What is the plastic recycling chain like?

Have you ever wondered what happens after you throw your garbage bag in the yellow bin? Well, you should know that there is a long chain behind that we are going to try to explain to you.

Recycling has numerous advantages, both environmental, economic and social, hence the importance of our commitment within the recycling chain.

The first thing that is taken into account in the recycling chain is the separation of waste according to its origin: domestic if it comes from our homes; commercial, if they are waste generated in stores, bars, or businesses in general; and the industrial one, if they come from companies and industries.

Each of these groups will have previously separated their waste between the different recycling containers: blue, yellow, green, brown or gray.

Sorting plants

Next, we find ourselves with the collection and transport of the garbage to the classification plants.

This stage is one of the most important since it is here where the waste that will go to the subsequent recycling plants is separated and classified from those that will not.

Those that will be recycled will be unified and reunited in groups that can be transported separately, facilitating and speeding up the work of subsequent treatment and recycling plants.

The work in sorting plants or also known as sorting plants can be automated or manual. In the case of being manual, the operators pick up those residues that are quickly identified and easy to pick up.

In these plants, bulky waste is classified and separated and large waste is divided. Next, the high-density polyethylene and the low-density polyethylene (plastic film, bags…), as well as the ferrous materials are separated by means of an electromagnet, which are pressed to compact them. Likewise, non-ferrous metal containers are separated and also pressed.

What is the plastic recycling chain like?  Photo: bigstock

Materials that cannot be recovered go to a so-called rejection zone.

The rest of the recoverable material is pressed again and packed to be sent to the storage area from where it will be sent to the different recycling plants.

Light packaging sorting plant

These plants exclusively receive the waste from the yellow container.

When the waste arrives here, the first thing to do is weigh it and send it to the bag opener. Then, selection begins (manual, magnetic, volumetric, by density, ballistics, optics, etc.) of the containers according to their composition.

Finally they go to the pressing and packaging area of ​​all those materials that have been selected and to their subsequent storage until they are sent to the waste treatment plants.

What is the plastic recycling chain like?  Photo: bigstock

Waste treatment plants or recycling plants

There are different plants to treat the different existing waste, which work with different techniques.

In the case of plastic, it can go through different processes until it is converted back into a material for new use.

Normally, in the case of plastic recycling, the main method used is mechanical. In the facilities designed for this purpose, the plastic is cleaned (dust, labels, food remains …), classified according to the needs and objectives of recycling (by colors, material, size …) and is crushed to convert it into small pieces or plastic pellets, which are then converted into new products by different methods.

These small pieces or plastic balls are cleaned again and finally homogenized to turn them into pellets and enable their subsequent transformation.

What is the plastic recycling chain like?  Photo: bigstock

Another way to recycle plastic is through a chemical process consisting in the degradation of plastic by heat or catalysts, with the aim of breaking down the macromolecules that form it. For this type of process there are different techniques such as pyrolysis, hydrogenation, gasification or cracking.

It is important to know that all waste that cannot be recycled as it happens with paper, cardboard or glass, among others, goes to controlled deposits (landfills) or to energy production plants.