Operation Principle
The CONTGRAV system was designed to control the linear weight and the regularity of extruded materials through the control of the haul off speed or the control of the rotating speed of the extruder screw. The operator can program the required linear weight in grams/meter. The CONTGRAV continuously measures with high accuracy the raw materials throughput at the inlet of the extruder screw (kg/hour) and the actual haul of speed (meters/minute). It is therefore possible to compare the linear actual weight with the programmed value and adjust speeds to meet the required value.

For thickness control it is sufficient to keep the external dimensions constant, like for instance the external diameter.

This principle of gravimetric control assures that the linear weight and the thickness of the extruded material is not affected by variations of apparent density of raw materials, fluctuations of the power supply voltage, variations of the screw rotating speed or haul off speed.