisation does not allow the plastic material garnered via this method to be used to create packaging for food as there could be hazardous substances still present on the granules even after they have been cleaned. 
 
Even though the plastics put through the mechanical method may start out as bright colours, the product of this process is always a black-grey colour. Again, this limits the uses of the recycled materials as they cannot be recoloured easily and cannot be used for items such as children’s toys. 
 
The primary benefit to the mechanical method is the fact that, in comparison to the chemical method, a lot less CO2 and gas are created and so it is better for the environment. In fact, manufacturing products from recycled material produces three times less greenhouse gas emissions than creating the same products from raw materials. 
 
Chemical Recycling:
 
Chemical recycling involves the splitting of polymers chains and produces products such as crude oil, naphtha and/or fuels. This method is currently seeing more investment and promotion by major corporations even though it produces a sizable amount of CO2. 
 
The main advantage of this chemical method is the flexibility and options it allows you. If the process is successful, you end up with the monomer - the most basic element of any plastic. By processing this monomer, you can virtually create a plastic product that has the same properties as the raw material itself. 
 
This naturally allows you to create any number of plastic products from scratch and does not encounter the same issues of discolouration and the potential for hazardous materials to be left on the recycled material as you see via the mechanical method. 
 
Chemical recycling is an expensive process. You need to reach incredibly high temperatures (500 to 900 degrees Celsius) in order to facilitate the break down in polymer chains and - even with the help of a catalyst - this is a difficult feat. The solution is to find new catalysts that allow for the process to take place at lower temperatures. 
 
As a result, few companies are thought to be pursuing this method. As of 2019, it was thought that as little as 60 companies worldwide had facilities to allow for mass recycling using the chemical method. That’s in comparison to thousands of sites worldwide that allow for mechanical recycling. 
 
There are other facets to the chemical recycling process as well. To be successful, it requires a particularly pure starting product. As plastic waste is generally mixed or dirty in some way, then the quality of the final, recycled product is dramatically reduced. This, too, limits what can then be produced from recycled plastic. 
 
It is thought that chemical recycling may be the way-forward if a method can be reached that does not produce high greenhouse gas emissions. Of the few companies that develop and recycle plastics following this method, some are able to recycle 100s of tonnes of plastic waste per year which will dramatically help reduce our overall plastic pollution. 
 
So how do these methods of recycling combat the mounting plastic waste we find in our oceans? The answer seems to lie in technology and continual developments. As we have discussed, both the chemical and mechanical methods of recycling have their drawbacks which results in many plastics slipping through the system and going on to pollute the environment. 
 
The best solution is to limit and eventually eliminate our reliance on and use of single-use plastics, such as plastic carrier bags. The increased plastic bag fee can only do so much and we all need to work together to reduce our personal plastic waste. 
 
We, here at The Plastic People, are proud to say all of our products are made from 100% recyclable materials and we are striving to become a zero-waste company. If more businesses, worldwide, are able to come to similar terms, we will be more successful in our fight against plastic. 
 
We hope you enjoyed our deep-drive into the world of plastics recycling if there is another topic you would like us to break down, get in touch on social media by tweeting us or messaging us on Instagram: @barkstonplastic