Surface Finishing Techniques in 3D Printing: Enhancing Printed Parts at Due Pi Greco

At Due Pi Greco, we specialize in both the production process and in the equally important post-production.
In 3D printing, achieving smooth surface finishes is often essential for both functional and aesthetic purposes. Smooth surfaces are particularly important for components such as mating parts, moving parts, and load-bearing surfaces.
Although 3D printing processes typically build parts layer by layer, modern additive manufacturing technologies are capable of producing relatively smooth surfaces. However, smoothness depends on factors such as the printing process, the material used, post-processing operations, and other secondary factors.

Various 3D Printing Technologies

Fused Deposition Modeling (FDM), due to its layer-by-layer technique and nozzle diameter, may not always produce very smooth surface finishes. However, modern industrial FDM machines can produce much finer surfaces. Selective Laser Sintering (SLS), Multi Jet Fusion (MJF), and Direct Metal Laser Sintering (DMLS) produce granular surfaces due to the powdery nature of the raw materials used in these technologies. Regardless of the 3D printing technology, a smooth surface can be achieved in printed parts using post-processing operations.

 

 

Post-Processing

Post-processing is the most effective way to ensure a smooth surface finish in 3D printing. In most cases, post-processing can be used to achieve surface uniformity, regardless of the material or technology used for printing.

There are various post-processing methods, but not all are suitable for every part. Part geometry and material are the two main factors that influence post-processing techniques. It should be noted that different methods will provide different textures and appearances.

1. Sandblasting:

Sandblasting involves directing a compressed air jet of tiny material beads (such as plastic or glass) onto the surface of the printed part. This jet removes the layer marks present on the surface, producing a smooth and uniform finish. Sandblasting is effective for most 3D printed parts, especially those made with FDM technology. However, it’s important to note that sandblasting with plastic beads is more common for these parts.

2. Vapor Polishing:

Industrial vapor polishing is a multi-phase process that operates under vacuum inside sealed chambers containing the 3D printed parts. In this process, a solvent is transformed into vapor and circulated over the part’s surface. The condensed vapor dissolves the surface of the printed part, creating a uniform and smooth finish. This method allows precise control of airflow and temperature, avoiding excessive polishing. It is particularly suitable for parts made from ASA, ABS, and other high-impact polymers.

3. Vibratory Finishing:

Vibratory finishing, also known as vibrofinishing, is an ideal process for relatively small parts containing a high percentage of metal powder. In this process, parts are placed inside a horizontal barrel along with fluids and finishing materials, such as stones. A vibrator rotates the barrel, continuously eroding and smoothing the parts with the finishing elements progressively. Vibratory finishing can significantly increase the smoothness of metal prints in a relatively short time.

4. Sanding and Polishing:

Sanding is the process of progressively removing a very thin layer of material to reveal a smoother underlying layer. This process smooths the surface using relatively rough materials like sanders or grinders. Sanding can be done by hand or using belt sanders and is often followed by polishing to achieve an even smoother and shinier surface. However, it’s important to note that sanding can be challenging for small and complex geometries and may alter the dimensions of the part.

5. Insert Installation:

At DuePiGreco, we apply self-threading inserts in various metallic materials to enhance the functionality and durability of components. Each insert is installed with precision, ensuring a perfect finish and meticulous attention to detail. This process ensures our components can withstand high mechanical stresses and deliver excellent performance in critical applications.

6. XXL Components:

To meet the production needs of large components exceeding the single-block printing limits (914x610x914 mm), we offer advanced joining solutions. We use high-quality structural adhesives and metal stapling techniques to reassemble XXL components, ensuring structural strength and piece integrity. This approach allows us to create large structures while maintaining high standards of precision and quality.

7. Waterproofing:

Our expertise in waterproofing ensures that every printed component is fully protected from moisture. We use a single-component water-based sealing polymer, certified for direct contact with food, which air dries. This solution not only prevents liquid ingress but also maintains compliance with food safety requirements, making our products ideal for the food and medical sectors.

8. Laser Marking:

For precise traceability and identification, we offer customized laser marking services. Our laser markings are detailed and durable, perfect for including codes, logos, expiration dates, and other critical information directly on the components. This service is essential for industries requiring high standards of identification and quality control, enhancing product management and recognizability.

9. Painting:

Aesthetic customization is crucial for many of our clients, and for this, we offer high-quality painting services. We can apply a wide range of colors and finishes, including special effects, to meet the desired aesthetic specifications. We use biocompatible and protective paints to ensure not only an excellent appearance but also the safety and durability of the finished product. Our painting enhances the visual appeal and surface protection, making components ideal for demanding and high-profile applications.

Each post-processing method has its advantages and disadvantages, and the choice depends on the specific needs of the printed part, its geometry, and the material used.

 

 

Due Pi Greco’s Commitment

At Due Pi Greco, we are committed to ensuring the highest quality in our 3D printed parts through careful surface finishing processes. From our single-component water-based sealing polymer, which air-dries and is certified for direct food contact, to mechanical smoothing that brings our parts to a surface roughness of Ra0.8, without the use of chemical additives that alter the base polymer composition, each step is designed to ensure excellent results. Whether it’s in food, medical, or packaging sectors, our attention to surface finishing ensures that our components are perfectly suited to the most demanding requirements. With a wide range of post-processing techniques, such as sandblasting, vapor polishing, vibratory finishing, and sanding and polishing, we can offer customized solutions to meet the specific needs of every customer.

Feel free to contact us for more information on our capabilities and to discover how we can enhance your 3D printed parts.