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Everything You Need to Know About Vapor Smoothing

Learn when vapor smoothing is the right finishing option for your 3D-printed part.

In additive manufacturing, printing part is just the beginning.


The post-processing techniques add the finishing touches, making the difference between a basic prototype and a final end-use product. Among these post-production processes, one popular method in polymer-based 3D printing is vapor smoothing.


But what exactly is this process, how does it transform 3D-printed objects, and when should you use it? This article takes a close look at vapor smoothing, which blends science, engineering, and artistry to produce high-quality, aesthetically pleasing parts.


Understanding Vapor Smoothing: The Process Explained


In short, vapor smoothing turns freshly a printed parts rough, layered surface into a sleek, glossy finish. The result resembles parts made from traditional manufacturing methods, such as injection molding.

A part that with no finishing (except for dyeing to turn it green) vs. a part that has been vapor smoothed.

At its core, vapor smoothing is a controlled chemical process. The 3D-printed part is placed in a specially designed chamber with a solvent. This solvent, which is carefully selected based on compatibility with the material of the printed part, is heated until it vaporizes.


As the part is exposed to this mist of solvent vapor, the chemical interaction unfolds. The outermost layer of the printed part starts to dissolve slightly due to the solvent. This dissolution smooths out irregularities and roughness on the part's surface, softening the appearance of the layer lines typical of 3D printed parts.


Then, the part is removed from the chamber and cooled. The dissolved surface solidifies as it cools, resulting in a significantly smoother and glossier finish than before.


Think of the process as ironing clothes. Just as the heat and steam from the iron smooths wrinkles from your favorite shirt, the vapor in the smoothing chamber smooths out the rough layer lines of the 3D printed part.


The Impact of Vapor Smoothing on 3D Printed Parts


Vapor smoothing does more than enhance the visual appeal of 3D-printed parts. It also fundamentally alters their physical properties. A part that has undergone vapor smoothing becomes more water-resistant, significantly reducing its porosity. This change in properties is due to the sealing of the part's surface during the smoothing process.


A vapor smoothed camera housing made from PA12 via Multi Jet Fusion. Photo courtesy of Yaak.
Read how Yaak, an innovative startup, sourced vapor smoothed 3D-printed parts with MakerVerse.

Furthermore, smoothing layer lines can enhance the part's structural integrity. The layer lines of a 3D printed part are essentially its weakest points, areas where the bonds between the material are less robust. By smoothing out these lines, vapor smoothing can result in a stronger part.


However, it's crucial to remember that vapor smoothing also slightly alters the part's dimensions due to surface material dissolution. This change might be minimal, but you must consider this during the design phase for parts where precise measurements are paramount.

Vapor Smoothing for SLS and MJF


Polyamide 11 (PA11) and Polyamide 12 (PA12) are two widely used materials in Selective Laser Sintering (SLS) and Multi Jet Fusion (MJF) technologies, offering excellent mechanical properties and chemical resistance.


However, even with these advanced materials, the characteristic roughness of 3D printed parts can be a concern. This is where vapor smoothing comes into play.


Vapor smoothing significantly enhances the surface finish of PA11 and PA12 parts, giving them a smooth, high-quality appearance. Common solvents used in vapor smoothing include Isopropyl Alcohol (IPA) and Ethyl Acetate.

Want to know more about the differences between SLS and MJF? Here’s the guide for you.

Vapor Smoothing vs. Post-Processing Techniques


Post-processing in polymer 3D printing is a broad field with numerous techniques available, each with its benefits and limitations. To appreciate the true value of vapor smoothing, it's beneficial to compare it with other popular post-processing methods.


Sanding, for instance, is a mechanical technique used to smooth the surface of 3D printed parts. While it can be effective in removing layer lines and reducing roughness, it is labor-intensive and doesn't enhance the mechanical properties of the part. Moreover, sanding may not be suitable for parts with intricate geometries or hard-to-reach areas.


Want to know more about the different finishes for Selective Laser Sintering? This guide is for you.

Coating or painting is another common technique. While it can significantly enhance the appearance of a part and provide additional resistance properties, it doesn't inherently smooth the surface. Moreover, the application process can be complex, and the choice of coatings may be limited by the part's material.


In contrast, vapor smoothing stands out with its ability to simultaneously improve aesthetic and mechanical properties. It can be applied to a wide range of materials, is suitable for complex geometries, and leaves parts with a high-quality finish that is comparable to traditional manufacturing techniques.


Vapor Smoothing through MakerVerse


With its ability to transform 3D printed parts into smooth, glossy, and robust pieces, vapor smoothing erases lines between 'prototype' and 'final product,' allowing for more extensive use of 3D printing in end-use applications.


On the MakerVerse platform, you get full access to all the manufacturing technologies and post-processing techniques. Upload your part, choose your manufacturing technology, and then select a range of finishes – including vapor smoothing. We’ll work with you to create parts that are not only structurally sound and functional but also aesthetically pleasing.


Get started with vapor smoothing

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