US 5,714,110 A · Process improvements for preparing catheter balloons

Abstract

A method for forming a balloon for a dilatation catheter may utilize the steps of extruding a tubing preform of a polyester resin and then blowing the tubing into an oriented balloon, wherein the tubing preform is dried prior to blowing into the balloon form. Other process steps by which balloon cone and waist thicknesses may be reduced involve varying the axial tension and blowing pressure at several stages as a mold containing the balloon preform is dipped into a heating medium. Specifically, tubing of a thermoplastic material is placed in a mold and blown by pressurizing and tensioning the tubing and gradually dipping the mold into a heated heat transfer media so as to sequentially blow a first waist, a body and a second waist portion. The tubing is subjected to a relatively lower pressure while the body portion is blown than while the first and second waist portions are blown.

Claims16

Dependent claims

In a method of preparing an oriented balloon of thermoplastic material comprising extruding a hollow tube of the thermoplastic material, and subsequently expanding the tube by subjecting the tubing, while in a mold, to an elevated temperature and an increased interior pressure to produce an oriented balloon, the improvement wherein the tube is subjected to a drying step, prior to said expanding step, thereby increasing the strength of the balloon relative to a reference balloon prepared in the same manner, except for said drying step.

In a process for forming an elongated balloon having a longitudinal body portion, first and second waist portions of reduced diameter relative to the body portion at opposite ends of the balloon and first and second cone portions connecting corresponding waist portions and respective ends of the longitudinal body portion, the process comprising the steps of placing an extruded and stretched tubular preform in a mold having an internal form corresponding to the desired outer configuration of the balloon, and forming the balloon by applying axial tension and internal pressure to the preform upon dipping of the mold into a heated heat transfer media, the improvement comprising that the forming step comprises:

pressurizing the preform to a first pressure in the range of 150-320 psi and applying a first tension in the range of 5-150 g;
dipping the mold to a first depth in the range of from the transition (C) from the first waist to the first cone to the transition (D) from the first cone to the body portion of the balloon while maintaining the first tension and the first pressure, and thereby expanding at least one portion of the preform in the mold;
pressurizing the preform to a second pressure less than the first pressure and between 80 and 170 psi and setting a second tension in the range of the first tension;
dipping the mold to a second depth in the range of from the transition (E) from the body portion to the second cone portion to the transition (F) from the second cone to the second waist while maintaining the second tension and the second pressure;
pressurizing the preform to a third pressure higher than the second pressure and between 150 and 320 psi and applying to the preform a third tension, higher than the first tension, and then,
dipping the mold to a third depth (H) beyond the depth of the second waist while maintaining the third tension and the third pressure.

3 more elements

pressurizing the preform to a first pressure in the range of 150-320 psi and applying a first tension in the range of 5-150 g;
dipping the mold to a first depth in the range of from the transition (C) from the first waist to the first cone to the transition (D) from the first cone to the body portion of the balloon while maintaining the first tension and the first pressure, and thereby expanding at least one portion of the preform in the mold;
holding the mold at the first depth for a predetermined first time interval while maintaining the first tension and the first pressure;
pressurizing the preform to a second pressure less than the first pressure and between 80 and 170 psi and setting a second tension in the range of the first tension;
dipping the mold to a second depth in the range of from the transition (E) from the body portion to the second cone portion to the transition (F) from the second cone to the second waist while maintaining the second tension and the second pressure;
holding the mold at the second depth while maintaining the second tension and the second pressure for a predetermined second time interval;
pressurizing the preform to a third pressure higher than the second pressure and between 150 and 320 psi and applying to the preform a third tension, higher than the first tension;
dipping the mold to a third depth (H) beyond the depth of the second waist while maintaining the third tension and the third pressure, and then
holding the mold at the third depth for a predetermined third time interval while maintaining the third tension and third pressure.

6 more elements

Dependencies are inferred from the claim text.

Process improvements for preparing catheter balloons

Life of this patent

Process improvements for preparing catheter balloons

Life of this patent

Abstract

Claims16