Thermoplastic foam injection molding (TSG) is an injection molding process that is suitable, especially for the production of thick-walled and variable-walled components. In this process, a blowing agent is added to the plastic granules used and, after injection, an expansion process begins so that the plastic expands to fit precisely into each area of the mold.

The result is a stable component with a light open-pored structure and a smooth, dense surface, which later remains dimensionally stable even with temperature changes.