Basic specification for twin screw operation

July 12, 2019

Basic specification for twin screw operation



1, driving operation

1.1 Preheating and heating: Put the main power switch and each section of the electric heater power switch on, and set the parameters for each heating zone (about 120 degrees) according to the process to start heating up.

1.2 After the heating temperature of each section reaches the set value, continue to maintain the temperature for 30~45 minutes. (Because a process is required to transfer the temperature from the cylinder to the screw, it takes a long time) and further test each section of the temperature control instrument and electromagnetic The accuracy of the valve work.

1.3 The flexible coupling is determined by the hand plate, and the metal sleeve of the twin-screw mandrel and the transmission box should be checked to see if it has slipped in the direction of the gearbox. (If it is too much, it is likely to damage the mandrel under high torque. The meshing end of the root, generally for some domestic twin-screw manufacturers) can prepare to start the main motor, close the power switch, auxiliary power switch and start button, set the main engine speed, gradually increase the main screw speed, and the idle speed is not higher than 40r/ Min, the time is no more than two minutes.

1.4 If there is no abnormality in the host idling, press the feeder start button to adjust the feed speed setting to start feeding at the lowest possible speed. After the material is discharged from the standby head, the feed screw speed and the main screw speed are slowly increased, so that the feeder and the main engine speed are matched. When the adjustment is made, the host current indication is closely monitored at any time, so that the host current does not exceed the rated current, and the unit is also noted. If there is any abnormality in operation, stop it in time.

1.5 In order to avoid overheating of the material high shear mixing, each section of the cylinder is equipped with a soft water circulation cooling system. Each section of the cylinder is controlled by a solenoid valve and a temperature control instrument. During the start-up phase, the cooling system does not need to be opened. After the operation, observe the temperature rise of each section of the mainframe and determine the use of the cooling system as appropriate. After the water volume is determined, there is generally no need to adjust it during normal operation. The adjustment of the cooling water valve is not easy to be too large, too large, it is possible to cool too much, and it takes time to heat up.


2. In-service inspection

2.1 Whether the current of the main motor is stable. If the fluctuation is large or rapid, the supply amount should be temporarily reduced. After the main current is stable, it will gradually increase. The speed should be adjusted smoothly. The screw is within the specified speed range.

2.2 Check the gear deceleration distribution. There is no abnormal sound in the transmission box and the main cylinder. If there is any abnormality, stop it immediately.

2.3 There should be no abnormal vibration, sturdiness, etc. during the operation of the machine, and the fastening part should be free from looseness.

2.4 Check if the temperature control, heating and cooling system works normally.

2.5 The water cooling system has a smooth pipeline and no leakage.

2.6 Check if the feeding of the feeder is normal and the screw feeds evenly.

2.7 Always check whether the machine head is stable and even, with or without broken bars, poor plasticization or overheating.

3, normal parking sequence

(1) Adjust the screw speed of the feeder to zero and press the feeder stop button.

(2) Gradually reduce the speed of the main screw, drain the residual material in the cylinder, wash the machine before the parking, and stop the twin-screw main machine after the material is basically discharged, that is, the speed is adjusted to zero, press the main motor stop button.
(3) Disconnect the main power switch of the electric instrument operation screen.
(4) Close each inlet valve.
(5) Clean the surface of the machine head and the entire unit surface.


4, emergency parking

When you need to stop the host in case of emergency, you can quickly press the electric machine to operate the screen emergency stop button. The system loses power, and the host and feed speed adjustment settings are reset to zero position, then the main power switch is reset and powered up, and the cause of the fault is found in time, and the fault is quickly processed to eliminate the fault and then restarted in the normal driving sequence.

Share on Facebook
Share on Twitter
Please reload

Featured Posts

The role of the three functional zones of the PVC extruder