Additive Manufacturing Services Spotlight: Stereolithography

When a dental patient needs Invisalign, the finished product is customized to fit every curve and indent of their teeth. The aligner must be smooth, precise, and body-safe; otherwise, it won’t function properly. Manufacturing Invisalign is a perfect job for stereolithography, or SLA. 

How Does SLA Work? 

SLA was the first patented 3D printing service and has developed a reputation for producing incredibly precise parts with top-notch surface finishes. In the SLA process, a build platform is positioned in a tank filled with a liquid photopolymer, or resin. Ultraviolet lasers then cure and solidify the resin, layer by layer, to construct a finished product. 

SLA is a quick, affordable 3D printing process. It allows manufacturers to create hollow internal diameters, and the resin can be sterilized easily with steam. These features make it perfect for medical and dental uses.

Is SLA the Right 3D Printing Service For You?  

With so many 3D printing methods available, it’s hard to know which one is right for your application. There are several advantages to using SLA, whether you make 3D printed aerospace parts or biomedical products. 

• Speed. SLA is a relatively fast 3D printing process due in part to the highly targeted nature of its lasers. SLA also emits less heat than popular 3D printing methods like Fused Deposition Modeling (FDM), which means it doesn’t require a cooling-off period after the material cures.
• Material capabilities. Many manufacturers rely on SLA because of its compatibility with materials that are certified for clinical use and can be sterilized. 
• Hollow internal structures. SLA is unique in its ability to create hollow structures. A method like FDM requires an internal honeycomb pattern to maintain structural support. Printing hollowed-out parts can save time and materials costs. However, these parts can bend or break more easily under applied pressure, so it’s essential to consider the end-use application before incorporating hollow structures. 
• Surface quality. SLA offers exceptional visual outcomes, including smooth surface finishes and incredibly precise corner radii. SLA parts typically require much less post-processing than FDM parts. 
• Cost. The price of SLA parts may vary significantly depending on material costs, but the overall investment is relatively low. Desktop SLA printers can produce parts of comparable quality to industrial SLA printers, whereas that gap is more significant for FDM. A manufacturer can invest a relatively small amount of capital (e.g., $4,000-$5,000) into a desktop printer to explore the uses of SLA. 

SLA is not the most common 3D printing method, but it’s incredibly valuable for certain parts. If we need to resolve tiny features, create fine detailing, or produce parts with biocompatible materials, SLA is our go-to for 3D printed parts.

Think SLA could be the right fit for your application? Request a quote today!