what is pla made from

What is PLA Made From?

Polylactic Acid, commonly known as PLA, is a popular biodegradable thermoplastic used primarily in 3D printing and various packaging applications. As environmental concerns grow regarding the impact of conventional plastics, PLA has emerged as a preferred alternative, owing to its eco-friendly properties. But what exactly is PLA made from, and how is it produced? This article delves into the origins of PLA, its raw materials, and the processes involved in its production.

Raw Materials

PLA is derived from renewable resources, primarily starches obtained from plants. The most common sources of starch include corn, sugarcane, and cassava. Of these, corn is the most widely used due to its high starch content and availability in industrialized countries. The starch extracted from these plants undergoes a series of transformations to become lactic acid, the fundamental building block of PLA.

The Production Process

1. Starch Extraction

The production of PLA begins with the extraction of starch from plant sources. In the case of corn, the kernels are ground, and a process called wet milling is employed to separate the starch from other components such as protein and fiber. The end product is a purified starch that is ready for fermentation.

2. Fermentation

The extracted starch is then subjected to a fermentation process, where microorganisms such as bacteria convert the starch into lactic acid. This step is crucial, as lactic acid serves as the monomer for PLA. The fermentation process can vary in duration, but it typically takes one to three days, depending on conditions such as temperature and pH levels.

3. Lactic Acid Polymerization

Once lactic acid is produced, it undergoes a polymerization process. There are two primary methods for this stage direct condensation polymerization and ring-opening polymerization. In direct condensation polymerization, lactic acids are heated to encourage them to react and form long chains, creating PLA. Conversely, ring-opening polymerization involves the use of a catalyst to facilitate the reaction between lactide, a cyclic dimer of lactic acid, to form a polylactic acid polymer.

4. Pelletization

After the polymerization process, the PLA is typically cooled and then cut into smaller pellets for easier handling and processing. These pellets are then used in various applications, including 3D printing filaments, biodegradable bags, and containers.

Environmental Benefits

One of the most significant advantages of PLA is its biodegradability. When exposed to suitable composting environments, PLA can decompose into non-toxic components, leaving minimal ecological footprint compared to traditional petroleum-based plastics. Moreover, PLA's production from renewable resources means that it has a lower carbon footprint. It requires significantly less energy to produce than conventional plastics, making it a viable sustainable alternative.

Applications

PLA is versatile and has found applications across various industries due to its favorable properties. In the sphere of 3D printing, PLA is favored for its ease of use and excellent print quality. Additionally, it is used extensively in the packaging industry for producing biodegradable containers, disposable cutlery, and films. The biocompatibility of PLA makes it an attractive option for medical applications, including sutures and drug delivery devices.

Conclusion

In summary, PLA is made from renewable resources, primarily starch derived from crops like corn and sugarcane. The production process involves extracting starch, fermenting it into lactic acid, and then polymerizing that acid into PLA. With its biodegradable properties and reduced environmental impact, PLA is establishing itself as a sustainable alternative to traditional plastics, paving the way for a more environmentally friendly future. As technology advances and consumer demand for eco-friendly solutions grows, the role of PLA in various industries is likely to expand even further.