The operator must be familiar with the extruder they operate, and must correctly grasp the characteristics of the screw, the control of heating and cooling, the characteristics of the instrument, the structure and assembly of the control mold of the tractor, etc., in order to correctly grasp the extrusion process conditions, correct Operate the machine.

Extrusion die debugging

(1) Before starting, check whether the temperature control is sensitive, whether the instrument is malfunctioning, and whether the cooling water channel is smooth. Usually use thermometer, cooling water and other methods for testing.

(2) Heat the screw, barrel and die of the extruder according to the operating rules of the extruder. After the temperature rises to the set temperature, it must be kept for about 10 minutes before it can be turned on, so that the temperature of each part of the machine tends to stable.

(3) Be sure to tighten the connecting screws and bolts of each part of the die head while it is hot. Before the material is squeezed out, the operator must not stand directly in front of the die to prevent the bolt or screw from breaking and causing injury.

(4) When starting extrusion, the screw speed should be slow, and then gradually accelerated to prevent overloading and damage to the machine during startup.

(5) When starting up, add a small amount of material first, and maintain a balanced feed. Pay attention to various table values such as torque when feeding. After the material is extruded from the die and the traction equipment is pulled, the amount of material can be gradually increased until Normal extrusion.

(6) When the traction starts, the setting die and the die head should have a certain distance to facilitate traction. Open the waterway (note that water should not be poured into the die, otherwise it will cause abnormal discharge of the die and cause material breakage or plugging), the shape of the complex cavity is small and a multi-cavity profile needs to open the cover of the mold After confirming that the extruded material is plasticized normally, the material is pulled to the traction machine through the traction rope that has been set. Shorten the distance between the setting table and the die head, close the cover plate, and start the vacuum pump. When the extrusion speed and traction speed are basically balanced, observe the profile to normal extrusion and then reduce the distance between the setting table and the die head to the ideal value.

(7) If it is found that the parison is not formed at the entrance of the shaping die or the inner rib is adhered to the inner cavity surface of the profile, use a pointed tool to poke a few at the unformed part or the inner rib of the entry end of the first section of the shaping die * * Make the small cavity penetrate the atmosphere, and the parison is open when entering the setting mold, which is convenient for the formation of negative pressure, and the parison is tightly attached to the mold wall of the setting mold.

(8) If the mold is blocked (not blocked), the setting table should be moved back immediately or the traction speed should be increased, or the above two schemes should be implemented at the same time, and then adjusted through the process to resume normal production. If the implementation of the above scheme is not effective, the setting table should be moved back immediately, and the material should be shoveled along the setting mold, the moisture of the setting mold should be closed, the traction speed should be reduced, and the profile should be slowly pulled out from the setting mold. If some of the profiles are broken in the mold, you need to disassemble the mold and completely remove the residue.

(9) When the machine is shut down, it is generally necessary to add a shut-down material to squeeze out the production material in the machine, and then shut down and remove the die head while hot to clean the mold.

Extrusion die maintenance

1. Improper loading, unloading or cleaning during maintenance and cleaning is one of the main reasons for damage to the mold. Therefore, the disassembly and cleaning of the mold should be done by professionals.

2. When disassembling and cleaning the die head, use copper devices.

3. The joint surface (sealing surface) of the die head can be cleaned with fine whetstone or metallographic sandpaper.

4. Before the mold is assembled, the flow channel should be polished to low roughness with metallographic sandpaper and coated with a thin layer of silicone ester, so as to reduce gas and moisture corrosion during long-term storage and protect the flow channel.

5. During the assembly process, all bolts, screws bearing surfaces and threads must be coated with high-temperature grease.

6. When disassembling the mold, please pay attention to avoid collision; when installing, it should be installed according to the order of the template.

7. In the daily maintenance of the water tank, make sure that there are proper adjustment activities on the four sides after the shaped block is loaded.