Cause of screw damage
1. The temperature is low when the raw materials are plasticized.
2. Metal foreign materials are mixed in the raw materials or there are many impurities in the raw materials.
3. The screw idle running time is too long.
4. Unreasonable choice of screw material.
5. Low screw manufacturing accuracy and low heat treatment hardness of thread working surface.
Disassembly sequence of screw
Use special tools when disassembling the screw. Do not strike with a hammer. The specific disassembly steps are as follows.
1. Remove the nozzle and the connection between the nozzle and the barrel.
2. Separate the key connection at the rear of the screw from the drive shaft.
3. Remove the connection flange and move the screw forward.
4. When the screw head is exposed from the barrel, immediately remove the screw head connection thread (note: most of the threads here are left-handed).
5. Remove the check ring and seal ring on the screw.
6. Remove the nozzle, check ring, seal ring and screw immediately with a copper brush, shovel and other tools to clean up the residual material in various parts. Specially difficult to clean sticky materials should be heated in an oven at the lowest temperature that can soften the material, and then the remaining material should be removed.
7. Assemble the parts on the screw together, and molybdenum disulfide heat-resistant grease should be applied to each threaded connection to facilitate the next disassembly.
8. After the surface of the unused screw is coated with protective oil, wrap it, and hang it in a safe place for ventilation.