Transparent 3D Printing: What You Need to Know

Transparent materials are widely used in many application fields. With the latest leap in additive manufacturing technology, 3D printing is increasingly used to produce transparent objects. For example, transparent 3D printing can be used to manufacture complex optical components such as lenses, prisms and light guides, which are used in precision instruments such as cameras and microscopes.

In this blog post, we will introduce the relevant information you need to know about transparent 3D printing, including transparent 3D printing methods, techniques and the selection of related raw materials to help achieve crystal clear 3D printed parts.

Principles of transparent 3D printing

Transparent 3D printing technology mainly relies on technologies such as light-curing 3D printing (SLA) and fused deposition modeling (FDM). SLA technology uses light sources to selectively cure photosensitive resins to build transparent objects layer by layer. FDM uses filaments to make 3D models. The filaments are heated in the nozzle and then sprayed layer by layer into the shape of the object.

How to choose the printing technology? SLA is more suitable for transparent 3D printing than FDM, mainly due to its printing principle, material properties and the surface quality and transparency of the final printing results. SLA uses lasers to cure liquid photosensitive resin layer by layer. This method can achieve very high printing accuracy and details because the laser beam can accurately control the curing position and range, and the bonding between layers is very uniform, with almost no layer lines. This uniformity is essential for achieving high transparency. In addition, the photosensitive resin used by SLA can be very transparent after curing, and the material itself has high optical properties, which can maintain a high degree of uniformity and reduce tiny bubbles and unevenness inside the material. The surface of the printed model is very smooth and the details are clear. Even without post-processing, high transparency can be achieved, and simple grinding and polishing can further improve transparency.

In contrast, FDM forms objects by heating and extruding thermoplastic filaments layer by layer. The printed layer thickness is large, the accuracy is low, there are obvious layer lines between layers, and the interlayer bonding is not as uniform as SLA, which causes light to scatter at these interlayer interfaces and affects transparency. Although FDM has transparent material options, these materials are prone to internal bubbles and interlayer unevenness during extrusion and cooling, and these defects will reduce the transparency of the final print. The surface of the object printed by FDM is relatively rough and requires a lot of post-processing to be close to smooth. Even so, the layer lines will still affect the final transparency. Finding the best settings for transparent printing with an FDM 3D printer is a challenging process, as you need to experiment and find the best parameters for your machine and chosen material. The settings you have to adjust include material extrusion temperature and flow rate, print bed temperature, print speed, layer height thickness, and nozzle diameter.

It is important to note, however, that achieving completely transparent printing can be difficult, but there are still some things we can do to achieve maximum transparency as much as possible.

Transparent 3D Printing Achieving Maximum Transparency

For a 3D model to be printed, more complex geometries tend to refract light more and are less likely to be very clear. This is especially true for curved designs, as curves redirect light. So to minimize light refraction, it is recommended that you 3D model your object with the thinnest walls possible. This is because thicker walls will scatter more light and result in a more opaque appearance after the object is 3D printed. However, it is also important to pay attention to the minimum wall thickness required by the technology to prevent problems such as breakage in the model.

Achieving maximum transparency in 3D printing requires careful optimization in material selection, print settings, and post-processing techniques. Choosing a high-quality transparent material is the first step to achieving high transparency. For SLA (stereolithography), specially designed transparent photosensitive resins should be used, such as Formlabs' Clear Resin or Anycubic's Clear Resin, which can maintain high transparency after curing. For FDM (fused deposition modeling), highly transparent thermoplastic filaments should be selected, such as eSUN's Clear PLA or Prusament's PETG, which can form relatively transparent structures during melting and cooling.

Source: https://3dprint.com/57124/formfutura-hdglass-filament/

Optimizing printing parameters is also crucial. For SLA printing, adjust the laser power and scanning speed to make each layer solidify evenly, choose a thin layer thickness (such as 25-50 microns), ensure the uniformity and fineness of each layer, and reduce the interface between layers. For FDM printing, choose the appropriate extrusion temperature and speed to make the material melt and deposit evenly, reduce internal bubbles and unevenness, and use a lower layer thickness (such as 0.1 mm) and a higher layer height to reduce the visibility of layer lines. In addition, keeping the printing environment stable and avoiding temperature fluctuations and wind interference can also help achieve higher transparency. Post-processing is the last step to achieve maximum transparency. For SLA printing, the uncured resin is thoroughly cleaned with solvents such as isopropyl alcohol, secondary curing is performed under UV light, and step-by-step grinding and polishing can remove minor surface defects and layer lines, ultimately achieving a smooth and transparent surface. For FDM printing, the surface is gradually polished with fine sandpaper, polished manually or mechanically with a polishing agent, or flame polishing technology is used to rapidly heat the surface to melt it and re-solidify it, further improving transparency. Combining these steps, optically transparent 3D prints can be produced to meet the needs of a variety of demanding applications.

Start your own transparent 3D printing project

If you have a need to produce transparent parts, consider exploring JLC3DP's services. Simply visit our website and upload your 3D model, then select our transparent resin material. We provide high-quality transparent printing services to ensure that your project can achieve your expectations.

If you have any questions or need help, please feel free to contact our customer service team. You can contact us through our official website, and our team will be happy to provide you with support and assistance.