Balloon mold design

Abstract

A catheter balloon molding system designed to facilitate multi-expansion step balloon forming processes using a segmented mold form. A multi-mating segment of the mold form, defining one end portion of the balloon, is retained throughout the multiple steps and the parison is kept in place in the multi-mating segment between expansion steps while the mold form is reconfigured for the next expansion step.

1 . A segmented mold system for forming a balloon from a tubular parison in a multi-step balloon expansion process, the balloon having α- and β-end portions and an intermediate body portion therebetween the system comprising: 
 a multi-mating α-end segment having a cavity sized to receive a portion of said parison and to define the α-end portion of the balloon configuration, said multi-mating end segment further having a mating edge portion adapted to mate with an adjacent mold portion,    a first-expansion-step portion having a mating edge portion adapted to mate with said mating edge portion of the multi-mating α-end segment and having a cavity that receives a portion of the parison and defines a portion of a partially expanded configuration to which the parison will be expanded in a first expansion step, and    a second-expansion-step portion having a mating edge portion adapted to mate with said mating edge portion of the multi-mating α-end segment and having a cavity that receives a partially expanded parison and defines a portion of the balloon configuration to which the partially expanded balloon parison will be further expanded in a second expansion step.    
     
     
         2 . A segmented mold system as in  claim 1  wherein each of the first-expansion-step and second-expansion-step portions consists of a single segment.  
     
     
         3 . A segmented mold system as in  claim 1  wherein at least one of the first-expansion-step and second-expansion-step portions comprises two or more linearly sequential segments.  
     
     
         4 . A segmented mold system as in  claim 1  wherein each of the first-expansion-step and second-expansion-step portions comprises two or more linearly sequential segments.  
     
     
         5 . A segmented mold system as in  claim 1  further comprising a multi-mating β-end segment having a cavity sized to define the β-end portion of the balloon, said multi-mating β-end segment further having a mating edge portion adapted to mate with both said first-expansion-step portion and said second-expansion-step portion.  
     
     
         6 . A segmented mold system as in  claim 1  further comprising at least one further expansion-step-portion having a mating edge portion adapted to mate with said mating edge portion of the multi-mating α-end segment and having a cavity that receives a partially expanded parison and defines a portion of the balloon configuration to which the partially expanded balloon parison will be further expanded in a further expansion step.  
     
     
         7 . A segmented mold system as in  claim 1  wherein the α-end segment is sized to provide a distal end of the balloon when mounted on a catheter.  
     
     
         8 . A segmented mold system as in  claim 1  wherein the α-end segment is sized to provide a proximal end of the balloon when mounted on a catheter.  
     
     
         9 . A segmented mold system as in  claim 1  adapted for immersion in a heated fluid.  
     
     
         10 . A multi-step balloon forming process comprising 
 providing a tubular parison of thermoplastic material    expanding the tubular parison in a first expansion step to provide a partially expanded parison and    expanding the partially expanded parison in a second expansion step, wherein    the first expansion step is performed in a segmented mold form comprising:    a multi-mating α-end segment having a cavity sized to receive a portion of said tubular parison and to define an α-end portion of the balloon, said multi-mating end segment further having a mating edge portion adapted to mate with an adjacent mold portion, and    a first-expansion-step portion having a mating edge portion adapted to mate with said mating edge portion of the multi-mating α-end segment and having a cavity that receives a portion of the parison and defines a portion of a partially expanded configuration to which the parison is expanded in the first expansion step, and    the second expansion step is performed in a segmented mold form comprising:    said multi-mating α-end segment, and    a second-expansion-step portion having a mating edge portion adapted to mate with said mating edge portion of the multi-mating α-end segment and having a cavity that receives a partially expanded parison and defines a portion of the balloon configuration to which the partially expanded parison is expanded in the second expansion step.    
     
     
         11 . A method as in  claim 10  wherein, between the first and second expansion steps the first-expansion-step portion is removed from the mold form and, during removal thereof, the partially expanded parison is held in engagement with the multi-mating α-end segment.  
     
     
         12 . A method as in  claim 11  wherein, prior to the second expansion step the second-expansion-step portion is assembled over the partially expanded parison and into mating relationship with the multi-mating α-end segment.  
     
     
         13 . A method as in  claim 11  wherein in the first expansion step the mold form further comprises a multi-mating β-end segment having a cavity sized to define the β-end portion of the balloon, said multi-mating β-end segment further having a mating edge portion adapted to mate with both said first-expansion-step portion and said second-expansion-step portion.  
     
     
         14 . A method as in  claim 13  wherein, prior to the second expansion step the second-expansion-step portion is assembled over the partially expanded parison and into mating relationship with the multi-mating α-end segment and the multi-mating β-end segment is assembled over the partially expanded parison and into mating relationship with the second-expansion-step portion.  
     
     
         15 . A method as in  claim 10  further comprising further expanding the parison in at least one further expansion step subsequent to said second expansion step.  
     
     
         16 . A method as in  claim 15  wherein each further expanding step in performed in a mold form that comprises said multi-mating α-end segment and a one further expansion-step-portion having a mating edge portion adapted to mate with said mating edge portion of the multi-mating α-end segment and having a cavity that defines a portion of the configuration to which the partially expanded parison is successively further expanded.  
     
     
         17 . A method as in  claim 10  wherein the α-end segment is sized to provide a distal end of the balloon when mounted on a catheter.  
     
     
         18 . A method as in  claim 10  wherein the α-end segment is sized to provide a proximal end of the balloon when mounted on a catheter.  
     
     
         19 . A method as in  claim 10  wherein at least one the first and second-expansion-step portions of the mold form consists of a single segment.  
     
     
         20 . A method as in  claim 10  wherein at least one of the first and second-expansion-step portions comprises two or more linearly sequential segments.  
     
     
         21 . A method as in  claim 10  wherein each of the first and second-expansion-step portions comprises two or more linearly sequential segments.