Vat photopolymerization
What is SLA and how does it work?
Cures light-sensitive liquid resin layer by layer with a laser to produce very finely detailed, smooth parts.
Stereolithography
SLA is the first commercial 3D printing technology, developed in the 1980s. In a vat of liquid photopolymer resin, a UV laser traces each layer's cross-section to cure the resin. The platform moves layer by layer and the part emerges from the resin. After printing, the part is washed and post-cured under UV light. Thanks to its smooth surface and high accuracy, it excels at precision casting patterns, dental and medical models and presentation prototypes.
| Typical tolerance | ±0.15 – 0.5% (lower limit ±0.1 mm) |
|---|---|
| Layer thickness | 25 – 100 µm |
| Minimum wall thickness | 0.5 mm (supported), 1 mm (unsupported) |
| Surface | Very smooth; close to injection molding |
| Supports | Required; support marks are sanded |
Process
SLA step by step
- 01
The platform lowers into the liquid resin vat.
- 02
A UV laser traces the layer cross-section to cure the resin (typically 25 – 100 µm).
- 03
The platform rises one layer and fresh resin flows in.
- 04
The part is washed in isopropyl alcohol.
- 05
It is post-cured under UV light and heat, and supports are cut off.
Advantages
- Very fine detail and sharp edges
- Smooth surface, little post-processing
- Specialty resins such as clear, flexible, castable and dental
- Isotropic (similar in all directions) mechanical properties
Limitations
- Resins can become brittle over time under UV
- Part size limited compared to FDM
- Requires washing and post-curing
Best suited for
- Precision (lost-wax) casting patterns
- Dental and medical models
- Jewelry and miniatures
- Presentation prototypes
- Transparent parts
Design
SLA design guidelines
- Minimum wall thickness0.5 mm (supported) / 1 mm
- Smallest detail0.2 mm
- Minimum hole diameterØ 0.5 mm
- Overhang angle≥ 30° from horizontal; flatter surfaces need support
- Clearance for moving parts0.2 – 0.4 mm
- Text and logosEmbossed ≥ 0.3 mm, engraved ≥ 0.4 mm
- Escape holeØ 3.5 mm drain hole in hollow parts
Surface and assembly
Post-processing
- IPA washing
- UV post-curing
- Sanding support marks
- Polishing (clear parts)
- Primer and paint
Materials
Materials printed with SLA
Standard resin
General-purpose SLA photopolymer
Tough resin (ABS-like)
Impact-resistant engineering resin
Clear resin
SLA resin with optical clarity
Water-resistant clear resin
ABS / PBT-like clear SLA resin (Somos® WaterShed® XC 11122 type)
Flexible / elastic resin
Rubber-like SLA resin (50A – 80A)
High-temperature resin
Heat-resistant SLA resin
Castable resin
Lost-wax casting resin (castable)
Dental resins
Model, splint and surgical guide resins for dentistry
Good to know
Frequently asked questions about SLA
What is SLA?
SLA is the first commercial 3D printing technology, developed in the 1980s. In a vat of liquid photopolymer resin, a UV laser traces each layer's cross-section to cure the resin. The platform moves layer by layer and the part emerges from the resin. After printing, the part is washed and post-cured under UV light. Thanks to its smooth surface and high accuracy, it excels at precision casting patterns, dental and medical models and presentation prototypes.
How does SLA work?
The platform lowers into the liquid resin vat. A UV laser traces the layer cross-section to cure the resin (typically 25 – 100 µm). The platform rises one layer and fresh resin flows in. The part is washed in isopropyl alcohol. It is post-cured under UV light and heat, and supports are cut off.
What applications is SLA suitable for?
SLA is especially suitable for precision (lost-wax) casting patterns, dental and medical models, jewelry and miniatures, presentation prototypes, transparent parts.
How accurate are SLA parts?
Typical tolerance is ±0.15 – 0.5% (lower limit ±0.1 mm). The exact value depends on the machine, material and part geometry.
Does TAİ Robotik produce with SLA?
Yes. We produce with SLA; upload your file to get a quote.
Other technologies
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