Methods for manufacturing multi-layer balloons for medical applications
A multi-layered balloon is provided where each layer is formed such that each layer is made from tubing that optimizes the inner wall stretch thus providing maximum balloon strength. The high pressure, multi-layer balloon is provided with layers that allow for slipping, such that the balloon has a very high pressure rating and toughness, yet excellent folding characteristics. Methods for producing such multi-layer balloons using existing balloon forming equipment are also provided. The multi-layer balloons can have alternating structural and lubricating layers, or layers with low-friction surfaces. The multi-layer balloons are preferably manufactured using a variety of methods including nesting, co-extrusion, or a combination of nesting and co-extrusion. The multi-layer balloons have balloon layers having substantially similar, or the same, high degree of biaxial orientation of their polymer molecules such that each balloon layer of the multi-layer balloon will fail at approximately the same applied pressure.
1. A method of making a nested balloon comprising:
selecting an inner balloon layer and an outer balloon layer, the inner balloon layer and the outer balloon layer comprising the same polymer material;
providing a lubricant, wherein the lubricant is configured to be co-extruded onto one or more layers or between layers, applied to one or more layers, or injected between layers;
blowing the inner balloon layer and the outer balloon layer separately to stretch the polymer material to align molecular chains along an inner wall of each balloon layer, wherein the inner balloon layer and the outer balloon layer have substantially the same shape and size along a body portion of the inner balloon layer and the outer balloon layer; and
positioning the inner balloon layer within outer balloon layer to form a nested balloon, wherein the nested balloon is configured to be expanded axially and radially in use.
2. The method as in claim 1 , wherein blowing is accomplished before positioning the inner balloon layer within the outer balloon layer.
3. The method as in claim 1 , wherein the lubricant comprises oil.
4. The method as in claim 1 , wherein the outer balloon layer comprises nylon.
5. The method as in claim 1 , wherein the inner balloon layer comprises nylon.
6. The method as in claim 1 , wherein the inner balloon layer and the outer balloon layer fail at approximately the same pressure when a pressure is applied to the nested balloon.
7. The method as in claim 1 , wherein the inner balloon layer and the outer balloon layer are configured to withstand at least about 40 atmospheres of applied pressure.
8. The method as in claim 1 , wherein the inner balloon layer and the outer balloon layer are configured to withstand at least about 50 atmospheres of applied pressure.
9. The method as in claim 1 , wherein the inner balloon layer and the outer balloon layer have substantially the same inner diameter.
10. The method as in claim 1 , wherein the inner balloon layer and the outer balloon layer have substantially the same outer diameter.
11. The method as in claim 1 , wherein blowing the inner balloon layer and the outer balloon layer separately comprises blowing the inner balloon layer and an outer balloon layer on the same mold at separate times.
12. The method as in claim 1 , wherein the inner balloon layer and the outer balloon layer comprise different necks.
13. A method of making a nested balloon comprising:
selecting an inner layer and an outer layer, the inner layer and the outer layer comprising the same material;
expanding the inner layer to within approximately 15% of the optimal radial stretch of an inner surface of the inner layer;
separately expanding the outer layer to within approximately 15% of the optimal radial stretch of an inner surface of the outer layer, wherein the inner layer and the outer layer have substantially the same shape and size along a body portion of the inner layer and the outer layer after expanding the inner layer and the outer layer; and
positioning the inner layer within outer layer to form a nested balloon.
14. The method as in claim 13 , wherein the outer layer comprises nylon.
15. The method as in claim 13 , wherein the inner layer comprises nylon.
16. The method as in claim 13 , further comprising providing a lubricant, wherein the lubricant comprises oil.
17. A method of making a nested balloon comprising:
selecting an inner balloon and an outer balloon, each balloon comprising the same material;
providing a lubricant between the inner balloon and the outer bal loon;
independently forming each of the inner balloon and the outer balloon by blowing the inner balloon and the outer balloon separately;
after independently forming each of the inner balloon and outer balloon, positioning the inner balloon within the outer balloon to form a nested balloon;
wherein, after positioning, the inner balloon and the outer balloon are configured to expand axially and radially.
18. The method as in claim 17 , wherein the outer balloon comprises nylon.
19. The method as in claim 17 , wherein the inner balloon comprises nylon.
20. The method as in claim 17 , wherein the lubricant comprises oil.