Methods of molding a syringe

Abstract

A syringe for use in a pressurized injection of a fluid includes a syringe barrel including a polymeric material having undergone expansion via blow molding. An inner diameter of the syringe barrel can, for example, be sufficiently constant (over at least a portion of the axial length of the syringe) that a plunger slidably positioned within the syringe barrel and in generally sealing contact with an inner wall of the syringe barrel can be used within the syringe barrel to generate a pressure of at least 1 psi within the syringe barrel. In several embodiment, the inner diameter of the syringe barrel is sufficiently constant to generate a pressure of at least 100 psi, at least 300 psi, or even at least 500 psi within the syringe barrel. A method of forming a syringe includes the steps of: injection molding at least one polymeric material to form a preform; placing the preform into an blow mold die; and expanding at least a portion of the preform while heating the preform within the die to form a barrel of the syringe. The syringes can be formed to withstand relatively high pressures as described above. The at least one polymeric material can, for example, be polyethyleneterephthalate, cyclic olefin polymer, polypropylene, polystyrene, polyvinylidene chloride, polyethylene napthalate and/or nylon.