Stereolithography (STL/SLA)

High precision with good surface conditions and a wide range of materials

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Detail accuracy and dimensional stability are trumps in stereolithography, as it is the most precise generative master model process. That’s why the parts created from 3D CAD data are perfect as visual models so that you can better assess ergonomics, design, proportions and functions. It is the first choice as a basis for vacuum casting because the quality properties are outstanding.

Stereolithography – SLA, also abbreviated to STL – is, like the Laser Sintering and Laser Melting to the additive manufacturing processes, which work with the layer-by-layer curing of formless or liquid building materials by laser. Invented in the early 1980s by the US American Chuck Hull, SLA is one of the oldest and most widespread 3D printing processes and, as a method, it is also the most widely used. mature and process-safe.

In stereolithography, liquid epoxy resin or acrylic resin is cured by means of a UV laser beam. We build these master models with a layer thickness of 0.100 mm as standard. Smaller components can also be built with 0.050 mm. This guarantees our customers the highest possible accuracy and the smallest deviation from the target geometry. Individual machining is thus ensured.

Post-processing: Intended use determines the scope

Stereolithography parts always have to be reworked. Because a manufacturing without support structures ist usually not possible. This applies not only to structures with cavities and undercuts, but to all SLA-produced components. These support structures are automatically calculated during the conversion of a 3D CAD model into a 3D printable .stl format and “printed” from the same material. After completion of the manufacturing process, these support structures mechanically removed and the components are cleaned with solvent.

Beyond this reworks are possible, but not absolutely necessary and essentially depend on the intended use. This is because the use of liquid resins as a building material achieves comparatively smooth and dense surfaces even without additional smooth grinding. The individual layers of material on the finished component or prototype can be recognised – similar to annual rings in tree trunks – but the surface quality does not fundamentally limit them.

This means: If “only” one DeMo prototype or a component is required for checking geometries, for early detection of design errors or as a basis for discussion in toolmaking, are surface treatments except cleaning is usually not necessary. Even simple components can be used directly.

At high demands on the surface quality SLA parts can be used on one or both sides smooth ground, lacquered, metal-coated, printed or laser-marked become. This is not only the case with design and trade fair models for marketing purposes. Also stereolithography master models for subsequent processes such as the Vacuum casting are often additionally smoothed and ground to increase the surface quality of the castings.