The ongoing development of policies by Local Governments to increase the recovery of recyclable materials and their resulting diversion from landfill has lead to the development of new collection programmes, which are in the main, automated with the benefit of improved health and safety.
One aspect, however which is not beneficial is the cessation of the traditional separation at source, the outcome of which is deterioration in the quality of glass offered for recycling and remanufacture.
The challenge is to minimise the effects of the reduction of quality while enjoying the benefits of increased collection tonnages. An additional option is the establishment of alternative uses for those collections, which do not meet the standard required for the manufacturer of new containers.
With the construction of an additional furnace and extra glass making capacity the Forum has two prime objectives:
This second objective requires not only the identifying of the alternative uses but also the establishment of them as acceptable.
Changes in the way Local Authorities collect household recyclables have had an adverse effect on the quality of glass available for recycling. This is a direct result of all recyclables being transported as a combined load for subsequent separation. Overseas experience has raised concerns that, notwithstanding increased volumes being collected, there is a reduction in the amount available for recycling and an increase in the volumes which need to be landfilled.
Below is independent report addressing the subject
Co-mingling report (PDF 333KB)
Questions & Answers about Glass Recycling in New Zealand
Q. What sort of glass can be recycled and what can't?
A. What you CAN recycle
If you have kerbside recycling, you can put out your glass containers for recycling. There are also some landfills and transfer stations that have bins for recycling glass.
Remember, you can only recycle food and beverage containers, for example:
Clear glass jars and bottles
Brown glass (beer bottles)
Green glass (wine bottles)
The above types of glass can be fully recycled WITHOUT loss of purity when making a new bottle
A. What you CAN'T recycle
You can't recycle light bulbs and fluorescent tubes, pyrex dishes and ovenware, china and crockery - cups, saucers, plates, decorated drinking glasses, window glass, opal glass, glass bricks, medical and laboratory glass containers, TV tubes and computer screens.
Why? Because if the recycled glass is being used to make new glass it must be pure and this means you can only use glass and beverage containers. Other types of glass can have a damaging or harmful affect on the quality of the new glass.
Q. Why do you have to separate the containers by colour?
A. Glass needs to be separated by colour if it is going to be used to make new glass containers.
O-I New Zealand, New Zealand's only glass manufacturer, makes bottles and jars in seven colours. These are flint or clear glass, amber glass, blue glass and four varieties of green. The reason for sorting the glass is to maintain the green, brown and clear colours which consumers want and which are an important part of a product's branding and also to ensure that the glass furnaces can be run as energy efficiently as possible.
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 they only add clear to clear glass in the furnace and green to green and so on.
Q. Some areas of New Zealand you can throw your bottles in with paper, plastics and cans - when the truck comes along it all goes in the one big bin on the back.
Does this mean you can't use this glass to make new glass?
A. If glass is mixed or co-mingled with cans, paper and plastics and is not separated by colour on the back of the recycling collection truck, it has to be separated when it gets to the sorting plant if it is going to make new glass containers.
If it is not going to make new glass it is not so important to have it colour separated but it still needs to be separated from other packaging.
Currently if glass is being collected with other packaging in large wheelie bins, this has to be sorted by a combination of magnets and hand picking. However if glass is mixed in by colour and compacted with other cans, plastic and paper on the collection truck, this does reduce the amount of glass which can be recycled into new glass.
In 2009 a new state of the art Materials Recovery Facility (MRF) opened at Visy's recovery facility at Onehunga servicing both Auckland and Manukau cities and was expected to increase recycling rates by an additional 15-20%. When fully operational it was expected that the new plant will separate glass by colour and separate materials by type.
However an independent report by Palmerston North City Council1 is concerned that based on overseas experience of co-mingled collections; glass should be kept separate from other materials at point of collection. This is because although more recyclables are collected, less good recycled glass is available to make new glass containers due to glass breaking into very fine pieces in transit. However glass collected in this way can still be used for other things such as aggregate for roads, concrete etc.
1 The Glass Packaging Forum has funded this research following a request for funding from Palmerston North City Council. As a result the Palmerston North City Council and a number of other Local Authorities are further considering the need for glass to be kept separate at the time of collections.
Q. What happens to bottle tops and paper labels?
A. Bottle Tops
It is really important to remove bottle tops and jar lids and other metals from your recycled glass, before it goes in the recycling bin. Metal can contaminate the glass recycling process. Of particular concern are the aluminium ring tabs and neck rings.
A. Paper Labels and SleevesPaper is also a contaminant in the glass recycling process. As much as possible paper sleeves and labels are removed from the bottles and jars when they are received at the sorting plant. Any small amount of paper left is burnt up in the furnace.
Q. Where do you recycle your glass?
97% of New Zealanders have access to facilities to household recycling facilities, either at kerbside or at drop-off centres.
77% of New Zealand councils offer households a kerbside recycling service.
A. At kerbside (outside your house) or at a bottle collection point.
Check with your local council to find your nearest recycling facilities.
Q. Who organises the recycling trucks and where the glass goes?
A. Your local council is responsible for waste management and will select a company or companies to collect your recycling and to process it.
When commercial glass recycling first started, glass from all over the country was returned to Auckland to make new glass at the glass furnace. However in 2006 New Zealanders recycled nearly 110,000 tonnes of glass which was more than was needed to make new glass so councils and recycling operators had to find alternative uses for the surplus. Currently the capacity for the production of bottles and jars has significantly increased and the manufacturer is again seeking increased volumes of colour sorted glass.
Q. What happens to the glass collected?
A. Most of it goes to make new glass containers and there will be the need for extra tonnages due to increased manufacturing capacity.
For that glass not of furnace quality we need to find alternative uses. It can be crushed and made into:
- Sporting Turf & Golf Bunkers
- Base Course for Roading
- Water Filtration
- Agricultural Mulch
- Erosion Protection
- Concrete Foundation
Q. Does recycled glass have a dollar / economic value?
A. 66.36% of all glass containers used in New Zealand were recycled in 2011/2012.
- Because recycled material uses less energy and a certain volume is required for optimum production there are savings. With commingling affecting local supplies there are at the current costs, (e.g. NZ dollar value etc for imported raw material ) benefits in using glass from the south of the South Island.
Over the last year 66% of glass recovered for recycling as utilized in the manufacture of new bottles and jars. The remaining 34% was used for alternative purposes.- Using recycled glass requires less energy to melt than using virgin materials (silica sand, soda ash etc)
- Less raw material is needed when recycled glass is used in a batch of new glass.
Q. What are the environmental benefits of recycling glass?
A. Lower energy usage leads to lower greenhouse gas emissions (pollution)
- Diverts glass from going into landfills
- Using glass as an aggregate for roads or concrete reduces quarrying