Hot runner systems

Hot Runner System Components: behind each part, the best know-how


What is a hot runner system?

The use of plastics has become widespread but not everyone is aware of the great engineering process behind the production of a hot runner system: the technology that revolutionized the injection molding world.

The main task of the hot runner solution is to maintain the melt flow - the material injected into the mold by the IMM barrel nozzle - at a constant temperature and a uniform pressure.


Main benefits of the hot runner technology

  • High-quality parts for a wide range of applications
  • Prevention of overfed or under-filled parts
  • No sink marks or flash formation on the molded components
  • Improved production efficiency
  • Resin waste reduction
  • Cycle time reduction
  • Design flexibility and customized solutions


Hot runner components

  • Nozzles are the hot runner components designed to inject the plastic melt into the cavities. There are three main types of injection:

    • Free flow: the plastic material flows freely through the hot runner

    • Torpedo: the material flows through a special torpedo tip into the mold cavity

    • Valve gate: each nozzle houses a valve gate that opens and closes the pin sequentially rather than simultaneously.

  • Manifolds are the components that hold the nozzles. The main task of the hot runner manifold is to distribute the plastic material into different nozzles.  

  • Flow Control refers to the use of valve gate technology to control the plastic melt flow through the nozzles and, more generally, over the entire molding process. Among our valve gate solutions available, we offer hydraulic, pneumatic and servo driven valve gate systems.