Mold heating tube is easy to break, is there a solution
The problem that many friends who use the single-head electric heating tube of the mold has been distressed is that the heating tube becomes black and it will be broken after a long time.
Then the main factors affecting the service life of the mold single-head heating tube are as follows:
1. Power design
The power is determined according to the surface load and size. The general surface load is:
Domestic process: 5W/cm2;
Imported process A grade: 5W-12W/cm2;
Imported technology AA grade: 12W-15W/cm2;
Imported technology AAA level: 15W-20W/cm2;
Beyond this standard, the greater the surface load of the mold heating tube, the shorter the life.
2. Material selection
Different materials are selected for different working environment and working temperature.
The working temperature is about 100-300 degrees, and the heating tube material can be stainless steel 304.
The working temperature is about 400-500 degrees, and the heating tube material can be stainless steel 321.
The working temperature is about 600-700 degrees, and the heating tube material can be stainless steel 310S.
Reasonable selection of the electric heating tube material can effectively control the service life of the electric heating tube. (Note: Whether there is vibration when the mold is heated, if there is vibration, it is recommended to use nickel-chromium wire with better flexibility)
Third, the gap between the pipe diameter and the mold aperture
Due to the obstructive effect of air on heat conduction, when the gap between the tube diameter and the mold aperture is too large, the surface temperature of the heating tube cannot be transferred to the mold in time, which will cause the surface temperature of the electric heating tube to continue to rise, thereby increasing the internal temperature of the electric heating tube , When the internal temperature rises to a certain degree, the heating tube will burn out, or even bursting in severe cases.
At the same time, the gap between the diameter of the mold electric heating tube and the mold hole cannot be too small, because the mold heating tube will expand due to the principle of thermal expansion and contraction after being installed and energized, and many molds cannot be taken out when the heating tube is broken.