Methods, apparatuses and systems for additive manufacturing with preheat

Abstract

The present disclosure provides methods for additive manufacturing of a three-dimensional (3D) object, comprising preheating a feed comprising a polymer material to a temperature in excess of a glass transition temperature and below a melting point of the polymer material. The preheating may occur at a first location in an additive manufacturing apparatus. Next, the polymer material may be melted at a second location that is spatially distinct from the first location.

1 - 26 . (canceled) 
     
     
         27 . A system for printing at least a portion of a three-dimensional (3D) object, comprising:
 a source of at least one feedstock that is configured to supply said at least one feedstock for printing said at least said portion of said 3D object, which said at least one feedstock comprises a polymer material;   a substrate for supporting said at least said portion of said 3D object during printing;   a printing unit that is configured to direct said at least one feedstock from said source of said at least one feedstock towards said substrate;   at least one energy source configured to provide energy; and   a controller operatively coupled to said printing unit and said at least one energy source, wherein said controller is programmed to direct said at least one energy source to provide said energy to:   (i) preheat, at a first location in said printing unit, said at least one feedstock to a preheat temperature in excess of a glass transition temperature and below a melting temperature of said polymer material, to thereby provide a preheated feedstock, and   (ii) melt, at a second location that is spatially distinct from said first location, said preheated feedstock to provide a melted feedstock.   
     
     
         28 . The system of  claim 27 , wherein said at least one energy source is selected from the group consisting of a direct contact heater, a hot air blower, and a laser. 
     
     
         29 . The system of  claim 27 , wherein said at least one energy source is a laser configured to provide said energy comprising a first light beam and a second light beam. 
     
     
         30 . The system of  claim 29 , wherein said controller is further programmed, in (i), to direct said at least one energy source to provide said first light beam to preheat said at least one feedstock. 
     
     
         31 . The system of  claim 29 , wherein said controller is further programmed, in (ii), to direct said at least one energy source to provide said second light beam to melt said preheated feedstock. 
     
     
         32 . The system of  claim 29 , further comprising a beam splitter configured to split a light beam from said at least one energy source into said first light beam and said second light beam. 
     
     
         33 . The system of  claim 29 , wherein said first light beam has a different intensity than said second light beam. 
     
     
         34 . The system of  claim 27 , wherein said controller is further programmed, prior to (ii), to use said printing unit to direct said preheated feedstock to said second location. 
     
     
         35 . The system of  claim 34 , wherein said second location is external to said printing unit. 
     
     
         36 . The system of  claim 27 , wherein said preheat temperature is in a range of about 0.7 to 0.95 times the melting temperature of said polymer material. 
     
     
         37 . The system of  claim 27 , wherein said preheat temperature is in a range of about 0.8 to 0.9 times the melting temperature of said polymer material. 
     
     
         38 . The system of  claim 27 , wherein (i) occurs in a first period of time and (ii) occurs in a second period of time, and wherein said first period of time is longer than said second period of time. 
     
     
         39 . The system of  claim 27 , wherein said at least one feedstock is a continuous fiber composite. 
     
     
         40 . The system of  claim 27 , wherein said polymer material comprises a semi-crystalline polymer. 
     
     
         41 . The system of  claim 27 , further comprising a compaction unit configured to compact said at least one feedstock along said substrate. 
     
     
         42 . The system of  claim 41 , wherein said compaction unit comprises a rigid body, one or more idler rollers, at least one freely suspended roller, a coolant unit, or any combination thereof. 
     
     
         43 . The system of  claim 41 , wherein said compaction unit is configured to be positioned along only one side of said melted feedstock. 
     
     
         44 . The system of  claim 41 , wherein said controller is further programmed to direct said compaction unit to compact said melted feedstock. 
     
     
         45 . The system of  claim 41 , wherein said controller is further programmed to direct said compaction unit to cool said melted feedstock. 
     
     
         46 . The system of  claim 27 , further comprising one or more sensors configured to measure one or more feedstock temperatures along said at least one feedstock during printing.