Injection molding machine production is generally 24-hour operation (shift system), except for reduced orders or public holidays, generally there will be no downtime. For machines that have been in working condition for a long time, we must do a good job of maintenance, and try to find and solve problems before the machine breaks down. Otherwise, once the machine breaks down, it must stop production and repair, which will seriously affect production and delay delivery. Therefore, it is particularly important to do a good job in the maintenance of injection molding machines.
In order to do a good job in the maintenance of injection molding machines, it is necessary to classify the maintenance content according to the frequency of possible failures: the content with the highest frequency is included in the daily maintenance, and the content with a lower frequency is included in the weekly maintenance, and so on. Classify the work content of monthly maintenance and annual maintenance.
After the maintenance content is determined, it is best to arrange a special person to be responsible to ensure that the determined maintenance work is carried out effectively according to the planned arrangement. The necessary record work must be done every time the maintenance work is completed, so as to have a basis for the evaluation of the machine in future work.
For hydraulic injection molding machines, the maintenance work is mainly carried out from the following aspects:
1. Maintenance of electrical system
A. When checking the high-voltage components in the machine, if it is not necessary, the main power supply should not be turned on.
B. When replacing the mold, it is impossible to let the cooling water flow into the control box.
C. Check whether the temperature inside the control box is too high, which affects the normal operation of the electronic board.
D. When replacing the relay, the specified voltage relay should be used.
2. Maintenance of hydraulic system
A. The pressure and temperature of the injection molding machine should be kept between 30-50 degrees Celsius. If the oil temperature exceeds 60 degrees Celsius, the following problems will occur:
Pressure oil deteriorates due to oxidation.
B. Oil pump damage caused by pressure oil viscosity reduction, oil leakage and pressure drop and working efficiency of decompression oil valve.
Accelerate the speed of oil seal aging.
C. Prevent cooling water from leaking into the oil cylinder, and pay special attention to check whether there is water leakage inside the oil cooler. Every 6 months or so, the oil cooler should be removed and cleaned inside.
D. The injection molding machine must replace the pressure oil every 3000-4000 hours of operation. When replacing the pressure oil, do not mix the old and new oils. At the same time, the oil screen in the oil tank should be twisted and cleaned.
E. The oil switch fails because the valve core is blocked by foreign objects. The valve core should be removed from the oil switch and cleaned with diesel or kerosene (or immersed in clean pressure oil for cleaning), and then use compressed air to remove foreign objects. Unless it is confirmed that the oil valve is blocked by foreign objects and the injection molding machine fails, the oil valve cannot be removed casually.
3. Maintenance of the mold locking part
A. The hinge of the clamping part has a long working life, but each moving part should be properly lubricated, otherwise the hinge will be worn and the life will be reduced.
B. Keep the four Corinthians clean.
C. Keep the sliding feet and rails of the mobile formwork clean and lubricated.
D. Avoid using mold clamping close to or exceeding the working pressure.
E. When adjusting the mold, the fast mold clamping speed is not available.
F. Control the stroke position of the mold clamping action at the most appropriate position to reduce the impact on the machine during mold clamping.
4. Maintenance of the injection part
A. Keep the injection platform guide rod lubricated and clean.
B. Keep the surface of the injection platform clean and dry.
C. Do not put anything into the hopper except plastics, pigments and additives. If you use recycled materials, you must add a hopper magnetic frame to the hopper to prevent metal fragments from entering the melt cylinder.
D. When the melting glue cylinder has not reached the pre-adjusted temperature, the melting glue motor cannot be started, nor can the reversing (loosening) action be used to avoid damage to the rotating system components.
E. Before using special plastics, you should consult the plastics supplier, which injection screw is more suitable for this kind of plastic.
F. Use the relevant plastic replacement and cleaning methods provided by the plastic manufacturer.
G. Periodically check each part of the injection platform, tighten the loose parts, and ensure that the two injection cylinders are installed in a balanced manner, so as to avoid damage to the oil seal of the injection cylinder, resulting in oil leakage and wear of the cylinder core.
H. Regularly drain the grease of the beer bell combination of the hydraulic motor and replace it with new grease.
I. When the temperature of the melt glue is normal but black spots or discoloration of the melt glue continue to appear, check whether the glue-passing apron of the injection screw and the glue-passing meson are damaged.
