Impregnation Section of Die and Method for Impregnating Fiber Rovings

Abstract

An impregnation section ( 150 ) and a method for impregnating fiber rovings ( 142 ) with a polymer resin ( 214 ) are disclosed. The impregnation section ( 150 ) includes an impregnation zone ( 250 ) and a gate passage ( 270 ). The impregnation zone ( 250 ) is configured to impregnate the plurality of rovings ( 142 ) with the resin ( 214 ). The gate passage ( 270 ) is in fluid communication with the impregnation zone ( 250 ) for flowing the resin therethrough such that the resin impinges on a surface ( 216 ) of each of the plurality of rovings ( 142 ) facing the gate passage ( 270 ) and substantially uniformly coats the plurality of rovings. The method includes impinging a polymer resin ( 214 ) onto a surface of a plurality of fiber rovings ( 142 ), and substantially uniformly coating the plurality of rovings with the resin. The method further includes traversing the plurality of coated rovings through an impregnation zone ( 250 ). Each of the plurality of rovings ( 142 ) is under a tension of from about 5 Newtons to about 300 Newtons within the impregnation zone ( 250 ).

1 . An impregnation section of a die for impregnating a plurality of fiber rovings with a polymer resin, the impregnation section comprising:
 an impregnation zone configured to impregnate the plurality of rovings with the resin; and   a gate passage in fluid communication with the impregnation zone for flowing the resin therethrough such that the resin impinges on a surface of each of the plurality of rovings facing the gate passage and substantially uniformly coats the plurality of rovings.   
     
     
         2 . The impregnation section of  claim 1 , wherein the gate passage extends vertically to the impregnation zone. 
     
     
         3 . The impregnation section of  claim 1 , wherein at least a portion of the gate passage has a decreasing cross-sectional profile in a flow direction of the resin. 
     
     
         4 . The impregnation section of  claim 1 , wherein the impregnation zone comprises a plurality of contact surfaces. 
     
     
         5 . The impregnation section of  claim 4 , wherein the impregnation zone comprises between 2 and 50 contact surfaces. 
     
     
         6 . The impregnation section of  claim 4 , wherein each of the plurality of contact surfaces comprises a curvilinear contact surface. 
     
     
         7 . The impregnation section of  claim 4 , wherein each of the plurality of contact surfaces is configured such that the plurality of rovings traverse the contact surface at an angle in the range between 1 degree and 30 degrees. 
     
     
         8 . The impregnation section of  claim 1 , wherein the impregnation zone has a waveform cross-sectional profile. 
     
     
         9 . The impregnation section of  claim 1 , wherein the impregnation zone comprises a plurality of pins. 
     
     
         10 . The impregnation section of  claim 9 , wherein each of the plurality of pins is static. 
     
     
         11 . The impregnation section of  claim 9 , wherein each of the plurality of pins is rotationally driven. 
     
     
         12 . The impregnation section of  claim 1 , further comprising a first plate defining a first inner surface and a second plate spaced apart from the first plate and defining a second opposing inner surface, wherein the impregnation zone is defined between the first plate and the second plate, and wherein the impregnation zone comprises a plurality of contact surfaces defined on only one of the first inner surface or the second inner surface. 
     
     
         13 . The impregnation section of  claim 1 , further comprising a land zone downstream of the impregnation zone in a run direction of the plurality of rovings. 
     
     
         14 . The impregnation section of  claim 13 , wherein at least a portion of the land zone has an increasing cross-sectional profile in the run direction. 
     
     
         15 . The impregnation section of  claim 1 , further comprising a faceplate adjoining the impregnation zone, the faceplate configured to meter excess resin within the plurality of rovings. 
     
     
         16 . The impregnation section of any of  claim 1 , wherein the resin is a thermoplastic resin. 
     
     
         17 . The impregnation section of  claim 1 , wherein the resin is a thermoset resin. 
     
     
         18 . A method for impregnating a plurality of fiber rovings with a polymer resin, the method comprising:
 impinging a polymer resin onto a surface of a plurality of fiber rovings,   substantially uniformly coating the plurality of rovings with the resin; and   traversing the plurality of coated rovings through an impregnation zone to impregnate the plurality of coated rovings with the resin, wherein each of the plurality of rovings is under a tension of from about 5 Newtons to about 300 Newtons within the impregnation zone.   
     
     
         19 . The method of  claim 18 , further comprising flowing the resin through a gate passage, and wherein at least a portion of the gate passage has a decreasing cross-sectional profile in a flow direction of the resin. 
     
     
         20 . The method of  claim 18 , wherein the plurality of rovings traverse from the impregnation zone through a land zone, the land zone positioned downstream of the impregnation zone in a run direction of the plurality of rovings.