Plastics and recycling

Plastic is an amazing material. It has changed the way we store and carry food, drinks and other items. Plastic is lightweight and resists breaking when dropped. Older people may remember when shampoo came in glass bottles – and what happened when the bottle slipped out of soapy fingers while in the bath!

Lightweight, unbreakable plastic packaging also reduces production and transportation costs. Plastics have given us durable, weather-resistant building products. Plastic pipes resist mildew, mould and insects – and a lot of our outdoor clothing, from polar fleece to puffer jackets, is made from plastic!

Plastic packaging – a short history

The first plastic products were made from cellulose – a natural product from plants and trees – in the 1860s. Named ‘Parkesine’ after its inventor, the material was mouldable when heated but kept its shape when it cooled down. The first totally synthetic plastic was called Bakelite. It became known as the material of a thousand uses. Most New Zealanders would have had at least one Bakelite item in their homes – their telephones.

Plastic food wrap – known as Saran – was produced in 1933. Although it was first used to protect military equipment, people saw how well it could cling to items like bowls. A decade later, Tupperware was invented. These airtight food containers changed the way we stored food. Another milestone came in 1978 when Coca-Cola introduced the world to the 2L PET bottle. Much of the world had been buying milk in plastic bottles since the 1970s, but New Zealand held on to reusable glass bottles until they were phased out in 1989.

Too much of a good thing

Plastic products and packaging became so popular that the amount buried in landfills was of concern to many New Zealanders. Towns and cities established recycling depots and kerbside collection recycling schemes for some plastics, glass and paper. By 2006, nearly 75% of Kiwis could have their recycling picked up from their homes. Today, most New Zealanders have access to recycling schemes. The Ministry for the Environment reports that, in 2010, 94% of New Zealand households participated in recycling, with three-quarters of people recycling all or most of the items they know can be recycled. However, only an estimated 14–18% of plastic waste is recycled globally.

The science behind plastics and recycling

All plastics are made out of hydrogen and carbon atoms (known as hydrocarbons) that are processed into long chains of molecules called polymers. ‘Poly’ means many, so that is why many plastic names begin with poly. Most hydrocarbons come from oil and natural gas. Other additives are mixed in during the processing to form different plastic materials with special characteristics.

Manufacturers use special names for the different plastics, but most of us recognise them by their resin identification code (RIC) numbers. For example, plastics made out of polyethylene terephthalate (PET) are marked with the number 1. High-density polyethylene (HDPE) products are marked with the number 2.

Plastic products have these numbers to make it easier to sort and separate items for recycling. Keeping the plastics separated preserves the material’s value and means it can be recycled for reuse.

What happens to the recycled materials?

Regional and local councils in New Zealand have a range of approaches to the types of plastics they collect for recycling. Plastics marked 1 and 2 are universally accepted in mainland New Zealand. The various household plastics are collected at the kerbside or at recycling depots. The products are sorted by RIC numbers, squashed and baled, and most are shipped overseas, depending on global demand. There, the plastics are washed and shredded for reuse as new products.

Some of the plastic types (3, 5, 6 and 7) are more difficult or unprofitable to recycle.

The changing industry of recycling

Until 2017, none of the PET collected in New Zealand was processed for reuse locally. It was sorted and then sent overseas to be processed or dumped. In the past, New Zealand has relied heavily on exporting our plastic waste to other countries such as China. Recent restrictions and a tightening of regulations has meant that China and other countries are not importing as much waste plastic, and here in New Zealand, stockpiles of waste plastic for recycling are growing.

Flight Plastics, a company based in Lower Hutt, imported recycled PET (RPET) flakes to make new PET packaging. In 2017, it opened New Zealand’s first PET wash plant, enabling Flight Plastics to close the recycling loop. Now, used PET plastic collected locally is baled and sent to Flight Plastics for processing and recycled into new packaging for many of your favourite foods. If you recycle a Flight Plastics container or package, it can be made into a new product over and over again.

Even with Flight Plastics PET recycling plant, we dispose of more than can be processed. Being forced to find a solution here in New Zealand will hopefully result in more innovation and technological developments in this space.