Updated: Mar 29, 2020
One of the great issues facing the world today, and one which is thankfully gaining traction amongst public attention is the damage that plastics are doing to our ecosystems and general environment. The many readily available videos of turtles or like getting caught up in plastic bags or ‘six-pack’ beer rings is a sad representation of the wastefulness and lack of respect that has crept into our society. This throwaway plastic issue is being tackled, finally. How can the Manufacturing Industry follow suit?
Conventional Manufacturing methods by their nature are wasteful. I want to specifically focus on Machining- a ‘Subtractive’ Technology. Subtractive Manufacturing means that you start with a volume of material (often referred to as a billet) which is greater in volume than the part you ultimately want to produce.
The diagram above shows how the biproduct of producing the finished component is a mass of waste material. Even in the best-case scenario- one where the company has an effective recycling strategy, the process required to produce more material from this waste would increase the environmental footprint, and so the vicious circle starts. Often, companies may not even have the time or resources to implement or maintain a recycling strategy. I have seen and heard of many cases where two different types of plastics are machined consecutively, and with no way to separate the waste, recycling no longer becomes a possibility. Incinerator or Land Fill it is.
This is where Additive Manufacturing (3D Printing) is a marked improvement. With ‘Additive’ technology there is a very small amount of waste material. Instead, only the volume of material that comprises the final part is utilised.
The schematic above shows a small amount of waste material accompanying the final product. This would usually be due to Support material used to aid construction of 3D Printed parts. However, the mass of this waste material would in no way be comparable to the considerably larger amount required to machine this item.
As well as the amount of waste material produced, there is another significant advantage that 3D Printing has over Machining in terms of their respective environmental impacts. This is based around their design flexibility- specifically ‘Infill’. Rewinding back to Secondary School Physics- in order to determine the mass of an object you would multiply its volume and density together.
As an example, let’s take the following cube that is going to be both machined and 3D Printed:
Producing this part through Machining, the Mass is very simple to work out. 1000 multiplied by the Density. The Density remains unchanged between Machining and 3D Printing. However, the Volume of the 3D printed cube can be reduced through ‘Infill’ design (something that cannot be done with the machined cube).
Because Additive 3D printing is produced by building up layers of material, designers have the chance to change the infill of the part, as seen above. Less Infill means less volume, which means less mass, which means less material, which means less environmental impact. Machining simply does not have this possibility.
Therefore, as the prominence of 3D Printing continues to rise, not only will it give companies the design freedom to produce complex shapes, it will also have the significant added benefit of steadily reducing the environmental impact and wastefulness that plague conventional manufacturing avenues.
Pietro La Torre
DIM3NSION 3D Printing