Let’s talk about bioplastics

Posted on: 05 August 2019

Let’s talk about PLA

PLA. Polylactic Acid, to be precise. A plastic with one stand-out difference. Unlike other thermoplastics, which are petroleum based and, thus, incredibly detrimental to the environment, PLA is not only biodegradable but also bio-based. Consisting of such raw materials as corn starch and sugarcane, PLA is, in the strictest sense, renewable, and is an innovative and exciting move away from the harmful other plastics currently occupying the majority of the space in the industry. In this article we will consider the fields in which PLA is already being used, its benefits, but also its potential drawbacks. Interestingly, unlike other thermoplastics whose value is diminished by their intrinsic nature, the downsides of PLA fundamentally concern the way in which our society is infrastructurally set up. This indicates that the solutions to our sustainability efforts are there, but it’s on us and our governments to guarantee that such solutions can be implemented properly.

Ok, so not all of us (or perhaps any of us) are degree-level chemists, and so the technical processes that go into the manufacturing of PLA may just go over our heads. With the knowledge that the process is tried and tested, what is most key for us consumers and creators is the fact that the building block of PLA is not petroleum nor anything else that is non-renewable, but raw materials that photosynthesise. In taking in carbon dioxide from the atmosphere, the final product made out of PLA will be nearly carbon-free, a massive improvement from the current status quo. In fact, using bacteria means that PLA production uses four time less energy than normal plastic production. Additionally, it is a very efficient process: 1.6kg of biomass yields 1kg of PLA. It is also a potential long-term answer to our current issues. Petroleum won’t last forever, you know.

What’s more, PLA products will not be flimsy and fall apart within two seconds. In fact, its properties are comparable to other plastics in the market. More specifically, it falls in line with other thermoplastics. With a relatively low melting point of around 180oC, it can be melted and shaped without affecting its mechanical properties. This is hugely beneficial in the recycling process.

PLA is not only bio-based, it is also biodegradable. Big bonus. In the right environment, it will break down into natural materials, including water and carbon dioxide.

It’s non-toxicity is a benefit, too. Registered safe by the United States Food and Drug administration, products made out of PLA have even been incorporated into medical practices. That is because PLA is biocompatible, and won’t give off toxic fumes when oxidised. Alongside food and medicine, PLA will be used in a range of different markets: from cosmetics to textiles, it’s applications are almost boundless.

Sound too good to be true? Well, there are some potential drawbacks. Remember when we said PLA is biodegradable. That was true, but decomposition can occur very slowly outside of the right environments. On a landfill, it will take any time between 100 and 1000 years for PLA to break down into its natural materials. The way around this issue relies on a structural shift, in which the waste PLA plastic has to be sorted and then sent to a separate, specific facility. This all costs money, effort and time. Furthermore, if we insist that waste PLA plastic has to go a different facility, an independent recycling process will have to be set up to prevent contamination. Again, more time, more money, more structural changes. Furthermore, the biodegradability issue becomes complicated further when we think of long-term storage. Of course, rapid decomposition sounds wonderful. However, logistically, the plastics will have to stay intact during the exportation, production, packaging, selling and consumption of certain produce. It is not clear how successful PLA will be in this regard.  At least, when left in landfill, it will be carbon neutral.

So there you have it, PLA. Radical, encouraging, the answer to all our problems? Perhaps. Intrinsically, the properties of such a plastic are extremely desirable. Nevertheless, for PLA to become a genuinely viable option, it is clear that larger, social alterations need to be made. As far as we are concerned at Freda, these are changes worth making.

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