Touted as a powerful environmental tool by some and considered just another greenwashing trend by others, bioplastics are currently enjoying their time in the spotlight.
Although this innovative plastic material is certainly no stranger to controversy, it’s hard to deny the potential of bioplastics.
As explained in our previous blog, bioplastics represent a definite improvement from the petroleum-based plastic materials we’re used to. And while they’re unlikely to be the answer we need to solve our rampant plastic pollution problem, they are being embraced by manufacturers as a more sustainable packaging option.
But what is bioplastic used for in 2021, and what types of degradable plastics are you most likely to come across when shopping?
In this guide, we’ll break down the most common uses for bioplastics along with their most popular types, so you can make informed choices and pick the right product for a more eco-friendly life.
Types of bioplastics – what are the most common?
Before we dive into what is bioplastic used for, let’s first take a look at the most common types of bioplastics being used today and find out how they’re made.
Modern technology can use a wide variety of natural materials to create degradable plastic materials – what can be described as bioplastics.
You’re most likely to come across four main types of bioplastics:
1. Starch-based bioplastics
Perhaps the type of bioplastic consumers are more familiar with, starch-based bioplastics are made out of natural food starch, most commonly the starches found in corn or potatoes.
This type of bioplastic is often mixed with biodegradable polyesters to enhance its durability. It accounts for roughly 50% of all bioplastics used today.
The popularity of this type of bioplastic is mostly because its production process is relatively simple and inexpensive – it relies on two of the most common crops in the world along with a blend of water-repelling widely available polymers.
Starch-based bioplastics are made by extracting the corn or potato starch and blending it with common plasticisers like sorbitol and glycerine, all adding in the water-resistant polyesters. While melting, the water-soluble starch will combine with the insoluble plastic materials to create durable and waterproof bioplastic.
The process is so simple that it can even be DIY’d from the comfort of your own kitchen!
2. Aliphatic Polyesters
This category includes two of the most commonly-used bioplastics for packaging and medical device production: PHA and PLA.
PHA bioplastic is a type of bio-based polyester produced by microorganisms like microbes and algae. These polyesters are considerably more expensive to manufacture compared to starch-based bioplastics, as they require extensive lab work and engineering to create durable and flexible materials.
PLA bioplastics, on the other hand, rely on a less resource-intensive process that is quite similar to starch-based bioplastic manufacturing. They require natural sugars from starchy foods (like cassava, corn, and sugarcane) and citric acid to create the long-chain polymers that make up the base structure of plastics.
3. Cellulose-based bioplastics
Cellulose-based bioplastics make for the second most common type of bioplastics used today.
As the name suggests, these bioplastics are made from a blend of cellulose derivatives (like celluloid) and cellulose esters. These are all products derived from natural cellulose, the main substance of a plant cell wall.
The main resource needed to create these materials is heated softwood, cooked and modified to create a thermoplastic material that is durable and more water-resistant than starch-based alternatives.
While making for one of the most popular types of bioplastic, the process behind cellulose-based plastics is considerably resource-intensive and expensive, not to mention a lot less sustainable than crop-relying bioplastics.
4. Bio-derived polyethylene
Finally, we have bio-derived polyethylene. This is a type of bioplastic derived from the fermentation of raw natural materials such as corn and sugarcane.
If this name rings familiar, there’s a reason: Polyethylene (PE) is the most widely used plastic polymer, most commonly found in cartons and shopping bags. The material is anything but sustainable, and yet, it’s usually classified as bioplastic when produced from organic sources as opposed to fossil fuel.
While using corn and sugarcane instead of petroleum will make the production more sustainable, this type of bioplastic is actually non-compostable, only recyclable!
5 examples of bioplastic use
So, what is bioplastic used for today?
Different types of bioplastic will be more suited for different uses, as their durability, flexibility, and water resistance will change depending on their chemical features.
Here are some of the most common uses for bioplastics.
1. Disposable utensils, straws, and bottles
One of the most common uses for bioplastics is disposable utensils, including forks, knives, spoons, and straws.
You’re likely to find these alternatives to traditional single-use plastics at your local food fair or takeaway spot, and they are most likely to be made out of cost-efficient and durable starch-based bioplastic or PLA plastic.
These items are both biodegradable and compostable, making for a good alternative to some of our most used single-use plastics, known for overstaying their welcome upwards of 400 years!
2. Bin liners and shopping bags
Ever wondered what your compostable food bin liner is made out of?
Well, they’re likely made out of corn-based bioplastic. The degradable carrier bags you can buy online or get at your local supermarket will either be made out of PLA plastic or cellulose-based bioplastic.
Keep in mind that not all bioplastic carrier bags are compostable and suitable for biowaste. Make sure you always double-check with the manufacturer to learn how to dispose of them!
3. Disposable food packaging and containers
You can also find bioplastic lids and food containers made out of rice starch, corn starch, and cellulose-based bioplastic.
Aside from the cellulose variety, most bioplastic hard containers are made from PLA plastic, as it’s considered the most durable and clear.
In fact, the transparency of the plastic becomes an issue when dealing with food packaging, as consumers will want to see the same clarity as they’re used to with traditional plastic trays and containers.
4. Medical devices
While PLA is often the go-to bioplastic of choice for packaging and utensils, PHA is the preferred variety for making medical devices and applications, such as sutures, hernia repair devices, patches, and meshes.
Silicone and polyethylene glycol have long been the go-to materials for these life-saving devices, but PHA bioplastics are quickly becoming more popular as they’re both biocompatible and biodegradable options.
5. Permanent fixings
When asking what is bioplastic used for, most people will instinctively think of green carrier bags, yogurt pots and disposable forks, but rarely think beyond single-use applications.
So, you might be surprised to hear that bioplastics are now being used to replace traditional plastic in plumbing, architecture, electronics, and even 3D printing!
Different manufacturers have started to produce PLA pipes, engineered to be just as heat resistant as the traditional plastic used in different plumbing and heating devices. On top of that, bioplastics have also started to be used as building materials in construction, with PLA once again leading the charge as the most versatile and cost-efficient bioplastic.
As research continues, it seems like everything plastic can do, bioplastic can too — just more sustainably.
But are these new materials really the answer to our single-use plastic woes?
Can bioplastics help solve the single-use plastic problem?
From disposable items to electronic parts, bioplastics are revolutionising the way we eat, shop, and even heat our homes.
When compared to traditional plastic, all types of bioplastics come out on top as a more sustainable option. You can read all about if bioplastics are good for the environment here.
The main reason is that they cut out fossil fuels and rely on renewable sources, leading to dramatically lower GHG emissions.
However, experts are still very cautious when highlighting the pros of biodegradable and compostable plastics, as their drawbacks are just as noteworthy.
In fact, very few facilities are equipped to dispose of them properly, and the compostable sign you might find on your carrier bag might lull consumers into a false sense of security, leading to even more littering. There’s also the argument of using crops and food sources to manufacture bioplastics, plus the associated issue of land use.
As of now, it’s clear that bioplastics won’t solve the single-use plastic problem — but they’re definitely a start!