Extruder and molding assembly

Abstract

An extruder and molding assembly comprising an extruder positioned upstream from a mold, the mold having a mold cavity and a separate pressurization member fluidly connected to the mold cavity wherein the extruder is operable at a first pressure to fill at least a majority of the mold cavity and the pressurization member is operable to fill a remainder of the mold cavity.

1 . An extruder and molding assembly comprising an extruder positioned upstream from a mold, the mold having a mold cavity and a pressurization member fluidly connected to the mold cavity wherein the extruder is operable at a first pressure to fill at least a majority of the mold cavity and the pressurization member is operable to fill a remainder of the mold cavity, wherein the extruder is operable at a pressure of 1-500 psi when filing the mold and the pressurization member is operable at a pressure above 500 psi to fill the remainder of the mold cavity and wherein the pressurization member is external to the mold. 
     
     
         2 . The assembly of  claim 1  further comprising an isolation mechanism operable to isolate an interior of the extruder containing a screw from the mold cavity. 
     
     
         3 . The assembly of  claim 1  wherein the extruder is operable at a pressure of 10-200 psi when filing the mold and the pressurization member is operable at a pressure above 1000 psi to fill the remainder of the mold cavity. 
     
     
         4 . The assembly of  claim 2  wherein the extruder is operable at a pressure of 10-200 psi when filing the mold and the pressurization member is operable at a pressure above 1000 psi to fill the remainder of the mold cavity. 
     
     
         5 . The assembly of  claim 1  further comprising a storage chamber positioned between the pressurization member and the mold cavity whereby operation of the pressurization member drives material from the storage chamber into the mold cavity. 
     
     
         6 . The assembly of  claim 5  wherein the storage chamber is fluidically connected to an outlet end of the extruder whereby the extruder fills the storage chamber concurrently with filling the mold cavity. 
     
     
         7 . The assembly of  claim 5  wherein the storage chamber is positioned on an opposite side of the mold cavity of the extruder. 
     
     
         8 . The assembly of  claim 2  further comprising a storage chamber positioned between the pressurization member and the mold cavity whereby operation of the pressurization member drives material from the storage chamber into the mold cavity. 
     
     
         9 . The assembly of  claim 8  wherein the storage chamber is fluidically connected to an outlet end of the extruder whereby the extruder fills the storage chamber concurrently with filling the mold cavity. 
     
     
         10 . The assembly of  claim 8  wherein the storage chamber is positioned on an opposite side of the mold cavity to the extruder. 
     
     
         11 . The assembly of  claim 2  wherein the isolation member comprises a valve. 
     
     
         12 . The assembly of  claim 2  wherein the isolation member comprises a cooling chamber between the mold cavity and the extruder whereby liquefied extrudate is solidified in the cooling chamber prior to operation of the pressurization member. 
     
     
         13 . The assembly of  claim 1  further comprising a mold heater. 
     
     
         14 . The assembly of  claim 2  further comprising a mold heater.