Power profile

Presentation of the performance trend

Red curve: The red curve represents the drive power from the screw shaft to the corresponding position in the curve. The drive power therefore starts at 0 kW at the screw shaft. The total drive power of the screw is represented by the value at the tip of the screw. The drive power represents the mechanical energy provided by the extruder motor. It is used to set the screw in rotation and thus enable the material flow, shearing and melting of the plastic.
Blue curve: The blue curve represents the heat flow density along the extruder. No heat flow is assumed upstream of the location of melt vortex formation. The calculated heat flux density represents the heat flux from the barrel into the plastic. This is a superposition of convection in the melt vortex (negative heat flux density also possible) and an increased heat flux density in the melting area above the solid bed (only positive heat flux density possible). The heat flux density in the melting area is therefore significantly higher than in the completely melted area.

Drive power: The individual value corresponds to the final value of the curve and thus the total drive power of the extruder screw (without losses), which must be provided by the motor.
Torque: The torque results from the drive power and the screw speed
Specific drive power: The specific drive power is a characteristic value that relates the drive power to the processed material volume. It is a measure of how much energy is applied per unit mass of plastic being processed.
Heating power: The heating power describes the energy that is supplied or dissipated by the heating zones along the extruder barrel. The heating power of the individual zones is also specified separately. The heating power can be positive or negative.
Total power: The total power is the sum of the various power contributions that are introduced into the process both mechanically (through drive power and torque) and thermally (through heating power).

Power curve (red curve): The performance curve shows which screw zone is feeding which power into the plastic. The power increases more in the melting area than in the pure melting area.
Heat flux density (blue curve): The heat flux density curve shows the heating or cooling power that occurs along the screw. High heat flux densities should be avoided, especially at the end of the screw, in favour of good thermal homogeneity.
Drive power and torque: It must be checked whether the potentially used extruder has a sufficiently powerful drive unit. The torque is also relevant for calculating the Screw strength.
Specific drive power: The specific drive power represents the energy (kWh) required per kilogramme of extrudate and is therefore a measure of the efficiency of the extruder.