what are biodegradable bags made of
Biodegradable bags have gained significant popularity in recent years, as people become more aware of the environmental impact of single-use plastics. Unlike traditional plastic bags that can take hundreds of years to decompose, biodegradable bags are designed to break down into natural elements within a relatively short period of time. In this article, we will explore what biodegradable bags are made of and how they contribute to sustainability.
Biodegradable bags can be made from a variety of materials, including plant-based substances such as cornstarch, vegetable oils, and agricultural waste. These materials are chosen for their ability to decompose naturally in the environment, reducing the amount of plastic waste that ends up in landfills or oceans.
One commonly used material for biodegradable bags is polylactic acid (PLA). PLA is derived from renewable resources such as corn or sugarcane. It is created through a fermentation process that converts the plant sugars into lactic acid, which is then polymerized into PLA. PLA-based bags have similar properties to traditional plastic bags, such as being transparent, strong, and flexible. However, unlike traditional plastic bags, PLA bags can be broken down by microorganisms in the soil or compost.
Another material used for biodegradable bags is polyhydroxyalkanoates (PHA). PHA is a type of polyester that can be produced through bacterial fermentation. Bacteria such as Alcanivorax borkumensis or Cupriavidus necator are used to convert plant oils or glucose into PHA. PHA-based bags have a similar shelf life and strength to traditional plastic bags but can be composted in industrial facilities or home composting systems.
Starch-based bags are another common type of biodegradable bag. These bags are typically made from a mixture of corn or potato starch and a biodegradable polymer such as polycaprolactone (PCL). Starch-based bags are not as strong as traditional plastic bags but are suitable for lighter items. They can decompose in composting conditions within a few months, leaving no harmful residue behind.
Other materials used for biodegradable bags include cellulose, which can be derived from wood pulp or cotton fibers, and vegetable-based oils. These bags are often combined with other biodegradable polymers to enhance their strength and flexibility.
It's important to note that not all bags labeled as biodegradable are equally environmentally friendly. Some bags may claim to be biodegradable but still take an extended period of time to break down or only decompose under specific conditions that are difficult to achieve in the real world. Therefore, it is crucial to look for certifications such as "compostable" or "ASTM D6400" on the packaging to ensure that the bag meets specific standards for biodegradability.
The use of biodegradable bags offers several benefits for the environment. By using renewable resources as raw materials, biodegradable bags reduce the dependency on fossil fuel-based plastics. They also have a lower carbon footprint compared to traditional plastic bags because the production process emits fewer greenhouse gases. Additionally, biodegradable bags are less likely to end up as litter, as they can decompose naturally without harming wildlife or polluting water bodies.
In conclusion, biodegradable bags are made from a variety of materials such as PLA, PHA, starch, and cellulose. These plant-based materials allow the bags to decompose naturally, reducing the environmental impact compared to traditional plastic bags. However, it is important to ensure that the biodegradable bags meet certain certifications to ensure their compostability. By using biodegradable bags, we can contribute to a more sustainable future and help protect our planet from plastic pollution.