Biodegradable film is a material designed to naturally decompose in the environment. Unlike conventional plastics, these films are designed to break down through biological processes. It offers a solution to plastic waste accumulation, reflecting a commitment to sustainable practices.
What is Biodegradable Film?
Biodegradable film undergoes decomposition through natural biological processes, primarily by microorganisms. This contrasts with traditional plastics, which are typically derived from petroleum and can persist in the environment for hundreds of years without significant degradation. Their defining characteristic is their ability to be consumed and broken down by living organisms like bacteria and fungi, rather than fragmenting.
These films are made from renewable resources, distinguishing them from fossil-fuel-based plastics. Common materials include plant-based polymers like polylactic acid (PLA) derived from corn starch or sugarcane, and polyhydroxyalkanoates (PHA) produced by microorganisms. Starch-based polymers, sourced from corn, potatoes, or wheat, are also used. Some synthetic polymers are engineered to be biodegradable and can be blended to achieve desired properties like flexibility and strength.
How Biodegradable Film Breaks Down
Decomposition of biodegradable films is driven by microorganisms. Bacteria and fungi release enzymes that break down the long polymer chains into simpler compounds.
The degradation process is influenced by environmental conditions, including moisture, temperature, and oxygen levels. Many biodegradable films require industrial composting facilities, which provide optimal heat and aeration, to decompose efficiently. The end products of true biodegradation are benign substances like water, carbon dioxide, and biomass, which are reabsorbed into the ecosystem. It is important to differentiate true biodegradation from “oxo-degradable” plastics; oxo-degradable materials contain additives that cause them to fragment into smaller plastic pieces, but these pieces do not fully biodegrade into natural components.
Where Biodegradable Film is Used
Biodegradable films have diverse applications, offering an environmentally conscious alternative to traditional plastics. In packaging, these films are used for various products, including food items, consumer goods, and industrial materials, serving as wrappers, pouches, and bags. For example, polylactic acid (PLA) films are utilized for fresh produce, meat, poultry, and even beverage packaging, providing protection while allowing for controlled gas exchange to extend shelf life.
Agricultural applications are another area for these films. Biodegradable mulch films are laid on soil to suppress weed growth, conserve moisture, and regulate soil temperature, eventually breaking down into natural components without requiring removal. Horticulture and nurseries also use biodegradable pots and containers made from these films, allowing plants to be directly planted without removing the container. Beyond these uses, biodegradable films are appearing in medical applications, such as dissolvable sutures and drug delivery systems, designed to break down safely within the body.
Environmental Contributions
Biodegradable films offer environmental advantages, reducing plastic pollution and landfill waste. Their ability to break down into natural components over time mitigates the accumulation of persistent plastic waste in various environments, including oceans and waterways. This contrasts sharply with conventional plastics that can endure for centuries.
Many biodegradable films are derived from renewable resources like cornstarch, sugarcane, or other plant-based materials, lessening the reliance on finite fossil fuels for production. The manufacturing process for some biodegradable materials can also result in lower greenhouse gas emissions compared to traditional plastics, as plant-based sources absorb carbon dioxide during their growth. While the environmental benefits are substantial, proper disposal, often through industrial composting, is necessary to ensure these films fully biodegrade and return organic matter to the soil, supporting circular economy principles.