Glass Recycling - Its all Sorted
December 06, 2006
Posted by Joseph Taylor at December 6, 2006 02:32 AM
If anyone needed substantiation of the benefits of being a member of a special interest group such as the Australian Institute of Packaging [AIP] it became clear in early November when members of AIP were privy to a site visit to Visy- Recycling Glass at Laverton in Victoria.
Visy Recycling Glass in Laverton played host to a number of members from the Australian Institute of Packaging (AIP) on two separate occasions during November
AIP members gained an insight into the current state of play with regards to glass packaging recycling in Australia and were given the privilege of being able to see the automated glass sorting facility in action.
The state of the art facility is the only one of its kind within Australia and allows mixed and broken glass to be sorted into different colours, whilst removing high levels of contamination during the process.
Broken glass is sourced from kerbside collections and arrives from Municipal Recycling Facilities [MRF] all over the country. It arrives in various states of cleanliness from very clean to almost unrecognisable and in many instances loads of glass can be highly contaminated.
Contamination, the group was advised, comes in the form of Pyrex baking dishes, ceramic cups and plates and of course the usual nappies and plastics with the latter being removed at the very start of the process by manual labour.
The removal of ceramics is an area of focus for the plant because if a piece of ceramic gets between the shear blades during the glass bottle production process it can result in broken shear blades. Pyrex is also an issue because the melt point is different to normal glass and as a result can create weaknesses in the glass during carbonated beverage filling of the bottle.
The automated glass facility is totally computerised with each step of the process accessible and adjustable through a computer monitored system.
Using a process similar to a digital camera, the automated glass facility identifies and separates the different types or colours of glass by taking individual snapshots of each piece of glass at high speed. The light then identifies and processes the colour whilst air jets shoot the glass off into individual colour streams.
The cameras used in the automated optical sort have the ability to sort up to a million individual pieces of glass per minute and can detect up to 16 million different colours in total.
The facility was upgraded in 2005 and has driven glass recycling rates from 65,000 tonne to up to 120,000 tonne per annum or just under a 50% improvement in recovery rates since its completion.
In an attempt to recover as much as they can of the glass that enters the plant, the final act of recovery involves ‘aging’ glass that is rejected because it may have pieces of the paper label stuck to it. This can render it unreadable by the plants optical sort equipment, however material is stockpiled and then resorted through the plant to ensure that every possible piece of glass is recycled.
Every piece of glass that can be recovered and sent on for reuse in bottle manufacture is a win for the environment. Each 1,000 kg of glass used saves 1,100 kilograms of raw material being used.
Not only does the use of recycled glass reduce the energy needed to make new glass but it extends the life of raw material deposits and the costs associated with mining, processing and transporting over distances.
The generation of glass that is simply too small in size to recover is an inevitable part of the recycling process and this material can be used in road base and also for drainage base under roads because of the stability of the material, Visy Recycling Glass continues to work hard on sourcing new markets for this material.
Benchmarking on a global scale we still have room for improvement. Each year one of Visy Recycling Glass’ customers manufactures more than a million tonnes of glass, but only about one third of the glass in the waste stream is recycled.
High Recovery Rates
In Switzerland where recycling world's best practice exists 91% of manufactured glass is recovered for recycling. Albeit a small country like Switzerland does not suffer the Australian tyranny of distance to get waste to recycling facilities there is certainly room for a quantum leap in the volume of glass recycled.
A number of the visitors adjourned to a local watering hole to continue networking and must have reflected on a Visy statement that "a million people can drink out of the same bottle" as glass can be recycled forever.
Whether or not folks were drinking from a glass or stubby made of recycled glass is simply not answerable as there is no discernable difference between virgin material glass and that made from recycle.
by Michael B Halley
Austrlian Institute of Packaging (FAIP)
Reviewed by Meredith Banks
Visy Recycling - Corporate & Environmental Affairs
I would like to know the details of the glass sorting plant as I have been into the glass business from the past 20yrs.
I am planning to setup a glass sorting plant as sorting of glass is consuming loads of time and is too expensive. So i would like you to sugest a glass sorting plant.
And I request you to send in more pictures of your running plant and would be intrested to see your plant.
Posted by: srinivas at January 13, 2007 12:56 AM
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Posted by: mutuelle at June 28, 2010 06:36 AM