In this guide, we break down stereolithography 3D printing method to help you understand it better even if you’re not too technical, and also help you to unlock an entire new business models and prototyping methods.
What Is Stereolithography?
Stereolithography (SLA) is a part of the addictive manufacturing processes for plastics. It’s also called vat photopolymerization, aka resin 3D printing.
It’s the first 3D printing technology for making very high accuracy and smooth surface finish parts, and it’s also very cost effective.
Uses Light To Solidify Liquid Material
SLA 3D printers use light-reactive thermoset materials called “resin.” When a certain wavelengths of light is shined onto the material, it solidify into the object, and this process happens very fast.
- Laser cures photopolymer resin
- Wide material selections
- Highest part resolution
- Great for tooling, prototyping and create molds
Here is a quick guide on what’s available:
- Standard resin – Smooth surface finish, but kinda brittle
- Clear resin – See through and requires post processing
- Castable resin – Use for mold patterns
- Durable resin ( ABS alike) – Low thermal resistance
- High temperature resin – Withstands temperature for injection molding, but it costs more
- Dental resin – Biocompatible, abrasion resistant, but expensive
- Rubber alike resin – Like rubber, lacks dimensional accuracy
Most SLA materials are liquid resin, the prices range from $50 / liter up to $400 for something more special such as dental resin.
For prototyping, SLA printed parts are much more brittle than FDM or SLS, so SLA parts are generally not used for testing where significant loading is needed.
SLA 3D Printer Core Components
A basic SLA printer consists of the following:
- Printed Part
- Build Platform
- XY Scanning Mirror
- Laser Beam
- Resin Tank
Most SLA printers have its core parameters set fixed by the manufacturer, and the only thing the user can adjust is the layer height and part orientation (Typically 25 – 100 microns, 100 microns is good for most common applications)
The build volume is based on the size of the printer, just like a regular paper printer. Larger object needs a larger printer that fits the print.
Basic SLA 3D Printing Process
3D Model Design
A talented 3D drafter will CAD the model, process it and make sure it’s compatible for the 3D printer to print by building structures
After adjustments and proper printer setting, start the print and walk away. Print time varies based on object size and complexity.
Once the part is complete, all parts requires the following steps:
- Rinse with isopropyl alcohol to remove any uncured resin from the surface
- Wait until it dry
- Post curing to increase strength and stability
- Remove support
- Final polish
- Prime for paint if needed
When To Use SLA Method To Print 3D Parts?
Use SLA 3D printing method for:
- Fast prototyping for relatively low cost
- Print artistic work
- Print scale model parts that aren’t subject to physical loading
Already-Proven SLA 3D Printing Applications
- Health Care
- Engineering Prototyping
- DIY Hobbies