The plasticizing device is generally provided with an integral rotating mechanism. When loading and unloading the screw nozzle, screw and barrel of the injection molding machine, firstly, the injection molding positioning screw should be loosened to deflect it from the original position by a certain angle, so that the axis of the injection molding machine cylinder avoids the axis of the clamping device, so as to facilitate the injection molding machine. Disassembly and repair of screws and barrels.
a. Disassembly of the screw nozzle of the injection molding machine
If there is leftover material in the barrel, it should be heated to the plasticizing temperature first, and the polyolefin resin or barrel special cleaning material with high thermal stability should be used to fully clean the high-speed cleaning, and the remaining melt should be discharged as much as possible before entering the disassembly. At work, since the residual material at the nozzle portion is always impossible to discharge completely, the nozzle or the head of the barrel should be heated, and then the nozzle is removed.
After the screw nozzle of the injection molding machine is warmed up, use a special hammer to knock it loose, and the bolt should not be loosened. When it is loose to 2/3, tap it gently. After the internal gas is released, remove the nozzle.
The cleaning inside the screw nozzle of the injection molding machine should be carried out at a high temperature to remove the residual melt in the flow path from the nozzle hole. The method is to inject a release agent from the nozzle into the interior, that is, to drip the release agent from the side of the nozzle thread to the wall of the material and the inner wall, thereby separating the material from the inner wall, thereby taking out the material from the nozzle.
b. Maintenance and repair of screw nozzle of injection molding machine
If there is a one-side contact or poor contact in the contact part between the nozzle and the mold positioning sleeve, the front end spherical portion R will be deformed to form a groove in which the melt escapes, causing the nozzle to overflow, and the caliber portion will also be deformed. Therefore, the occurrence of flash should be checked and repaired in time.
c. Regularly check the condition of the threaded part of the nozzle and the sealing surface on the side of the barrel. If it is found to be worn or corroded seriously, it should be replaced in time.
d. Check the internal passage of the screw nozzle of the injection molding machine. The surface quality of the ejected melt strip can be observed by the air injection molding, and the residual melt discharged from the nozzle can more accurately reproduce the flow path condition in the nozzle. This allows analysis of the residual amount of the melt in the nozzle and the temperature distribution.
Keywords: injection molding machine screw