Aligned fiber reinforced molding

Abstract

Methods and apparatus for additive manufactures of complex parts using co-aligned continuous fibers are disclosed. Filament subunits having complex shapes are fabricated and inserted into a mold cavity. The layup is compression molded to form a complex part having high tensile strength.

What is claimed: 
     
         1 . A method of fabricating a fiber-reinforced composite part, the part consisting of a plurality of fibers and matrix material sourced from a plurality of filament subunits, the method comprising:
 placing the plurality of filament subunits into a mold cavity, the plurality of filament subunits defining a layup, wherein;
 (i) each of the filament subunits independently comprises a plurality of fibers impregnated with a matrix material; 
 (ii) each of the filament subunits has a substantially circular or oval cross section; 
 (iii) the plurality of fibers extends the length of the filament subunit; and 
 (iv) each of the filament subunits is not in the form of a tape or sheet of material; and 
   consolidating the layup in the mold cavity by compression molding to provide a fiber-reinforced composite part.   
     
     
         2 . The method of  claim 1 , wherein each of the filament subunits is independently selected from a linear filament subunit, a shaped filament subunit, or a combination thereof. 
     
     
         3 . The method of  claim 1 , wherein the plurality of filament subunits comprises a linear filament subunit. 
     
     
         4 . The method of  claim 1 , wherein the plurality of filament subunits comprises a shaped filament subunit. 
     
     
         5 . The method of  claim 1 , wherein at least some of the filament subunits have a shape that corresponds to a shape of a portion of the mold cavity in which the respective filament subunit is placed. 
     
     
         6 . The method of  claim 1 , wherein the matrix material comprises a thermoplastic composition. 
     
     
         7 . The method of  claim 1 , wherein the matrix material comprises a thermosetting composition. 
     
     
         8 . The method of  claim 1 , wherein the matrix material comprises a moldable ceramic composition. 
     
     
         9 . The method of  claim 1 , wherein the matrix material further comprises a filler. 
     
     
         10 . The method of  claim 9 , wherein the filler comprises an inorganic filler, an organic filler, or a combination thereof. 
     
     
         11 . The method of  claim 1 , wherein the plurality of fibers comprises silica fiber, glass fiber, carbon nanotubes, carbon fiber, polymer fiber, metal fiber, ceramic fiber, natural fiber, synthetic fiber, or a combination of any of the foregoing. 
     
     
         12 . The method of  claim 1 , wherein the plurality of fibers comprises braided fiber, woven fiber, twisted fiber, or a combination of any of the foregoing. 
     
     
         13 . The method of  claim 1 , wherein the plurality of fibers comprises co-aligned fiber. 
     
     
         14 . The method of  claim 1 , wherein some of the filament subunits consist of non-aligned fiber. 
     
     
         15 . The method of  claim 14 , wherein the non-aligned fiber is milled fiber. 
     
     
         16 . The method of  claim 14 , wherein the non-aligned fiber is chopped fiber. 
     
     
         17 . The method of  claim 1 , wherein placing comprises placing a filament subunit onto an underlying filament, adjacent filament, or a combination thereof. 
     
     
         18 . A method of fabricating a fiber-reinforced composite part, the part consisting of a plurality of fibers and matrix material sourced from a plurality of filament subunits, the method comprising:
 placing the plurality of filament subunits into a mold cavity, the plurality of filament subunits defining a layup, wherein;   (i) each of the filament subunits independently comprises a plurality of fibers impregnated with a matrix material;   (ii) each of the filament subunits has a substantially circular or oval cross section;   (iii) the plurality of fibers extends the length of the filament subunit;   (iv) at least some of the filament subunits have at least one bend therein; and   (v) each of the filament subunits is not in the form of a tape or sheet of material; and   compression molding the layup to provide the fiber-reinforced composite part.