Bioplastic bags from cassava and shrimp waste on Plastic Bag Free Day
In the past years, we have discussed many sources of bioplastic. From cheese waste to pine needles, and from milk to cow dung, all of these materials are a viable source to make a more sustainable world. In honour of Plastic Bag Free Day, today we discuss two sources to make plastic bags from biodegradable material: made from cassava starch that dissolve in water, and bioplastic bags made from shrimp waste.
Cassava plastic bags
Cassava is a cheap and common root vegetable across Indonesia, home of the inventor of the plastic, Kevin Kumala. The bioplastic contains cassava starch, vegetable oil, and organic resins.
The material is biodegradable and compostable, breaking down over a period of months on land or at sea. However, it dissolves instantly in hot water. The inventor claims it leaves no trace of toxic residue, which he demonstrates by drinking the dissolved plastic.
The company Kumala founded in 2014, Avani Eco, produces all kinds of disposable and eco-friendly products, from coffee cups to ponchos. Not everything is made from cassava. The poncho, for example, is made from corn, soy, and sunflower seeds.
While bioplastics should of course be supported and applauded, as petroleum based plastic products are slowly destroying our oceans, using edible resources may not be the most viable option. Unless we all start drinking our cassava plastic bags, we should keep looking for alternative resources to make bioplastics.
Shrimp waste plastic bags
In collaboration with the Nile University in Egypt, bioengineers at the University of Nottingham are studying how to use shrimp shells, rather than food crops, to make biodegradable shopping bags, as well as new food packaging material to extent product shelf life.
Shrimp shells are part of the waste problem in Egypt. Using a degradable biopolymer for bioplastic bags leads to lower carbon emissions and a reduction in food and packaging waste.
The material is made from chitosan, an artificial polymer made from the organic compound chitin, which is extracted from crustacean shells. Chitosan is biodegradable polymer that is antimicrobial, antibacterial, and biocompatible. In the project, the substance is used to create a nanocomposite material that is biodegradable, affordable, and suitable for shopping bags and food packaging.
A second strand of the project aims to develop an active polymer film that absorbs oxygen, to enhance the shelf life of food.