SLA Tech.
FDM technology can go about building quick prototypes with strength and speed, at a very economical price in a wide range of thermoplastic materials, which makes it a very attractive option.
Technology Overview
Stereolithography (SLA) is an additive manufacturing process that belongs to the Vat Photopolymerization family. In SLA, an object is created by selectively curing a polymer resin layer-by-layer using an ultraviolet (UV) laser beam. The materials used in SLA are photosensitive thermoset polymers that come in a liquid form.
SLA has many common characteristics with Direct Light Processing (DLP), another Vat Photopolymerization 3D printing technology. For simplicity, the two technologies can be treated as equals.
A laser beam is directed in the X-Y axes across the surface of the resin according to the 3D data supplied to the machine (the .stl file), whereby the resin hardens precisely where the laser hits the surface. Once the layer is completed, the platform within the vat drops down by a fraction (in the Z axis) and the subsequent layer is traced out by the laser. The resin that is not touched by the laser remains in the vat and can be reused. This continues until the entire object is completed and the platform can be raised out of the vat for removal.
Support structure is always required in SLA. Support structures are printed in the same material as the part and must be manually removed after printing. The orientation of the part determines the location and amount of support. It is recommended that the part is oriented so that so visually critical surfaces do not come in contact with the support structures
Material & Property
| Material | Tensile Strength | Yield Strength | Young Modulus (Modulus Of Elasticity) | Elongation At Break | Flexural Strength | Impact Strength |
|---|---|---|---|---|---|---|
| Clear Resin | 50-70 MPa | 45-65 MPa | 2,000-3,000 MPa | 6%-10% | 70-100 MPa | 10-20 kJ/m² |
| Grey Resin | 70-90 MPa | 60-85 MPa | 2,500-3,500 MPa | 5%-8% | 90-120 MPa | 15-25 kJ/m² |
| Flexible Resin | 20-30 MPa | 15-25 MPa | 300-600 MPa | 50%-150% | 20-40 MPa | 30-50 kJ/m² |
| Castable Wax Resin | 30-50 MPa | 25-45 MPa | 1,500-2,500 MPa | 8%-12% | 40-60 MPa | 5-15 kJ/m² |
| ABS-like White Resin | 60-80 MPa | 55-75 MPa | 2,000-3,000 MPa | 10%-15% | 70-100 MPa | 20-30 kJ/m² |
Applications
- High-Precision Prototyping for Detailed Designs
- Custom Dental and Orthodontic Appliances
- Intricate Jewelry and Fashion Accessories
- Medical Models and Surgical Planning Tools
- Complex Engineering Components
- Detailed Miniatures and Figurines
Design Consideration for FDM
Minimum Wall Thickness: 1.2 mm
Minimum Details Size: 2 mm (for text, hole diameters, etc.)
Layer Thickness: 0.1 mm – 0.3 mm
Max Dimensions: 220 x 220 x 200 mm.
Standard Accuracy: ± 0.3% (with a limit of ± 1 – ± 0.3 mm)
Lead Time: Minimum 2 working days for dispatch
Surface Finish: Visible layers with texture
Embossed/Engraved Details: 0.4 mm
Post Processing
Basic: Support Removal & Sanding / Polishing
Add-on: Primer, Putty, & Coating / Painting