How Sustainable is 3D Printing?


As a manufacturing process, 3D printing has attracted significant attention due to its potential to reduce waste, use less energy, lower costs, and potentially enable the creation of more sustainable products. In the following article, Efrat Friedland, the founder of materialscout and co-founder of Positive Plastics, explores the various ways in which 3D printing is sustainable, how the technology is viewed by designers, and how it can become a game-changing technology in the world of manufacturing.

Know your printer

Before diving into the sustainable reasoning behind additive manufacturing, it is important to understand the various different technologies that fall under the umbrella of 3D printing and additive manufacturing, each of which with its own unique approach to creating objects. Some of the most common 3D printing technologies are the following:

•  Fused Deposition Modelling (FDM): one of the most widely used technologies. It works by melting a thermoplastic material and extruding it through a nozzle to create a 3D object.
• Stereolithography (SLA): this involves using a laser to cure a liquid resin into a solid object. The resin is cured layer by layer, and the object is built from the bottom upwards.
• Digital Light Processing (DLP): similar to SLA, but instead of using a laser, it uses a projector to cure the liquid resin.
• Selective Laser Sintering (SLS): using a laser to selectively fuse powdered material. The unfused powder supports the object during printing.
• Binder Jetting: spraying a binder material onto a powdered material to bind the particles together and form a solid object.
• Material Jetting: using printheads to deposit droplets of liquid material onto a build platform to create an object. This process is known for enabling the creation of objects that combine several materials and colours.
• Direct Energy Deposition (DED): using a high-energy heat source, such as a laser or electron beam, to melt and fuse powdered or wire material onto a substrate
• Direct Energy Deposition (DED): using a high-energy heat source, such as a laser or electron beam, to melt and fuse powdered or wire material onto a substrate

Each technology has its own advantages and limitations, so the choice of technology should take into account the desired outcome, the material to be used, and the specific requirements of the application.

Why sustainable?

Over the past few decades, alarm about the impact of human activities on the environment has steadily risen. One major area of concern is that of manufacturing. Manufacturing activities are known to consume significant quantities of natural resources and the vast amount of waste tey produce. With the advent of 3D printing, a viable solution to these environmental problems has emerged. While the technology has been around since the 1980s, it has only recently become widely available and affordable. As for its potential applications, these range from aerospace engineering to medical implants to consumer products.
So, what makes 3D printing sustainable? There are several key factors to consider:

Reduced waste
A significant advantage of 3D printing is that it produces less waste than traditional manufacturing processes. Conventional, substrative processes involve cutting, drilling, and shaping raw materials to create the desired product. This often generates a significant amount of waste, as much of the raw material is simply discarded during the process. In contrast, 3D printing, because of its additive nature, only uses the amount of material that is needed to create the product. The printing process is precise and efficient, ensuring that very little, if any, material is wasted. 3D printing is said to produce between 70% and 90% less production scrap compared to some traditional manufacturing methods.

Reduced water and energy usage
Conventional manufacturing methods often require large amounts of water for cooling and cleaning processes, and consume huge amounts of energy to produce, transport, and assemble products. In contrast, 3D printing typically does not require any water usage and it uses significantly less energy as it only requires the energy needed to heat the printing material and operate the printer - thus further reducing the environmental impact of manufacturing.

Localised production
Shipping raw materials and finished products across long distances tend to be energy intensive and high-emission activities. 3D printing allows products to be created on site, eliminating the need for transportation and reducing the carbon footprint of these products. This is particularly beneficial for small-scale production, as it allows businesses to produce goods locally and on-demand.

Customisation and Personalisation
Creating a large number of identical products, even if there is no demand for them, is common practice. This can lead to excess inventory and waste, as well as higher energy consumption and carbon emissions. Using 3D printing allows for the creation of unique, customised products that are tailored to individual preferences, creating no excess inventory or waste. In addition, the ability to create replacement parts for existing products through 3D printing extends the lifespan of products, reducing the need for new purchases and further contributing to sustainability.

Recycling and repurposing
Finally, 3D printing is sustainable because it enables the recycling and repurposing of materials. Many 3D printers can use recycled plastic or metal, materials, which reduces the need for virgin materials and minimises the environmental impact.

Additionally, due to the ability to print very complex geometries, designers can create parts that require no screws or adhesives and that are designed to be disassembled and recycled at the end of their useful life.

The right material
As a materials strategist, my first focus is always on choosing the right material, as this is key to achieving a successful product. Obviously, if the printed object is a concept sketch or a prototype, it rarely matters. However, for serial production and commercial products, it is crucial to first carefully select the material, immediately followed by determining the printing technology to be used.

Among the materials for 3D printing that are considered sustainable are those that have already been recycled, are renewably sourced or biodegradable. Here are some examples:

• PLA (Polylactic Acid): is a bio-based plastic derived from natural resources such as cornstarch or sugarcane. Certain grades are biodegradable.  It is one of the most popular materials for 3D printing because it is easy to print and produces high-quality prints. Among the many providers of this material are 3D-Fuel, ColorFabb, Filamentive, and Proto-pasta.
• Hemp-based filaments: these are made from hemp fibres mixed with a binding agent. Hemp is a fast-growing plant that requires less water and fewer pesticides than other crops, making it an eco-friendly option. Companies that produce hemp-based filaments include 3D-Fuel, Advanced BioCarbon 3D, and Extrudr.
• Recycled filaments: these are made from recycled plastic materials, such as PET bottles, ocean plastics or waste from other manufacturing processes. Recycled filaments are an eco-friendly option, as their use reduces waste, keeps valuable resources from ending up in landfills,  and promotes a circular economy. Companies like Filamentive, RePLAy 3D, and Proto-pasta produce recycled filaments
• Wood-based filaments: are made from recycled wood particles mixed with a binding agent. They can be biodegradable and create a natural-looking finish. Such filaments are supplied by 3D-Fuel, ColorFabb, Formfutura, and Proto-pasta.
• Bio-based powders: made from partially or 100% plant based raw materials. One company supplying various grades is Arkema, including 100% bio-based produced from castor oil.

An important note in this regard: the use of compostable filaments is not a licence to litter. In all cases, appropriate end-of-life disposal routes must be established, even if a product comes with degradable properties. In that case, proper disposal  - in the organic waste stream - should be ensured.

A playground for designers
The potential for 3D printing to disrupt the way in which a product is designed, developed and manufactured is huge. Additive technologies require designers to completely rethink their design approaches and open up new ways of overcoming typical design constraints. 3D printing allows designers  to focus on geometries that are hard or impossible to otherwise manufacture, enable the individualisation of products, design spare parts, and more.

An example such rethinking is intelligent application conceived by EOS, a platform called “Digital Foam”. They develop and produce 3D-printed foams for applications like helmets and soles. These can replicate and outperform most conventional foams and be tailored to specific needs.

Dirk van der Kooij uses discarded refrigerators to harness the plastic parts and turn them into furniture. His Chubby chair is printed from 10kg of chipped, recycled fridge interiors. Or the new Ecoalf store in Las Rozas, Spain, designed by Nagami to replicate the look of a melting glacier that has been completely printed from 100% recycled plastic. The walls, shelves and display tables are made from 3.3 tonnes of recycled plastic. The entire space is recyclable at the end of its lifecycle.

Many designers have already taken their first steps in the field of 3D printing. A studio that has been tango-dancing with it for over a decade, is WertelOberfell in Munich. One of their first commercial 3D printed products was the Fractal Table they exhibited at the 2008 Salone del Mobile in Milan, produced by Materialise. The designers were fascinated by the object’s grown and organic nature in parallel to its structured and mathematical quality. Both in terms of size and complexity, this product, which is produced as a single piece SLA in epoxy resin, pushes the manufacturing process to its limits.

Smaller products that can be printed in larger series have also been developed by the studio overthe years. One example is a decorative element for a LUMIX camera housing. The designers’ aim was to push the boundaries of how thin and minuscule (partly around 0.5mm) it is possible to go with 3D printing without jeopardising strength and durability. By using real metals like copper and nickel, they also added value.
Or take the Razor Maker by Gillette , an initiative to make 3D printed products available to the broader public. The handles fit standard Gillette heads, they can be customised and ordered online, are very durable and able to withstand daily use.
And while I am familiar with almost all printing materials on the market and have mastered the technology, what I also found interesting during my visit to the studio was the open-source approach they were discussing. Using 3D printers with a treadmill, it is possible to hack the printer’s software to create flexibility in the hardware itself. Apparently, there are huge online communities, especially in China, that provide tips and tricks on how to tweak the printer to extend its printing possibilities.
That, in itself, contributes greatly to a sustainable approach. After all, compared to the amount of effort needed to accommodate changes within an injection moulding process the savings in time, effort and energy are enormous:  here, changes are only a few mouse clicks away.

Show me your footprint
All in all, 3D printing has the potential to reduce the carbon footprint of manufacturing by reducing both the amount of waste generated and the energy used, thus enabling more efficient production processes.
As we saw, choosing a more sustainable material also counts in the overall environmental impact, as does the post-processing and disposal options of 3D printed objects. Choosing energy-efficient printers and renewable energy sources, as well as printing for local production can definitely benefit the final calculation.

Will 3D printing change the game?
Clearly, this is the million-dollar’s question and I wish I had a crystal ball. There are so many dependencies and various scenarios, it is hard to give clear answer. In an ideal world, where an emergent circular economy is flourishing, 3D printing will, too. When mass-production and consumerism tune down, when the common understanding of aesthetics accommodates less-than-perfect finishes in parallel to the advancement of the printing surface technologies, when production becomes local and knowledge of manufacturing and repair is open-source and common to all. Then, we are talking about a new game, where 3D printing can be a key player.