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Disassembly and assembly of extruder screw components

The screw components of the extruder are planned according to the principle of building blocks, and can be replaced according to the processing technology and operation requirements. When disassembling the screw, try to drain the main material (if the material is high viscosity plastic such as PC or medium viscosity plastic such as ABS, POM, etc., PP or PE material can be added before parking), then stop the main machine and auxiliary machines, disconnect The head electric heater power switch (but the electric heaters in each section of the fuselage still have to maintain normal operation in order to organize the materials) and disassemble the screw according to the following procedure.

1. Remove the temperature measuring and measuring component of the machine head and the cast aluminum heater, wear the thickened asbestos gloves, remove the head assembly (pay attention to avoid burns), add white wax in time, scrub with wire brush and cotton cloth. Clean the material in the hole of the machine head and the end of the screw head of the machine head.

2. Loosen the fastening screws (or two caps) of the two sleeve spline coupling shaft ends and the two screw tail seal glands, and investigate the two output shafts of the gearbox. The left side is the A axis and the right side is the B axis.

3. Remove the two screw head pressing screws (left-hand thread) and replace the special bolts for the pumping screw. Pull the bolt and pry the screw at the coupling. Slowly draw the two screws one at a time. Immediately use a wire brush or a copper shovel to heat the material on the outer surface of the screw until the screws are cleaned. Then pull it out on a wooden board or two wooden pillows, remove the screwing things, do not disassemble the screw components from the heat, do not use sharp and hardened things to hit, can use wooden hammers, copper rods along the axis of the screw components It is quietly tapped. If material is infiltrated into the core, it is difficult to disassemble. It can be put into the cylinder for heating. After the material in the gap is softened, it can be removed hot.

4. The end face of the removed screw element and the inner keyway should also be cleaned and placed on the spare rack. It is forbidden to bump each other (the anti-embroidering grease should be applied to the screw components that are not used temporarily). The residual material on the outer surface of the mandrel should also be thoroughly cleaned. If it is not assembled for the time being, it should be suspended straight to prevent deformation.

5. After the screw is taken out, the remaining material in the inner hole of the cylinder is arranged in time (can be arranged with a rod and a circle of white wax), and the heater is stopped after finishing.

6. The assembled configuration of the two screws must be identical (only when the toothed disc is used). When assembling, the inner hole of each component and the outer surface of the mandrel must be thin and evenly coated with a high temperature (350 ° C) lubricant. When the screw elements are set on the mandrel, the end faces should be fully engaged, and the joints should be smooth and free from misalignment. Finally tighten the screw head screw (lubricant should be applied to the screw thread).

7. Place the two screws side by side according to the working direction, check the full radial and axial meshing gap of the thread, and the dryness and the phenomenon between the screws are qualified. Then press the screw tail spline and the corresponding orientation of the sleeve coupling. The two screws are pushed into the cylinder body so that the tail end of the screw is tightly engaged with the gear shaft surface of the gear box, and the fastening screw is fastened (or the spline caps are fastened), and the gland is sealed from the top of the head. Apply a thin layer of lubricant to the tail spline before loading the screw.

8. After the screw is installed, it should be manually driven to make the screw rotate for more than 2 weeks. After the abnormal phenomenon such as no dryness and scraping is recognized, the machine head can be installed. When the device is installed, the molybdenum disulfide lubricant should be evenly applied to the surface of each screw thread.

9. Rehabilitation After the machine head is heated to the set temperature, it can be driven according to the normal procedure.

Screw element