1. Power Design
The power of ordinary mold heating tubes should not be too high. The normal surface load is about 5W/cm², while imported heating tubes have a surface load of about 12W/cm². Exceeding this standard, the higher the surface load of the mold heating tube, the shorter its lifespan.
2. Clearance with the Mold Hole
Because air hinders heat conduction, if the internal temperature of the heating tube cannot dissipate, the surface temperature of the heating tube will rise, causing the internal temperature to also increase. When the internal temperature of the mold heating tube reaches a certain level, the resistance wire will burn out, shortening the lifespan of the mold heating tube, and in severe cases, tube rupture may occur. Therefore, the gap between the heating tube and the mold should not be too large. However, the gap cannot be too small either, because the mold heating tube expands due to thermal expansion after being powered on, making it difficult to remove when the heating tube fails. Therefore, it is generally recommended that when customers purchase mold heating tubes, the gap between the mold hole diameter and the heating tube diameter should be 0.1-0.2mm.
