Coinjection nozzle

摘要

Disclosed is a coinjection nozzle for a two-component injection molding tool, which is used for producing parisons. The inventive nozzle comprises a nozzle holder ( 1 ) and an nozzle tip ( 4 ) that is mounted therein. A shut-off needle ( 11 ) is directed within a needle guide ( 3 ) at least in a top portion (K) of the needle tip ( 4 ). An additional nozzle sleeve ( 2 ) is disposed between the needle guide ( 3 ) and the nozzle tip ( 4 ). A first tubular delivery duct (A) extends between the nozzle sleeve ( 2 ) and the nozzle tip ( 4 ) while a second tubular delivery duct (B) extends between the nozzle sleeve ( 2 ) and the needle guide ( 3 ). The needle guide ( 3 ) is provided with a conical needle-guiding head ( 3 a) located in the top portion (K) of the nozzle. A throat is provided in the first tubular delivery duct (A) in the area (E) of the nozzle. The needle-guiding head ( 3 a) and the nozzle sleeve ( 2 ) are shaped in such a way that the second tubular delivery duct (B) narrows in a final area so as to form a shear edge (F).