AUSTRALIA consumes more than one and a half million tonnes of plastic each year. With around one third of this plastic being used for packaging, it is no surprise that the environmental consequences of plastic packaging waste are a major concern for industry and the community.
This concern, coupled with growing market demand for environmentally friendly packaging lead the Cooperative Research Centre (CRC) for International Food Manufacture and Packaging Science to develop a biodegradable plastic, known as Plantic.
Tim Lord of Plantic Technologies, the company formed to commercialise the Plantic product, said the new plastic material will fully decompose in less than 12 weeks. “This means that Plantic products will degrade by biological processes and the end result is carbon dioxide and water,” he said.
Lord told Manufacturers’ Monthly while other biodegradable plastics had been developed which breakdown via biological processes, some leave toxic or non-compostable residues.
Plantic is made from corn starch mixed with other common organic compounds. The current version of the product dissolves in water, and this makes it unsuitable for packaging wet products. Lord said this is the subject of further application development work for the company.
At present, the Plantic product is used mainly for packaging dry food products such as chocolates and biscuits, although Lord says its applications stretch to a range of other dry industrial packaging.
The company plans to use a $1.73m research and development grant it recently received to develop an overlay wrap over the next three years.
Converting to use the Plantic product instead of oil-based plastics requires no modification to existing plant. “The Plantic product is processed on standard industry equipment used for polymer film extrusion and thermo-forming,” Lord said.
Other organisations are also developing compostable plastic materials.
Researchers at the University of Warwick in England have developed a biodegradable mobile phone casing containing a sunflower seed. When the phone casing is buried, the sunflower seed germinates, feeding off nitrates released as the polyvinylalcohol casing breaks down. Earlier this year, the University was discussing with Motorola the possibility of incorporating the new plastic in commercial products, but Motorola has not yet announced a decision.
Victorian company, Pro-pac, produces protective void fill packaging which it claims is 100% biodegradable and will compost without residue. The company, which recently listed on the Australian Stock Exchange, uses wheat and potato starch in the production of its product.
US-based company NatureWorks LLC also produces plastic derived from natural plant sugars, based on lactic acid. Since January 2003, the company has increased production capacity more than 15-fold and reduced product costs to be competitive with petroleum-based polymers such as polyethylene terephthalate (PET). The product is rapidly gaining acceptance with sales 40% higher in 2004 than in 2003.
These products are all said to be comparable in price with traditional oil-based plastics that perform the same functions, and at the same time meet market demands for environmentally friendly packaging.
Other approaches
While creating plastics from renewable sources that quickly break down to non-polluting materials is a positive step, straight disposal is generally considered a last resort in waste management.
Organisations such as the National Packaging Covenant Industry Association (NPCIA), advocate an approach to waste management based on a “waste hierarchy”.
According to the waste hierarchy, the first priority is to avoid waste creation; the second preference is to reuse the materials without processing; and if that is not possible, the waste should be recycled. The fourth option is energy recovery, typically through burning the plastic at high temperatures to produce energy for power and heating. It is only if all other avenues have proved impractical, that waste should be sent to landfill.
Increasing numbers of manufacturers are following the National Packaging Covenant. The Packaging Covenant started in 1999 and was extensively reviewed in 2004. Mark II of the Covenant is due to start in July and expands on the earlier version.
Manufactures are encouraged, under the Packaging Covenant, to minimise the amount of packaging required by their products, and to use environmentally friendly alternatives where practical.
Government and community groups have lead the charge in avoiding packaging at the consumer end, encouraging consumers to avoid plastic shopping bags. The Department of Environment and Heritage, in 2003, challenged retailers to reduce the number of bags issued at the end of 2004 by 25% compared with the number issued in 2002, with a further reduction to 50% by the end of 2005.
Recycling programs are also widespread, with extended producer responsibility schemes (EPR) in place in several target areas including the packaging industry.
Local councils have also implemented kerbside recycling, and according to research from the National Packaging Covenant Industry Association (NPCIA), this has lead to recovery of 51% of all packaging materials in Australia. Environmental groups have questioned this figure however, with the Boomerang Alliance of green NGOs putting recycling rates from at closer to 20%.