Ashes to ashes, dust to dust
Plastic littering the countryside could soon be a thing of the past. Researchers have come up with an additive that enables plastic bags to be quickly decomposed by sun and rain.
Nor-X Industry AS, a company located in Sunnmøre, has launched the additive that makes plastic decompose in a short time when exposed to light and humidity. The additive also makes the plastic considerably stronger, and it is cheap to produce. This is all the result of a collaboration between the company and SINTEF,which began in 1999.
The relationship started when Nor-X Industry’s parent company, Nor- Mors AS, wanted to make chin-collars to enable dead people to look nicer in their coffins. They wanted the collars to start the decomposing process after the burial so they contacted SINTEF to solve the problem. The research scientists were successful in finding an additive on the market that had the desired effect. But there was one problem: the collars became dark and extremely visible, but the aim was for them to be as neutral as possible. This was difficult to achieve with the additives available on the market.
The solution turned up together with a newly appointed research scientist from France. He suggested an idea to alter the additive so the end product would be lighter. This provided the desired result and the colour of the end product was virtually perfect. However, at that stage the manufacturing was so expensive that it would not have been economically viable in a manufacturing process.
The research collaboration developed further through ‘SkatteFunn’ tax incentive scheme project. The objective now was an additive for plastic that could be handled industrially and used in plastic foil, plastic bags and food packaging. The product is a ferric organic compound. If it is added during manufacturing, it will provide both a rapid decomposition and a light colour. The results were so promising that NorMors started the new company, Nor-X Industry, to handle production and marketing.
THE TECHNOLOGY BEHIND IT
“Polyethylene and polypropylene,which we are talking about here, are sensitive to ultraviolet light, so we are just talking about assisting nature a bit,” says SINTEF senior research scientist Ferdinand Männle.
In addition to light, a little humidity, heat and oxygen are required, all of which are abundantly available in nature. Nevertheless, an ordinary polyethylene bag would take more than a year before it began to decompose, but the new plastic bags will break down quicker than an apple on the ground. After two weeks in sunlight, the bags will still have 90 percent of their strength, but after five weeks only traces will remain. The decomposition process occurs in several stages. Firstly, the light cuts the molecules in the plastic down to such small pieces that they are ideal food for micro organisms.
The satisfied micro organisms are in turn eaten by others and play a part in the food chain. The end products, which are common materials in nature, can be found in plants, moss and perhaps in earthworms. The amount of rust that remains will be so minute that it will be virtually impossible to measure. The concentration of iron in the plastic is so low that in numerical terms it would be some parts per million.
In addition to conventional shopping bags, plastic for silo bales in agriculture is another actual use. As this plastic contains formic acid, no one is willing to recycle it. The bales need to last at least a year to satisfy users, and the alternative is to add a less aggressive form of the additive in the plastic so that it only begins to decompose after 18 months. Nor-X Industry has also reached an agreement with the German Farmers’ Co-operative to produce an agricultural film foil for the fields around Berlin.
The film will keep the soil warm in Spring and protect against the fear of frosty nights when farmers have planted potatoes. It will start to decompose after four to six weeks. Research is currently underway on additives in several other contexts, including for use in oil protection preparedness. The product has shown that it has the capacity to materialise and break down oil.
Åse Dragland/Jan Helstad