by Cassandra Balentine
Post processing is an essential step in thee-dimensional (3D) printing. Several types of automated post-processing solutions specifically target additively manufactured (AM) parts.
Above: MicroTek Finishing’s MMP is utilized to finish everything from prototypes to high-volume parts across all industries.
PostProcess Technologies caters to a variety of industries and categorizes its AM post-processing solutions into four main categories—surface finishing, support removal, resin removal, and wax removal.
Marc Farfaglia, head of technical services and application development, PostProcess, explains that surface finishing is suited to metal or polymer parts, support removal is for fused deposition modeling (FDM) soluble support removal, resin removal takes uncured resin from stereolithography (SLA)/digital light processing (DLP) prints, and wax removal is utilized for MultiJet printing.
Post-processing selection ultimately depends on the application and what the customer needs. “Different applications sometimes need different solutions. It is not the price that decides in the end. Most important is the problem that we solve or the value the customer receives,” shares Michael A. Brokordt, marketing and sales manager, MicroTek Finishing.
Surface Finishing
PostProcess’ advanced suspended rotational force (SRF) technology employs specially selected abrasive media tailored for AM. Farfaglia says this media gently abrades the surfaces of additive parts, effectively reducing the roughness average to industry acceptable levels. SRF technology ensures uniform and consistent interaction between the media and the part surfaces, achieving a smooth finish without compromising part integrity.
This method is particularly beneficial for industries where surface finish is crucial, such as aerospace, medical devices, and automotive sectors. “By achieving an optimal surface finish, our process enhances both the aesthetic appeal and functional performance of the parts, reducing friction and improving durability,” shares Farfaglia.
Another surface finishing solution for AM is offered by MicroTek Finishing. After a detailed analysis of the initial surface to determine the treatment parameters, MicroTek Finishing applies its super-finishing process, micro-machining process (MMP), which utilizes a unique physical-catalytic mechanical treatment. “We respect parts’ geometry—and chemistry—and remove five to ten times less materials than other technology,” shares Brokordt.
MMP selectively filters the surface roughness to achieve the customer’s objectives. It yields a reproducible consistency and homogeneity on the most complex geometries and the hardest alloys.
According to Brokordt, MMP reduces the roughness to a 0.5 µin Ra / 0.013 µm if needed. “Customers experience parts with higher lifetimes, decreased friction, or a more precise measurement among other benefits.”
MMP is utilized to finish everything from prototypes to high-volume parts across all industries. Aerospace, medical parts, tooling, gears, or PIMs.
The technology is not capable of complicated serpentine internal channels.
Support Removal
According to 3D printer manufacturer, BigRep, unless your print is optimized for support-less 3D printing, you’ll most likely be printing with support structures. The company’s blog titled, Guide to Post-Processing 3D Printed Parts: 16 Methods, points out that these are usually easy to snap off, but even well-designed supports will leave behind imperfections where they were once attached.
To smooth these areas, it is recommended to post process the entire part by a number of methods. For example, “with dual extrusion you can print soluble support structures that disintegrate in water and leave no trace on your part. They’re especially useful when post processing isn’t otherwise necessary,” says the BigRep post.
PostProcess’ volumetric velocity dispersion (VVD) technology is designed to revolutionize the process of removing soluble supports in FDM printing. “By significantly cutting cycle times compared to traditional methods used in additive labs, VVD technology enhances efficiency and productivity. Using proprietary chemistry, the solution is sprayed directly onto the parts, allowing for dissolution times of less than one hour. This is a significant improvement compared to the typical eight-plus hours required with conventional methods for identical parts,” says Farfaglia.
For polyjet soluble support, PostProcess’ submersed vortex cavitation (SVC) technology is designed to efficiently remove supports from polyjet prints. “This advanced method is compatible with various support materials, including SUP705, SUP706B, SUP707, SUP710, and SUP711. The solution immerses the parts in a controlled cavitation environment to effectively remove support structures. By utilizing PostProcess’ proprietary chemistry in combination with precisely engineered hardware and software, SVC technology provides thorough and rapid support removal,” offers Farfaglia.
Resin Removal
Resin removal is possible with PostProcess’ SVC technology, which provides an automated solution for removing the uncured layer of resin from DLP and SLA prints in an efficient manner. “This eliminates the need for large quantities of isopropyl alcohol (IPA) and reduces manual labor significantly. PostProcess’ specialized chemistry, PLM-403, ensures consistent cycle times and effectively cleans parts even when the solution reaches a saturation level of up to 40 percent resin, compared to less than five percent saturation in IPA. PLM-403’s high flashpoint of over 200 degrees Fahrenheit is a substantial improvement over IPA’s flashpoint of 53 degrees Fahrenheit, minimizing evaporative losses. This makes our resin removal method not only more efficient but also safer and more cost effective,” explains Farfaglia.
Farfaglia points out that resin removal for SLA and DLP prints has become a critical priority for many industries in the AM space. “Streamlining this process has become a crucial focus due to the safety concerns that arise with traditional post-printing processes. Traditional resin removal methods for post-printing processes include the use of IPA in open containers. This creates significant risks for the user, with fume exposure, chances for spills, and apparent safety risks. As companies begin to scale their printing procedures, health and safety becomes a critical component, and the hazards of IPA become even more problematic. IPA can also negatively impact the quality of finished parts, creating bottlenecks in production lines,” he cautions.
Recognizing these challenges, resin removal is an important focus for PostProcess. “We have developed automated workflows for resin removal that include proprietary software, advanced hardware, and specially formulated chemistry to address these issues. Our solutions are designed to scale both safely and efficiently, making them suitable for companies of all sizes,” notes Farfaglia.
An automated solution for resin removal reduces the need for manual intervention, minimizing the risk of accidents and exposure to harmful chemicals. “This not only protects workers but enhances overall productivity and consistency in the quality of the finished parts. One of our main goals at PostProcess is to create a shift in the industry towards a safer and more efficient resin removal process,” he explains.
Wax Removal
Leveraging PostProcess’ advanced SVC technology, users can efficiently remove wax support material from 3D printed parts designed for casting. “This innovative approach offers a significantly higher level of automation compared to traditional methods, which often requires extensive manual labor,” says Farfaglia. “Our SVC technology streamlines the wax removal process, reducing the time and effort involved while ensuring precision and consistency. This not only enhances productivity but also improves the overall quality and reliability of the final casted parts.”
Post-Processing for AM
3D prints made with AM are created layer by layer and generally require some form of post-processing technique to complete the build.
Automated post-processing solutions target AM parts for a range of industries and categories.
Oct2024, Industrial Print Magazine
