how to make biodegradable plastic bags
Plastic bags have become an integral part of our lives, but their persistent nature has raised significant environmental concerns. These bags take hundreds of years to decompose, causing serious harm to our oceans, wildlife, and overall ecosystem. However, one solution to this problem is the development and use of biodegradable plastic bags. These bags break down over time, reducing their impact on the environment. In this article, we will explore the process of making biodegradable plastic bags.
The first step in making biodegradable plastic bags is selecting the right materials. Traditional plastic bags are made from non-biodegradable polymers like polyethylene or polypropylene. In contrast, biodegradable bags are made from a different type of polymer, one that is capable of breaking down naturally. The most commonly used biodegradable polymer is called polylactic acid (PLA). PLA is derived from renewable resources such as cornstarch, sugarcane, or other plant-based materials.
Once the appropriate materials are chosen, the next step is to convert them into usable plastic. The process begins with extracting the starch from the chosen plant-based source. This starch is then processed to produce lactic acid. Fermentation is one of the most commonly used methods to obtain lactic acid. Under controlled conditions, bacteria convert the sugar present in the starch into lactic acid.
The next step involves turning lactic acid into lactide, a compound used to create the polymer PLA. Lactide undergoes a process called polymerization, wherein its molecules bond together to form large chains, resulting in a biodegradable plastic. Various methods, such as condensation polymerization or ring-opening polymerization techniques, can be employed for this purpose.
After the polymerization process, the molten PLA is shaped into film, which will later be transformed into bags. This process can be achieved through either extrusion or blow molding. Extrusion involves melting the PLA pellets and pushing the material through a die, creating a continuous film. On the other hand, blow molding is used to create different shapes by inflating the polymer using compressed air.
Once the biodegradable plastic film is formed, it is sent to a converting facility where it can be made into bags of various sizes and shapes. Here, the film is cut, folded, and sealed to form the desired bag design. The bags can be customized with handles, zippers, or other features according to the intended use.
Biodegradable plastic bags have various advantages over their conventional counterparts. Firstly, they break down much faster, typically within a few months to a few years, depending on environmental conditions. In contrast, traditional plastic bags can persist for hundreds of years. Secondly, as biodegradable bags are made from renewable resources, they help reduce our dependency on fossil fuels. Additionally, their production emits fewer greenhouse gases, reducing the overall carbon footprint associated with plastic bags.
Efforts to improve the efficiency and reduce costs of biodegradable plastic bags are ongoing. Innovations such as blending PLA with other biodegradable polymers or incorporating additives to enhance decomposition are being explored. Additionally, advancements in recycling technologies are being pursued to ensure that biodegradable bags can be recycled effectively, further reducing their environmental impact.
In conclusion, making biodegradable plastic bags involves using plant-based materials and converting them into a polymer called polylactic acid (PLA). The process includes extracting starch, converting it to lactic acid through fermentation, and then polymerizing lactide to produce PLA. Once the PLA is in the form of a film, it is molded into bags and customized as required. The development and use of biodegradable plastic bags offer an environmentally friendly alternative compared to traditional plastic bags. By reducing the time it takes for bags to decompose and utilizing renewable resources, we can mitigate the damaging effects of plastic pollution and work towards a more sustainable future.