What Matters Need Attention in Daily Maintenance of Hot Runner Systems

In order to extend the total service life of hot runner systems, lower the frequency of failure shutdowns, and stabilize the quality of injection molding products, scientific and systematic daily maintenance and routine inspection work are crucial. The daily inspection, calibration, and protection of supporting thermocouples and temperature measuring circuits are the essential maintenance components that cannot be disregarded. The daily maintenance work of hot runners encompasses many links, including temperature control system maintenance, main body flow channel maintenance, heating accessory maintenance, and installation structure maintenance.

Businesses must create uniform temperature regulation operation criteria for their daily start-up and shutdown maintenance tasks. In order to prevent thermal stress damage caused by rapid temperature rise of the hot runner manifold and nozzle structure, as well as to prevent the thermocouple from producing data deviation due to sudden temperature change, graded slow heating must be used when the hot runner system is started up for heating. Setting the temperature to the production target value at one time is prohibited. The residual melt inside the flow channel must be emptied before shutting down for parking, and heat preservation and cooling treatment must be performed in accordance with the properties of various raw materials. In addition to accelerating the aging and temperature measurement accuracy fall of built-in thermocouples, prolonged high-temperature standby without material emptying can easily result in molten carbon buildup inside the flow channel.

To prevent blockages and black line flaws, hot runner flow channels should be cleaned internally on a regular basis. The nozzle and manifold must be routinely disassembled in order to remove any remaining carbon deposition and raw material impurities from the flow channel after carbonized, easily decomposed raw materials and modified polymers with a high filler content are produced. The implanted thermocouple temperature measuring ends must be protected during the disassembly and assembly process to prevent scratches, bending, and position deviation brought on by collisions and friction, which could result in poor contact and temperature measuring component failure. To make sure there is no loose slipping issue, all thermocouples must have their fixing firmness checked again after cleaning and reassembly.

Every set production cycle, temperature control accessories should be routinely inspected and calibrated. The appearance integrity of each hot runner thermocouple must be examined individually by maintenance staff. They must also determine whether the external high-temperature wires are old, worn out, and cracked, whether the wiring terminals are loose and oxidized, and promptly replace any aging or damaged temperature measuring accessories. In order to ensure that the temperature display data of the temperature controller is entirely consistent with the actual working temperature of the hot runner, eliminate temperature deviation sensors, calibrate the temperature measurement accuracy of thermocouples one at a time, and prevent various forming failures caused by inaccurate temperature control, professional temperature measuring tools are utilized. Additionally, it is essential to match the power parameters with the temperature measurement range of thermocouples, prevent burnout failure of heating components due to over-temperature operation, and routinely monitor the functioning state of heating rings and heating pipes.

It is also impossible to overlook the hot runner system's external protection and mold matching maintenance. The hot runner's installation environment must be kept dry and clean to prevent oil contamination, cooling water leaks, and mold growth that could corrode the temperature monitoring circuit and hot runner main body. In order to minimize heat loss and vibration friction, periodically check the hot runner's fixed bolts, the integrity of the thermal insulation gasket, and the gap between the hot runner and the mold plate. You should also promptly modify the assembly gap. In order to prevent dust and moisture from entering and damaging internal circuits, hot runner systems that are not in use for an extended period of time must be kept in a dry, consistent temperature environment. Additionally, the thermocouple wiring ports must be sealed and secured. Perfect daily maintenance requirements can guaranty long-term stable and effective operation of injection molding production lines, maximize the functionality of hot runner systems and supporting thermocouples, and lower the overall equipment use cost for businesses.