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Injection molding machine electrical system, hydraulic system, mold clamping part, injection molding part maintenance points


Injection molding machine production generally operates 24 hours a day. For machines that are in working condition for a long time, we must do a good job in maintenance and strive to find and solve problems before the machine breaks down.

Otherwise, once the machine fails, production must be stopped and repaired, affecting production.

Therefore, it is particularly important to do a good job in maintaining the injection molding machine. To do a good job in the maintenance of the injection molding machine, the maintenance content must be classified according to the frequency of possible failures:

the content with the highest frequency is included in the daily maintenance, the content with a lower frequency is included in the weekly maintenance, and so on. Monthly maintenance and annual maintenance work contents are classified.

After the maintenance content is determined, it is best to arrange for a dedicated person to be responsible to ensure that the determined maintenance work is effectively executed in accordance with the planned arrangements.

Necessary records must be made every time maintenance work is completed, so as to provide a basis for evaluating the machine in future work.

Maintenance of electrical systems

  1. When checking high-voltage components in the machine, the main power supply should not be turned on unless necessary.
  2. When replacing the mold, do not allow cooling water to flow into the electric control box.
  3. Check whether the temperature inside the electric control box is too high, which may affect the normal operation and service life of the electronic board.
  4. When replacing relays, use designated voltage relays.

Maintenance of the hydraulic system The hydraulic oil temperature of the injection molding machine should be maintained between 30-55 degrees Celsius. If the oil temperature exceeds 60 degrees Celsius.

the following problems will occur

  1. Hydraulic oil deteriorates due to oxidation.
  2. The viscosity of the hydraulic oil decreases, causing oil pump damage, oil leakage, pressure drop, and overall machine efficiency decrease.
  3. Accelerate the aging of oil seals.
  4. Prevent cooling water from leaking into the system oil tank, and pay special attention to check whether there is water leakage inside the oil cooler. The inside of the cooler should be cleaned every 6 months or so.
  5. The hydraulic oil of the injection molding machine must be replaced every 3000-4000 hours of operation. When replacing the oil, new and old oils cannot be mixed, and the filter in the oil tank should be unscrewed and cleaned.
  6. If the directional valve fails because the valve core is blocked by foreign objects, the valve core should be removed and cleaned with diesel or kerosene (or immersed in clean hydraulic oil for cleaning), and then use compressed air to remove foreign objects.

Maintenance of mold clamping part

  1. The machine hinge of the clamping part has a long working life, but each movable part should be properly lubricated, otherwise the machine hinge will wear and reduce its service life.
  2. Keep the four tie rods clean.
  3. Keep the sliding feet and slide rails of the moving template clean and lubricated.
  4. Avoid using molds that are close to or exceed the working pressure.
  5. When adjusting the mold, the fast mold clamping speed cannot be used.
  6. Control the mold clamping action stroke to the most appropriate position to reduce the impact on the machine during mold clamping.

Maintenance of the injection part

  1. Keep the guide rod of the shooting platform lubricated and clean.
  2. Keep the surface of the shooting platform clean and dry.
  3. When using recycled materials, a hopper magnetic frame must be added to the hopper to prevent metal fragments from entering the melt barrel.
  4. Let the barrel temperature reach the set temperature for about 3 minutes before starting production (ensuring that the raw materials in the barrel are completely softened) to prevent damage to the screw and transmission system. ​
  5. When the barrel has not reached the preset temperature, do not start the melting motor or use the rewinding (loosening) action to avoid damaging the rotating system components.
  6. Use the correct plastic replacement and cleaning methods provided by the plastic supplier.
  7. Periodically check all parts of the injection platform, tighten loose parts, and ensure that the two injection cylinders are installed in a balanced manner to avoid damage to the oil seal of the injection cylinder and oil leakage, as well as damage to the cylinder, piston rod, etc.
  8. When the melt temperature is normal but black spots or discoloration of the melt continue to occur, check whether the injection screw thrust ring and thrust ring are damaged.

Contact Person: Alex Chu
WhatsApp/ WeChat: 0086 18968677763
Email: sc10@solidcomould.com
Website: www.solidcomould.com

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