Scientists have come up with different solutions, like manufacturing oxo-biodegradable and hydro-biodegradable plastic. Plastic Pakaging (Private) Limited is a Sri Lankan company which manufactures oxo-biodegradable , mainly for an export market
Beating the menace of non-degradable plastic
By Sara Nazoor
Scientists have come up with different solutions, like manufacturing oxo-biodegradable and hydro-biodegradable plastic. Plastic Pakaging (Private) Limited is a Sri Lankan company which manufactures oxo-biodegradable , mainly for an export market.
Innovation of a new product
“We started by manufacturing thin bags 24 years back. We had the technology to manufacture polythene food wrapping sheets and bin liners, but we were worried because the polythene film wasn’t degradable. That is why we started looking in to polythene film that degrades,” says Mervyn Dias, Chairman of Plastic Pakaging. The research for this developed bio film was conducted by Prof. Gamini Seneviratne, Research Professor at the Microbial Biotechnology Unit of the Institute of Fundamental Studies, Kandy. “This was the first research that was conducted in Sri Lanka on developing a bio film which can degrade. We received samples from Plastic Pakaging to conduct the research,” says Prof. Seneviratne.
Apart from adding a pro- degradant additive, there is no difference in the process. The additive represents less than three percent of the product and it can be manufactured with the same machines and the same workforce, making it cost-effective. The additive breaks the molecular chain in the polymer, making it fall apart at the end of its useful life product. With this product, the plastic does not fragment. Once the additive has reduced the molecular weight to a level which permits micro-organisms access to the carbon and hydrogen, it will be consumed by bacteria and fungi. When the bio film reach the fragmenting stage, it is no longer plastic; it is ‘biodegradable’ just like the natural waste. The process continues the material biodegradation to CO2 and water and it does not leave fragments of petro-polymers in the soil. The oxo-biodegradable bag contains transition metal ions of cobalt, iron or manganese – trace elements required in the human diet. Toxic heavy metals such as lead, mercury, cadmium and chromium are not used in manufacturing oxo-biodegradable polythene.
Oxo-biodegradable polythene has been certified by Smithers Rapra Technology as safe for long-term contact with any food type at temperatures up to 40°C. Rapra is accredited by United Kingdom accreditation authorities as meeting the requirements of International Standards Organization norm No.17025. It is also certified as compliant with requirements of the Food and Drug Administration (FDA) in the United States. The important advantage of the oxo- biodegradable polythene bags is that it can be programmed to degrade in required time scale. The average useful lifespan of a carrier bag is about eight to 12 months. If required, the bags can be programmed to degrade in a shorter or longer period. During its useful lifespan, bags can be re-used. Heat and light normally accelerate the process or degrading.
“First the mixture is heated and poured into the machine and the polythene rolls are printed and separated according to the requirement. If you do not add the additive, it won’t be biodegradable. We currently export biodegradable bags to the Maldives, and they want us to print certain subjects on the bag, such as the manufacturing date, the name of the additive, the brand name and many other things. Once the bags are packed in boxes, we store them and ship them,” says Dias, explaining the manufacturing procedure. Polythene being one of the major environmental issues, we all should look in to the fact of degradable polythene. if saving the Earth can be done without eliminating polythene it is the best option we all have for a greener planet.