Australian compostable bag company BioBag has won the tender to supply 10,000 bags to Armidale-Dumaresq Council as part of its City to Soil project which aims to divert organic waste from landfill by encouraging residents to deposit kitchen waste in their green waste bins. As part of the tender, BioBag Australia’s director Neil Thomson told Inside Waste Weekly that the properties of the bag were an important component of the selection process.
“The bag themselves had to have a high water vapour transmission rate,” Thomson said, explaining that many compostable polymers did not allow water to pass through, a key property needed to minimise odours. “This is a premium product, so we concentrated on the food waste market”.
Traditionally a niche product used principally for medical applications, growing environmental standards over the last decade have seen biodegradable plastic used in packaging bulk consumer products. Biodegradable plastics are typically composed of blended starch, cellulose (which makes cellophane) or organic polyesters such a polylactide (PLA).
Thomson said the compostable plastic used was a blended starch biodegradable bag marketed under the name Mater-Bi, developed by chemical company Novamont. Another aspect of the bags supplied was the unique identification number printed on each bag. This number allowed waste processors to identify the household with the lowest contamination rates in their waste stream and award prizes under the City to Soil program.
Australia wide, Thomson said that BioBag supplied between 120,000 and 180,000 biodegradable bags to councils including City of Port Adelaide Enfield, Port Macquarie-Hastings and Ballina Shire Council. Despite bans on single use plastic bags in several states and territories, Thomson said he does not expect compostable bags to replace polyethylene bags as they are not price competitive.
“Whatever you do, they are going to cost three to four times as much,” he said. “The answer to cutting plastic bag consumption is to make people pay for them”.
Despite this Thomson said that the market [for bioplastics] is growing quite well. “There is also application in products like feminine hygiene, diapers and agricultural plastics.”
