Important Steps For Overhaul Of Mold Parts
The annual maintenance program required for each injection molding location of the mold depends on the different mold cycle times. The following are some mold parts maintenance tips that can be used by each mold user to ensure the effective operation of hot runners, heaters, guide posts and ejectors, and molding inserts to prevent accidents.
First of all, check if there is an alarming rust or dampness at the diffuser hole.
If you find rust or moisture near the hot runner vents, that means internal condensation or water pipes may break. Moisture causes a fatal short circuit to the heater. If the machine does not run for the entire year and it needs to be turned off in the evening or on weekends, the chance of this condensation will increase.
Second, remember to remind the operator not to “clean” the hot nozzle at the gate.
If the operator happens to see a small piece of stainless steel at the die nozzle, it may be a point nozzle assembly. “Cleaning up” this seemingly obstructing thing often destroys the hot head. In order not to damage the hot mouth, confirm the type of tip of the hot runner system before taking action, and ensure that all operators are well trained to identify the different types of mouths they are exposed to.
Third, taxi stop.
For machines that run throughout the year, this work should be done once a week. The end of the year is a very good time to perform a routine lubrication service for these parts.
Fourth, verify the resistance of the heater.
You should have measured the resistance of the heater just before you started using it, and the end of the year is the time to measure it again and compare it. If the resistance value is ±10% floating, consider replacing the heater to ensure that it does not fail at a critical point in the production process. If you have never measured the initial resistance value, measure it now and use the resulting value as reference data for future inspections of the heater.
Fifth,look for signs of wear between the guide post and the guide bush.
Looking for traces of scratches or scratches, this type of mold fitting wear is due to lack of lubrication. If traces are only present, you can extend the life of the guideposts and guide bushes by adding lubricant. If the wear is serious, you should replace the new part. Otherwise, the cavity and the core part may not be well matched, resulting in a thin and thick part wall.
Sixth, check the flow of water.
Connect a hose at the outlet of the waterway and let the water stay in the bucket through the water pipe. If the outflow of water is not clear or colored, there may be rusting, and a lack of smoothness means that it is blocked somewhere. If you find any of these problems, drill all the pipes again (or clean them in any way you like). Improving the plant’s water treatment system will prevent future problems caused by rusting and blocking.
Seventh, clean the thimble.
After a year, the ejector pin becomes very dirty due to gas accumulation and filmy impurities. It is recommended to clean it with a mold cleaning agent every 6-12 months. After cleaning, apply a layer of lubricant to the thimble to prevent galling or breaking.
Eighth, see if there is a break in the radius of the hot mouth.
Fractures are caused by loose, stiffened plastic chips that remain in the hot mouth of the machine as a result of clamping forces from the barrel assembly during forward injection molding. The cause of the problem may also be misalignment of the centerline. When you find a fracture, consider both possibilities. If damage is severe enough to prevent petal-like leakage (a term previously used by the user of the mold to refer to plastic leakage between the guide sleeve and the hot mouthpiece of the machine), the sprue bushing should be replaced promptly.