Have you ever wished to own a replica of a weapon or armor from your favorite game, movie, or TV series? Or, maybe you want to try out the increasingly popular hobby of cosplay. But, you don’t want to spend money on expensive pre-made items from a store. Instead, you want to create something unique and personal. That’s why we are here to show you how to use a 3D printer and other tools to make an amazing model. The process of refining 3D prints is called post-processing.
Post-processing techniques for 3D printing can transform unfinished models into functional and aesthetically pleasing parts fit for their intended use. This article explores the primary methods available.
Post-processing is a crucial step in the 3D printing process. It aims to improve the quality, appearance, and mechanical properties of printed objects. Different 3D printing technologies, such as Fused Deposition Modeling (FDM), Stereolithography (SLA), and Selective Laser Sintering (SLS), require different post-processing methods to address issues like uneven surfaces, visible layer lines, and support marks. It is essential to have expertise in these techniques to ensure that 3D-printed parts meet industry standards and achieve the desired functional and aesthetic qualities.
Now let’s talk about different post-processing techniques
- Sanding & Polishing
Both sanding and polishing techniques involve the use of abrasive materials to remove surface layers. Sanding typically involves the use of coarser grit sandpaper and specialized tools, while polishing may use finer sandpaper, steel wool, polishing paste, or cloth.
Sanding is effective in removing larger imperfections, such as support remnants and print irregularities, reducing the visibility of layer lines. However, it can leave a somewhat gritty yet more uniform surface texture and there is a risk of surface scratches when using very coarse sandpaper. After sanding, polishing the part can yield an even smoother surface.
Sanding and polishing are popular post-processing methods due to their simplicity and affordability, but they do require a significant amount of labor, especially for larger parts and batches, which can make them time-consuming. Additionally, these methods may not be suitable for parts with hard-to-reach cavities.
- Tumbling
A tumbling machine is used for smoothing batches of parts in a largely automated subtractive method. It consists of a vibrating vat filled with lubricating fluid and abrasive media, which are specialized stones that grind down objects based on their size, shape, and hardness as they tumble together. To use the machine, a 3D-printed part is simply placed into the vat of tumbling abrasive media for a specific length of time. However, it requires some expertise to match parts with the correct abrasive media and processing time, but when done correctly, it can produce uniform finishes effectively.
Tumbling vats are available in a range of sizes, making it possible to process larger parts. Since the abrasive media is continually in contact with the part, larger pieces don’t require longer processing times, but rather larger machines with a sufficient amount of abrasive media. However, tumbling can cause complex shapes to lose detail, and sharp edges may become slightly rounded.
- Vapor smoothing
Vapor smoothing is a technique that can be used to reduce or eliminate visible layer lines in 3D printed parts. This technique involves exposing the parts to a vaporized solvent that smooths the surface without adding or removing any material. The result is a surface that looks like it has been injection-molded, without any visible signs of layer lines.
To perform vapor smoothing, the parts are suspended in a chamber and exposed to a solvent vapor that is compatible with the print material. The vapor condenses on the parts, smoothing the surface polymers without any mechanical action.
The benefits of vapor smoothing are numerous. It results in a uniform and sealed surface, without requiring any extra coatings. Additionally, there are no losses in geometry, weight, or material volume.
- Gluing
Gluing 3D prints is an essential step when you want to combine different parts of a model or if you need to create a larger, more complex object that can’t be printed in one go. Epoxy is a popular adhesive for this purpose. Additionally, you can use non-epoxy glues like Cyanoacrylate, commonly known as “super glue”, to join thinner pieces together. However, the strength of the bond depends on the quality of the adhesive, so make sure to choose an adhesive that can endure relevant stress to ensure a strong bond.
- Chemical Dipping
Chemical dipping or aid dipping is the process of submerging parts in a chemical bath that eats away the surface. Caustic materials like lye, sodium hydroxide, or dichloromethane are used. The process should only be done by experts in facilities with requisite safety features. The appropriate chemical choice is dependent on the material of the 3D print.
Expertise is required to determine the appropriate duration of submergence. Too short and the part will not be smooth, too long and it could be ruined. Air bubbles should be avoided as they will prevent the chemical treatment of the surface. This process is ideal for complex geometries, as all surfaces of submerged parts are treated simultaneously. However, the size of the chemical dipping container limits the part dimensions of treatable prints.
Conclusion
It is possible to perform some post-processing operations on your 3D model by yourself, but it is highly recommended to get it done by professionals. This will help you avoid the risk of damaging your product, and eliminate the need for specialized equipment and materials, some of which can be dangerous if handled improperly. Chemtron Pte Ltd provides a comprehensive range of 3D printing services and provides excellent results every time.