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 optionally but preferably detachable carrier platform on which an object can be produced (e.g., a carrier platform removably coupled to a platform mount); (b) a resin cassette configured for carrying a light-polymerizable resin, said cassette including a light-transmissive window, said 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 and configured for advancing said carrier platform and said resin cassette away from one another; (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 window supply bed and said gas exchanger liquid side; and (g) a pump (e.g., an optionally reversable 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 (e.g., an oxygen concentrator) operatively associated with said gas exchanger gas side.

We claim: 
     
         1 . A method of making an object from a light polymerizable resin and a data file, comprising:
 (a) filling a resin cassette in an apparatus with resin, said apparatus comprising:
 (i) a carrier platform on which an object can be produced; 
 (ii) a resin cassette configured for carrying a light-polymerizable resin, said cassette including a light-transmissive window, said window having a liquid inhibitor supply bed therein, said supply bed having an inlet and an outlet; 
 (iii) a light source positioned beneath said resin cassette and configured for projecting an enlarged image through said window; 
 (iv) a drive operatively associated with said resin cassette and said carrier platform and configured for advancing said carrier platform and said resin cassette away from one another; 
 (v) 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; 
 (vi) an oxygen carrying liquid in said liquid inhibitor supply bed and said gas exchanger liquid side; and 
 (vii) a pump operatively associated with said liquid inhibitor supply bed and said gas exchanger liquid side for circulating said oxygen carrying liquid therebetween; and 
 (vii) an oxygen gas source operatively associated with said gas exchanger gas side; and 
   (b) producing said object from said data file and said resin by intermittently and/or continuously exposing said resin to an enlarged image that is spatially and temporally modulated from said light source to photopolymerize said resin, while advancing said carrier platform and said resin cassette away from one another.   
     
     
         2 . The method of  claim 1 , wherein said resin comprises a dual cure resin. 
     
     
         3 . The method of  claim 1 , wherein said oxygen carrying liquid is a non-aqueous, or organic, liquid. 
     
     
         4 . The method of  claim 1 , wherein said liquid inhibitor supply bed comprises a plurality of channels. 
     
     
         5 . The method of  claim 1 , wherein said window comprises a sandwich of at least top portion an intermediate portion, and a bottom portion, and said liquid inhibitor supply bed is formed in said intermediate portion. 
     
     
         6 . A resin cassette for manufacturing an object from a light polymerizable resin, comprising:
 (a) a light-transmissive window, said window having a liquid inhibitor supply bed therein, said liquid inhibitor supply bed having an inlet and an outlet;   (b) a circumferential frame surrounding said window, said window and frame together forming a well configured to receive a light polymerizable resin;   (c) a gas exchanger carried by said frame, said 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 liquid inhibitor supply bed inlet connected to said liquid side outlet, and said liquid inhibitor supply bed outlet connected to said liquid side inlet;   (d) an oxygen carrying liquid in said liquid inhibitor supply bed and said gas exchanger liquid side; and   (e) a pump carried by said frame, said pump operatively associated with said liquid inhibitor supply bed and said gas exchanger liquid side for circulating said oxygen carrying liquid therebetween; and   (f) gas connectors on said frame and operatively associated with said gas exchanger gas side for connecting said gas side to an oxygen gas source.   
     
     
         7 . The resin cassette of  claim 6 , wherein said pump comprises a pneumatically actuated pump. 
     
     
         8 . The resin cassette of  claim 6 , wherein said liquid inhibitor supply bed comprises a plurality of channels.