What is DLP 3D printing?

the process

DLP stands for digital light processing (or direct light projection), and is a type of vat polymerization. Vat polymerization 3D printing technologies make use of a (liquid) photopolymer resin which is able to solidify under a UV light source [1].

In the case of DLP, light is projected indirectly upwards either by a galvanometer [2] or directly by a UV OLED display with a resolution similar to a smartphone display.

An adjustable build plate [3] is initially submerged in the resin bath which has a transparent surface [4] at the bottom. The UV projector or light source [1] then projects a cross section of the model through the transparent base of the bath which solidifies a single layer of the photopolymer onto the build plate.

Support structures can be created if the fluid cannot support the weight of the component's overhanging parts. The build plate is then raised a fraction of a millimetre for each individual layer and the process repeats until the semi-processed model [5] is formed.

Lastly, after the model has its support structures removed and is cleaned, it is then cured in a UV oven. Unsolidified resin in the bath can be recycled to produce new printed models.