Needle shut-off nozzle A(S)

injectionfor meltaxial

The original needle shut-off nozzle from herzog® which has over the years enabled processors increase productivity. Strong, reliable and above all economical, it can be adapted to any machine type with the simplest of installations. The nozzle operation is melt pressure dependant. The axial aligned needle is held in the closed position by spring force. Once the injection pressure rises above 200 bar, it will overcome the spring force and open the nozzle. Applications: Thermoplastics (not applicable for PVC, PPS) Shut-off mechanism: Operated with one axial high performance spring The spring actuated machine needle shut-off nozzles type A(S) are used in processing of thermoplastics, principally with low viscosity materials. Operation: The nozzle is opened directly from the injection pressure and closed again with spring force. A needle which moves axially in the needle shut-off nozzle is held in the closed position by the force of the spring. The nozzle orifice is normally closed.  If the standard opening pressure is not appropriate, the needle must be modified to the requirements (modification of the spring is not possible).  A temperature resistant material (to max. 520°C) is used for the spring construction  The nozzle size required depends on the injection rate per second (cm3/s). Prevents:  Stringing, drooling  Material leakage when dosing with a withdrawn injection unit  Material leakage while vertically injecting