It is the most widely used thermocouple in the hot runner system, and it is characterized by low price and is suitable for vacuum oxidation in reduction or inert atmosphere, the temperature range is -200～800℃, but the commonly used temperature is only below 500℃ because the oxidation rate of the iron hot electrode will increase when over this temperature, the thick wire diameter wire can still be used in high temperature and has a long life, the thermocouple is resistant to hydrogen (H2) and carbon monoxide (CO) gas corrosion, but it can not be used in a high temperature (for example, 500°C) atmosphere containing sulfur (S).
1. In order to prevent the hot runner from being damaged during the assembly process, the hot runner with a manifold should be designed with a hot runner protection guidepost, and the protection guide post must be higher than the highest point of the hot runner nozzle by more than 10mm, the diameter of the hot runner protection guidepost can be same as the reset lever.
2. The front of the hot runner nozzle (normally the core side) must be made unilaterally larger by 2mm and 1.5mm deep to avoid the empty round table to reserve the thermal expansion space of the hot runner nozzle.
3. The runner at the front end of the hot runner nozzle is generally designed on the side of the movable mold to avoid processing the runner on the hot runner nozzle.
4. The hot runner nozzle needs to design a separate cooling gate to cool the nozzle to prevent problems such as gate drooling and string, gate vestige too high, the part surface at gate area too hot and deformation, cycle time too long.
5. Drain and venting slot should be designed on the ground side of the hot runner plate.
6. The outlet must be chamfered to prevent the temperature sensing wire or heating wire from being scratched.
7. The water and oil gates of the hot runner are generally designed in the direction of the non-operator side and the ground side.
8. For hot runner molds, a 5mm thick insulator plate should be added to the top plate, which is generally made of a bakelite board to prevent heat loss.