Since the plant was established in 1922, O-I NZ has recycled glass.

In recent years recycling has become a major focus worldwide, and O-I continues to be a leader in this field.

The Benefits

Glass can be fully recycled without any loss of purity.

Less energy is used to melt recycled glass than is needed to melt raw materials.

Less raw material is needed when recycled glass is used in the batch.

Using recycled glass reduces pollution.

Recycling glass reduces the amount of waste going to landfill.

The Cycle

(Note:  this process is covered in more detail in the "Making Glass" segment)

1. Raw Materials

Cullet is mixed with other raw materials – silica sand, soda ash and limestone, plus a variety of minor ingredients – ready for the furnace.

2. Furnace

The raw materials are fed into the furnace with the glass temperature in the furnace ranging from about 1100 – 1590 degrees Celsius.

3. Forming

From the furnace, the melted glass goes to the refiner and then the forehearth where the glass is “conditioned” before entering a bottle forming machine. These are either double or triple gob machines.

4. Annealing Lehr

Because the glass is a poor conductor of heat, annealing is necessary to allow even cooling of the whole bottle or jar. The process first re-heats the bottles to 550 degrees Celsius and then gradually cools them until they emerge at the cold end between 30 minutes to one hour later.

5. Quality Inspection

After leaving the cold end of the lehr, bottles then pass through electronic inspection machines, which automatically detect faults. Quality inspection is an essential part of the manufacturing process. It ensures the best product possible is always distributed to customers.

6. Distribution/Customer

Once the bottles have passed inspection, they are packed in pallets. Quality bottles and jars are then distributed to customers around New Zealand to be filled with food and beverage products.

7. Recycling

Once the glass bottle or jar is empty, it can be recycled either through kerbside recycling or a public recycling facility operated by O-I’s appointed Principal Supplier/s. The recycled glass is sorted by colour (clear, green and amber) and transported to the Visy Recycling plant in Penrose, Auckland.

8. Beneficiation

Waste glass (cullet) arrives at the Visy Recycling plant in Penrose to be reprocessed, removing most impurities. The process starts all over again.

What Should You Know?

1. What do we recycle?

What DO we recycle? Empty glass bottles and jars

What DON’T we recycle? Light bulbs and fluorescent tubes, pyrex dishes and ovenware, china and crockery – cups, saucers, plates, drinking glasses, window glass, opal glass, glass bricks, medical and laboratory glass containers, TV tubes and computer screens, because these other glass types have a detrimental affect on the quality of our glass.

2. Why separate containers by colour?

O-I New Zealand makes bottles and jars in seven colours. These are flint or clear glass, amber glass, blue glass and four varieties of green. When the raw materials are mixed in the furnace, other minor ingredients are added (some of which will determine the colour of the glass). When recycled glass (cullet) is added to the mix, it already contains these minor ingredients and can have an impact on the colour of the glass made. It is really important that the bottles and jars are consistent in their colour, so we only add clear to clear glass in the furnace and green to green and so on.

3. What happens to bottle tops?

It is really important to remove bottle tops and jar lids and other metals from the glass recycled, before it goes in the recycling bin. Metal is a contaminant in the glass recycling process. Of particular concern are the aluminium ring tabs and neck rings.

4. Does paper affect the glass recycled?