Torrive variable frequency inverters used for Screw extruder

1. Working principle

Depending on the pressure and shearing force generated by the rotation of the screw, the material can be fully plasticized and uniformly mixed and then formed by die molding; therefore, sometimes an extruder can be used to simultaneously complete mixing, plasticizing and molding for continuous production. After using the variable frequency technology, the pressure can be controlled so that the machine will work under the most suitable linear speed.

2. Frequency converter requirements

Concerning about the extruder, there are three kinds of resistances to be overcome during work: 

1.  Friction, which contains the friction of the solid particles (feed) against the wall of the cylinder, 

2. Tthe adhesion of the melt on the wall of the cylinder; 

3. The internal logistics resistance when the body is pushed forward, it belongs to the constant torque load, the starting torque requirement is relatively high, and the application site generally has a relatively high temperature and a large dust. 

Therefore, the inverter needs to have the following three characteristics:

A. Large starting torque

B. Good heat dissipation

C. Good sealing performance

3. Energy-saving effect

Extruder energy saving can be divided into two parts: power part and heating part. Power part of the energy: most of the inverter, energy-saving way is to save the motor's residual energy, such as the actual power of the motor is 50Hz, and IT actually only need 30Hz enough to produce, and those excess energy consumption in vain Wasted, the inverters throgh changing the power output of the motor to achieve the effect of energy saving, generally can reach 20%

4. Precautions

A. Before the motor starts, confirming whether the temperature of the equipment is up to standard. If the temperature of the equipment is not up to standard, it may cause the material blockage in the screw head and the starting current will be large and the starting torque will not be enough. Thus, the inverter in the low frequency start will skip the overload protection.

B. The motor direction is prohibited to reverse

C. Regularly clean and maintain, pay attention to ventilation and heat dissipation

5. The basic parameters settings