Patent ID: 8257623
Filing Date: 2012-09-04
Classification: B28B,B29C,B29L

Abstract:
1. A method of modifying an extrusion die to alter a flow of extrudable material through the die comprising: collecting a data set that correlates each one of a set of extrudable material flow front heights z in an extrusion direction D through the die with a corresponding set of lateral location coordinates x,y referencing a discharge location on a discharge face of the die, the flow front heights z being determined from calculated or observed flows of extrudable material through the die; determining a minimum flow front height zMIN and corresponding lateral location coordinates xMIN and yMIN from the data set; inserting a graded resistance flow restrictor upstream of the die, the flow restrictor having a minimum flow resistance portion disposed upstream of lateral location coordinates xMIN and yMIN on the discharge face of the die; forcing an abrasive extrudable material through the flow restrictor and the die for a time and at a flow rate sufficient to abrade a section of the die having coordinates xMIN and yMIN to a greater extent than sections of the die spaced away from coordinates xMIN and yMIN; and removing the flow restrictor from upstream of the die.