Abstract: The invention relates to a balloon for a catheter. The manufacturing of the balloon comprises providing of mold which has a mold cavity corresponding to an intended expanded form of the balloon member; placing opposite ends of a tube-like semimanufacture (parison) into securing elements for the purpose of securing their opposite end sections in the mold cavity; heating the semimanufacture; and generating a pressure difference between the inside and the outside of the semimanufacture to expand the balloon member against the walls of the mold cavity. In the molding, the end sections of the semimanufacture are twisted about an angle in relation to each other so that helical ridges are formed in balloon transition sections.

Abstract: A method is provided for manufacturing a balloon for a catheter. The method comprises the steps of providing a mold having a mold cavity that generally corresponds to an intended expanded form of the balloon. Securing elements are provided at opposite ends of the mold cavity for securing end sections of a tubular parison. The end sections of the tubular parison are twisted in opposite directions with respect to each other. The end sections of the tubular parison are secured in the securing elements, the parison is heated, and a pressure differential is created between the inside and the outside of the parison to cause it to expand into a balloon against the walls of the mold cavity. The previously twisted end sections of the parison result in the balloon transition sections having spiral ridges, allowing the balloon to be folded into a small diameter.