The operator must be familiar with the extruder operated by him. He must correctly master 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 master the extrusion process conditions and correctly operate the machine.
The general operating steps for debugging are as follows:
(1) Before starting the machine, it should check whether the temperature control is sensitive, whether the instrument is malfunctioning, and whether the cooling waterway is smooth. Thermometers, cooling water and other methods are usually used for testing.
(2) The screw, barrel and die head of the extruder are heated according to the operating rules of the extruder. After the temperature rises to a set temperature, it must be kept warm for about 10 minutes before it can be turned on, so that the temperature of all parts of the machine tends to be stable.
(3) Make sure that all parts of the die head are connected with screws and bolts before starting. Before the material is extruded, the operator must not stand directly in front of the mold to prevent the bolt or screw from breaking and causing injury.
(4) At the beginning of extrusion, the screw speed should be used slowly, and then gradually accelerated to prevent overload and damage to the machine parts at startup.
(5) When starting the machine, add a small amount of material first, and maintain the material balance. When adding the material, pay close attention to the torque and other values. After the material is squeezed out of the die die and brought to the traction equipment, it can gradually increase the amount of material. Until normal extrusion.
(6) When starting traction, the mold and the mold head should have a certain distance to facilitate traction. Open the waterway(note that water must not be poured to the mold head, otherwise it will cause the mold head to produce abnormal material and cause the mold to be cut or blocked). The shape of the complex cavity is small and the shape of the multi-cavity profile needs to open the cover plate of the mold.; After confirming the normal plasticization of the extruded material, the material is brought to the traction machine through a set of traction ropes. Shorten the distance between the molding table and the die head, cover the cover plate, and start the vacuum pump. When the extrusion speed and traction speed are basically balanced, observe the profile to the normal extrusion and then shrink the distance between the molding table and the die head to the ideal value.
(7) If it is found that the billet is not formed at the entrance of the shaped mold or that the inner muscle adheres to the inner cavity surface of the profile, a pointed tool can be used to poke several small holes in the unformed part or the inner tendon part of the first section of the shaped mold entrance, so that the small cavity body and the atmosphere are connected; The type of blank is open when entering the mold, which facilitates the formation of negative pressure and urges the blank to adhere tightly to the mold wall of the mold.
(8) In the case of blockage(not blocked), the stereotyped table should be moved back or the traction speed should be increased immediately, or both schemes should be implemented at the same time, and then the normal production should be resumed through process adjustment. If it is blocked and the above plan is invalid, the stereotyped platform should be moved back immediately, and the material should be cut off along the stereotyped mold, the water vapor of the stereotyped mold should be closed, the traction speed should be reduced, and the profile should be slowly pulled out of the stereotyped mold. If part of the material is broken in the mold, the mold must be opened and the residue must be completely removed.
(9) During downtime, it is generally necessary to add the stop material to drain out the production material in the machine, and then stop the machine and remove the die head for die cleaning.
Maintenance of extruding die
1, during the maintenance and cleaning process loading and unloading or cleaning improper, is one of the main causes of damage to the mold. Therefore, the removal and cleaning of the mold should be done by professionals.
2, the die head should be used in the removal and cleaning of copper devices.
3, the mold head joint surface(close cover) can be cleaned with fine oil stone or gold sand paper.
4, before the die has assembly, the runner should be polished to a low roughness with gold phase sand paper, and coated with a thin layer of organosilicon, in order to reduce gas and water corrosion during long-term storage to protect the runner.
During assembly, all bolts, screw bearing surfaces and threads must be coated with high temperature grease.
6, when the model is dismantled, care should be taken to avoid collisions; When installing, install according to the order of the plates.
7, in the daily maintenance of the water tank should ensure that the shape of the block into the four sides of the proper adjustment space.
Storage of extrusion die
1, the mold should be stored in a dry, clean and ventilated warehouse, and it is forbidden to store with corrosion products;
2, after the mold is used, it must be cleaned and reassembled. After the oil is sealed, it is stored in the warehouse;
3, the mold should be stored in a dedicated mold storage shelf to ensure that the safe and easy to access