Things to be aware of when operating plastic extruders

For many people who have not known plastic extruders, the operation of plastic extruders is very mysterious, and there are many people who already have, or who are using plastic extruders, the correct operating specifications for plastic extruders. I understand, today I will talk about the precautions in the use of plastic pelletizing extruders.
Operators should pay attention to the use of plastic extruders:

1. The plastic extruder operator should memorize the operation requirements and operation sequence in the manual of the plastic extruder.

2. Before driving, check whether the screws and nuts of each connection part of the equipment are firm; whether the lubrication parts are filled with sufficient lubricating oil; whether the amount of lubricating oil in the fuel tank is within the specified oil level indicator.

3. Check that the hopper is clean and free of any foreign matter.

4. Check whether the raw materials meet the quality requirements; if the quality of the raw materials is qualified, feed the hopper and fill it up.

5. Verify that the structure of the screw meets the production process requirements.

6. After confirming that the barrel is clean and free of any foreign matter, install the filter, manifold, and molding die.

7. According to the requirements of raw material plasticizing process conditions, adjust the temperature of the automatic control instrument on the control box.

8. The heating system is started, and the barrel and mold are heated to heat up. When the temperature required by the process is reached, the heating is constant for more than 1.5 hours to ensure uniform temperature at each part.

9. The manual V-belt part of the car should be flexible, easy and without blockage.

10. Start the lubricating oil pump, check whether the lubricating oil pipeline is unobstructed and whether the lubricating oil supply position is accurate.

11. After the lubricating oil is supplied for 3 minutes, adjust the main motor speed knob to zero position; the low-speed start screw rotates the main motor. At the same time, observe the swing of the main motor ammeter pointer, which should be within the specified load range. Note: The shorter the screw running time, the better, the maximum should not exceed 3min to avoid scratching the screw and barrel.

12. Open the hopper feed gate and feed less and evenly and slowly.

13. Start the cooling unit. Open the cooling water supply system. Start the traction device.

14. Check the plasticizing quality of the melt extruded from the die mouth (if necessary, adjust the process temperature), and install the sizing sleeve when the melt is completely plasticized. If the tube blank extruded from the die mouth is skewed, the gap between the die and the mandrel should be adjusted immediately. When adjusting, first loosen the adjusting screw on the thin side of the tube blank (the bending side of the tube blank), and then tighten the adjusting screw on the thick side of the blank wall until the tube blank runs straight out. Note: When adjusting the gap between the die and the mandrel or observing the quality of the melt plasticization, the operator should not face the die mouth to prevent the melt from decomposing and scalding the operator.

15. After the tube blank extrusion adjustment is normal, the tube blank introduces a sizing sleeve, a human water tank, and a traction machine, and the traction speed is appropriately adjusted to match the extrusion speed of the tube blank from the die mouth.

16. Cut the tube product and take a sample. Check the quality and size of the pipe products in accordance with the quality requirements of the production regulations.

17. After checking the quality of the pipe products, there is no abnormality in the working sound of the equipment, and the current load is normal, which can increase the working speed of the screw to the normal production speed.

After the extrusion production is transferred to normal work, the operator should always pay attention to observe the following work conditions:

·Whether the load current of the drive motor for screw rotation is normal and is within the rated value range;

· Whether the sound of each moving work part is abnormal;

·Whether the temperature rise of each bearing part is normal, the highest temperature rise should not exceed 55 °C;

• Whether there is leakage in the lubricating oil or cooling water pipeline, and whether the working flow pressure is within the specified value.

18. When there is a sudden power outage or abnormal accident during work, stop the emergency (press the emergency stop button) and turn each speed adjustment knob to zero.

If the parking time is long, the raw materials in the barrel are polyolefin-based materials (polyethylene, polypropylene, etc.), which do not need to be removed. If it is a PVC material, it must be removed in time: use a special tool to remove the screw and clean the residual material on the barrel, screw and forming mold.

Note: When cleaning the residual material, use a copper knife, brush or bamboo tool to scrape the material. It is not allowed to use steel knives and boring tools to clean the residual material. It is not allowed to use the fire barbecue screw to remove material. After cleaning, apply anti-rust oil and assemble it on the equipment.
When troubleshooting or restoring power, first heat up the barrel and mold. When the temperature of the process is reached, the temperature is 1.5h or more. It is easy and flexible to use the manual disk to turn the V-belt. At this time, the main motor can be started at a low speed and work in the normal driving sequence.

19. The sequence of normal stop production operations is as follows.

• Close the supply gate.

· Minimize screw operating speed.

• The screw works until the mold stops without the melt.

· If the extruded material is a polyolefin resin, stop at this time, turn off the heating and cooling system, and wait for the next production; if the barrel is made of polyvinyl chloride resin, immediately remove the mold, screw, and remove all parts. Residual material; after the screw is not cleaned, Xu anti-rust oil, wrapped in a dry and ventilated place. Note: When disassembling the mold and the screw, it is not allowed to directly hit the parts with the heavy hammer. If necessary, the hardwood should be placed on the hit part to avoid damage to the parts.

• Turn off heating, wind, water, and various lubrication systems.

• Cut off the main power supply.