How Plastic Waste Is Recycled
March 26th 2018
With all the talk of pollution and people becoming fanatical about recycling in recent years, you’re probably wondering HOW plastic waste is recycled and how easy it is to do so? Well.. look no further! We’ve got you covered on all the know-how’s on how plastic is recycled!
Below are the multiple stages to the recycling process:
The most common recycled plastics include PET (polyethylene terephthalate), HDPE (high-density polyethylene), PP (polypropylene) and PVC (polyvinyl chloride). In the first stage of recycling, it is vital that the plastic items are sorted into plastic types. If this is not done properly, large batches of plastic can be contaminated and therefore can no longer be recycled. The sorting process is either done through machines, or manually by hand.
2. SIZE REDUCTION
The second step is reducing the size of the plastic materials, in order to make the process easier to handle. This can be done by either granulators or shredders (but not the same ones you find in the office store room!). These large machines are for industrial use only, and have blades that cut down the plastic in a rotational motion. The plastic is then passed through a screen in its reduced size.. ready for the next stage.
3. THE TWO STAGES OF SEPARATION
The vital stages of separation now get into motion. After the sorting and the resizing, the plastic needs to be washed in order to rid it of any traces of dirt and unwanted products, such as grit or glue, along with any other sort of plastic that can be washed away and seperated with water.
Large “float tanks” are the mostly used to separate the plastic. A whole range of machines from the water tanks, to washers or large water baths are used to ensure the plastic is as clean as possible. These machines work by spraying hot water over the plastic for a period of time until they are stripped of any labels remaining and of course, dirt. Disinfectants and detergents are also used to speed up the separation and cleansing process.
In dry separation, to put it simply, thinner materials are separated from thicker materials – which in fancier terms is called “air classification”. Depending on the company who recycle the materials, plastics can also be separated by a range of other features such as shape and size. Heat is often then applied to separate the materials at melting point, and the use of ultraviolet light helps separate them according to their colour.
The last step in the plastic recycling processes is compounding, this means the plastic is converted into pellets and most of the time elements will be added to the plastic to ensure they are of a high quality and are reusable. After this, plastic is then remanufactured and reused by you!