How Do Cartridge heaters Work?
A cartridge heater is designed and fitted in an application based on its wattage and the quantity of heat that is required. It consists of a resistance coiled around a ceramic core that is surrounded by a dielectric material and covered within a metal sheath. The performance of a cartridge heater is influenced by its dielectric strength, the heat transmitted to the sheath and the heat transferred from the sheath to the metal being heated. The heater will operate efficiently and have a longer life expectancy with a tighter fit.
The electrical termination of a cartridge should also be considered in relation to the operating temperature. Cartridge heaters have a low, medium or high operating wattage. They can resist temperatures of up to 1400° F or 760° C.
What Are Cartridge heaters Used For?
Cartridge heaters are extensively used in heating dies, platens and molds. They are suitable in applications that are immersed in liquid. They are also used in:
- Heating gases and liquids
- Hot stamping
- Laminating presses
- Medical equipment
- Scientific equipment
- Food production
- Sensor measurement devices
- Hot melt adhesives
- Plastic welding
- Fluid heating
- 3D printers
- Seal bars
- HVAC (Heating, Ventilation and Air Conditioning) compressors
- Mass spectrometry
Types of Cartridge heaters
- There are many types of cartridge heaters:
- Cartridge heaters with thermocouple
- Flanged cartridge heaters
- Swaged cartridge heaters
- Miniature cartridge heaters
- Multizone cartridge heaters
- Square cartridge heaters
- High-temperature cartridge heaters
- High-density cartridge heaters
Why do Cartridge heaters Fail?
An incorrect or improper fitting between the cartridge heater and its hole tolerances is the main cause of cartridge heater failures. The temperature within the heater continues to grow until the MGO or resistance wire breaks down. The heater fails if it cannot release the heat created by contact with the sheath. For every .001” of an inch we can decrease the gap between a cartridge heater and the hole we can reduce the heaters core temperature 150 ‘F.
An incorrect supply of voltage can cause the heater to fail as the voltage has a great effect on the power and heat generated.
The air around the heater is contaminated with moisture or pollutants. This can cause an internal short circuit if the heater wires are not properly sealed.
Incorrect wattage density
The power density of a heater is crucial to its performance. The higher the watt density, the greater the need for heat management. When this is not met, then high power densities can lead to the failure of a cartridge heater.
What Are the Cons if You Install Cartridge heaters Incorrectly
· Increased production time: Decrease in throughput
· Premature failure of the heater
· Lack of efficiency
Cartridge heater Care and Maintenance
· Heaters should be stored in a dry environment
· Protect leads from damage and misuse.
· The temperature should be maintained and controlled at all times
· The accessories should be in good working conditions
· Make sure the heating element fits tightly