Large temperature fluctuations in the injection molding machine barrel, local overheating on the heating coil surface while current remains normal, are mostly caused by insulation degradation due to carbon buildup in the mica layer or cracking of the ceramic core. First measure the cold insulation resistance; if below 5MΩ, disassembly and inspection are required. If the surface temperature is uneven, check the gap between the inner diameter and the barrel; it is recommended to control it at 0.3mm to 0.5mm. An excessively large gap reduces heat conduction efficiency, while too small a gap makes installation and removal difficult.
Every three months, shut off power to check whether the terminal connections are oxidized or loose, and use compressed air to remove surface dust to prevent dust accumulation from affecting heat dissipation. If the operating environment has oil contamination, shorten the interval to once a month. When disassembling, do not use metal tools to scrape the heating surface to prevent damage to the insulation layer.
Confirm that the voltage, power, inner diameter, and barrel dimensions match, and the withstand temperature must be more than 20°C above the maximum process temperature. Higher power is not always better; exceeding the barrel's heat capacity will cause temperature control overshoot. This model is compatible with 220V or 380V, and the power density should be selected according to the barrel diameter.
