Stereolithography machines use liquid plastic.

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The Stereolithography Machine

PT CAM uses a stereolithography machine produced by 3-D Systems and shown here:

This machine has four important parts:

  • A tank filled with several gallons of liquid photopolymer. The photopolymer is a clear, liquid plastic.
  • A perforated platform immersed in the tank. The platform can move up and down in the tank as the printing process proceeds.
  • An ultraviolet laser
  • A computer that drives the laser and the platform

The photopolymer is sensitive to ultraviolet light, so when the laser touches the photopolymer, the polymer hardens.

If you stand next to the stereolithograph apparatus (SLA), you can actually see the laser as it builds each layer.