Regular maintenance of mold parts plays a vital role in the life of the mold. The annual maintenance program required for each injection molding location depends on the different mold cycle times. Here are some mold parts overhaul tips that every mold user can use to ensure the effective operation of mold components such as hot runners, heaters, guide pillars and ejectors, molding inserts, etc. to prevent unexpected situations from occurring.
1. Check for warning rust or moisture at the air dispersal holes. If you find rust or moisture near the hot runner vent, it means internal condensation, or a possible rupture in the plumbing. Humidity can trigger a short circuit that is fatal to the heater. If the machine is not running year round and needs to be shut down at night, then the chances of this condensation occurring increase.
2. Remember to remind the operator not to "clean out" the hot nozzle tip at the gate. If the operator happens to see a small piece of stainless steel at the mold spout, it may be a spot spout assembly. "Cleaning out" what appears to be an obstruction can often ruin the hot nozzle head. To avoid damaging the hot nozzle, verify the nozzle type of the hot runner system before taking action, and make sure all operators are trained to recognize the different types of nozzles they are touching.
3. Slide the stopper. For machines that run year-round, this work should be done once a week. And the end of the year is a good time to give these parts a routine lubrication maintenance.
4. Interactively calibrate the resistance value of the heater. You should have measured the resistance value of the heater when you first started using it, and the end of the year is the time to measure it again and compare it. If the resistance value has a ±10% fluctuation, it is time to consider replacing the heater to ensure that it does not fail at a critical point in the production process. If the initial resistance value is never measured, measure it once and use the resulting value as reference data for future inspections of the heater.
5. Look for signs of wear between the guide pillar and guide bushing. Look for any
traces such as scratching or scuffing, this kind of mold parts wear is caused by lack of lubrication. If the marks only just appear, then you can still extend the life of the guide pillar and guide bush by adding lubricant to them. If the wear is already severe, then it is time to replace the parts with new ones. Otherwise, the cavity and core parts may not fit well, resulting in parts with different cavity wall thickness.
6、Check the water flow. Connect a hose at the outlet of the water line and let the water stay in the barrel through the hose. If the water flowing out is not clear or has a color, rust may have occurred, and a poor water flow means a blockage somewhere. If you find these problems, drill through all the hoses again (or take whatever method you most often use to clean them) to ensure a clear flow. Improving the plant's water treatment system can prevent future problems caused by rust and blockages.
7. Clean the thimble. After a year, the thimble will become dirty due to gas hoarding and film-like impurities. It is recommended to clean it well with mold cleaning agent every 6~12 months. After cleaning, then apply a layer of lubricant to the ejector pin to prevent scuffing or breakage.
8. Check the radius area of the hot nozzle for fractures. The fracture is caused by the loose hardened plastic pieces left in the hot nozzle of the machine during forward injection by the clamping force from the barrel assembly. The cause of the problem may also be a misalignment of the line. Both possibilities are considered when finding a break. If the damage sustained is severe enough to prevent a petal-like leak, the gate bushing should be replaced promptly.
