Chemical smoothing of plastic components from 3D printing

Vapor Smoothing improves the surface quality of SLS parts by chemically smoothing the rough structures. This results in components with increased density, improved haptics and an attractive appearance.

Vapor Smoothing: for surfaces similar to injection molding

Smoother surfaces in 3D printing

Chemical smoothing, also known as vapor smoothing, is a process for surface finishing of additively manufactured plastic components. The aim is to create a smooth, compacted and sealed surface that is not only visually appealing, but also offers functional benefits.

The process is based on the controlled effect of solvent vapors, which briefly dissolve the layer of plastic near the surface. This physical-chemical process causes the surface structures to soften slightly, resulting in the rearrangement of micro-roughnesses and irregular structures. The surface levels out, becomes more homogeneous and has a uniform feel. This means that even complex geometries can be completely smoothed without changing the shape of the component.

In addition to the improved cosmetic appearance, the components also benefit from functional properties: The reduced porosity makes them less susceptible to the penetration of liquids or dirt, facilitates cleaning and increases resistance to moisture and chemicals. Vapor Smoothing therefore not only contributes to higher component quality, but also opens up new possibilities for use in demanding industrial applications.

Which materials are particularly suitable for vapor smoothing?

Polyamides such as PA 11 and PA 12 are particularly suitable as their surfaces can be reliably dissolved and evenly smoothed. Flexible plastics such as TPU can also be refined by vapor smoothing and thus gain in density and feel. However, high-performance plastics with high chemical resistance are less suitable, as they hardly react to solvent vapors. The right combination of material and solvent is therefore crucial for the success of the process in order to achieve a homogeneous, closed surface without impairing the component geometry.

These 3D printing processes particularly benefit from chemical smoothing

Components manufactured using the powder bed process are particularly suitable for vapor smoothing. These primarily include selective laser sintering (SLS) and multi-jet fusion (MJF). Both processes produce components with a slightly rough and porous surface that can be reliably compacted and homogenized by chemical smoothing.

The process is less relevant for technologies such as SLA or DLP, as very smooth surfaces are already created during printing. Vapor smoothing is not used for metal or ceramic components, as these materials do not react to solvent vapours.

Areas of application for chemical smoothing

1. Improved mechanical properties

The compaction of the surface structure through chemical smoothing has a positive effect on the mechanical performance of the component surface. A smooth and uniform surface reduces notch effects and can therefore increase resistance to mechanical influences. This opens up additional application possibilities in areas where resilience and durability are required.


2. Optimized hygiene and easy cleaning

By reducing porosity and roughness, smoothed components are less susceptible to the adhesion of particles or microorganisms. The surfaces are easier to clean and disinfect, which makes them particularly interesting for applications where hygiene and regular cleaning play an important role.


3. Efficient fluid and gas routing

A smoothed inner and outer surface improves the flow properties and reduces turbulence in fluid or gas-carrying components. The sealed surface can also reduce the risk of leaks and therefore contributes to functional reliability in hydraulic or pneumatic systems.


4. High-quality visible and design components

Vapor Smoothing eliminates visible layer lines and roughness, giving components a uniform, professional and high-quality appearance. The process is therefore particularly suitable for consumer goods and other applications where appearance plays a decisive role.

Why vapor smoothing? The most important advantages

Technical advantages:

  • Compacted and sealed surface structure
  • Reduced porosity and improved density
  • Easier cleaning due to closed surfaces
  • Reduced adhesion of particles and liquids

Visual and haptic advantages:

  • Uniform, smooth surfaces without visible layer lines
  • High-quality appearance for visible or design-relevant components
  • Pleasant feel thanks to smooth surfaces

Frequently asked questions about vapor smoothing 3D-printed components

What influence does chemical smoothing have on the color of the part?

The color generally remains unchanged. However, due to the smoothed surface, the part may appear slightly darker or glossier, as light is reflected differently compared to a matte, untreated surface.

Does the delivery time increase?

Yes. Since chemical smoothing is an additional processing step, the delivery time increases slightly. The exact duration is displayed transparently during the ordering process.

How does chemical smoothing affect the strength of the part?

The material properties change primarily at the surface:

  • • Porosity is reduced
  • • Notch effects are minimized

This can locally improve impact resistance and durability. However, the fundamental strength of the material remains largely unchanged.


What costs should I expect for chemical smoothing of 3D-printed parts?

The costs depend on the part size and quantity. The exact price is automatically calculated and displayed during the ordering process.

Do the dimensions change after chemical smoothing?

The process affects only a very thin surface layer. Any dimensional changes are within a few micrometers and are generally negligible. For high-precision applications, this effect should still be taken into account.

Are your 3D files ready?

Just upload your data. All files are automatically checked and optimized for printing.


Do you have any questions?

We will be happy to advise you personally regarding your 3D project.