How is polystyrene recycled?
Despite being one of the most widely used forms of plastic, used in cups, packaging, and packing materials, polystyrene is not as widely recycled as many other plastics. In the UK, local authorities aren’t able to collect polystyrene from the curb-side, unlike paper, cardboard, and other widely recycled materials. However, that doesn’t mean that polystyrene can’t be recycled. While many businesses and consumers are pushing for the UK’s polystyrene recycling infrastructure to be expanding, private recycling companies are picking up the mantle with their own services and recycling sites.
How is polystyrene recycled?Polystyrene is recyclable, especially expanded polystyrene (or EPS), which can be immediately reused and it accepted by some local council plastic recycling schemes. There are three common methods of recycling, known as granulation, compacting, and densifying. They work as follows:
- Granulation: Lighter density forms of polystyrene can go through a machine known as a granulator. This machine separates down to the tiny beads that make it up, which are then are mixed into unused polystyrene granules. In these cases, there is no reduction to the strength, insulating properties, or other qualities of the material. Recycled EPS has all the same benefits of brand new polystyrene after it has gone through granulation.
- Compacting: For denser forms of polystyrene, they have to go into a compactor that presses them together. The resulting material is a very heavy and thick bale of pure polystyrene. These bales go through a machine that then shreds them into new General Purpose Polystyrene Pallets.
- Densifying: There are other methods of recycling that are used less frequently, too. For instance, expanded polystyrene can be fed into a machine called a foam densifier. After it’s shredded, this machine exposes the foam to heat and pressure, melting it down into a paste which is then cooled into a block of solid polystyrene, extracting all of the air. Like compacting, the blocks of polystyrene can then be shredded into new General Purpose Polystyrene Pallets.