With discontinuous screen changers, the screens are changed when the machine is stopped. The piston carrying the screen is moved out and the screen pack is switched.
For melts with very low viscosity (e.g. PET or PA), the ESD has been further developed to the "ECON thermo sealer" (ETS). This model offers air cooling at the end of the pistons and is therefore leak-free, even with low-viscosity materials.
To change the screens the machine has to be stopped. The piston carrying the screen is moved out hydraulically and the screen can be exchanged.
The discontinuous screen changers are appropriate for throughputs from only a few kg/hr up to 2,500 kg/hr.