Multilayer medical balloon
An expandable medical balloon including an inner layer formed of a poly (ether-block-amide) copolymer and an outer layer formed of a polyamide, the expandable medical balloon having a burst strength of greater than 50,000 psi, and to methods of making and using the same.
1. A method of making an expandable medical balloon, the expandable medical balloon having an inner layer formed of a poly(ether block amide) copolymer; and an outer layer formed of a polyamide; the method comprising:
forming a tubular parison, the tubular parison comprising the inner layer formed of a poly(ether-block-amide) copolymer and the outer layer formed from a polyamide;
longitudinally stretching the tubular parison at a stretch ratio of less than 4.0; and
radially expanding the tubular parison in a balloon mold to form the expandable medical balloon.
2. The method of claim 1 further comprising heat setting said balloon at a temperature of less than about 150° C.
3. The method of claim 2 wherein said heat set temperature is about 120° C.
4. The method of claim 1 wherein said stretch ratio is about 3.5 or less.
5. The method of claim 1 wherein said polyamide is formed from laurolactam.
6. The method of claim 1 wherein said balloon mold is at a pressure of about 500 psi to about 600 psi.
7. The method of claim 1 wherein a radial cross-section of said tubular parison comprises a material ratio of about 70% to about 30% based on the outer layer to the inner layer.
8. The method of claim 1 wherein the resultant expandable medical balloon has a burst strength of 45,000 psi or more.
9. The method of claim 1 wherein the inner layer has a Shore D hardness of about 50D to about 70D.
10. The method of claim 1 wherein the outer layer has a Rockwell hardness of about 80 to about 115.
11. The method of claim 1 further comprising the step of applying a lubricious coating to at least a portion of said outer layer.
12. The method of claim 11 wherein said lubricious coating is applied by a method selected from the group consisting of dipping, spraying, brushing, sponge coating, and pad printing.
13. A method of making an expandable medical balloon, the expandable medical balloon having an inner layer formed of an elastomer; and an outer layer formed of a non-elastomer; the method comprising:
forming a tubular parison, the tubular parison comprising the inner layer from an elastomer and the outer layer formed from a non-elastomer;
longitudinally stretching the tubular parison at a stretch ratio of less than 4.0; and
radially expanding the tubular parison in a balloon mold to form the expandable medical balloon.
14. The method of claim 13 further comprising heat setting said balloon at a temperature of less than about 150° C.
15. The method of claim 13 wherein said heat set temperature was about 120° C.
16. The method of claim 13 wherein said stretch ratio is about 3.5 or less.
17. The method of claim 15 wherein the outer layer has a Rockwell hardness between about 70 and about 115 and the inner layer has a Shore D hardness of about 50D to about 75D.
18. The method of claim 13 wherein the outer layer has a Shore D harness of 80D or greater or a Rockwell hardness of greater than about 95.
19. The method of claim 13 wherein a radial cross-section of said tubular parison comprises a material ratio of about 70% to about 30% based on the outer layer to the inner layer.
20. The method of claim 13 wherein the resultant expandable medical balloon has a burst strength of 45,000 psi or more.