CSIR develops promising biodegradable plastic polymer from agri waste

Biodegradable plastic bags – developed by local scientists – could soon be coming to a retailer and compost heap near you.

South Africans will soon be able to dispose of their plastic bags along with the rest of their waste without having to worry about any possible negative effects on the environment.

A team of local scientists from the CSIR’s polymer and composite research group in Port Elizabeth have broken new ground in their recent development of 100% biodegradable plastic bags made from agricultural by-products.

The maize and sugar cane bio-based bags are completely biodegradable in mud‚ soil‚ water and compost and break down completely in just three to six months.

So advanced is the technology that the bags can also be recycled, and major retailers such as Woolworths and Pick n Pay are already in line to test the product in a pilot phase.

The recycling issue scuppered a much-publicised launch by Tiger Brands in 2008, and then abandoned, of biodegradable bread bags for its Albany breads [read more here].

This Monday, CSIR senior researcher, Sudhakar Muniyasamy‚ who led the team that made the discovery‚ said the new bags had the same durability as normal plastic bags but with “many more advantages”.

“These biodegradable plastic bags can improve market opportunities and end-user industry and reduce the amount of plastic waste in SA‚” said Muniyasamy.

“The technology is mainly designed to meet physical-chemical properties but after their use when disposed in natural environments it undergoes biodegradation in landfill‚ compost and marine water by process of natural micro-organisms in a timely and efficient manner.”

In SA about 90% of current conventional plastics bags are made from petroleum-based chemical materials and are not biodegradable in natural environments.

Muniyasamy said the new bags currently cost two to three times more to manufacture than normal bags‚ but that costs would come down once they began to up scale production.

“We hope that by September we will be able to give them some pilot samples to try out and we expect to be in the commercial stage by early next year.”

Plastics SA sustainability manager, Jacques Lightfoot, believed that the new bags would be good for the environment but had concerns over its effect on existing jobs in the industry.

“This bag would have a lot of solutions to what we are facing right now and has its place as long as it doesn’t destroy our recycling sector‚” Lightfoot said.

“We have 1‚800 convertors in the industry making plastic products with … about 50‚000 employees‚ and 231 recyclers with close to 5‚000 employees.

“The problem for us is that the normal bags are also being recycled so if the new bags are not marked correctly they will contaminate normal bags if they are stored. We hope it doesn’t affect our recycling industry.”

Source: BDLive.co.za