Over the past two years, one environmental issue has increasingly stolen the limelight: Plastic pollution. Our dependence on plastic - especially single-use plastics - is now one of the leading global environmental concerns. Recent studies have found plastic particles in our fish, uninhabited islands drowned in plastic waste, and even plastic bags at the bottom of the Mariana Trench. 3D printing utilizes the versatile, durable nature of plastics in a wide range of applications from aerospace to healthcare; but does it come at a cost to the planet?
The 3D Printing Process
At first glance, 3D printing seems like a far more environmentally friendly manufacturing technique than typical subtractive methods. Rather than sculpting from one block of raw material, producing offcuts and waste, 3D printers use only the amount of material they need by building objects layer by layer. However, it is the accessibility of 3D technologies which is a leading concern where plastic pollution is concerned. Since the first commercially available machines in the late 2000s, 3D printing has opened up limitless possibilities for on-demand manufacturing. The rapid prototyping capability of 3D printers means that manufacturers can produce in-house, lowering turnaround times and saving money; but there are concerns that this could lead to an overall increase in the number of disposable products on the market.
Typical Printing Materials
3D printers come in many different forms: some now capable of printing with steel and other metals, but the most common materials are various types of plastic. Polyethylene terephthalate (PET) is one of the most popular filaments, and is more famously used in plastics such as disposable drinks bottles and food packaging. Other filaments include Polycarbonate and ABS: both are relatively cheap, versatile and quick to produce. Unfortunately, these materials are not widely recyclable and thus any waste produced in the printing process will find its way to landfill or into the natural environment. What’s more, 3D printers have become increasingly available for use at home or in smaller businesses, and so the demand for cheap materials continues to rise.
In recent years the rise of plant-based alternatives to traditional plastics has been significant. Polylactic acid (PLA) is a popular material for “eco-friendly” disposables such as straws, cutlery and coffee lids – and it is now a popular option for 3D printers. Although biodegradable, PLA can still withstand high manufacturing temperatures, up to 230 °C, and comes in a variety of colors. At first glance, plant-based materials may seem like an excellent option to combat disposable plastic pollution within the 3D printing industry; however they are not quite the wonder material that they are presented to be. PLA plastics can still take hundreds of years to break down as they require specific cocktails of temperature, oxygen and chemical substrate to actually decompose. This, unfortunately, renders them more often than not as eco-friendly as their oil-based counterparts; unless they are disposed of in specially designed commercial composting facilities.
A Circular Economy for 3D Printing
With plastic pollution so heavily in the spotlight, many start-ups have jumped at the opportunity to create a more circular economy within the realms of 3D printing. They are capable of turning plastic waste such as old yoghurt pots, laser printer cartridges and even ski boots into recycled filaments for use in printers. In the current climate, however, virgin plastics are generally still cheaper to produce than those from recycled plastic waste. More investment into recycled printing technologies is needed to make it a financially viable alternative for large scale manufacturers. Whilst critics maintain that we need to turn away from disposables altogether, introducing a circular element to the 3D printing process is surely a good first step towards a more sustainable future.
- Unlocking value for a circular economy through 3D printing: A research agenda, M. Despeissem M. Baumers et al, 2017 https://www.sciencedirect.com/science/article/pii/S0040162516303341
- Products that go round: exploring product life extension through design .Conny Bakker, Feng Wang et al, 2014 https://www.sciencedirect.com/science/article/pii/S0959652614000419?via%3Dihub
- Polymer Recycling and Additive Manufacturing in an Open Source context: Optimization of processes and methods, Fabio Cruz, Silvia Lanza, 2015 http://sffsymposium.engr.utexas.edu/sites/default/files/2015/2015-127-Cruz.pdf
- Circular Economy, 3D Printing, and the Biosphere Rules, Gregory Unruh 2018 https://journals.sagepub.com/doi/full/10.1177/0008125618759684
- Plastic pollution facts, https://www.plasticfreeme.org/
- Human footprint in the abyss: 30 year records of deep-sea plastic debris, Sanae Chiba, Hideaki Saito 2018 https://www.sciencedirect.com/science/article/pii/S0308597X17305195