Both imported and domestic injection molding machines have the following characteristics:


Large: investment in fixed assets of injection molding machine, production scale, raw material consumption,labor productivity, and output value. At the meantime, it is a form of production organization with high labor efficiency.


The injection molding machineorganically is composed of machinery, hydraulics, electrical appliances, special supporting parts, etc. according to the needs of injection molding processing technology. They have a high degree of automation and close correlation with each other as well. And the injection molding machine can run continuously for 3 shifts 24h. If a component in the injection molding machine fails, it will cause a shutdown. It will be one of the failures of injection molding machine.


Although the operation on the injection molding machine is simple and with few workers, the management and maintenance of the injection molding machine has high technical content and heavy workload. Therefore, ensure that the injection molding machine is always in good condition, it is necessary to strengthen the management of the injection molding machine and strictly control the failures of injection molding machines. The purpose is to reduce the failure rate, maintenance costs, and also extend the service life.


Injection molding machine failure generally refers to the event or phenomenon in which the injection molding machine or system loses or reduces its specified function. The injection molding machine is equipped by the enterprise to meet the production process requirements of injection products.


The function of the injection molding machine reflects its value in the production activities of injection molded products and the guarantee degree for injection molding production. In the modern production, for the complex structure of the machine, the high-degreed automation and the close connections of hydraulic, electronic control and mechinery, so the failure of injection molding machine or even a partial failure will stop the entire injection molding machine from working. The failures of the injection molding machine directly affect the quantity and quality of the products.

To ensure quick and effective fault analysis and elimination, certain procedures must be followed. Such procedures are roughly as follows:

Step 1 Perform symptom analysis while keeping the scene

      1. Ask the operator

1) What happened? Under what circumstances? When did it happen ?

2) How long has the injection molding machine been in operation?

3) Are there any abnormal phenomena before the fault? What is the sound or sound and light alarm signal? Is there smoke or odor? Is  there any wrong operation? (pay attention to the inquiry method)?

4)Finally.  Is the control system operating normally? Are there any changes to the operating procedures or any special difficulties or abnormalities in operation?

     2. Observe the overall condition and various operating parameters

1) Are there any obvious abnormalities? Are the parts stuck or damaged? Is the hydraulic system loose or leaking? Are the wires broken, scratched or burnt?

2) What are the changes in the operating parameters of the injection molding machine? Are there any obvious interference signals? Are there any obvious signs of damage?

     3. Check the monitoring and indicating device

1) Whether all readings are normal, including pressure gauge and other meter readings, oil level height.

2) Whether the filter, alarm and interlock device, motion output or display are normal.

    4. Check the injection molding machine (under the allowed conditions)

Check the intermittent, long-lasting, fast-forward or slow-forward conditions to see if the output is affected under these conditions, whether it may cause damage or other hazards.

Step 2 Detect the injection molding machine (including parts, components and circuits)

   1.  Use sensory examination  (continue to observe in depth)   

1 ) See:   7 Whether

  • the plug and socket are abnormal
  • the motor or pump is operating normally
  • the control adjustment position is correct
  • there are traces of arcing or scorching
  • the fuse is good or bad
  • the liquid leaks
  • the lubricating oil passage is smooth

2 ) Touch:

  • the vibration of the injection molding machine
  • the heat of the component ( module )
  • the temperature of the oil pipe
  • the state of the mechanical movement

3 ) Listen:

  • whether there is abnormal sound

4 )  Smell:

whether there is burnt smell, leakage odor, other odor.

5) Check:

  • change in shape and position of the workpiece
  • change in performance parameters of the injection molding machine
  • check for abnormal lines.

  2.  Evaluate the inspection results   

Evaluate whether the fault judgment is correct, the fault clue is found, and the inspection results are consistent.

Step 3  Determine the location of the fault

   1. Identify the system structure and determine the test method

Consult the instruction manual of the injection molding machine and identify:

  • the structure of the injection molding machine,
  • the method used for testing,
  • the test means required,
  • the test parameters or performance parameters that may be obtained,
  • the operating conditions under which the test is performed,
  • what safety measures must be observed,
  • whether they are required Operation license.

   2. System detection

Adopt the technology test most suitable for the system structure. At the appropriate test point, the results obtained from the input and feedback are compared with normal values or performance standards to find suspicious locations.

Step 4 Repair or replace

 1. Repair

Find the cause of the failure, repair the injection molding machine and take preventive measures.

Then, check the relevant parts to prevent the failure from spreading.

   2. Replace

Correctly assemble and debug replacement parts, and pay attention to related parts.  Next, Repair or scrap the replaced parts.

Step 5 Perform performance measurement

 1. Start the injection molding machine

After assembling and debugging the parts, start the injection molding machine. First manually (or jog), and then carry out no-load and load determination.

   2. Adjust the load change speed from low to high, load from small to large.

The maximum system pressure cannot exceed 140kg / cm2. The performance is measured according to the prescribed standards.

   3. Expand the performance test range
According to the requirements, gradually expand the performance test range from part to system. Pay attention to the operating status of the system in the non-fault area. If the performance meets the requirements, it will be delivered for use. If the requirements are not met, the fault location will be determined again.

Step 6 Record and feedback

 1. Collect valuable information and data

Such as the time when the failure occurs, the malfunction phenomenon, the downtime, the repair time, the parts replaced, the repair effect, the problem to be solved, the settlement fee, etc., shall be deposited in the file according to the prescribed requirements.

  2. Statistical analysis

  • Regularly analyze injection molding machine usage records and downtime losses.
  • Revise memo catalogs.
  • Find key measures to reduce maintenance operations.
  • Study failure mechanisms.
  • Propose improvement measures.

  3. According to the procedure, feedback the relevant faults to the competent department and give feedback to the injection molding machine manufacturer.

Now, do you think this guide is helpful for you to deal with the failures of injection molding machine ?

Which procedure do you think is the most vital ?