Additive manufacturing post-processing

Building stronger, lightweight, complex parts in one piece, while using less material and consolidating components across applications, is how additive manufacturing (AM) emerged as a disruptive technology for prototyping and production. Many view these advantages as a result of AM hardware, but that partial picture excludes an ecosystem of technologies that enable pre- and post-build AM.

Focusing only on the AM build process overlooks a fundamental part of the production chain – part post-processing. Manufacturers using AM for serial production first need to identify the appropriate process for the application. From there, they must identify post-processing steps, otherwise AM production benefits may be negated.

Stages

After AM build, but before end-use, parts may go through any or all the following:

• Excess material removal
• Curing, heat-treatment
• Support removal
• Machining
• Surface finish processes (e.g. bead-blasting)
• Coloring
• Inspection

Post-processing can be up to 60% of the overall cost for each AM part, depending on the applications, so it’s important to consider an end-to-end approach when looking at serial production viability. Support removal and other post-processing activities can be labor intensive, costly, and time-consuming, but they are necessary to enhance final part functionality or aesthetics.

Focusing on design for AM (DfAM) reduces some post-processing steps, but this relies on how well the designer understands AM process intricacies and system capabilities – how to orientate parts and generate optimal support structures for build and removal.

Still, no matter how well a product is designed, it’s impossible to eliminate the need for post-processing.

AM post-processing

Digital and automated AM post-processing solutions developed by Additive Manufacturing Technologies Ltd. (AMT) increase efficiency and reduce overall production time and cost, specifically with polymer AM processes and thermoplastic materials. These solutions – together with advances in the number of and nature of thermoplastics, and AM system improvements in resolution, accuracy, repeatability, and quality – enable prototyping, tooling, and production applications.

However, the critical mass of production applications remains lower because of limitations in post-processing. Powder-bed processes require significant powder handling and post-build removal, infiltration operations, and finishing processes, particularly if aesthetics are important alongside laser sintering strength advantages. If parts require color, that’s applied at the finishing stages of post-processing.

With filament thermoplastic material processes, the nature of the AM process creates a stepping effect, and traditional post-processing steps to remove them are considerable, costly, and time consuming.

Automated post-processing can remove one of the biggest hurdles in the production process supply chain by smoothing high volumes of thermoplastic polymer parts to injection-molded surface quality standard.

AMT’s PostPro3D range of hardware integrates systems, software, and virtual services to address this hurdle. Built on the company’s Boundary Layer Automated Smoothing Technology (BLAST), simplicity is key. Post-build, parts are loaded onto a rack, placed in the PostPro3D post-processing chamber, and the appropriate program starts (running 90 minutes to 120 minutes). Once complete, parts are removed, inspected, and ready for use. (See sidebar.)

Summary

Work needs to continue to develop whole process chains to convince AM users and potential AM users that the transition to AM is worthwhile for an increasing number of production applications. Showing that AM’s not nearly as complex as it may have been even a few years ago demands a unified approach across the AM sector to develop more capable and connected systems, simplifying the overall process to provide economically viable, automated solutions. This can be achieved through partnerships and collaboration. Automated turnkey post-processing hardware is one step forward, however, there are still more steps in terms of connected, customized, end-to-end digital manufacturing systems.

Additive Manufacturing Technologies Ltd. (AMT) https://www.amtechnologies.com