Better and faster is our motto for KUHNE High Speed Extruders (KHS) for flat film lines. 

Improvements in screw geometry combined with a new generation of drive technology made it possible to raise the output capacity of a 70 mm extruder up to 2.000 kg/h.  

Another innovative feature is the possibility to instal the extruder above the roll stack on a platform. The entire line needs much less space and the efficiency of the line will be significantly improved. 

Already in the 60ies there were ideas in the R&D centers of the machinery builders to improve the productivity of extruders by higher rpm of the screw. 

However a higher amount of wear in the screw and barrel was to be considered and it was not fully investigated whether the higher rpm and melt temperatures would have negative influences in the properties of the finished film. 

Meanwhile the practical experience has shown that these worries were not justified. On the contrary: film made on high speed extruders are more homogenious and are offering better optical and mechanical properties. 

Before we started offering the high speed extrusion concept intensive R&D work has taken place. It was necessary to optimize the feeding zone of the extruder in order to allow the production of virgin as well as reground material. 

Special attention has been paid to the geometry of the extrusion screws. The geometry has to be adapted to the higher circumferential speed. The downstream equipment like the roll stack, post cooling rolls, roller conveyor with active cooling and the winder has been adapted to the higher speed as well. Nowadays line speeds of up to 100 m/min are possible. 

Further aspects are the drives of the high speed extruders. The integration of the drive motor directly in the gear box and asynchronous AC motors with integrated thrust bearing increase the energetic efficiency of up to 10%. Furthermore wear and tear parts are eliminated and less space is needed. 

Our KUHNE High speed extruders KHS60 and KHS70 for processing of basic polymers are available with various drives for capacities from 600 to 2.000 kg/h. Last year we were able to deliver over 10 lines with KHS concept with one single order.