Do you know what one of the first plastics was? Would you guess that it was plant based? It was actually cellophane, a bio-based film. Cellophane got its name from Cellulose (the raw material) and diaphane (a word that had roots implying it was transparent). As you could guess, with a raw material of cellulose, cellophane is made from the same raw material as paper products, typically trees.
After being invented in 1908, cellophane dominated the packaging world for decades. It wasn’t until the 60’s, when polyethylene, a common fossil fuel based resin, was created. Sourcing from cheap resources like oil and natural gas made it hard for products like cellophane to compete with polyethylene.
Today polyethylene is still one of, if not the most, popular plastics. It’s used for a lot of plastic bags and bottles in some way, shape, or form. However, in a surprising turn of events, many plastic manufacturers are adopting bio-based plastics such as cellophane again. The negative association many people have with fossil fuel based plastic has been the driving force back to bio-based plastic.
The concern of working with fossil fuel based materials is understandable. Fossil fuels are a finite resource that won’t last forever. There are also a lot of concerns with the leaching of chemicals both during the processing of the plastic raw materials and in the end use when they are in direct contact with consumer products.
Bio-based plastic can be a good solution to a lot of these concerns. One of the most popular bio-based plastics today is PLA, or polylactic acid, which is typically derived from corn. Other Bio plastics are made from other starchy/sugary plants like sugar cane or potatoes. These sugars are eventually converted into the polymer chain that makes the finished plastic. This allows us to make plastic from things that can be regrown every year and thus are made from a renewable resource. This also means that as those crops grow, they process and convert CO2 that will be created later in the process, helping bring them closer to carbon neutral.
On top of this, when it comes time to disposal of a bio-based plastic, it can often be composted. This is really important when it comes to flexible packaging because it is currently really challenging in most places to dispose of plastic in an environmental way effectively since recycling has proven to be such a challenge. It’s important to note that this is not always the case and the compost-ability of bio-based plastic needs to be tested and validated on a case-by-case basis.
While this sounds great in theory, there are still shortcomings. One major concern is the amount of land required to grow the required crops to create enough raw materials. Growing crops specifically for bio-based plastic would require huge amounts of land that would likely encroach on wildlife habitats. One alternative that some companies have taken is to use only food scraps from places like potato processing facilities rather than growing crops directly for bio-based plastic. However, there are definitely not enough food scraps to create the plastic we need. Another important thing to consider is the crops used to grow the raw ingredients used for bio-based plastic take away from our ability to grow edible food. With so many people going hungry in our world, it’s critical that we do everything we can to make sure they are fed.
Additional aspects that a lot of people don’t consider when looking at the branding of bio-based plastic is their performance. Alone, it can be challenging for them to offer the appropriate barrier properties and protection to the food and other products they contain. The industry has found work-arounds to this by creating super thin coatings either from metals or fossil fuel based resins. Lastly, many of these bio-based resins are recyclable. The polymer chains simply can’t hold up to the reprocessing.
On top of all of this, bio-based plastics are expensive. They can be as much as 4X as expensive or more. This might not seem like a big deal when we think of how cheap plastic usually is, but you would be surprised how sensitive both customers and brand owners can be to this. Many customers, while claiming to be eco-conscience, often don’t want to pay anything extra. This means brand owners would be forced to absorb the cost if they want to make the change.
Despite all of this, I believe bio-based resins have a place in our plastic packaging. They might not be the silver bullet that we are looking for, but they certainly bring a lot of value. But what do you think? Do you think we should be switching to bio-based plastics? Or do you think there are better approaches? Let me know in the comments.