Balloon for a dilation catheter and method for manufacturing a balloon

Abstract

A method for forming a balloon for a dilation catheter is provided herein. The method includes the steps of: (i) positioning a tube in a preconditioned mold; (ii) expanding the tube in a preconditioned mold to form a parison; (iii) positioning the parison in a balloon mold; and (iv) expanding the parison within the balloon mold to form the balloon. Thus, the tube is initially expanded into a parison in the preconditioned mold. Subsequently, the parison is expanded into a balloon in the balloon mold. Because of this unique manufacturing process, polyester block copolymers can be formed into balloons. Some of these polyester block copolymers could not be formed into a balloon using prior art blow molding processes. The resulting balloon exhibits superior characteristics, including relatively thin and consistent walls, soft texture, low uninflated crossing profile, expansion in a predictable fashion, and good tensile strength.

What is claimed is:  
     
         1 . A balloon for a dilation catheter, the balloon being made from a polyester block copolymer.  
     
     
         2 . The balloon of    claim 1    wherein the polyester block copolymer consists of an aromatic polyester hard segment and an aliphatic polyester soft segment.  
     
     
         3 . The balloon of    claim 2    prepared by a process comprising the steps of: 
 providing a tube;  
 positioning the tube in a precondition mold, the precondition mold having a precondition mold inner diameter;  
 expanding the tube within the precondition mold to form a parison;  
 positioning the parison in a balloon mold, the balloon mold having a balloon mold inner diameter which is larger than the precondition mold inner diameter; and  
 expanding the parison within the balloon mold to form the balloon.  
 
     
     
         4 . The balloon of    claim 1    wherein the polyester block copolymer consists of a polybutylene terephalate hard segment and a long chain of polyether glycol soft segment.  
     
     
         5 . The balloon of    claim 4    prepared by a process comprising the steps of: 
 providing a tube;  
 positioning the tube in a precondition mold, the precondition mold having a precondition mold inner diameter;  
 expanding the tube within the precondition mold to form a parison;  
 positioning the parison in a balloon mold, the balloon mold having a balloon mold inner diameter which is larger than the precondition mold inner diameter; and  
 expanding the parison within the balloon mold to form the balloon.  
 
     
     
         6 . The balloon of    claim 1    prepared by a process comprising the steps of: 
 providing a tube having a tube outer diameter and a lumen, the tube including an aromatic polyester hard segment and an aliphatic polyester soft segment;  
 positioning the tube in a precondition mold, the precondition mold having a precondition mold inner diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than the tube outer diameter;  
 heating the tube;  
 forming a parison by pressurizing the lumen at a first pressure (P 1 ) which is at least approximately five hundred (500) psi, the parison having a parison outer diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than the tube outer diameter;  
 positioning the parison in a balloon mold, the balloon mold having a balloon mold inner diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than the precondition mold inner diameter;  
 heating the parison in the balloon mold; and  
 forming a balloon from the parison by pressurizing the lumen at a second pressure (P 2 ).  
 
     
     
         7 . A polyester block copolymer balloon for a dilation catheter, the balloon being prepared by a process comprising the steps of: 
 providing a tube;    positioning the tube in a precondition mold, the precondition mold having a precondition mold inner diameter;    preconditioning the tube within the precondition mold to form a parison;    positioning the parison in a balloon mold, the balloon mold having a balloon mold inner diameter which is larger than the precondition mold inner diameter; and    expanding the parison within the balloon mold to form the balloon.    
     
     
         8 . The balloon of    claim 7    wherein the step of preconditioning the tube includes the step of expanding the tube in the precondition mold.  
     
     
         9 . The balloon of    claim 8    wherein the step of expanding the tube includes the steps of heating the tube and pressurizing a lumen of the tube to a first pressure (P 1 ), which is at least approximately five hundred (500) psi.  
     
     
         10 . The balloon of    claim 9    wherein the step of expanding the tube includes radially expanding the tube so that the parison has a parison outer diameter, which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than a tube outer diameter of the tube.  
     
     
         11 . The balloon of    claim 10    wherein the step of expanding the tube includes axially stretching the tube between approximately one and one-half (1.5) to two and one-half (2.5) times a tube length of the tube.  
     
     
         12 . The balloon of    claim 8    wherein the step of expanding the tube includes radially expanding the tube so that the parison has a parison outer diameter which is at least over one (1) times larger than a tube outer diameter of the tube.  
     
     
         13 . The balloon of    claim 8    wherein the step of expanding the parison includes radially expanding the parison so that the balloon has a balloon outer diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than a parison outer diameter of the parison.  
     
     
         14 . The balloon of    claim 13    wherein the step of expanding the parison includes axially stretching the parison between approximately one (1.0) to one and one-half (1.5) times longer than a parison length of the parison.  
     
     
         15 . The balloon of    claim 7    wherein the step of preconditioning the tube includes radially expanding the tube so that the parison has a parison outer diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than a tube outer diameter of the tube and the step of expanding the parison includes radially expanding the parison, so that the balloon has a balloon outer diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than the parison outer diameter.  
     
     
         16 . The balloon of    claim 15    wherein the step of providing a tube includes the step of forming the tube with an aromatic polyester hard segment and an aliphatic polyester soft segment.  
     
     
         17 . The balloon of    claim 15    wherein the step of providing a tube including the step of forming the tube with a polybutylene terephalate hard segment and a long chain of polyether glycol soft segment.  
     
     
         18 . A balloon for a dilation catheter, the balloon being prepared by a process comprising the steps of: 
 providing a tube having a tube outer diameter, the tube being made of a polyester block copolymer;    expanding the tube to form a parison, the parison having a parison outer diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than the tube outer diameter; and    expanding the parison to form a balloon, the balloon having a balloon outer diameter which is between approximately one and one-half (1.5) to two and one-half (2.5) times larger than the parison outer diameter.    
     
     
         19 . The balloon of    claim 18    wherein the step of providing a tube includes providing a tube in which the polyester block copolymer consists of an aromatic polyester hard segment and an aliphatic polyester soft segment.  
     
     
         20 . The balloon of    claim 18    wherein the step of providing a tube includes providing a tube in which the polyester block copolymer consists of a polybutylene terephalate hard segment and a long chain of polyether glycol soft segment.