First, power design
The power of the heating element for ordinary mould should not be too large, and the normal surface load should not exceed 8W /cm2. The surface load of the imported heating element is 11-12W /cm2. Beyond this standard mold the greater the surface load of the heating tube, the shorter the life.
Second, material selection
The material of the mold heating element will be different according to its working environment, working temperature.
The working temperature is about 100-300 degrees, and the heating tube is made of 304 stainless steel.
The working temperature is about 400-500 degrees, and can be made of stainless steel 321.
The working temperature is about 600-700 degrees, and the material of stainless steel 310S should be selected.
Therefore, if the material is not chosen correctly, which is also the reason for the short life. And whether the mold has vibration, if there is vibration to use good flexibility of nickel chrome wire.
Three, and the gap between the die hole
For mould heating element, the most important thing is to ensure that the heat generated by the heating rods in a timely manner to the heating medium, lower the temperature of the heating rods inside material, in order to effectively improve the service life of the heating rods, at the same time, we know that air is in the role of heat conduction, so the mold single-head heating pipe diameter and average mould hole of the aperture between the gap as small as possible, In order to better conduct heat conduction, thus extending the life of the electric heating tube.
