Manufacturing Process Selection Handbook

Chapter 8

Rapid Prototyping Processes

8.1 Stereolithography (SLA)

Process Description

A low-power laser beam is directed by a mirror to trace a thin 2D cross-section in a liquid photopolymer resin that is stored in a build chamber. Through the process of photopolymerisation, a layer of hardened and cured 3D pixels of polymer are created, a process which only takes place near the surface due to absorption and scattering of the laser beam. The build platform is lowered down an amount equal to the thickness of the previously cured layer, and a sweeper blade moves across replenishing a layer of resin. The laser traces out the next 2D cross-section and the process is repeated. The self-adhesive property of the material used causes the layers to bond ...