Medical device balloons with improved strength properties and processes for producing the same

Abstract

A tubular parison for forming a medical device balloon. The parison is formed of a polymeric material, for instance a thermoplastic elastomer. The parison has an elongation at break which is not more than 80% of the elongation of the bulk polymeric material. The elongation of the parison is controlled by altering extrusion conditions. Balloons prepared from the parisons provide higher wall strength and/or higher inflation durability than balloons prepared from conventional parisons of the same material.

1 . A method of making a parison for forming a medical device balloon, the method comprising extruding a tube of polymeric material to form the tube, wherein the extrusion is controlled to provide the extruded tube with an elongation at break which is not more than 80% of the elongation at break of the bulk polymeric material.  
     
     
         2 . A method as in  claim 1  wherein the elongation at break of the extruded tube is not more than about 70% of the elongation at break of the bulk polymeric material.  
     
     
         3 . A method of making a parison for forming a medical device balloon, the method comprising extruding a tube of polymeric material to form the tube, the extrusion having a draw down ration of about 8 or higher.  
     
     
         4 . A method of making a parison for forming a medical device balloon, the method comprising extruding a tube of polymeric material from an extruder having a barrel where the mixture is kept in molten state at a barrel temperature and a die zone where the molten material is pushed through a die to form the tube, wherein the die zone is kept at a temperature at least 5° F. below the barrel temperature.  
     
     
         5 . A method as in  claim 4  wherein said die zone temperature is 10-40° F. below the barrel temperature.  
     
     
         6 . A method as in  claim 4  wherein said die zone temperature is 20-30° F. below the barrel temperature.  
     
     
         7 - 24 . (canceled)