Molds and related methods and articles

Abstract

Low polymer stress balloons are made by expanding a tube radially while allowing the ends of the tube to move axially in response to the radial expansion.

1 . A method of making a medical balloon, comprising: 
 providing a polymer tube suitable for being formed into the medical balloon, the tube having two ends;    drawing the tube axially; and    expanding the tube radially while allowing the ends of the tube to move axially in response to said radial expansion.    
     
     
         2 . The method of  claim 1 , wherein the tube is below a glass transition temperature of a material of the tube during drawing.  
     
     
         3 . The method of  claim 2 , wherein the tube is below about 100° C. during drawing.  
     
     
         4 . The method of  claim 1 , wherein the tube is internally pressurized during drawing.  
     
     
         5 . The method of  claim 1 , wherein expanding the tube comprises heating the tube.  
     
     
         6 . The method of  claim 5 , wherein the tube is heated to a temperature about equal to or greater than a glass transition temperature of a material of the tube.  
     
     
         7 . The method of  claim 1 , wherein the tube is expanded to an expanded diameter about 5 to 9 times larger than an unexpanded diameter of the tube.  
     
     
         8 . The method of  claim 1 , wherein expanding the tube comprises simultaneously heating and pressurizing the tube.  
     
     
         9 . The method of  claim 1 , wherein expanding the tube comprises: 
 positioning the tube into a mold; and    simultaneously heating and pressurizing the tube.    
     
     
         10 . The method of  claim 1 , wherein expanding the tube comprises contacting the tube with a liquid.  
     
     
         11 . The method of  claim 10 , wherein the liquid comprises water.  
     
     
         12 . The method of  claim 1 , wherein the ends of the tube are allowed to move axially a distance between about 5 and about 30 percent of an original length of the tube.  
     
     
         13 . The method of  claim 1 , wherein the tube is formed of a polymer having regions of different hardnesses.  
     
     
         14 . The method of  claim 1 , wherein the tube comprises a block copolymer including hard segments and soft segments.  
     
     
         15 . The method of  claim 14 , wherein the block copolymer comprises a material selected from a group consisting of a polyether-ester elastomer, a polyester elastomer, and a polyether block amide.  
     
     
         16 . The method of  claim 14 , wherein the block copolymer comprises a polyether-ester elastomer.  
     
     
         17 . The method of  claim 1 , wherein the tube comprises a material selected from a group consisting of a polyester and a polyamide.  
     
     
         18 . The method of  claim 1 , wherein the tube is a multilayer tube.  
     
     
         19 . The method of  claim 1 , wherein the tube is a coextruded tube having layers of different hardnesses.  
     
     
         20 . The method of  claim 1 , further comprising characterizing the balloon by birefringence.  
     
     
         21 . The method of  claim 1 , further comprising attaching the balloon to a catheter to form a balloon catheter device.  
     
     
         22 . The method of  claim 1 , further comprising sterilizing the balloon by heating between about 32° C. and about 60° C.  
     
     
         23 . The method of  claim 1 , wherein expanding the tube radially comprises allowing the ends of the tube to move inwardly in response to said radial expansion.  
     
     
         24 . A method of making a medical balloon, comprising: 
 providing a polymer tube suitable for being formed into the medical balloon, the tube having two ends; and    expanding the tube radially while allowing the ends of the tube to move axially in response to said radial expansion.    
     
     
         25 . The method of  claim 24 , further comprising axially orienting a material of the tube.  
     
     
         26 . The method of  claim 25 , wherein axially orienting the material comprises axially drawing the tube.  
     
     
         27 . The method of  claim 26 , wherein axially orienting the material further comprises internally pressurizing the tube.  
     
     
         28 . The method of  claim 24 , wherein expanding the tube comprises contacting the tube with a liquid.  
     
     
         29 . The method of  claim 28 , wherein the liquid comprises water.  
     
     
         30 . The method of  claim 24 , wherein expanding the tube comprises: 
 heating the tube to a temperature about equal to or greater than a glass transition temperature of a material of the tube; and    introducing a gas into the tube.    
     
     
         31 . The method of  claim 24 , wherein expanding the tube further comprises placing the tube into a mold.  
     
     
         32 . The method of  claim 24 , wherein the tube comprises a block copolymer.  
     
     
         33 . The method of  claim 24 , further comprising characterizing the balloon by birefringence.  
     
     
         34 . The method of  claim 24 , further comprising attaching the balloon to a catheter to form a balloon catheter device.  
     
     
         35 . The method of  claim 1 , further comprising positioning a stent on the balloon.  
     
     
         36 . The method of  claim 24 , further comprising positioning a stent on the balloon.  
     
     
         37 . A medical balloon product made according to the method of  claim 1 .  
     
     
         38 . A medical balloon product made according to the method of  claim 24 .  
     
     
         39 . A medical balloon comprising a block copolymer having a cylindrically-shaped region exhibiting a birefringence pattern of substantially parallel lines before and after an exposure to temperatures of about 32° C. to about 60° C.  
     
     
         40 . The balloon of  claim 39 , wherein the cylindrically-shaped region has a length between about 1.5 cm and about 14 cm.  
     
     
         41 . The balloon of  claim 39 , wherein the cylindrically-shaped region has an outer diameter between about 1 mm and about 12 mm.  
     
     
         42 . The balloon of  claim 39 , formed of a polymer having regions of different hardness.  
     
     
         43 . The balloon of  claim 39 , wherein the block copolymer includes hard segments and soft segments.  
     
     
         44 . The balloon of  claim 39 , wherein the block copolymer comprises a material selected from a group consisting of a polyether-ester elastomer, a polyester elastomer, and a polyether block amide.  
     
     
         45 . The balloon of  claim 39 , wherein the block copolymer comprises a polyether-ester elastomer.  
     
     
         46 . The balloon of  claim 39 , comprising a material selected from a group consisting of a polyester and a polyamide.  
     
     
         47 . The balloon of  claim 39 , formed of multiple layers.  
     
     
         48 . The balloon of  claim 47 , formed of multiple coextruded layers having different hardnesses.