Coil heaters are categorised into four types namely Supercoil Heaters, Maxicoil Heaters, Minicoil Heaters (Husky type) and Encapsulated Coil Heaters. All of these are flat and rectangular in shape to optimise heat transfer to the nozzle or sprue bush. Watts densities are extremely high thus it is imperative that excellent contact is made between the coil heater and the nozzle of the equipment.
Flat Supercoil Heaters (4.2mm wide x 2.5mm high) are the most common coil heater in industrial use and are available ex-stock from Swift Heat in a wide range of lengths and wattages that can be bent to your specifications within a working day.
Maxicoil Heaters have larger physical dimensions (10mm wide x 3.8mm high) and are suitable for increased wattage and robust working condition requirements.
Minicoils are most commonly used in PET pre-form moulding as their physical dimensions allow fitment into small cavities. Swift Heat stocks a standard 19.05mm dia x 30.5mm wide 268W 240V Minicoil available in axial or tangential clamping arrangements.
Encapsulated Coil Heaters are flat supercoils which are fitted into either a brass or bronze sheath to improve even heat distribution throughout the length of the heater.
Typical applications include heating of nozzles in injection moulding machines where high temperatures are required, and in moulds where space is often problematic, therefore conventional heaters cannot be used.