3D printing of transparent materials: what are your options?

With the recent acceleration of industrial upgrading in various industries, 3D printing technology has made progress, and R & D personnel have gradually become accustomed to using 3D printers in projects that produce transparent objects. The transparency of product materials is pursued in many industry applications: from the production of lenses for optical engineering or medical purposes to the manufacture of beautiful product casings. In this article, we will introduce the knowledge about 3D printing of transparent materials, the available 3D printing materials and how to overcome the challenges related to 3D printing technology, so that you can get the best possible results.
What is transparent 3D printing
Transparent 3D printing refers to 3D printing models with different transparency. The final result is from translucent to relatively transparent. The diversity of the final product can be attributed to many factors, including the nature of the 3D printing model, the type of 3D printer used, 3D printing settings, material selection, and post-processing. It is important to understand that depending on the 3D printing technology and the selected printing materials, achieving fully transparent 3D printing can be challenging.
3D printing modeling maximizes transparency
For product models to be 3D printed, it is important to remember that the more complex the geometric shape tends to make the light refract more, and the possibility of becoming very clear is less. This is especially true for curved designs, because the curve redirects light.
Having said that, to minimize light refraction, it is recommended that you use the thinnest possible wall to 3D model the printed model. This is because once the model is 3D printed, the thicker wall will disperse more light and cause the appearance to be more opaque. However, remember the design guidelines and the minimum wall thickness required to use this 3D printing technology.
Which 3D printing technology is best for your project?
Choose the correct 3D printing method according to the nature of the project. Are you making a prototype? Or do you need a fully functional final product? Considering the purpose of the 3D printed model, you should choose the required technology. Each proposed technology will benefit your production in different ways.
FDM 3D printing technology
FDM 3D printing technology is one of the most famous printing technologies in the 3D printing industry. It uses fine wire to make your 3D printed model. The filament is heated in the nozzle and ejected layer by layer in a flat pattern of objects.
Due to the technical characteristics of FDM 3D printing, a small gap may be formed between the layers, thereby helping to reduce the light passing through the surface of the 3D printed model. Layer lines that are often easier to see when using FDM 3D printers also disperse light. It is this light refraction that interferes with transparency, and minimizing it during design and production can significantly improve results.
In addition, using the FDM 3D printer to find the best settings for transparent printing is a challenging process, because you need to try repeatedly to determine the best parameters for the machine and the selected material. In these settings, you must adjust the following parameters: material extrusion temperature and flow rate, printing platform temperature, printing speed, layer height thickness, and nozzle diameter.
SLA 3D printing technology
SLA stereolithography uses photochemical processes to produce parts using polymer photosensitive resins. A powerful advantage of this 3D printing process is the very thin layers, so it produces very good results for transparent 3D printing.
SLA has very satisfactory results in terms of optical transparency. This 3D printing method is best suited for visual applications that pursue smooth surface finishes and high levels of detail. However, it is important to note that SLA 3D printing has a support structure that needs to be removed in the post-production stage, which may affect the final appearance of the model.
Transparent materials for 3D printing
After determining the 3D printing technology, the next step is to choose the right material. Materials for various technologies are different. Your decision should depend on the purpose of the 3D printed model and how it is used. The prototype may not need to be 100% transparent, but it must withstand extensive testing. However, the decorative elements need not exhibit sufficient strength, but must be aesthetically pleasing.
Transparent wire for FDM 3D printing
After determining the 3D printing technology, the next step is to choose the right material. Materials for various technologies are different. Your decision should depend on the purpose of the 3D printed model and how it is used. The prototype may not need to be 100% transparent, but it must withstand extensive testing. However, the decorative elements need not exhibit sufficient strength, but must be aesthetically pleasing.
Transparent wire for FDM 3D printing
There are many post-processes that can increase the transparency of 3D printing made with more or less transparent materials. These include sanding, resin dipping, spraying and epoxy coating, and steam smoothing using acetone and polishing (suitable for multi-jet printing).
When polishing 3D printed models, it is recommended to gradually increase the particle size of the sandpaper used. Both SLA and FDM 3D prints can be polished. Despite the labor intensity, this method can improve the optical transparency of the model. Spray coating and epoxy coating are also suitable for SLA and FDM 3D printing. This is a very popular post-treatment method, but usually requires repeated spraying.
Resin impregnation is a post-processing method used only for SLA 3D printing. It involves immersing the 3D printed model in resin and then immersing it to dry it. It only applies to flat objects, such as lenses. After treatment, the model surface is clear and very smooth.
The future of transparent 3D printing
Just as the transparent 3D printing project is introduced in this article, there are many ways to make the 3D printing model have different degrees of transparency. With the right material selection, the best print settings to meet your needs and some of the best techniques for post-processing, you can also create objects with special optical transparency.