How Sustainable is 3D Printing?
Published on : Sunday 06-06-2021
Looking at 3D printing as a whole, one can conclude that 3D printing can be named as a sustainable process, says Sreeja Gadhiraju.
The Fourth Industrial Revolution (or Industry 4.0) is the ongoing automation of traditional manufacturing and industrial practices, using modern smart technology. Large-scale machine-to-machine communication (M2M) and the Internet of Things (IoT) are integrated for increased automation, improved communication and self-monitoring, and production of smart machines that can analyse and diagnose issues without the need for human intervention. In other words, the Fourth Industrial Revolution is a way of describing a common ground between the physical, digital, and biological worlds. It is a fusion of advances in artificial intelligence (AI), robotics, the Internet of Things (IoT), 3D printing, genetic engineering, quantum computing, and other technologies. Each of these technologies are very much in coexistence with one another apart from 3D printing. 3D printing or additive manufacturing is still being considered as it is at its infancy being the technology which is approximately 40 years old.
Additive manufacturing has emerged as a technology which is a tough competition for conventional manufacturing processes. The ability for mass customisation of products, less time to market and freedom for designers, are some of the features which makes 3D printing so special and a part of Industry 4.0. But can we rely on this technology forever? What is the impact of this technology on the environment? Is this technology sustainable? Most of the other parts of the fourth industrial revolution have proven to be sustainable in their own ways. Being the newest technology, is 3D printing sustainable and environment friendly? In comparison with the existing manufacturing technologies, where does AM stand? Let us dive deep into the details.
The primary stage of 3D printing is designing the object on the computer. As the design process is primarily conducted on computers, the resulting blueprints can be shared digitally, and parts printed nearby, onsite, or even in people’s homes. This decreases the need for the extensive transport required of conventional mass manufacturing, where not only the final products but the raw materials need shipping over long distances, reducing carbon dioxide emissions.
The manufacturing approach
Let us remember the definition of 3D printing again: ‘conversion of a digital model into a physical model by adding material in a layer-by-layer approach’. So unlike traditional manufacturing like cutting or milling in which the material is removed till we get the final product, we add material in a step-by-step approach in additive manufacturing. Thus, the material waste is very less in 3D printing compared to conventional manufacturing. The scrap waste in 3D printing is almost 70% less than CNC machining or injection moulding.
The reality today does not allow the 3D printing technology to be fully eco-friendly. Different researchers reveal that this technology uses large amounts of energy, larger than the amount used by milling and drilling machines. A research (Atkins Project) done at Loughborough University in the United Kingdom revealed that to produce the same object of the same weight, some 3D printing processes require 50 to 100 times more electrical energy than a typical injection moulding machine.
Another setback is the heavy reliance on plastic materials for the printing process. Plastic is not considered an eco-friendly material. Studies show that industrial grade 3D printers have a substantial plastic by-product left behind that in most cases is not suitable for reuse. Furthermore, a study led by Brent Stephens reveals that the second-hand printing fumes emitted when the plastic material is heated to high temperatures, hold toxic by-products. Although the emissions levels were found somewhat normal – close to those of cooking indoors (Source: Ultrafine particle emissions from desktop 3D printers on ScienceDirect), the research demonstrates the need for further investigation.
However, observing the 3D printing eco-friendly status in comparison to all other manufacturing processes, especially mass production, demonstrates the fact that the technology has far less of an impact on our environment in comparison to traditional manufacturing. Moreover, when we consider the entire product life cycle – extracting raw materials, assembly, refining, manufacturing, assembly, use, maintenance, and end of the product's life – 3D printers demonstrate considerable advantage over traditional machines in terms of carbon footprint. In manufacturing, 3D printers generate less waste by using a little more than the amount of material necessary for the product, eliminating completely the process of drilling, cutting, and milling. Another advantage of 3D printers is gained by reducing the refining and assembly stage and removing the storing necessity of the products before and during their sale which in terms of traditional manufacturing contributes to the overuse of resources.
Nevertheless, as of today all manufacturing in its initial stage (extracting raw materials) and the disposal stage, involve heavy environmental pollution. Many damaging effects are caused by the methods used to extract the raw materials and a large amount of energy is consumed in merely obtaining them raw materials.
According to many researchers, progressively more dangerous extraction methods are used to retrieve scarce oil resources to produce plastic material so widely used today. Transportation, refining and manufacturing of products require additional energy, raw material waste and dumping toxic waste from the processes themselves into the air, earth, and water. One the most evident and harmful consequences occurs at the completion of the life cycle when the products are discarded.
3D printing is striving to respond and correct all those problems inherent in a product's life cycle. As mentioned previously, the technology is all about its unlimited potential, the potential in this technology allows us to say that 3D printing will continue developing and improving its continuous development and improvement in every aspect, especially in terms of being 3D printing eco-friendly.
Is 3D printing sustainable?
Looking at 3D printing as a whole which includes Pre-processing, Production, Post-processing and Distribution, we can conclude that 3D printing can be named as a sustainable process according to the 3R approach for sustainability: Reduce, Reuse and Recycle. The material waste is reduced, the material which is left during the production can be reused and most of the plastics which are being produced through additive manufacturing can be recycled similar to the plastic waste in conventional manufacturing.
Will 3D printing replace conventional manufacturing as it is sustainable?
Well, definitely not. But it is undeniably possible that the future of manufacturing is a blend of both conventional and additive manufacturing. At least it is not hard for me to imagine a manufacturing plant in which a CNC machine is making surgical knives on one and an SLM machine is making implants on the other. The future is definitely unpredictable. I cannot wait for the day when digital factories which have organ 3D printers managed by artificial intelligence connected together as one entity are going to come to life and become a part of it. Well, imagination can think beyond boundaries, isn’t it?
Sreeja Gadhiraju is a young engineer pursuing Masters in Mechatronics in Germany. A former team lead in Amazon, for Sreeja the craving to know and study latest technologies is an addiction. Presently studying Robotics, Modelling and Simulation, Cyber Physical Systems, etc., she has fallen in love with additive manufacturing. “There is so much to know, there are so many things which can do using this amazing technology. I want to finish my masters and proceed further towards PhD in Additive Manufacturing,” says Sreeja.