Stereolithography (SLA)

Stereolithography is an additive manufacturing process that employs a vat of liquid ultraviolet curable photopolymer “resin” and an ultraviolet laser to build parts layers one at the time.

For each layer the laser beam traces a cross section of the part pattern on the surface of the liquid resin. Exposure to the ultraviolet laser light cures and solidifies the pattern traced on the resin and joins it to the layer below.

Stereolithography requires the use of supporting structures which serve to attach the part to the elevator platform. Supports are generated automatically in the process of preparing the file for printing and can also be manipulated manually. Supports have to be removed after the built is complete and cured manually.

Parts produced through steriolithography are strong enough to be machined and can be used as master patterns for injection molding, thermoforming, blow molding and various metal casting processes. Although SLA can produce multiple parts at the same time, but it tends to be expensive due to the cost of the liquid resin and the post processing required removing supports and smoothing the surfaces by sanding.

Advantages:

  • Parts are accurate
  • SLA parts can be used to create molds
  • SLA parts are strong enough to be machined if required
  • Good surface finish

Disadvantages:

  • Limited materials
  • High cost or materials
  • Slow process
  • Poor mechanical properties