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Possible causes
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Suggested solution
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| Injection molding machine |
1. The injection pressure within the cavity is too low.
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Rise injection pressure, check the size of the injection molding parts each time the pressure rises, until the injection molded parts slightly appear.
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| 2. Insufficient plastic inside the cavity. |
Increase the amount of plastic injection molding or check the bedding.
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| 3. Mold temperature is too high. |
Reduce mold temperature.
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| 4. Unusual injection molding conditions. |
1. Using an incorrect injection molding conditions (temperature and pressure, and so on).
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2. In the absence of stability samples before the injection process.
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| 5. Injection hole is too small. |
Increase the diameter of injection nozzle hole.
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| 6. Mold cavity filling speed is too slow. |
Increase injection speed or multistage fill rate.
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7. Gate no condensation within the mold.
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Increase the screw forward time and increases measurement samples at a time.
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| 8. Melt temperature is different inside the injection volume. |
1. Lower the screw rotation speed to return the screw just before the cooling is completed.
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2.Increase the back pressure.
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| Mold |
1. The gate is too small or poorly designed. |
Increase the gate size or reduce the length of the junction area.
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| 2.Improper design of runner system. |
1.Circular or ladder-shaped flow path.
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2.Increase the viscosity of runners to fit plastic or plastic flow characteristics.
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| 3. Insufficient cooling pipe design of the mold. |
1. Measure the cavity surface temperature and actual temperature with the corresponding shrinkage value.
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2.If there is a clear difference, the new design of cooling pipe in order to overcome the problem.
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| Plastic |
Plastic liquid is too low (that is, plastic flow is too difficult). |
With a lower viscosity (ie: easier flow levels) of polymers.
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