Here is your comprehensive guide to 3D printing surface finishing solutions to help you choose the best option for your rapid prototyping job.
3D printing has progressed amazingly in recent years, evolving from a niche and even experimental process to a widely used prototyping and manufacturing technology. Today, 3D printing is broadly used for prototyping applications in many industries because of its high level of design freedom, ability to produce one-off or short batch parts and its rapid manufacturing speeds. At RapidDirect, 3D printing is one of our integral rapid prototyping solutions, and we offer a range of polymer-based additive manufacturing processes, including fused deposition modeling (FDM), selective laser sintering (SLS), stereolithography (SLA) and PolyJet 3D printing.
One particular area where 3D printing has excelled is in the production of visual prototypes. For instance, car manufacturers now often turn to the technology to produce early prototypes with high visual accuracy for new car designs, and jewelry makers can produce customized jewelry prototypes for fittings before moving into final production. These visually accurate 3D printed prototypes make it easier to showcase to clients or shareholders what the final product will look like and determine the design’s ergonomic and aesthetic quality.
However, despite 3D printing’s propensity for design freedom and one-off production, the technology on its own is not quite capable of producing parts with professional-grade surface finishes: post-processing is still an essential step in 3D printing. At RapidDirect we therefore offer an array of finishing solutions as part of our complete 3D printing rapid prototyping services. Read on for a detailed guide to our 3D printing finishing solutions.
Surface finishing options for 3D printing
Often, 3D printed parts require multiple post-processing steps. For instance, if a component requires supports in the printing process, these have to be removed (using either cutting and sanding, or a bath for soluble support materials). Because support removal is fairly standard across 3D printing, we’ll skim over that step and dive into RapidDirect’s surface finishing options for customers.
First up is painting. Painting is an important finishing solution especially for prototypes that require high visual accuracy. A monochromatic part off the 3D printer might not look like much, but apply a professional coat of paint and it can be made to resemble nearly anything, from a car body, to an electronics casing, to homeware product.
When it comes to painting 3D printed parts, there are many options available, including acrylics, sprays, airbrushes and enamels. In almost all cases, the painting process has a few requirements: 3D printed parts should be cleaned (this means no oil or dust), primed and dried for optimal paint adhesion. In some cases, it is also necessary to sand the 3D printed part to ensure that the surface is smooth and printed layers are not visible.
The painting process is multi-purpose: it serves to add a high visual quality to the part (it can even be matched to a customer’s specific branding), but it can also add a protective layer to the prototype. Painted 3D printed parts can have a variety of finishes, including matte or shiny, they can be customized in terms of color, and some are even food-safe. At RapidDirect, our professional finishing services ensure that your product is painted to the highest degree of quality.
If your part requires a high quality and shiny finish, but the color or branding is not critical, then polishing might be the ideal finishing solution for your job. Polishing is especially applicable for parts 3D printed using an FDM process, because this filament extrusion technique results in parts with visible layers. There are different polishing approaches for different 3D printing materials. For instance, ABS and other petroleum-based filaments can be polished and smoothed by vaporizing a solvent.
Other materials, such as PLA, require a more manual approach that involves sanding and a polishing agent. Different types of polishing materials work for PLA 3D printed parts, including liquid metal polish or wax-based polishing materials. From there, the process is relatively straight forward, the polishing agent is carefully rubbed onto the part’s surface until the part is smooth. Using this approach can even result in a shiny mirror surface, transforming a dull surface texture into a highly aesthetic one.
Bead blasting is a common finishing technique for many manufacturing processes, including CNC machining and sheet metal fabrication. The process, which consists of shooting tiny abrasive particles at the surface of a metal object using compressed air, is also compatible with 3D printed parts. The impact of the particles on the surface of the object results in a smooth surface with a typically matte finish. Bead blasting is an effective method for removing the visible layers of a 3D printed part.
Bead blasting is compatible with almost all FDM filament materials, however it is best suited for one-off or small batch parts, because the process takes place in an enclosed chamber. A 3D printed part that has undergone even just a few minutes of bead blasting will have a uniform and matte surface finish. If further post-processing is required, such as painting, it can follow.
3D printing and finishing with RapidDirect
RapidDirect is one of China’s leading rapid prototyping and manufacturing services, and we pride ourselves on our mastery of multiple manufacturing processes, including CNC machining, sheet metal fabrication, injection molding and 3D printing. In the case of the latter, we know how useful 3D printing is for producing prototypes with high visual quality, so we understand the importance of a professional surface finish. Thanks to our surface finishing solutions, your 3D printed products will be taken to the next level: clients no longer have to imagine what a final product will look like, they can hold an accurate prototype in their hands thanks to 3D printing and finishing.