Method for producing injection-molded parts

Abstract

In a method of producing an injection-molded part, a material is processed and/or plasticized by means of a multi-screw extruder having a plurality of processing zones. An additive having barrier characteristics is admixed by a feed unit in at least one of the processing zones. The material is processed and dried in the extruder, and can then be transferred to a transfer reservoir for further processing.

1 . A method of producing an injection-molded part, comprising the steps of:
 processing and/or plasticizing a material by means of a multi-screw extruder having a plurality of processing zones;   admixing an additive having barrier characteristics by a feed unit in at least one of the processing zones; and   processing and drying the material in the extruder.   
     
     
         2 . The method of  claim 1 , further comprising the step of degassing the material in one of the processing zones. 
     
     
         3 . The method of  claim 1 , further comprising the step of degassing the material in at least two of the processing zones. 
     
     
         4 . The method of  claim 1 , wherein the injection-molded part is a PET preform. 
     
     
         5 . The method of  claim 1 , wherein the material is selected from the group consisting of PET, PP, PEN, PET/PEN, PAT/PA, PET/EVOH, PLA, amorphous/partially crystalline recycled substances and flakes. 
     
     
         6 . The method of  claim 1 , wherein the additive is at least one member selected from the group consisting of filler, oxygen scavenger, UV stabilizer, brightener, increaser or viscosity, color additive, polyamide, and aromatized polyamide. 
     
     
         7 . The method of  claim 1 , wherein the additive is in powder form. 
     
     
         8 . The method of  claim 6 , wherein the filler is selected from the group consisting of titanium dioxide and nano-composites.