The maintenance procedure required for each injection molding position depends on different mold cycles.
Here are some general principles that every mold user can use to ensure the effective operation of mold components such as hot runner, heater, guide and thimble to avoid accidents.
1. Check the vent for rust or early warning moisture.
If you find rust or moisture near the hot runner vent, it means internal condensation or a possible water pipe rupture.
Moisture can cause a fatal short circuit in the heater.
If the machine does not run all year round, but turns off at night or on weekends, the likelihood of this condensation will increase.
2. Remember to remind the operator not to “clean” the hot gate nozzle.
If the operator sees a small piece of stainless steel on the die nozzle, it may actually be a sharp nozzle assembly.
“Clearing” what appears to be an obstacle often destroys the hot mouth.
To avoid damaging the hot nozzle, confirm the nozzle type of the bottom hot runner system before taking steps to ensure that all operators are well trained and can identify all the different types of nozzles they come into contact with.
3. Slip Buckle
For machines that operate continuously throughout the year, this work should be carried out once a week.
4. Check heater resistance value interactively
You should have measured the resistance of the heater when you started using it.
Now it's time to measure and compare again.
If the resistance value fluctuates by 10%, consider replacing the heater to ensure that it will not fail at a critical time in the production process.
If you have never measured the initial resistance value, measure it now and use the obtained value as reference data when checking the heater in the future.
5. Check the guide post and guide sleeve for signs of wear .
Look for scratches.
This wear is due to lack of lubrication.
If the marks are just emerging, you can also extend the life of the guide post and guide bushing by adding more lubrication.
If the wear is severe, it is time to replace the parts with new ones.
Otherwise, the cavity and core may not fit together well, resulting in different cavity wall thicknesses of the parts.
6. Check the water flow
Connect a hose to the waterway outlet and let the water remain in the bucket through the hose.
If the water flowing is not clear or colored, rust can occur, and poor flow means there is a blockage somewhere.
If these problems are found, drill all water pipes again to ensure they are unblocked (or clean them by whatever method you use most often).
Improving the plant's water treatment system can prevent future problems caused by rust and clogging.
7. Clean the ejector pin
After a year, the thimble will become very dirty due to the accumulation of gas and impurities in the membrane.
It is recommended to clean mold with mold cleaner every six to twelve months.
After cleaning, apply a coat of lubricant to the thimble to prevent scratches or fractures.
8. Check the hot nozzle radius area for fracture
The fracture is caused by the clamping force brought by the hardened loose plastic fragments left in the hot mouth of the machine by the injection cylinder assembly during direct injection molding.
The cause of the problem could also be misalignment of the center line.
These two possibilities must be considered when finding fracture.
If the damage is so severe that petal leakage cannot be prevented (a term previously used by the mold user: plastic leakage between the guide sleeve and the hot nozzle of the machine), the gate sleeve must be replaced.
