Gear pumps for extrusion
The extrusion process is very diverse. In the extrusion of plastics a wide variety of profiles and tubes can be produced. It is also possible to produce monolayer or multilayer films by means of extruders. In coextrusion, various materials are made into a film using multiple extruders. Besides the classical polymers, e.g. Polypropylene or polycarbonate are also used in extruding filled polymers. In Wood Plastics Composites (WPC) wood parts are bound in a polymer matrix.
In the food industry extrusion technology is also used. For extrusion of foodstuffs very high demands on the purity. The production of licorice should be mentioned here as an example.
Due to the design, extruders do not ensure a very constant pressure at the outlet. Also, the efficiency of increasing the pressure in an extruder is not very good. Therefore, a gear pump is used after the extruder. On the one hand, the pump takes over the pressure build-up and thus relieves the extruder. On the other hand, the gear pump ensures even pressure and reduces the pulsations. The extrusion tools are optimally supplied with the melt.