Quick Comparison
| Aspect | SLA | SLS |
|---|---|---|
| Resolution | 0,025 - 0,1 mm | 0,08 - 0,12 mm |
| Surface quality | Very smooth | Slight texture |
| Support material | Required | Not required |
| Material variety | Limited to resins | Wide range |
| Price from | €0,45/cm³ | €0,52/cm³ |
SLA - Stereolithography
How does SLA work?
SLA uses a laser to cure liquid photopolymer resin layer by layer. The process begins with a tank filled with liquid resin. A UV laser traces the cross-section of the object onto the surface of the resin, causing it to harden.
After each layer, the platform moves down slightly and a new layer of resin is applied over the cured part. This process repeats until the object is complete.
Advantages of SLA
- Very high precision: layer thickness down to 0.025 mm
- Smooth surfaces: minimal post-processing required
- Fine details: perfect for complex geometries
- Transparent materials: possibility of clear parts
SLA Materials
- Standard Resin — €0,45/cm³
- Clear Resin — €0,50/cm³
- Tough Resin — €0,60/cm³
- Flexible Resin — €0,65/cm³
Disadvantages of SLA
- Support structures needed for overhanging parts
- Limited material choice (photopolymers only)
- Post-processing required (washing and UV curing)
- Material can be brittle
SLS - Selective Laser Sintering
How does SLS work?
SLS uses a powerful laser to fuse small particles of plastic, metal, ceramic or glass powder into a solid structure. The process begins with a thin layer of powder spread across the build platform.
A laser scans across the cross-section of the object and heats the powder just above its melting point, causing the particles to fuse. After each layer, new powder is added and the process repeats.
Advantages of SLS
- No support needed: unused powder supports the object
- Strong materials: functional, durable parts
- Complex geometries: moving assemblies possible
- Wide material range: from nylon to metals
SLS Materials
- PA12 Nylon — €0,52/cm³
- PA12 + Glass fibre — €0,68/cm³
- TPU Flexible — €0,85/cm³
- Aluminium — €4,50/cm³
Disadvantages of SLS
- Rougher surface texture than SLA
- Higher initial equipment costs
- Powder cleaning after printing
- Heat management during the process
Choose SLA when you:
- Need very high precision and detail
- Want smooth surfaces
- Make transparent parts
- Create prototypes for visual presentation
- Print small, complex parts
- Need masters for vacuum casting
Choose SLS when you:
- Want functional, strong parts
- Don't want to use support structures
- Print complex assemblies
- Make end-use components
- Need flexible materials
- Want to produce higher volumes
Conclusion
Both technologies have their place in the world of 3D printing. SLA excels in precision and surface quality, perfect for prototypes and visual models. SLS offers more versatility in materials and produces functional parts without support structures.
The choice depends on your specific requirements: if you need the highest precision, choose SLA. If you want strong, functional parts, SLS is the better option. At Makernaut, we are happy to help you make the right choice for your project.