by Industrial Print Staff
Often a three-dimensional (3D) printed piece isn’t completely finished right off the printer. Various technologies are employed to create a final product that is acceptable to the end user. Post processing of a 3D printed piece means many things from removing the support structure to achieving the desired look and feel of the finished surface through technologies like sanding, polishing, or de-powdering.
“Post processing is a crucial step in the additive manufacturing (AM) workflow, where 3D printed parts undergo various finishing processes to achieve customer-ready quality,” states Marc Farfaglia, head of technical services and application development, PostProcess Technologies.
Determining if Necessary
Many factors help determine whether and which post-processing technique is necessary. This includes the type of material and end use of the part, as well as the 3D print method employed.
According to Farfaglia, the intended purpose or end use of 3D printed parts influences the need for post processing. “If the parts require additional steps such as painting or plating, post-processing becomes crucial to prepare the surface for subsequent treatments.” One example is before painting, a part might require surface finishing to achieve a smooth, uniform texture. This ensures better paint adhesion and a visually appealing final result.
The part itself, and how complex it may be, is another reason to consider post processing like sanding or polishing. “Intricate geometries, fine details, or delicate features may require additional post-processing steps to refine the part’s appearance and functionality,” explains Farfaglia.
Achieving high-quality surface finishes is possible with the PostProcess Technologies RADOR solution. This advanced system employs software-driven algorithms to achieve the desired roughness average on a 3D printed part. The RADOR solution reduces manual finishing and delivers consistent results.
More often than not, post processing is necessary. “While each technology requires different post processing, almost all will require at least one, if not more, post-processing steps to make their 3D printed part customer ready,” shares Farfaglia.
Andreas Hartmann, CEO/CTO, Solukon, states that for the industrial use of 3D printed parts via laser powder bed fusion (PBF) technology adequate post processing “is always required to ensure smooth performance of the part and to meet safety and occupational health requirements.”
Post-processing parts manufactured from PBF involves de-powdering or removing powder from complex parts. Solukon offers automatic de-powdering solutions that utilize programmable (two-axis) rotation and targeted vibration, which allows the cleaning units to remove excess powder even from the finest internal channels of the component. All Solukon de-powdering systems are based on Solukon Smart Powder Recuperation technology (SPR).
Fused deposition modeling (FDM) is an AM method that requires post processing to remove support structures. While the support structures are essential during the build process, once printing is complete they must be discarded. “Post-processing steps, such as support structure removal, are typically required to achieve the desired part geometry and surface finish for FDM printed components,” states Farfaglia.
For efficient support structure removal in FDM parts, PostProcess Technologies offers two solutions—the BASE and the VORSA 500. These intelligent spray systems leverage cutting-edge software algorithms to automate the support removal process, eliminating the need for time-consuming manual labor.
Stereolithography (SLA) also benefits from post processing, especially with resin printed parts. After printing, residual resin may remain on the parts and “post-processing techniques are employed to remove and clean the excess resin, ensuring the final parts meet the desired specifications,” explains Farfaglia.
PostProcess Technologies’ DEMI family of solutions is designed to address the post-processing needs of both resin-based and PolyJet materials. With proprietary chemistry and software intelligence, the DEMI series ensures efficient and effective removal of residual resin and support materials, resulting in clean and customer-ready parts.
When to Invest
When a 3D printer is purchased, it might be advantageous to purchase post-processing equipment at the same time—however there could be cost restraints or even a lack of staff to help facilitate the process successfully.
Hartmann believes it is better to consider post processing when buying a 3D printer for two reasons, higher cost transparency, as you will know exactly what the AM line will cost in total; and better connection of the individual process steps. “Digital networking of prints and post-processing equipment in particular can be considered right at the start if everything is acquired at the same time.”
Solukon considers the digital integration of the equipment in its solutions. Its de-powdering software, the SPR-Pathfinder, uses the build job’s CAD file to automatically calculate the motion sequence for the Solukon system to remove excess powder. The Digital Factory Tool—a sensor and interface kit—enables process tracking, quality assurance, and automation integration.
“It is crucial to establish a well-coordinated process workflow from the outset, ensuring seamless integration between the printer and the post-processing equipment. In AM, printers and post-processing solutions play interconnected roles in achieving the desired end result for 3D printed parts,” agrees Farfaglia.
It is important to approach the printer and post-printing solutions as connected elements that work together, continues Farfaglia. The best results equal a seamless integration. “This integration enables data transfer, process automation, and real-time monitoring, ensuring a smooth transition from printing to post processing.”
This is achieved by PostProcess Technologies’ CONNECT3D software platform, enabling streamlined and completely connected workflows that help maximize the potential of AM.
“By considering the entire process upfront, manufacturers identify potential bottlenecks, anticipate challenges, and design an optimized workflow that maximizes efficiency and productivity. This proactive approach saves time, resources, and reduces the likelihood of costly rework,” adds Farfaglia.
Thoughts to Note
In PostProcess Technologies’ 4th Annual Post-Process Survey, the company found that a majority of users are investing in material extrusion, VAT photopolymerization, and PBF technologies. While these methods offer versatility, application range, and reliability advantages, they do present unique post-processing requirements.
“One of the key findings of the survey is that respondents frequently face challenges related to the time required to finish parts during post processing. This struggle is prevalent in material extrusion processes, which often involve manual support removal. The manual nature of this step can create bottlenecks in the additive workflow, resulting in slower overall production rates for manufacturers. Recognizing this issue, manufacturers seek solutions to streamline and accelerate their post-processing operations,” states Farfaglia.
Copper-based 3D printed parts are also challenging to post process, according to Hartmann, and increasing in usage as the material of choice for aerospace companies and rocket manufacturers. “Copper is an exceptional de-powdering challenge because powder residues on the inside of the part’s channels show sticky behavior and powder tends to clog in cavities,” he states. To loosen these powder bulks Solukon offers an additional knocking system for its de-powdering solutions.
Another issue to keep aware of as technology advances—larger manufactured parts. “This means outstanding challenges for post processing and automated powder removal,” adds Hartmann.
A pivotal piece of the AM workflow, post-processing technologies range from removing support structures to de-powdering depending on the 3D print process used. As more materials become applicable for use in 3D printing, the post processing of the same materials will be an interesting area to watch.
Oct2023, Industrial Print Magazine