Song Bang has successfully researched and produced biodegradable plastic bags with 100% corn starch
Recognizing the importance of protecting the environment, Song Bang has researched and successfully produced biodegradable bags made of 100% corn.
Decomposition time is 3-6 months
High mechanical strength, sharp color printing
There is much debate about the total carbon, fossil fuel and water usage in manufacturing bioplastics from natural materials and whether they are a negative impact to human food supply. To make 1 kg (2.2 lb) of polylactic acid, the most common commercially available compostable plastic, 2.65 kg (5.8 lb) of corn is required. Since 270 million tonnes of plastic are made every year, replacing conventional plastic with corn-derived polylactic acid would remove 715.5 million tonnes from the world's food supply, at a time when global warming is reducing tropical farm productivity. "Although U.S. corn is a highly productive crop, with typical yields between 140 and 160 bushels per acre, the resulting delivery of food by the corn system is far lower. Today’s corn crop is mainly used for biofuels (roughly 40 percent of U.S. corn is used for ethanol) and as animal feed (roughly 36 percent of U.S. corn, plus distillers grains left over from ethanol production, is fed to cattle, pigs and chickens). Much of the rest is exported. Only a tiny fraction of the national corn crop is directly used for food for Americans, much of that for high fructose corn syrup."
Traditional plastics made from non-renewable fossil fuels lock up much of the carbon in the plastic, as opposed to being burned in the processing of the plastic. The carbon is permanently trapped inside the plastic lattice, and is rarely recycled, if one neglects to include the diesel, pesticides, and fertilizers used to grow the food turned into plastic.
There is concern that another greenhouse gas, methane, might be released when any biodegradable material, including truly biodegradable plastics, degrades in an anaerobic landfill environment. Methane production from 594 managed landfill environments is captured and used for energy;some landfills burn this off through a process called flaring to reduce the release of methane into the environment. In the US, most landfilled materials today go into landfills where they capture the methane biogas for use in clean, inexpensive energy. Incinerating non-biodegradable plastics will release carbon dioxide as well. Disposing of non-biodegradable plastics made from natural materials in anaerobic (landfill) environments will result in the plastic lasting for hundreds of years.
Bacteria have developed the ability to degrade plastics. This has already happened with nylon: two types of nylon eating bacteria, Flavobacteria and Pseudomonas, were found in 1975 to possess enzymes (nylonase) capable of breaking down nylon. While not a solution to the disposal problem, it is likely that bacteria have developed the ability to consume hydrocarbons. In 2008, a 16-year-old boy reportedly isolated two plastic-consuming bacteria.