Project Butterfly: Sustainability improvements for 3D printing processes

Challenge

To demonstrate the use of AMRC’s process sustainability calculator – developed as part of Project Butterfly – by evaluating two 3D printing processes to assess the opportunity for improvements in sustainability and rank their priority.

Background

The University of Sheffield Advanced Manufacturing Research Centre (AMRC) has collaborated with an industry-led consortium of partners to deliver Project Butterfly - a direct response to the urgent need to decarbonise the manufacturing industry.

The research project drives forward the innovation of digital technologies at the heart of manufacturing processes – with an aim of reducing any environmental impact and accelerating the industry’s journey to net zero. The project explores scalable digital solutions for factory processes to lower CO2 emissions by reducing material consumption and energy use.

Funded by Innovate UK under the Made Smarter innovation challenge, the project consortium comprises a wide array of partners, including the AMRC, BAE Systems, Leonardo, Nissan, Accenture, Intellium, GKN Aerospace, Moy Park and University of Lincoln, UK. The consortium represents a cross-sector interest in developing solutions for decarbonising industry and manufacturing, bringing together research, innovation, demonstration and growth.

As part of the project, the AMRC, a member of the High Value Manufacturing (HVM) Catapult network of research centres, is equipping manufacturers with innovative digital tools to assess and improve process sustainability with ease.

The two chosen 3D printing processes – Fused Deposition Modelling (FDM) and Stereolithography (SLA) – are frequently used in the AMRC to print prototypes and complex parts used in projects. The same part was chosen to print on the two 3D printers and collect data from the full process, including post processing.

Innovation

Both selected processes, FDM and SLA, were mapped out with the start and end of the processes being defined. The resources used as part of the processes were identified and for each resource that was measured, a value for the CO2 equivalent (CO2e) was retrieved from an existing database. This allowed for the environmental impact of gathering, processing, manufacturing and using a particular resource to be equated to an amount of CO2 in kilograms, enabling it to be compared with one another using a common unit.

Data was collected from a singular job for both selected processes on each machine using the AMRC’s Factory+ framework and with the help of machine operators. In addition, operators of all of the machines completed a questionnaire on the ability for both processes to be changed and/or adapted.

Process and resource efficiency were calculated using historical data. This, combined with the changeability scores and the data collected for individual processes, was entered into the process sustainability calculator to ascertain a priority score for both processes, which were then analysed to recognise opportunity to improve process sustainability.

Result

It was seen from the results of the prioritisation calculator that overall, process two (SLA) scored a higher priority and hence offered the greatest opportunity for improvements in sustainability. This higher score was significantly influenced by the process efficiency and CO2e scores for process two.

For this case study, process efficiency was calculated by analysing the number of failed prints for the month of February 2024. The SLA process had a much higher tendency for the build failing, hence giving it a lower efficiency score and presenting an area where this process can improve. With regards to CO2e, it was discovered that nitrile gloves and IPA wipes were much larger contributors in comparison to model/support material and energy usage, resulting in process two receiving a higher score.

Overall, process one (FDM) scored higher in terms of both process and resource changeability but both processes were reasonably similar in terms of their ability to change meaning this did not have a big sway on the final scores.

It was considered that some of the priority scores may have been exaggerated, as there were only two processes to compare, hence providing less context for calculating the priority scores.

Impact

The process sustainability calculator developed by the AMRC enables manufacturing organisations to identify high-carbon intensity processes qualitatively. The tool helps manufacturers compare several processes (up to five) with the associated resources to identify areas of focus to improve process CO2 equivalent (carbon dioxide equivalent) emissions and prioritise decarbonisation efforts, based on existing sources of data.

The tool can also fill the gap between carbon accounting and life cycle analysis, and will encourage questions about how processes are set up and what can be done to make them more efficient in the short and long-run. It also accounts for the changeability factor, and taking into consideration the ease or difficulty of changing a process, leading to the identification of quick wins in industrial decarbonisation.