Method of forming a co-extruded balloon for medical purposes

摘要

A method of forming a balloon for medical purposes including co-extruding in a tubular shape a base structural layer of polyamides, polycarbonates, polyesters and copolymers thereof and a heat sealable layer of polyethylene and copolymers thereof. The tubular member is then biaxially oriented by inflating the tube with a gas to a predetermined central diameter greater then the initial diameter of the tube and simultaneously heating the inflated tube to a temperature sufficient to biaxially orient the base structural layer. The member is then cooled the inflated tubular member and then elevated in temperature for a second time to the biaxially orienting temperature. The twice-heated tube is allowed to cool and the gas is withdrawn whereby the tubular member will assume a generally tubular shape and the main structural layer will remain biaxially orientated and the heat sealable layer will not be biaxially orientated.