Chemical Reactions via Twin Screw Extrusion
Reactive extrusion describes a special process in extrusion technology in which individual components are bonded by a chemical reaction. Extrusion systems from Coperion are particularly suitable for the reactive extrusion process due to the excellent product handling and mixing properties.
To produce TPU (thermoplasic polyurethane) in the extruder the liquid raw materials are fed into the ZSK twin screw extruder infeed in the stoichiometric ratio via highly accurate liquid feeders. 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.
Various other reaction processes like polycondesation, polyaddition, e.g. are possible.