Stereolithography: speeding time to market

Stereolithography (SL) was introduced by 3D Systems in 1988. Stereolithography Apparatus (SLA) systems produce accurate plastic solid objects from solid or fully surfaced CAD data. After “slicing” the CAD model into the chosen layer thickness anywhere between 0.004 inch and 0.020 inch, ultraviolet laser radiation is directed onto a vat of liquid photopolymer. Where the polymer is sufficiently exposed to the laser´s beam, it hardens to the regulated depth. After each cross-section is drawn by the laser, the platform on which the exposed cross-section of the part rests is lowered, submerging the hardened material under the surface of the liquid in the vat. Another laser-drawn cross-section creates the next layer of the part. Layer by layer, the part is built up through repeatedly drawn cross-sections. Since its introduction, SL has come to be used worldwide as a tool for rapid product development. According to figures compiled for SME, stereolithography represents approximately 75 percent of all Rapid Prototyping and Manufacturing (RP&M) equipment in use at the present time