Types of plastic and how they are recycled

This is part two of our series on plastic, to read the first part, click here.

Internationally, plastics are clasified for their recycling properties according to seven numbers, contained within the international recycling symbol of three arrows chasing each other in a triangle.

Number one is PET,  which stands for polyethylene terephthalate, a form of polyester.

Plastic PET bottle ~ recyclable.

PET is recycled into filling for jackets, duvets and pillows, fibre for creating polyester used in items such as luggage and clothing. It is used in dam linings. It is even turned back into PET bottles.

One kilogram is equal to around 50 500ml buddy bottles.

South Africa’s PET body, Petco, has been instrumental in driving the recycling of PET which grew from only 19 000 tons recycled in 2007 to 95 800 tons in 2019. Petco believes South Africa recycles around 62% of all PET plastic ~ above the global average and much higher than global powerhouses such as the US who only recycles 29% of PET, and most European countries which recycle around 50%.

However, in South Africa, the industry is limited by the facilities available at recycling plants. In some cases, this makes certain PET items unrecyclable. Most commonly, some food packaging such as to-go sandwich containers and clear plastic fruit punnets, are widely used but unrecyclable.

Thermoform sandwich container ~ not recyclable.

These are Thermoform PET plastics. According to Petco, “Thermoform products are by their nature far more flexible that PET bottles. This means that generally speaking, the plant and machinery installed by existing PET bottle recyclers is not suitable for converting PET thermoform products into PET flake. This process represents the first step in PET recycling.”

Petco also says that a lot of PET thermoform products used in the South African market either contain additives or are manufactured with a multi-layer construction, comprising PET and other plastic polymers, which compromises the quality of end-use products. The inconsistency in thickness and colour is also a challenge.

Number two is HDPE ~ high density Polyethylene. This is thicker, often coloured plastic like milk bottles, motor oil bottles, cleaning products, toiletries (shampoo, body wash etc), pipes used in industry as well as carrier bags. Recycled HDPE is turned into dustbins, toys, car parts like mud flaps, rubbish bags and pipes.

PVC Pipe ~ recyclable.

Number three is PVC ~ Polyvinyl Chloride. There are two basic types of PVC, rigid and flexible, both of which are recyclable. Rigid PVC is used mostly in construction in things such as pipes, vents, conduit and guttering. Flexible PVC is used to make shower curtains, garden hoses, gumboots, tubes used in medical procedures and cable insulation. Recycled PVC is turned into shoe soles, hoses, door mats, conduit and pipes.

Number four is LDPE ~ Low-density Polyethylene which is used predominantly for packaging. Things like the bags your frozen veggies come in, one litre milk sachets, rubbish bags, cling-film, bubble wrap. When recycled, it is turned into bin liners, irrigation pipes, and film for construction and building.

Number five is PP ~ Polypropylene. Our fridges are probably filled with PP in the form of ice cream and yoghurt containers, margarine and cream cheese tubs. Other things like lunch boxes, plastic chairs like outdoor garden furniture. The bottle tops found on PET bottles are made of PP and PP is also recyclable. It can be made into coat hangers, shopping baskets, paint trays and storage containers.

Polystyrene ~ recyclable.

Number six is PS ~ Polystyrene. There are two types of polystyrene: We are most familiar with the type of polystyrene used by the food and restaurant industry (called expanded PS), while high-impact polystyrene is used is the manufacture of items such as coat hangers, bread tags and CD cases. 

Contrary to common understanding, polystyrene is in fact recyclable. In fact, according to Plastics SA, it is the country’s sixth most recycled polymer product.

Recycled polystyrene can be turned into seedling trays, toys, hair combs and lightweight cement blocks. Polystyrene recycling is managed by the Polystyrene Association of South Africa (Pasa).

However, not all recycling centres accept Polystyrene. If you are a conscious recycler, it will be best to speak to your recycling centre directly. If you rely on waste pickers to pick out your recyclables, you cannot ensure they are taking your polystyrene products.

Number seven indicates all other plastics. The symbol should ~ in theory ~ be accompanied by the material name, but according to Plastics SA this doesn’t always happen. Common number sevens include multi-layered plastics like toothpaste tubes and filter coffee packs. Plastics SA says these plastics can only be recycled if they can be separated.

For more on how to recycle, click here.

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