Recycled milk bottles — where do they go?

More than 10 million, two-litre plastic milk bottles are recycled in Christchurch every year. But where do they go once the green kerbside recycling crates are emptied?

There is a chance that they may have began a new life as a recycling crate.

Most people are familiar with the process — you rinse your milk bottle, take the lid off, squash it and place it under something heavier in your recycling crate at the end of the driveway and forget about it.

As far as plastic milk bottles are concerned though, the journey has “only just begun”.

From your green crate, the bottles end up on the back of an Onyx truck and are sorted in with other plastics and cans.

With the variety of recyclable items these days, the full sorting process is not one that can be completed on trucks.

Once an Onyx truck is full, it heads to the Recovered Materials Foundation (RMF) in Parkhouse Road to unload its recycleable cargo. The RMF is a trust set up by the Christchurch City Council to increase diversion of materials from the waste stream for reuse and recycling. The RMF encounters 200,000 two-litre plastic milk bottles a week, or put another way, 10.4 million a year!

Once the trucks are unloaded, it is then the job of between four to six people to sort different plastics from cans which is done by conveyor belt. Once separated, plastic bottles are compacted together into bales of about 7000 bottles.

During this baling process there are many bangs which, as it turns out, are lids left on by recyclers. One in four bottles have the lid left on and one in five have not been rinsed as required.

The RMF sells its recycled bottles mainly to offshore markets in container loads of 70 bales. A local market includes Vertex Pacific in Hamilton where bottles are chopped, granulated, washed and re-palletised.

These pallets are then used for plastic moulding into, for example, green kerbside recycling crates. About 32 two-litre bottles are enough to make a recycling crate. This means that the amount of bottles recycled in Christchurch could potentially make 325,000 crates every year — more than enough for each one of Christchurch’s 316,277 citizens.

• For more information about recycling see www.ccc.govt.nz/waste/recycling/