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Additive manufacturing: how repairing molds using 3D printing minimizes environmental impact

23 March 2021
Article by Joana Gouveia, INEGI's researcher in the area of Product Development.


Additive manufacturing has been breaking conventions and revolutionizing the manufacturing universe thanks to its low cost, flexibility in the materials used, and the speed of printing parts - regardless of the variation in geometry complexity or the necessary customization.

Also known as 3D printing, this disruptive technology allows for essentially waste-free production with energy savings per piece. It has the potential to reduce the consumption of resources during the manufacturing process and increase productivity, being a possible answer to the "Manufacture-Zero defects" challenge, to which the TOOLING4G - Advanced Tools for Smart Manufacturing project intends to answer with INEGI's help.

Adding value to products and processes by reducing consumables and obtaining gains in terms of energy is a strategy increasingly in the sights of companies. That is why INEGI, as part of the work on developing additive and hybrid equipment and manufacturing processes, also assesses technologies from the point of view of environmental impact.

By increasing the life cycle, the environmental footprint is reduced

To demonstrate the technological potential of additive manufacturing of metals, the Institute and the partners of this project focused their attention on the application in the repair of damaged molds. They concluded that, with 3D printing, it is possible to rehabilitate these molds, increasing their useful life and reducing their environmental footprint. This avoids the consumption of resources to produce a new mold, at the same time that the possibility of a new area of ​​activity within companies in the sector is born.

To make this scenario a reality, DED (Directed Energy Deposition) technology is used, which consists of the fusion and deposition of metallic powders through the energy provided by a high power laser beam.

This innovative hybrid system (since it allows for the addition and subtraction of material) was developed by INEGI, which operated the first DED laboratory station in Portugal. The technology allows high rates of material deposition of parts with dimensions up to 2000 mm per 1000 mm, and includes post-processing for finishing (subtractively) and dimensional control, with a high degree of precision and quality.

In parallel with the operationalization, within the scope of the TOOLING4G project, we seek to determine the environmental performance of this technology, in order to identify potential points for improvement and optimize its performance.

With this objective, a study was carried out to quantify the environmental impact of the production of metal parts by additive manufacturing, through Life Cycle Assessment (LCA). The case study analyzed is a stainless steel insert, produced in a conventional way, which during its use suffers a break or defect.

The LCA study focused on the processes that occur when the insert arrives damaged in the hybrid manufacturing process, that is, in the cutting, additive manufacturing with DED technology, and machining finishing. The business as usual scenario of conventional manufacture of a new insert through milling was also analyzed for comparison purposes.

Environmental impact of hybrid manufacturing is lower when used with large components

The study concluded that the hybrid process has more impacts than the conventional process, however, from a mass of around 148 grams, the hybrid manufacturing process becomes the most environmentally friendly option.

In other words, the repair scenario has a high potential to improve the environmental performance of the analyzed wedge. Extrapolating to other cases, with larger parts that need to be repaired, hybrid manufacturing technology has the potential to not only reduce the impacts generated by the manufacture and replacement of these parts, but also reduce costs and waiting time in the replacement of the part.

Through this analysis, the potential for improving the environmental performance of processes arising in the mold industry is evident through the use of hybrid manufacturing technologies.

Although this analysis focuses on a small part and the repair takes place under laboratory conditions, the difference between scenarios was minimal. As the geometrical specifications of the part become more complex, additive manufacturing technology becomes more advantageous, improving environmental performance and reducing processing time compared to conventional production technologies.

Thus, by enabling the reduction of maintenance time and associated costs, this technology allows to increase the availability and responsiveness of the system where the component is inserted.

With the results obtained, it can be seen that hybrid manufacturing technology is an innovation-enhancing tool for the development of a more economical, competitive, circular and sustainable industrial ecosystem.

This work was created in the scope of the Project Mobilizador TOOLING4G. Project No. POCI-01-0247-FEDER-024516 financed by the Operational Program Competitiveness and Internationalization and the Regional Operational Program of Lisbon, PORTUGAL 2020, through the European Regional Development Fund (ERDF).






A version of this article was originally published in the January 2020 issue of O MOLDE magazine.