When we talk about 3D printing, it stands without saying that most would think first about the actual printing process. However, additive manufacturing comprises several stages, from modeling to final part, including design and optimization, slicing, 3D printing and post-processing. However, the crtical post-processing in additive manufacturing. As post-processing is the final step, carried out after additive manufacturing of a part, it is the one that will dictate some of the final aesthetic and mechanical properties. But how can we benefit from post-processing? What are the different methods and what are they used for? Find out the answers to these questions, plus 10 reasons why post-processing deserves your full attention.
#1: Ensuring Part Quality
One of the reasons that post-processing is so important is because it helps to achieve the quality standards required for 3D printed parts. After printing, parts may show defects such as visible layer lines or surface imperfections. Post-processing includes steps such as sanding, polishing or sandblasting, which eliminate these defects and produce smooth, uniform surfaces. This ensures that parts meet quality requirements and can perform their function optimally.
Machining is a post-processing method that removes material to ensure dimensional accuracy and optimum surface finish (photo credits: TPI Texas)
#2: Improving the Aesthetics of a Part
In addition to functional quality, the aesthetic appearance of 3D printed parts is also crucial, particularly in fields such as product design or consumer goods. Post-processing offers the possibility of improving the appearance of parts by eliminating print marks and adding aesthetic finishes such as specific textures or color effects. This enables parts to meet not only technical requirements, but also the aesthetic and design criteria of customers.
#3: Improve Mechanical Properties
Certain post-processing techniques, such as heat treatment or surface finishing, can improve the strength of 3D printed parts. Heat treatment, for example, can improve the mechanical properties of materials by eliminating residual stresses and increasing fatigue resistance. Similarly, the application of protective coatings can protect parts against corrosion, abrasion or other forms of wear, extending their life and reliability in demanding environments.
Supports can be essential for successful 3D printing, but should be removed during post-processing (photo credits: Formlabs)
#4: Removing Supports
Print supports are often necessary to support overhanging parts during 3D printing. However, they often leave marks or traces on part surfaces, requiring post-processing to remove them. Support removal can be carried out manually, by cutting, or by dissolving in appropriate solvents. Proper post-processing ensures that supports are completely removed without damaging the parts, thus ensuring optimum finishes.
#5: Clean Parts After Printing
Some additive manufacturing technologies, such as powder bed 3D printing or vat photo-polymerization, require parts to be cleaned before final use. To clean parts and get rid of excess material, parts are immersed in a solvent bath such as isopropyl alcohol, or sandblasted. This frees the part from excess material not required for the final part, and ensures a more uniform surface finish.
Depowdering removes excess powder from 3D printed parts (photo credits: Formlabs)
#6: Prepare Parts for Other Processes
In many cases, 3D printed parts need to undergo further treatment or processes after printing. This may include operations such as machining, welding or assembly. Post-processing prepares parts for these subsequent processes by eliminating surface imperfections, adjusting dimensions and reinforcing mechanical properties where necessary. This ensures smooth integration of printed parts into the overall manufacturing process, without compromising their quality or performance.
#7: Modify Material Properties
Some post-processing treatments modify the properties of the materials used for 3D printing. For example, resin-printed parts can be cured by UV polymerization to improve their UV resistance and long-term durability. Similarly, specific surface treatments can be used to modify the chemical, electrical or thermal properties of parts, adapting them to specific applications in various environments. Some treatments, for example, make parts conductive or resistant for electrical applications, or watertight to withstand submersion.
Painting or coating 3D printed parts enhances their aesthetics and adds a layer of protection (photo credits: Bigrep)
#8: Reduce Residual Stress
3D printed parts may have residual internal stresses due to the printing process. These stresses can lead to warping or premature part failure. Post-processing, in particular controlled heat treatment, can be used to reduce these residual stresses, improving dimensional stability and long-term part reliability.
#9: Ensure Compliance With Standards and Regulations
In some regulated industries, such as aerospace, automotive or medical, 3D printed parts must meet strict standards and regulations for quality, safety and performance. Post-processing can include extensive testing and inspection to ensure that parts meet these requirements. This may involve laboratory analysis, non-destructive testing or specific certifications, ensuring that parts comply with applicable standards.
#10: Optimize Surface Properties
Post-processing can be used to optimize the surface properties of 3D printed parts by adjusting their roughness, gloss or texture. This can be achieved by techniques such as polishing, sandblasting or surface coating. By modifying surface properties, we can improve the functionality of parts for specific applications, such as adhesion, friction or abrasion resistance.
Sanding 3D prints makes surfaces more uniform and homogeneous (photo credits: Bigrep)
Do you post-process your 3D printed parts? Which are the most important reasons to integrate post-processing? Let us know in a comment below or on our LinkedIn, Facebook, and Twitter pages! Don’t forget to sign up for our free weekly newsletter here, the latest 3D printing news straight to your inbox! You can also find all our videos on our YouTube channel.