Stereolithography (SLA)
Stereolithography (SLA) is an additive manufacturing process using a vat of liquid UV-curable photopolymer "resin" and a UV laser to build parts a layer at a time. To create each layer, the laser traces a part cross-section pattern on the surface of the liquid resin. Exposure to the UV laser light cures, or, solidifies the pattern traced on the resin and adheres it to the layer below.
After a pattern has been traced, the SLA elevator platform descends by a single layer thickness, after which a resin-filled blade sweeps across the part cross section, re-coating it with fresh material. On this new liquid surface, the subsequent layer pattern is traced, adhering to the previous layer. A complete 3D part is formed by this process.
Stereolithography requires the use of support structures to attach the part to the elevator platform and to maintain the integrity of the geometry. This is done to counteract deflection due to gravity, and to accurately hold the 2-D cross sections in place. Supports are generated both automatically and manually during the preparation of 3D CAD models. After building, parts are cleaned of excess resin support structures by immersion in a chemical bath, then cured in a UV oven.
Machines:
most build envelopes are 20 x 20 x 24in or 50 x 50 x 60cm
iPro 9000 XL (build size = 59 x 30 x 22in) or 150 x 76 x 56cm
iPro 9000
iPro 8000 MP
iPro 8000
Feature size = .030 Standard mode (high resolution .006 with a feature size of .010)
Minimum wall thickness is .020” or .508mm
Resolution = Standard .004, medium .003, high .0015
Available Resin List:
| SLA Matrix | |
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Accura XTREME (RTV master patter - 600C thermal resistance) |
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Accura 25(polypropylene like - opaque white) |
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Accura 55 (ABS like - opaque white) |
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Accura 60 (polycarb like - rigid) |
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Somos 9420 (polypropylene like - opaque white) |
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Somos 11122 Watershed (ABS like - translucent or clear) |
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Somos 18420 (ABS like - opaque white) |
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Somos DMX - SL 100 (flexible - high impact - opaque white) |
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Somos NanoTool (high temp - opaque white) |
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Somos NeXt |
We offer several finishing options for your SLA parts, please inquire about the finishing you would like to achieve with a GPI associate.
Finishes levels:
1. Strip n Ship – part is cleaned, cured and shipped.
2. Phase 1 – part is cleaned but defined with supports, cured and bead blasted.
3. Phase 2 – the part(s) are cleaned and all supports are removed, then lightly sanded with 180 grit and bead blasted.
4. Phase 3 – GPI Prototype’s most requested finish – all supports are removed, 90% of stair stepping sanded varying from 220-320 grit than a final bead blast.
5. Phase 4 – finish with all exterior stair stepping removed optional primer as needed.
6. Phase 5 – ready for paint, painting is included after sanding and putty as needed.
7. Clear – part receive phase 3 finishing with clear coat applied.
8. Super Clear – all stair stepping is removed from exterior and interior of the part (in most cases), 420 grit sanding with seal and clear coat.
9. Ni Plating – Phase 4 finish level with a nickel plating of semi bright, brushed or polished look.
*** Builds are cleaned by immersion in a chemical bath and cured in a UV oven***
