Major Components of Cartridge Heaters

The cartridge heater is a cylindrical shaped industrial heater used in the injection molding process. They are fabricated from annealed pieces of metal and come with different voltage options. There are seven major components in cartridge heaters. They are heating coil, sheath, insulation, sealant, lead wire type, termination, and watt density.

The heating coil is the most important component in a heater because this is where the electrical load takes place. Nickel-chromium metal alloy is used for fabricating the heating coil and the wires are wound around a thick ceramic core. The number of spirals of the wire varies depending on the required watt density. An alternating current source is attached to the heating coil. When the power supply is switched on, the current flows through the wire and heats up the sheath of the heater. Stainless steel or metal alloys are used for manufacturing the sheath. Stainless steel is used for highly acidic environments and metal alloys like Incoloy are used for corrosive environments.

The coils are insulated in order to prevent short-circuits. A short-circuit can be disastrous and can lead to major equipment failure. Some advanced injection molding systems use a ground fault interrupting circuit for added safety. The Nichrome coil is inserted into the sheath and filled with magnesium oxide. A sealant is applied in order to prevent the coil from coming out. The sealant also prevents moisture and contamination inside the heater. The heaters can be exposed to high temperatures, and pressures.

It is very important for engineers to terminate the lead wires in order to prevent wire damage. Braided metal or metal conduits are used to protect the wires. The type of lead wire used varies depending on the design of the injection molding machines. Fiberglass and silicone rubber is commonly used because it can withstand rough temperature conditions.

A wide range of heater bands for injection molding systems are available in the market today and they can be easily bought online. Some of the popular and bestselling ones include Mica bands, Ceramic bands, and Mineral insulated bands. Always go for heaters that have high watt density. A higher watt density ensures better control and quicker response over the process. These industrial heaters can also be customized depending on application requirements. Make sure you buy branded heaters from trustworthy dealers. They are not only reliable but also durable.

Cartridge heaters play a very important role in the manufacturing process and have become an indispensable part of the injection molding process.