CPC B29C 64/124 (2017.08) [B29C 64/188 (2017.08); B29C 64/20 (2017.08); B33Y 10/00 (2014.12); B33Y 30/00 (2014.12)] | 24 Claims |
1. A method for printing a 3D part in a layer-wise manner, the method comprising the steps of:
providing a pool of polymerizable liquid in a vessel over a build window;
positioning a downward-facing build platform in the pool, thereby defining a build region above the build window;
selectively curing a volume of polymerizable liquid in the build region by imparting electromagnetic radiation through the build window to form a printed layer of the part with a polymerization reaction, wherein the printed layer is adhered to the build platform;
actively cooling the build window to remove energy imparted by the electromagnetic radiation and the polymerization reaction of the polymerizable liquid such that the printed layer is between about 1° C. and about 30° C. below an average part temperature, wherein the active cooling is transient and is performed after the selectively curing step;
separating the cooled printed layer from the top surface of the build window;
raising the build platform to a height of a next layer to be printed; and
repeating the selectively curing, actively cooling, separating and raising steps until the part is printed.
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