Frequency Converter Helps Plastic Machinery Save Energy

Because plastic products are widely used in industrial and agricultural production, plastic machinery has become an important industry in the machinery industry.

Plastic machinery can save energy (save electricity about 20-60%), reduce the impact on the power grid, realize green power consumption, and improve product quality and output after applying variable frequency speed regulation technology.

There are many kinds of plastic machinery, including plastic calender, plastic film blowing machine, plastic film bag sealing machine, plastic injection machine, plastic grooved slot machine, plastic buckle plate machine, plastic extruder, film extruder, molding machine, plastic coated composite machine, drawing machine, kneading machine, plastic blower, auxiliary machinery (blower, liquid feeding, stirring, mixing).

In the above plastic machinery, except for four roller calender and other synchronous machines with higher accuracy, the rest are very ordinary production machines.

The requirements for the drag system are basically the same.

1, it can smooth speed regulation within a certain range to facilitate the production of different varieties of products.

2. Start and brake smoothly.

Plastic machinery is usually a constant torque load. When starting at low speed, there must be a certain torque to make the machine run smoothly.

3, stable performance and reliable operation.

To ensure the quality of plastic products, the work of dragging system must be very stable.

Taking the frequency conversion control system of blown film machine as an example, a brief introduction is given.

The frequency conversion speed control system of the blown film machine includes two parts: one is the variable frequency speed regulator for extruding the main motor, and the other two is the variable frequency speed regulator of the traction motor. Their control is very simple, and the speed of the motor can be adjusted by the keyboard of the panel or the external potentiometer.

The function presetting of frequency converter is mainly in the following aspects:

1, frequency given: you can use keyboard or external potentiometer to give.

2, upper and lower limit frequency: the upper limit frequency should be slightly higher than the rated frequency, and the lower limit frequency is usually set to 3Hz.

3, point frequency: generally preset to 8Hz.

4, rise and fall time: because plastic machinery does not need frequent start and brake, there is no strict requirement for speed up or down.

The basic principle of not exceeding the rated current is, but the sealing machine should be preset as short as possible.

5, torque compensation: due to the low requirements for the hardness and dynamic response of plastic machinery to mechanical properties, v/f control mode can be adopted.

6, preset of DC braking function: general plastic machinery does not need preset DC braking function, but for sealing machine, in order to reduce deceleration time, preset DC brake is suitable.