At Vesta Smart Packaging, we strive to significantly reduce plastic pollution and, by extension, carbon emissions used in the life cycle of one of our containers, or Vestas. It is also important that our containers be recyclable and preferable that they be made from recycled, recyclable and sustainable materials. However, choosing the materials for our refillable and reusable containers has been a more complex exercise than we had first envisioned. On first glance, bioplastics seemed to be the answers to our problems because it is a plastic derived from renewable biomass sources, such as vegetable fats, vegetable oils, corn starch, or microbiota (https://en.wikipedia.org/wiki/Bioplastic).
With a current-life of 2 years, our Vestas already show that we can reduce the number of plastic bottles containers over 2 years per product by at least 23. They can be reused after the 2 year period if the plastic container has not sustained too much damage, as we can simply steam clean them, replace their batteries and re-deploy them. However, not all of them will be re-usable and at some point, all of our Vestas will need to be recycled.
Bearing this in mind, we decided to investigate using bio-plastics as the building material for our product. The main considerations for us when choosing a material were:
- Strength
- Recyclability
- Bio-degradability
- Carbon Footprint
1. Strength
Bioplastics are generally not as strong as regular plastics. Currently, the only known way to increase their strength is to mix them with regular plastics – which we would need as it is intended to be used multiple times over a 2 year period. Though this might be better than pure plastic, it can also reduce the recyclability of the plastic and how bio-degradable it is, whilst increasing the cost. These are also important factors in choosing the correct material for our containers. There is currently research being conducted into including cellulose fibres or particles in bio-plastics to increase its strength, which will be watching closely. (see http://pubs.acs.org/doi/abs/10.1021/bm050897y)
2. Recyclability
Recyclability varies considerably with bioplastics. However, those bioplastics that are recyclable cannot be recycled with regular plastics. They require a new stream of recycling, which most recycling plants do not have. A method would have to be developed to separate bio-plastics from regular plastics to make bioplastic recycling on a large scale viable. There is also some concern that bioplastics would contaminate normal plastic recycling (https://waste-management-world.com/a/napcor-concerned-over-pla-contamination-of-pet-stream), increasing the cost and decreasing the effectiveness of plastics recycling. So in short, while many bioplastics are theoretically recyclable, very few places are equipped to process them.
3. Bio-degradability
If a bottle cannot be recycled, it is important that it is bio-degradable. Being made from bio-plastics does not automatically make a bottle recyclable or biodegradable, it just means that the plastic has come biological sources rather than fossil fuels. For example, CocaCola’s PlantBottle, which is made from bio-plastics cannot be composted and does not bio-degrade because it has the same chemical structure as a plastic made from oil (https://www.alternet.org/story/151543/compostable_or_recyclable_why_bioplastics_are_causing_an_environmental_headache). The more bio-degradable a plastic is, the weaker it tends to be. This means they might be more suited for plastic packaging of items such as fruit, or potato chips and don’t lend themselves to tough, robust packaging like that produced by Vesta Smart Packaging. The bio-degradability of many of these bioplastics is also questionable. Many require special high-temperature composting plants and won’t biodegrade in a domestic compost heap.
4. Carbon Footprint
David Grewell of Iowa State University (http://dgrewell.public.iastate.edu/research/bioplastics/cost_comparison.html) has conducted some research on the life-cycles of bio-plastics and has found that many types of bioplastic have a higher carbon footprint throughout their life than regular plastic bottles. See the video below for a more detailed analysis of this problem
Having considered these factors, we believe that bioplastic technology is not ready to be deployed for Vesta Smart Packaging….YET. However, we believe that as the technology is developed and problems are solved we will be able to move to bioplastics. The technology is constantly being researched and in time we believe that bioplastics will become stronger, more recyclable and more bio-degradable. Bioplastics are the future, but that future is not quite with us.
Useful Sources
https://earth911.com/eco-tech/recycling-mystery-bioplastic/
http://www.explainthatstuff.com/bioplastics.html
http://green-plastics.net/posts/74/qaa-starch-plastic-tensile-strength/
https://www.alternet.org/story/151543/compostable_or_recyclable_why_bioplastics_are_causing_an_environmental_headache
https://www.theguardian.com/environment/2016/may/23/biodegradable-plastic-false-solution-for-ocean-waste-problem
http://dgrewell.public.iastate.edu/research/bioplastics/cost_comparison.html