Shut-off nozzles are used exclusively for injection moulding processing and are often an essential component of the machine. Installed at the crucial interface between heated injection unit and cooled mould, the nozzle is the gateway which regulates the melt flow while bearing the entire contact force of the machine. 

Shut-off nozzles were originally developed in the 1960’s to prevent melt drooling from the nozzle orifice once the injection unit pulled back from the cold mould after injection. This not only prevented loss of material but also reduced process breakdowns. Even today shut-off nozzles can still be used for this purpose but of course the advantages of using them have increased considerably since those times. Nowadays the primary functions of the shut-off nozzle include;

• Reducing cycle times by dosing the next shot regardless of whether the mould is open or if the injection unit is retracted.