Brief Description:The co-rotating twin-screw extruder consists of several parts including the drive system, feeding device, barrel, and screws. The functions of these components are similar to those in a single-screw extruder, as shown in Figure 1. The difference from a single-screw extruder is that the twin-screw extruder has two parallel screws placed within a barrel with an "∞"-shaped cross-section.
Characteristics of Co-rotating Parallel Twin-screw Extruders:
It has a wide range of applications and can be used for processing various materials.
2. Directly observe the wear condition of vulnerable parts; since it is easy to open, the degree of wear on the screw elements and barrel liner can be discovered at any time, allowing for effective maintenance or replacement.
3. It possesses all the advantages of traditional equipment, achieving high output, high quality, and high efficiency.
4. Reduce production costs; when changing colors, the barrel can be quickly opened in just a few minutes for manual cleaning, thus eliminating or reducing the need for cleaning materials and saving costs.
5, High torque and high speed. Currently, the development trend of twin-screw granulation equipment is towards high torque, high speed, and low energy consumption. The effect of high speed is high productivity.
6. Improve labor efficiency. During equipment maintenance, traditional equipment often requires the removal of the heating and cooling systems before the entire screw can be pulled out. However, with a split twin-screw, it is not necessary to do so. Simply loosen a few bolts, turn the worm gear box handle to lift the upper half of the barrel, and the entire barrel can be opened for maintenance. This not only shortens the maintenance time but also reduces the labor intensity.
Co-rotating parallel twin-screw extruderFrequently Asked Questions and Solutions:
The main motor cannot start
1. Cause of occurrence:
Start-up procedure error.
(2) The main motor thread has an issue, communication failure
(3) The interlock device associated with the main motor is activated.
2. Processing Methods:
(1) Check the procedure and restart the machine in the correct sequence.
(2) Check the main motor circuit.
(3) Check if the lubricating oil pump has started, and check the status of the interlock devices related to the main motor; the motor cannot be started if the oil pump is not running.
(4) Check if the emergency button has been reset.
II. Unstable main motor current
1. Cause of occurrence:
Feeding is uneven.
(2) A certain heater has malfunctioned and is not heating.
(3) The screw adjustment shim is incorrect, or the phase is wrong, causing component interference.
2. Treatment methods:
Check the feeder and troubleshoot.
(2) Check if all heaters are working properly, and replace them if necessary.
(3) Check the adjustment shim, pull out the screw to inspect for any interference.
III. The starting current of the main motor is too high
1. Cause of occurrence:
Insufficient heating time, high torque.
(2) A certain heater is not working.
2. Processing methods:
Before starting, the machine should be turned by hand. If it does not turn easily, then extend the heating time or check whether each section of the heaters is working properly.
IV. Poor discharge or blockage at the die head
1. Cause of occurrence:
(1) A section of the heater is not working, resulting in poor plasticization of the material.
(2) The operating temperature is set too low, or the molecular weight distribution of the plastic is wide and unstable.
(3) There may be foreign objects that are not easily melted.
2. Treatment Methods:
Check the heater and replace if necessary.
(2) Verify the set temperatures for each section, and if necessary, consult with the process engineer to increase the temperature settings.
(3) Clean and inspect the extrusion system and die head.
V. Unstable Die Head Pressure
1. Cause of occurrence:
The main motor speed is uneven.
(2) The feeding motor speed is uneven, causing fluctuations in the feeding amount.
2. Treatment methods:
Check the main motor control system and bearings.
(2) Check the feeding system motor and control system.
VI. Low lubricating oil pressure, oil pump alarm
1. Cause of occurrence:
Insufficient lubricating oil.
(2) Pipeline blockage, the filter has not been cleaned on a regular basis.
(3) Oil pump damage
2. Processing methods:
Check and add the correct grade of gear oil.
(2) Check the oil lines and filters and clean them.
(3) Check the oil pump and replace if necessary
VII. The nylon pin is cut off
1. Cause of occurrence:
The torque of the extrusion system is too high.
(2) The main motor and the input bearing are not concentric.
2. Treatment methods:
(1) Check if any metal or other objects have entered and jammed the screw in the extrusion system. When it first occurs, check whether the preheating warm-up time or temperature increase value meets the requirements.
(2) Adjust the main motor.
VIII. Sudden decrease in extrusion volume
1. Cause of occurrence:
The feeding system has malfunctioned or there is no material in the hopper.
(2) The extrusion system has jammed the screw, preventing the material from passing through.
2. Processing Methods:
Check the material level in the feeding system or hopper.
(2) Inspect and clean the extrusion system.
Nine, inaccurate temperature control
Causes of occurrence
The temperature controller is not functioning properly.
The thermocouple is not in good contact.
(3) The cooling system is not functioning properly.
2. Processing Methods
Check the temperature control meter's wiring and parameters, and if necessary, perform auto-tuning or replace the instrument.
(2) Check if the thermocouple is in good contact
(3) Check if the corresponding solenoid valves are functioning properly, and ensure that the water lines are unobstructed.
10. Insufficient vacuum or no effect
Causes of occurrence
Vacuum pump failure
(2) Pipe leakage, blockage
(3) The material has not formed a closed cavity
2. Treatment Methods
Check the vacuum pump and ensure that the circulating water is flowing smoothly. The exhaust piping should not be reduced in size.
(2) Check for any leaks or blockages in the pipelines, and reinstall if necessary. Pay special attention to the sealing gaskets.
(3) Check if gas is being sucked in at the opening position, and modify the screw structure if necessary.
Eleven, sudden power outage during the normal operation of the extruder
Treatment method:
Immediately turn off the main switch of the extruder, and manually rotate the extruder motor by hand or with a crank to discharge as much material from inside the extruder as possible, minimizing the residue in the screw barrel. If the main motor of the extruder is directly connected to the gearbox and there is no device for cranking the motor, you can also increase the cooling water in the cooling system to rapidly cool down the temperature of the screw barrel and screw, preventing the material in the extruder from aging.
Nanjing Xintuo Intelligent Equipment Co., Ltd. was established on May 29, 2020, with Zhou Xianting as the legal representative. The registered capital is 10 million RMB, and the unified social credit code is 91320113MA21LF2H92. The company is located in the Baima Town Industrial Concentration Zone, Lishui District, Nanjing City. It belongs to the other manufacturing industry. Its business scope includes: Permitted projects: import and export of goods; import and export of technology (projects that require approval by relevant departments can only be carried out after obtaining such approval, specific business items are subject to the approval results). General projects: sales of intelligent material handling equipment; research and development of machinery and equipment; general equipment manufacturing (excluding special equipment manufacturing); specialized equipment manufacturing (excluding licensed specialized equipment manufacturing); sales of metal products; wholesale of electronic components; sales of instruments and meters; sales of artificial intelligence hardware; processing and sales of mechanical parts and components; general component manufacturing; sales of plastic products; production and sales of Class I medical devices; sales of Class II medical devices; sales of health supplies and disposable medical supplies; sales of special labor protective equipment; technical services, technical development, technical consultation, technical exchange, technology transfer, and technology promotion (except for projects that require approval, activities can be conducted independently according to the business license). The current operating status of Nanjing Xintuo Intelligent Equipment Co., Ltd. is active (in operation, open, registered).
