Reactive extrusion describes a special process in extrusion technology in which individual components are first bonded by a chemical reaction. Twin screw extruders from Coperion are particularly suitable for the reactive extrusion process due to the excellent mixing properties.
Typical plant set-up for reactive extrusion shown by the example of linear thermoplastic polyurethane TPUs
The liquid raw materials are fed into the twin screw extruder infeed in the stoichiometric ratio. The reaction to polyurethane takes place in the twin screw extruder under constant mixing and kneading. Surplus reaction heat is dissipated through the barrel wall.
Discharge takes place via a gear pump and a screen pack changer directly to an underwater pelletizer. The pellets mature into a ready to sell product in the downstream drying plants, mixing or storage silos.