Resin cassettes with liquid inhibitor beds to minimize ghosting during additive manufacturing

Abstract

An apparatus for manufacturing an object from a light polymerizable resin includes (a) an carrier platform on which an object can be produced; (b) a resin cassette configured for carrying a light-polymerizable resin, said cassette including a light-transmissive window having a liquid inhibitor supply bed therein, said supply bed having an inlet and an outlet; (c) a light source positioned beneath said resin cassette and configured for projecting an enlarged image through said window; (d) a drive operatively associated with said resin cassette and said carrier platform; (e) a gas exchanger comprising a liquid side, a gas side, and an oxygen permeable barrier therebetween; said liquid side having an inlet and an outlet, with said supply bed inlet connected to said liquid side outlet, and said supply bed outlet connected to said liquid side inlet; (f) an oxygen carrying liquid in said liquid inhibitor supply bed and said gas exchanger liquid side; and (g) a pump operatively associated with said supply bed and said gas exchanger liquid side for circulating said oxygen carrying liquid therebetween; and (h) an oxygen gas source operatively associated with said gas exchanger gas side.