Causes of mold heating tube damage

1. Power Design

Ordinary mold heaters should have a limited power rating, with a normal surface load of no more than 8W/cm². Imported heaters have a surface load of 11-12W/cm². Exceeding this standard increases the surface load and shortens the lifespan of the mold heater.

2. Material Selection

Mold heaters fall within a specific range, so the material selection will vary depending on the operating environment and temperature.

For operating temperatures between 100-300°C, the heater should be made of 304 stainless steel.

For operating temperatures between 400-500°C, 321 stainless steel can be used.

For operating temperatures between 600-700°C, 310S stainless steel should be used.

Therefore, incorrect material selection can also contribute to a short lifespan. Also consider whether the mold is susceptible to vibration. If so, use nickel-chromium wire for increased flexibility.

3. Clearance Between the Mold and the Holes

Because air impedes heat conduction, heat cannot be dissipated, causing the surface temperature of the heater tube to rise, leading to a rise in the internal temperature of the heater tube. When the internal temperature of the mold heater tube reaches a certain level, it can burn out the resistor wire, shortening the life of the mold heater tube. In more serious cases, it can cause the tube to burst. Therefore, the gap between the heater tube and the mold should be kept small. However, the gap should also be kept small. After installation and power supply, the mold heater tube expands due to thermal expansion and contraction, resulting in many molds being unable to be removed when the heater tube breaks.