When the screw of plastic processing equipment is damaged, it shall be disassembled in time
When the screw of the plastic processing equipment is damaged, the injection molding work will certainly not be completed. Although the screw is only an accessory of the equipment, if it is used, it will be found that it is really impossible without the screw. Therefore, once the screw of the plastic processing equipment is damaged, it should be disassembled and replaced in time, so as not to delay our normal work. The screw of the plastic processing equipment should be disassembled step by step.
Causes of screw damage of plastic processing equipment:
1. Low temperature during plasticization of raw materials;
2. Metal foreign matters are mixed in the raw materials or there are many impurities in the raw materials;
3. The screw idling time is too long;
4. Unreasonable selection of screw material;
5. Plastic processing equipment has low screw manufacturing accuracy and low heat treatment hardness of threaded working face.
Specific disassembly steps:
1. Disassemble the nozzle and the connecting piece between the nozzle and the barrel;
2. Separate the key connection at the rear of the screw from the drive shaft;
3. Remove the connecting flange and move the screw forward;
4. When the screw head is exposed from the barrel, immediately remove the connecting thread of the screw head (Note: most of the threads here are left-handed).
5. Remove the check ring and sealing ring on the screw rod;
6. The disassembled nozzle, check ring, sealing ring and screw rod shall be immediately cleaned with copper brush and shovel tools while it is hot. The sticky material that is particularly difficult to clean shall be heated in the oven at a lower temperature that can soften the material, and then the residual material shall be removed;
7. Assemble the parts on the screw, and coat the threaded connection with molybdenum disulfide heat-resistant grease to facilitate the next disassembly.
Precautions for use of plastic processing equipment:
- If there are slight wear or scratch marks on the working surface of the screw of plastic processing equipment, the damaged parts can be ground and polished with oilstone or fine abrasive cloth.
- In case of serious wear on the working surface of the screw and deep scar groove, check and analyze the causes of screw wear, eliminate the faults, so as to avoid similar phenomena again, and then repair the deep scar groove by repair welding. If the thread of the whole screw is seriously worn, the fit gap between the screw and the barrel increases, the melt leakage increases and the injection quantity is unstable during operation, the outer circle of the screw thread shall be thermally sprayed with wear-resistant alloy, and then the screw shall be ground according to the actual size of the inner diameter of the barrel of the plastic processing equipment and the fit gap requirements of the parts.
If the barrel of the plastic processing equipment is seriously worn, the diameter of the inner hole increases after repair, and the grinding after spraying of the screw can no longer meet the requirements of the fit gap between the barrel and the screw, the screw shall be remanufactured, and the thread outer diameter of the screw shall be processed according to the fit gap requirements of the two parts and with reference to the actual inner hole diameter of the barrel.
This is how to disassemble the screw of plastic processing equipment. I hope it will be helpful to you. If you still have anything unclear, you can log in to our official website to contact our staff, or leave a message directly. Our staff will answer all your doubts in time. Thank you for reading.
