Plastics are highly valuable materials that make modern life possible. They keep our goods protected, our food fresh and are vital for the functioning of daily life, whether we are aware of it or not. Plastic packaging has many advantages, including economic benefits and ease of recycling or reuse. Plastics need to be recycled properly in order to maximise their economic value and to minimise their environmental impact.
To understand more about plastics, we will shed some light on the different types of polymer, their benefits and their recyclability properties, including what products can be made from recycled plastic. We will go according to the material identification codes found on plastics. These are numerical symbols from one to seven that are used to identify the type of plastic.
This coding system is used around the globe by recyclers, waste management companies and plastics manufacturers. It enables them to separate and sort plastics so that they can be processed according to the main polymer present. All plastic packaging should display these material identification codes. The sixth polymer used for plastic packaging is polystyrene (PS).
What is PS?
Polystyrene is a lightweight polymer that comes in two types; high-impact polystyrene (HIPS) and expandable polystyrene (PS-E or EPS). It was first sold commercially in the 1930s as an economic plastic to enhance food hygiene and extend product shelf-lives. PS is commonly used in the food and beverage industry as takeaway containers, vegetable punnets, disposable cutlery and plastic cups. PS is also recycled into lightweight cement blocks for the building industry.
Its lightweight nature makes PS an energy-efficient plastic to produce with a low carbon footprint. This plastic is in high demand by recyclers as it is used to manufacture seedling trays, combs, rulers, picture frames and clothing hangers. It is the sixth-most processed polymer by South African recycling facilities. Due to the well-established waste collection network and the fact that plastic food and drink containers form a large portion of our waste, 5572 tonnes of lightweight polystyrene packaging were recycled in 2018 alone.
Benefits of PS packaging
PS has numerous unique characteristics that make it a valuable packaging material. The two types of polystyrene have different applications. HIPS is a transparent and semi-flexible plastic that is used to make fruit and vegetable containers (like grape punnets) as well as CD cases. PS-E is a foam-like polymer that is used to make vending cups, meat trays (like boerewors punnets) and cooler boxes.
PS is heat-resistant and acts as a good insulator – hence its widespread use in the food and beverage sectors. It is fairly easy to recycle and can even improve the aeration in landfills if it is not sent to a recycling facility. The furniture and domestic housewares markets are the two largest consumers of PS recyclate.
PS is non-toxic and non-reactive, so it can be used in food and beverage contact applications without affecting the consumer. These characteristics and benefits make PS a highly-valuable plastic packaging material in South Africa.
Plastics SA represents all sectors of the South African plastics industry. Together with our associations, we play an active role in the growth and development of the industry and strive to address plastics related issues, influence role-players and make plastics the material of choice.
Plastics SA has been mandated to ensure a vibrant and sustainable plastics industry in South Africa. The plastics sector is uniquely placed to meet the needs of a sustainable society and to deliver solutions to many challenges such as recycling, climate change, water scarcity, resource usage and energy recovery.