We live in a world that demands affordable products on a rapid timeline. We are also increasingly seeing more demand for sustainably produced products. It is difficult to reconcile these two seemingly contradictory requirements. However, additive processes such as 3D printing are offering up resource-saving solutions that are changing the game. Here are some of the ways 3D printing can help make production more sustainable.

Use only the manufacturing material that you need

By nature, additive manufacturing tends to be less wasteful than subtractive processes such as CNC machining. The 3D printing process begins with essentially nothing and successively adds layers of material until the part is complete, whereas CNC machining starts with an amount of a material and subtracts layers until only the part is left. The latter can lead to a significant amount of material being wasted. Of course, there is still some wasted material in 3D printing, namely failed parts and support material that may need to be generated for a part to properly form. However, with proper production management both of these issues can be limited. 

3D printing is also beginning to compete with other traditional manufacturing processes such as injection molding. Injection molding is highly efficient, with little to no waste, and allows for the rapid production of parts at a low unit price, however the start-up costs can be significant. There can be advantages compared to 3D printing in terms of sustainability, but oftentimes mass production can lead to excess inventory. Companies may place bulk orders to lower their unit costs and/or to try to lower the risk of a shortage down the line (lead times for injection molded parts can be long and unpredictable). The make-to-order strategy employed by 3D printing companies may offer cost and resource savings by avoiding over-production of parts.

3D printing is an agile production method that can be quickly stopped or restarted if a design edit is needed; therefore, limiting wasted parts and materials. The part validation process is streamlined because all designs edits are done digitally, unlike other manufacturing processes where you may need to create a whole new mold. 3D printing companies also tend to operate on a smaller scale and locally, making communication easier and more efficient than having to work with an overseas organization. This means production runs can be stopped and restarted with an updated design very quickly. This usually is a simple process and does not incur significant costs so long as the design remains printable and the printing process and material don’t change.

Efficiently design parts to streamline production

3D printing has made it possible to design and manufacture whole components where in the past you’d have to create individual parts and assemble them to create the full component. This is due to the ability to print geometries that aren’t replicable in most other traditional manufacturing processes. An example of this is an antenna used in the aerospace industry that was able to be designed and 3D printed in one whole piece where it was previously manufactured in 100 discrete parts. This efficient design of parts cuts down on not only the time needed to create something but also the excessive use of parts needed for assembly. 

The digital design process can also help optimize the amount of time and material needed to print a part. CAD software can be used to hollow parts to make them lighter weight without compromising integrity. The amount of excess support material needed for the part to form properly can also be adjusted so that less material is wasted. 

Product and industrial design professionals are already utilizing digital models to produce 3D printed prototypes and parts - other industries could be benefiting as well. Many architecture, engineering and construction firms are already incorporating digital technology such as BIM and digital twins into their work and thereby creating 3D files. These files can be used to print scaled models of terrain, buildings, and interiors. Printing a physical model prior to construction can help stakeholders align on expectations and reduce the likelihood of expensive and wasteful rebuilds. 

Reduce emissions and energy use

The current manufacturing economy relies heavily on parts being produced in low-wage countries such as China. This helps keep the cost of producing goods low, but also perpetuates a reliance on questionable workplace practices. Parts also need to be transported over long distances which contributes to excess emissions and energy use, and can make lead times unreliable and long. Today, most metropolitan areas have at least one 3D printing company within or nearby. That means that producers of 3D printable parts could be relying on local businesses for manufacturing. Locally sourced parts may not be the most economical in terms of unit price, but there can be savings on transportation costs and value from access to more reliable production. 

Printed parts also tend to be lighter than their traditionally manufactured counterparts. When used in things such as cars, airplanes, and other machines that rely on fuel to operate it can make them lighter and therefore more fuel efficient. 3D printers themselves can also use less energy than traditional manufacturing equipment.

Availability of eco-friendly and optimized materials

There are thousands of 3D printable materials available for use today. Many of which are biodegradable, recycled, recyclable, and/or organic. Here is a small selection of eco-friendly materials:

• PLA - Polylactic acid (PLA) is a corn-based plastic that is durable enough to be used for simple prototyping and can maintain its shape and look for years if kept in the right environment. PLA does not hold up well against extreme temperatures, prolonged sun exposure, or humid/wet conditions. The reason it cannot withstand those conditions is because it’s biodegradable. This makes the material ideal for those who want to create parts, but don’t need them to last for an extended period of time. 

  PLA is not easily degraded in “normal” conditions, such as a garden composter or landfills because it requires high levels of humidity, temperatures above 60 °C , and specific microorganisms to begin breaking down. A specialized composting facility is recommended for those who want their PLA parts properly decomposed. 

• Ocean plastics - There is no shortage of plastic waste on earth. New ways of recycling it are constantly being developed and improved upon. One of the latest ways of recycling plastic waste is to turn it into 3D printing filament. The process typically involves grinding up large quantities of similar materials (plastic bottle caps, for instance) into small shards, melting them down, and extruding them into lines of filament. The filament can then be used to print new parts on an FFF/FDM printer.

• Ceramics - Materials such as clay are becoming more popular in 3D printing due not only to their look and functionality, but also their sustainable properties. Because they are directly sourced from the earth and typically do not contain chemical additives there is no risk of toxins leaking from the parts. They can also be easily broken down and reintroduced into the environment.

  One example of how sustainable efforts are incorporating ceramic 3D printing into their strategy is coral reef restoration. Labs are 3D printing and deploying artificial reefs that act as starter systems in regions where natural reefs have been depleted. Ceramic is an ideal option for this due to its porous texture and neutral impact on the existing ecosystem.  

• Reusable powders - Even printing processes that use less eco-friendly materials such as nylon and metal powders are continually looking for ways to be less wasteful. Currently, these machines are able to reuse up to 70% of the material that is not fused during printing. This significantly reduces the amount of new material that needs to be used during each print.