by Markus Heilemann
Head of DED Systems Team at Fraunhofer - Institute for Additive Production Technologies
The supply chains of goods and services have become increasingly complex due to global interconnectedness. The current pandemic has clearly shown that individual failures within a supply chain can lead to a disruption of the entire chain. Even without a pandemic, bottlenecks can occur outside of stable supply routes. Transforming traditional supply chains through additive manufacturing can help to tackle this problem. The progress in research and development of these technologies made it possible that some companies have already readjusted their supply chains to respond more flexibly to changes and avoid bottlenecks.
Particularly where downtime results in high outage costs, resilient systems have to be deployed in order to avoid total shutdowns and maintain emergency-operation mode in case of malfunctions or partial failures. The ability of systems to be resilient is crucial. For example, a system failure in the offshore sector (e.g. oil platforms or energy turbines) could quickly produce a loss of up to a million euros per day. However, high cost is not the only motivation for the supply chain's resilience. Another motive is ensuring the supply of spare parts even in places without a stable supply chain, like in short-term emergency areas.
Large spare part inventories are kept nowadays in order to be able to react quickly to failures and minimize downtimes. The stored components are intended to ensuring a promptly repair of malfunctioning machines and systems. However, the operation of such warehouses is expensive and inflexible. It is common for warehouses to hold millions of dollars worth of spare parts used solely as a failsafe, but most of which are never actually called up.
How can additive manufacturing help to make supply chains resilient while reducing costly warehouses? Additive manufacturing is already being used to manufacture spare parts on-demand and thus reducing inventory levels. Taking the idea a step further, companies can now print components not only on-demand but also directly on-site. The shortened transport routes not only reduce costs but also delivery time. However, not all locations where the components are needed have the necessary infrastructure to print them. The solution is provided by mobile units that can be used as independent manufacturing cells at different locations as required.
Printed on demand and on site: a stainless steel reducing pipe for the repair of a wastewater plant
Companies from the offshore sector are already showing interest in these solutions, for example, by repairing some components directly on-site using various welding processes. Another field of application is pipeline construction. The pipelines are installed in mobile construction sites, sometimes crossing unexploited areas. Defects in the pipeline or damaged installation equipment can be repaired directly on-site with a mobile manufacturing unit. In emergency areas, the solution can be used as a part of first aid. The mobile unit enables first-aid teams on-site to print or repair missing or damaged components and manufacture necessary equipment on-demand. Waiting times for required material can be reduced with on-site manufacturing. Companies with a stationary manufacturing facility can also take advantage of the solution. Due to a plant breakdown or a sudden peak in demand, companies can quickly reach their capacity limits. The mobile manufacturing unit then serves as a buffer to reduce the workload of the existing plants. If the stationary production capacities are sufficient again, the mobile manufacturing unit can be dismantled.
Fraunhofer IAPT is developing mobile manufacturing solutions for challenges like this. Equipment for metallic 3D printing is installed in a standard sea container and adapted to the conditions of the container. The units have a length of either 10 ft (2.99 m), 20 ft (6.06 m) or 40 ft (12.19 m), a width of 2.44 m and a height of 2.59 m. These containers offer sufficient working space for on-site manufacturing. Thanks to their standardized dimensions, sea containers are very well suited for worldwide transport by truck, train, ship and plane. The first additive mobile 10 ft manufacturing container is already in research operation. The container is used to print components using robot-based Wire Arc Additive Manufacturing (WAAM). The process, which belongs to the group known as Directed Energy Deposition (DED), involves melting a metal wire with an electric arc. Since almost all weldable wires can be processed, the user has a wide variety of materials available. Furthermore, the wire material is well suited for mobile use, as it is resistant to environmental conditions and the requirements for safe operation are lower compared to powder materials.
For finishing the components, a post-processing station is incorporated in the container, where components are cut with a milling spindle. Companies will be enabled to choose from different additive and post-processing methods in the future versions of the mobile manufacturing container. Amplifications of the functional scope to further stages of pre-processing and quality assurance are also feasible. The combination of different additive processes and post-processing methods will enable companies to respond more specifically to the requirements of their components and application site.
In order for companies to manufacture on-site with sufficient quality, they need access to the necessary equipment and must be able to control and document the production process. A process manager software tool is provided for this purpose. This tool simplifies workflows by combining individual process steps in a software environment. The software takes over the data management tasks and enables the operators of the manufacturing container to fully focus on the process itself. The process manager allows to assign process parameters in work preparation and to export robot paths automatically. As a benefit, files do not have to be converted into other file formats. This reduces the effort required for data cleansing and further processing and can even prevent information loss due to conversions. In addition, data regarding process flow and component history are made accessible in the software.
The concept of a mobile additive manufacturing container has the potential to disrupt supply chains in the future and make them more resilient. A prerequisite for this is the continuous development of additive manufacturing technologies in order to create robust processes for mobile use with reliable quality and as automated as possible.
About the author:
Markus Heilemann is a research associate at Fraunhofer IAPT, where he and his group are responsible for different deposition welding technologies for 3D printing (DED technologies). A particular focus of his group is the mobile use of these DED technologies for repair and spare parts applications.
You can reach Markus here: firstname.lastname@example.org
Link to the original article (in German)