What is PLA?
Polylactic acid (abbreviated as PLA) is a type of plastic that has become very popular, partly because it can be produced cheaply from renewable resources such as corn starch (and thus not petroleum/oil, which is the case for conventional plastics). Types of plastics made from biomaterials (such as PLA) are also known as bioplastics. In 2010, PLA was the second most used bioplastic in the world (measured by volume). However, it is the most widely used material within 3D printing.
PLA is also popular because it can be used to produce many different items. In addition to 3D printing, it is also used for the manufacturing of:
- Plastic bottles
- Biodegradable medical devices (such as screws and plates, which are expected to break down within 6-12 months)
- Prototypes in pharmaceuticals and other industries
PLA has a low melting point of around 160 °C, making it ideal for 3D printing, as it does not require a lot of energy to heat during the production process. However, it also has the downside of limiting usage possibilities, as deformation may occur in the product if it is used, for example, in an oven.
How is it produced?
As mentioned earlier, PLA is made from renewable and natural resources such as corn. The starch in corn is extracted from plants and converted into dextrose by adding enzymes. It is then transformed into lactic acid using microorganisms, which can eventually be converted into PLA. This process results in PLA resembling petroleum-based plastic at a molecular level.
It is very positive that PLA is made from renewable resources, as traditional plastic production methods use oil, which is a limited resource. However, it raises the question of whether we should be using food to produce plastic instead of using it to feed the world's population.
Is it environmentally friendly?
Although there are elements of 'greenwashing', PLA is biodegradable and therefore a step in the right direction away from oil-based plastics. Besides being plant-based, the production of PLA also emits significantly fewer greenhouse gases and uses much less energy in the production process.
Does that mean we can just throw it in nature without any concern?Biodegradable should not be confused with compostable, as there are important differences between these two definitions and they are often misunderstood. A biodegradable material can be broken down under certain conditions. PLA can be 100% recycled if included in the recycling system. Although it is classified as biodegradable, it only breaks down in nature under the right conditions and is, for example, only partially degraded over a period of 6 months at a temperature of about 60 °C. However, it can be incinerated, producing only carbon, oxygen, and hydrogen upon combustion.
So, one cannot just throw it in nature and feel good about it. The best option is still to include it in the recycling system.
Why do we use it at WeShape?
At WeShape, we use PLA in our production because:
- It is the most environmentally friendly alternative. Although it is far from a natural product, it is still better for the environment than traditional plastic.
- Additionally, there are also practical advantages of PLA, including its relatively low melting temperature, which is beneficial in the printing process.
- It is relatively inexpensive, which means it is also cheaper for our customers.
- It is a reliable material, as there has been a high usage of PLA for a long time. This has led to massive investments in producing high-quality PLA, resulting in good and stable prints in a 3D printer.